4D printing of biodegradable elastomers with tailorable thermal response at physiological temperature

4D printing has a great potential for the manufacturing of soft robotics and medical devices. The alliance of digital light processing (DLP) 3D printing and novel shape-memory photopolymers allows for the fabrication of smart 4D-printed medical devices in high resolution and with tailorable functionalities. However, most of the reported 4D-printed materials are nondegradable, which limits their clinical applications. On the other hand, 4D printing of biodegradable shape-memory elastomers is highly challenging, especially when transition points close to physiological temperature and shape fixation under ambient conditions are required. Here, we report the 4D printing of biodegradable shape-memory elastomers with tailorable transition points covering physiological temperature, by using poly(D,L-lactide-co-trimethylene carbonate) methacrylates at various monomer feed ratios. After the programming step, the high-resolution DLP printed stents preserved their folded shape at room temperature, and showed efficient shape recovery at 37 °C. The materials were cytocompatible and readily degradable under physiological conditions. Furthermore, drug-loaded devices with tuneable release kinetics were realized by DLP-printing with resins containing polymers and levofloxacin or nintedanib. This study offers a new perspective for the development of next-generation 4D-printed medical devices.

The Ornaments of the Arma Veirana Early Mesolithic Infant Burial

Personal ornaments are widely viewed as indicators of social identity and personhood. Ornaments are ubiquitous from the Late Pleistocene to the Holocene, but they are most often found as isolated objects within archaeological assemblages without direct evidence on how they were displayed. This article presents a detailed record of the ornaments found in direct association with an Early Mesolithic buried female infant discovered in 2017 at the site of Arma Veirana (Liguria, Italy). It uses microscopic, 3D, and positional analyses of the ornaments as well as a preliminary perforation experiment to document how they were perforated, used, and what led to their deposit as part of the infant's grave goods. This study provides important information on the use of beads in the Early Mesolithic, in general, as well as the relationship between beads and young subadults, in particular. The results of the study suggest that the beads were worn by members of the infant's community for a considerable period before they were sewn onto a sling, possibly used to keep the infant close to the parents while allowing their mobility, as seen in some modern forager groups. The baby was then likely buried in this sling to avoid reusing the beads that had failed to protect her or simply to create a lasting connection between the deceased infant and her community.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10816-022-09573-7.

Insight into 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced disruption of zebrafish spermatogenesis via single cell RNA-seq

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a potent and environmentally persistent endocrine disrupting chemical. Our previous work demonstrated the latent reproductive maladies of early-life TCDD exposure in zebrafish. Zebrafish acutely exposed to low, environmentally relevant levels of TCDD (50 pg/mL) during two windows of sexual differentiation in development (1 hour of exposure at 3 and 7 weeks postfertilization) were later infertile, showed a reduction in sperm, and exhibited gene expression consistent with an altered microenvironment, even months after exposure. Due to the highly heterogeneous cell- type and -stage landscape of the testes, we hypothesized various cell types contribute markedly different profiles toward the pathology of TCDD exposure. To investigate the contributions of the diverse cell types in the adult zebrafish testes to TCDD-induced pathology, we utilized single-cell RNA-seq and the 10x Genomics platform. The method successfully captured every stage of testicular germ cell development. Testes of adult fish exposed during sexual differentiation to TCDD contained sharply decreased populations of late spermatocytes, spermatids, and spermatozoa. Spermatogonia and early spermatocyte populations were, in contrast, enriched following exposure. Pathway analysis of differentially expressed genes supported previous findings that TCDD exposure resulted in male infertility, and suggested this outcome is due to apoptosis of spermatids and spermatozoa, even years after exposure cessation. Increased germ cell apoptosis was confirmed histologically. These results provide support for an environmental exposure explanation of idiopathic male infertility.

Comparative Toxicotranscriptomics of Single Cell RNA-Seq and Conventional RNA-Seq in TCDD-Exposed Testicular Tissue

In this report, we compare the outcomes and limitations of two methods of transcriptomic inquiry on adult zebrafish testes exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during sexual differentiation: conventional or bulk RNA-seq (bulk-seq) and single cell RNA sequencing (scRNA-seq) data. scRNA-seq has emerged as a valuable tool for uncovering cell type-specific transcriptome dynamics which exist in heterogeneous tissue. Our lab previously showed the toxicological value of the scRNA-seq pipeline to characterize the sequelae of TCDD exposure in testes, demonstrating that loss of spermatids and spermatozoa, but not other cell types, contributed to the pathology of infertility in adult male zebrafish exposed during sexual differentiation. To investigate the potential for technical artifacts in scRNA-seq such as cell dissociation effects and reduced transcriptome coverage, we compared bulk-sequenced and scRNA-seq-paired samples from control and TCDD-exposed samples to understand what is gained and lost in scRNA-seq vs bulk-seq, both transcriptomically and toxicologically. We hypothesized that the testes may be sensitive to tissue disruption as they contain multiple cell types under constant division and/or maturation, and that TCDD exposure may mediate the extent of sensitivity. Thus, we sought to understand the extent to which this dissociation impacts the toxicological value of data returned from scRNA-seq. We confirm that the required dissociation of individual cells from intact tissue has a significant impact on gene expression, affecting gene pathways with the potential to confound toxicogenomics studies on exposures if findings are not well-controlled and well-situated in context. Additionally, a common scRNA-seq method using cDNA amplified from the 3’ end of mRNA under-detects low-expressing transcripts including transcription factors. We confirm this, and show TCDD-related genes may be overlooked by scRNA-seq, however, this under-detection effect is not mediated by TCDD exposure. Even so, scRNA-seq generally extracted toxicologically relevant information better than the bulk-seq method in the present study. This report aims to inform future experimental design for transcriptomic investigation in the growing field of toxicogenomics by demonstrating the differential information extracted from sequencing cells—despite being from the same tissue and exposure scheme—is influenced by the specific protocol used, with implications for the interpretation of exposure-induced risk.

Pet ownership and mental health during COVID-19 lockdown

Owning a pet has often been associated with improved mental health among owners, including enhanced quality of life, and decreased levels of depression and loneliness. The aim of this study was to identify whether owning a cat and/or dog was associated with better psychological wellbeing during a strict lockdown period in Victoria, Australia, during the COVID-19 pandemic. Data were analysed from a large-scale mental health study: the COvid-19 and you: mentaL heaLth in AusTralia now survEy (COLLATE). The impact of pet ownership on levels of resilience, loneliness and quality of life were examined in a sample of 138 pet owners and 125 non-pet owners. Hierarchical linear regression analyses indicated that pet ownership was significantly associated with poorer quality of life, but not significantly associated with resilience or loneliness, after accounting for situational factors (e.g. job loss) and mood states. Contrary to expectations, the findings suggest that during a specific situation such as a pandemic, pets may contribute to increased burden among owners and contribute to poorer quality of life.

Detection of endocrine disrupting chemicals in Danio rerio and Daphnia pulex: Step-one, behavioral screen

Anthropogenic surface and ground water contamination by chemicals is a global problem, and there is an urgent need to develop tools to identify and elucidate biological effects. Contaminants of emerging concern (CECs) are not typically monitored or regulated and those with known or suspected endocrine disrupting potential have been termed endocrine disrupting chemicals (EDCs). Many CECs are known to be neurotoxic (e.g., insecticides) and many are incompletely characterized. Behavioral responses can identify chemicals with neuroactive properties, which can be relevant to EDC mechanisms (e.g., neuroendocrine disturbances). Two freshwater species, Daphnia pulex and Danio rerio, were evaluated for swimming behavior alterations resulting from 24-hr exposure to 9 CECs: triclosan, triclocarban, chlorpyrifos, dieldrin, 4-nonylphenol, bisphenol-A, atrazine, metformin, and estrone. This is the first step in the development of a bioassay for detecting estrogenic and/or anti-androgenic activity with the goal to evaluate complex mixtures of uncharacterized contaminants in water samples. The second step, described in a subsequent report, examines transcriptome alterations following chemical exposure. Significant differences in the swimming behavior response and sensitivity were found across chemicals within a species and across species for a given chemical in this unique optical bioassay system. In the concentration ranges studied, significant behavioral alterations were detected for 6 of 9 CECs for D. pulex and 4 of 9 CECs for D. rerio. These results underscore the utility of this bioassay to identify behavioral effects of sublethal concentrations of CECs before exploration of transcriptomic alterations for EDC detection.

Left Ventricular Assist Device Implantation in a COVID-19 Positive Patient

Introduction

Case Report

Summary

Extracorporeal Membrane Oxygenation Dependent COVID19 Hospital Transfers

Introduction

The World Health Organization has recorded over 8 Million cases of COVID19 as of October 2020. Despite receiving appropriate lung protective ventilation and medical treatment, some of these patients develop refractory hypoxemia and acute respiratory distress syndrome . Extracorporeal membrane oxygenation has been recognized as a lifesaving therapy for patients with ARDS secondary to COVID19. There are few centers in the United States equipped with the necessary staff and the experience to take care of such critically ill patients. Some patients are too ill to be transferred with conventional mechanical ventilation, and they require interhospital transport while on ECMO.

Case Report

We have developed a highly specialized ECMO Deployment Team dedicated to the cannulation and transport of COVID19 patients while on venous-venous (VV) ECMO or venous-arterial (VA) ECMO. We use routine bedside ECMO cannulation via bilateral femoral vessels configuration at the outside hospital. The patient is stabilized and transported by air or ground to one of our affiliated hospitals.Here we present a series of five patients who were cannulated by our team at an outside institution and transported while on ECMO support to one of our three system hospitals. Patient ages ranged between 49-64 years old. Four patients required VV ECMO for severe hypoxemia secondary to COVID19 ARDS. One patient required VA ECMO due to viral myocarditis secondary to COVID19. Time on ECMO ranged from 9-33 days. Three of the five patients recovered successfully and were discharged home, rehab or LTAC. One patient is still currently on ECMO and one patient is deceased. There were no reported or documented transmission of COVID19 to the members of the ECMO deployment team.

Summary

The potential for survival of the critically ill due to COVID19 often demands a higher level of care. However, stable transport to an appropriate institution presents a limiting factor. Our method of a dedicated ECMO Deployment Team appears to provide favorable outcome for these patients.

Relationship between dairy cows' hind leg activity and vacuum records during milking

In a number of dairy farms, a restlessness of hind legs of cows during milking can be observed for no apparent reason. Previous studies have associated the hind leg activity of cows with mental or physical discomfort. Aim of this study was to investigate whether the observed hind leg activity was influenced by the milking process. The analysis was performed for total milking period and also separately for the following milking periods: let-down, main milk flow and over-milking. The following variables were analyzed for their influence on dairy cows' hind leg activity: the vacuum level in the MPC and SMT, the length of the milking periods, the vacuum curve type, bimodal curves and the presence of teat-end hyperkeratosis. In turn, it was also investigated whether the cows' hyperkeratosis is influenced by milking duration, length of milking periods or by the vacuum level in the SMT. Measurements and observations were done in ten milking parlors, each visited twice. Four milking units per parlor were equipped with vacuum loggers (VaDia 2.0, BioControl AS, Norway). One observer recorded hind leg activity per up to four cows, using the following categories: (1) stepping (claw raised < 15 cm) and (2) kicking (claw raised > 15 cm). A powerful, purposive kick to milking unit/milker was classified as p-kick (3) initially. Due to a small number of p-kicks, they were added to the number of kickings for further analysis. The analyses showed that none of the milking process-related variables had a significant influence on the dairy cows' prevalence to show hind leg activity. Although the prevalence was not influenced, the type of hind leg activity was. The hind leg activity kicking was observed at significantly higher average mouthpiece chamber vacuum levels than steppings. Cows showing kickings had a higher degree of teat-end hyperkeratosis than those showing steppings. The degree of teat-end hyperkeratosis was related to the milking duration.

[Symptomatic testicular metastasis of acinar adenocarcinoma of the prostate]

We report about the rare occurrence of symptomatic testicular metastasis of an acinar adenocarcinoma of the prostate. Testicular metastases are usually incidentally detected in patients treated with bilateral orchiectomy or more often during autopsy. In the literature, there are only a few clinical cases describing symptomatic testicular metastases. However, the possibility of such metastases should be considered in patients diagnosed with advanced prostate cancer. Testicular examination should be performed regularly, even in patients with low prostate-specific antigen levels.

Constructed wetlands for combined sewer overflow treatment: A state-of-the-art review

Combined sewer overflows (CSOs) are a major source of surface water pollution and degradation. This is particularly visible where sewage collection with combined sewer and centralized treatment are well established, such as in Europe and North America: an overwhelming number of surface water bodies are in insufficient status of ecology, hydrology and physico-chemical parameters. Therefore, several countries have started implementing constructed wetlands (CWs) as mainstream on-spot treatment. This paper summarizes the main design approaches that can be adopted. We identified eight different schemes for the implementation of CSO-CWs, based on our international experience and documented by a literature analysis. The performance review includes conventional water quality parameters, as well as pathogen and emergent contaminant removal. Furthermore, modelling tools for advanced design and for understanding a wide applicability of these green infrastructures are presented. This paper also provides a review on other side benefits offered by the adoption of Nature-Based Solutions for CSO treatment, such as ecosystem services, and the most common issues related to their operation and maintenance. Our analysis has produced a list of key factors for design and operation, all derived from full-scale installations in operation up to more than ten years.

Microbial Shifts and Shorter Time to Bowel Resection Surgery Associated with C. difficile in Pediatric Crohn's Disease

BACKGROUND

Clostridioides difficile infection and colonization are common in pediatric Crohn's disease (CD). Our aims were to test the relationship between C. difficile positivity and bowel resection surgery and to characterize microbial shifts associated with C. difficile carriage and surgery.

METHODS

A retrospective single-center study of 75 pediatric CD patients tested for association between C. difficile carriage and bowel resection surgery. A prospective single-center study of 70 CD patients utilized C. difficile testing and shotgun metagenomic sequencing of fecal samples to define microbiota variation stratified by C. difficile carriage or history of surgery.

RESULTS

The rate of bowel resection surgery increased from 21% in those without C. difficile to 67% in those with (P = 0.003). From a Kaplan-Meier survival model, the hazard ratio for time to first surgery was 4.4 (95% CI, 1.2-16.2; P = 0.00) in patients with positive C. difficile testing in the first year after diagnosis. Multivariable logistic regression analysis confirmed this association (odds ratio 16.2; 95% CI, 2.2-120; P = 0.006). Larger differences in microbial abundance and metabolic pathways were observed in patients with prior surgery than in those with C. difficile carriage. Depletion of Alistipes and Ruminococcus species and reduction in methionine biosynthesis were noted in patients with both C. difficile carriage and past surgery.

CONCLUSIONS

A positive C. difficile test during the first year after diagnosis is associated with decreased time to first bowel resection surgery in pediatric Crohn's disease. Depletion of beneficial commensals and methionine biosynthesis in patients with C. difficile carriage may contribute to increased risk for surgery.

Development of an on-farm model to predict flow of fecal volatile solids to the liquid and solid handling systems of commercial California dairy farms

A source of methane (CH₄) emissions from dairy farms arefecal volatile solids (VS) produced by cattle, which is impacted by herd size, cattle type, feed intake/composition and farm management practices. Where cattle deposit fecal VS in their pen is important in this regard since that deposited on concrete, which will be handled and stored in a liquid form, is a likely source of CH₄ emissions, whereas fecal VS deposited on drylot surfaces will be handled and stored in a dry form and is a minor source of CH₄ emissions. Our objective was to create a model to assist dairy farmers and regulators make informed evaluations of impacts of dairy farm management practices on potential CH₄ emissions from fecal VS. Evaluation of initial model outputs led to on-farm data collection of the model inputs which influenced predicted fecal VS entering the liquid and solid manure handling systems. A key input limitation was lack of information on cattle fecal deposition locations within pens. Data collection used four dairy farms to measure time that cattle spent on concrete surfaces within day among season, as well as other model inputs. The final model, populated with collected data, showed that lactating cattle contribute the overwhelming proportion of fecal VS, 77% in the composite dairy farms, and that a composite freestall dairy farm had 65% of total fecal VS deposited on concrete annually with the remainder on drylot surfaces. In contrast, a composite drylot dairy farm had 37% of fecal VS deposited on concrete annually.

Thermionic microwave gun for terahertz and synchrotron light sources

Conventional thermionic microwave and radio frequency (RF) guns can offer high average beam current, which is important for synchrotron light and terahertz (THz) radiation source facilities, as well as for industrial applications. For example, the Advanced Photon Source at Argonne National Laboratory is a national synchrotron-radiation light source research facility that utilizes thermionic RF guns. However, these existing thermionic guns are bulky, difficult to handle and install, easily detuned, very sensitive to thermal expansion, and due for a major upgrade and replacement. In this paper, we present the design of a new, more stable, and reliable gun with optimized electromagnetic performance, improved thermal engineering, and a more robust cathode mounting technique, which is a critical step to improve the performance of existing and future light sources, industrial accelerators, and electron beam-driven THz sources. We will also present a fabricated gun prototype and show results of high-power and beam tests.

Create a Safe Night

Background: The ultimate goal and purpose of healthcare is to improve health while preventing morbidity and mortality. The optimal approach to this is through teamwork using a reliability framework. Upon review of our institution’s 2012 patient safety culture survey data, we noted that the teamwork domain of the Agency for Healthcare Research and Quality (AHRQ) assessment was in the lowest decile. Our institution implemented the Crimson Analytics tool in 2013, and an analysis of inpatient mortality data revealed higher than expected mortality statistics. Objective: Hospital systems and team-based care are more developed during daytime hours, leaving patients more vulnerable to adverse events (morbidity and mortality) during the overnight period. Our objective was to develop optimal transitions of care and proactive risk identification/mitigation through an interprofessional team-based approach, with resultant decrease in patient harm and improvement in safety culture. Methods: In a community hospital, standardize transitions to identify “at risk” patients for nurses, physicians, and respiratory techs with subsequent interprofessional review of care plans/patient status in a centralized midevening standup briefing, subsequent proactive rounding on “at risk” patients, use of error prevention behaviors aimed to mitigate cognitive bias, and end-of-shift reflection process. Results: Inpatient mortality rates fell from a baseline level of 2.08% in April 2013–March 2015 to 1.56% during the intervention period from April 2015–March 2018. The observed/expected mortality ratio fell from 1.04 to 0.76. AHRQ safety culture data improved in the teamwork domain from 81% to 83%. A custom survey for this intervention was developed and found significant improvements in risk awareness and mitigation response, teamwork, efficiency, and—potentially—joy at work. Conclusion: An interprofessional approach to high-quality transitions in care, risk identification, and mitigation, along with structured huddles and proactive rounding, can improve patient safety at night while simultaneously improving staff satisfaction, joy, and safety culture.

Ristocetin and Botrocetin Involve Two Distinct Domains of von Willebrand Factor for Binding to Platelet Membrane Glycoprotein lb

We have evidence that ristocetin and botrocetin mediate binding of von Willebrand Factor (vWF) to platelet glycoprotein lb (GPIb) through two distinct domains on the vWF molecule. This was established by using monoclonal antibodies (MAbs) to vWF and synthetic peptides derived from the sequence of vWF. MAb 322 and MAb NMC/vW 4 both recognize native vWF as well as fragments containing the GPIb-binding domain of vWF, obtained with the following enzymes: trypsin (116 kDa), V-8 pro tease (Spill, 320 kDa) and V-8 protease plus subtilisin (33-28 kDa). Nevertheless, the lack of reciprocal displacement between the two MAbs in experiments of competitive inhibition for binding to vWF demonstrate that their respective epitopes are separate. Both MAbs inhibit 125I-vWF binding to platelet membrane GPIb and vWF-dependent platelet agglutination induced by ristocetin. However, only MAb NMC/vW4 inhibits these functions in the presence of botrocetin and when ristocetin-induced platelet agglutination is inhibited by MAb 322, botrocetin is still able to restore the agglutination. The involvement of two distinct domains of vWF for binding to GPIb in the presence of ristocetin or botrocetin was confirmed in experiments of binding of 125I-vWF to platelets using as competitor synthetic peptides corresponding to the GPIb binding domain of vWF (Cys 474 to Pro 488 and Ser 692 to Pro 708). At a final concentration of 2.5 mM both peptides inhibit more than 90% of the binding of vWF to ristocetin-treated platelets but are unable to modify this binding in the presence of botrocetin. In conclusion our data suggest that botrocetin and ristocetin involve distinct sites on vWF for binding to GPIb.

Familial Variant of Antithrombin III (AT III Bligny, 47Arg to His) Associated with Protein C Deficiency

The association of a variant of antithrombin III (AT III Bligny) and protein C deficiency is described in a 36-year-old patient having suffered from severe thrombotic episodes. His mother has protein C deficiency and showed a single episode of thrombophlebitis following surgery. His father, sister and daughter have the variant AT III and are asymptomatic. The abnormal AT III was characterized in plasma by the discrepancy between a normal progressive activity and a reduced heparin cofactor activity. This variant AT III was purified, separated from the normal protein by heparin-Sepharose chromatography and was eluted with increased NaCI concentrations. At pH 7.4, the variant AT III eluted at lower (0.3 to 0.5 M) NaCI concentrations than normal (1 to 1.5 M) AT III, thus demonstrating a decreased affinity for heparin. At pH 6.0, however, the abnormal molecule bound more avidly to heparin-Sepharose and was eluted like normal AT III at pH 7.4. Similarly, the heparin enhancement of intrinsic fluorescence of the variant AT III, markedly reduced at pH 7.4, was normalized at pH 6.0. The abnormal AT III showed a normal antiprotease activity, a normal molecular weight by SDS-PAGE, but displayed only a partial immunological identity with the normal protein. Analysis of amplified genomic DNA from this patient by dot-blot demonstrates a heterozygous substitution of arginine by histidine at position 47.

Carrier Detection in Severe (Type III) von Willebrand Disease Using Two Intragenic Restriction Fragment Length Polymorphisms

DNA from a family with a female member affected with severe (type III) vWD was analysed using three restriction enzymes and a partial vWF cDNA probe. Two restriction fragment length polymorphisms (RFLPs) detected with the enzymes Bgl II and Xba I proved to be informative in this family. A 36.0 Kb allele, demonstrated with the enzyme Xba I was rare in the general population but very important in this family for segregation analysis of the alleles and their association with the putative defective chromosome. The propositus was homozygous for the 36.0 Kb Xba I polymorphic band and heterozygous for the Bgl II polymorphism. She was the only member of the family showing this allelic pattern. The linkage of the alleles could be determined because her mother was homozygous for the 9.0 Kb Bgl II polymorphism but heterozygous for the Xba I polymorphism. The segregation of the alleles could be traced to the proband’s son and a niece. The genotypic analysis revealed that her niece could be considered as carrying a defective gene for severe vWD.

Multicenter Comparison of von Willebrand Factor Multimer Sizing Techniques

A multicenter study of various types of von Willebrand’s disease (vWD) was conducted in order to compare the different electrophoretic techniques used to evaluate von Willebrand factor multimers in plasma. Seven laboratories participated in the blind study of eight plasma samples from two healthy subjects and six vWD types and subtypes (la, lb, IIA, IIB, IIC and IID). From the results of the multimeric analysis of these samples, it appears that the differential diagnosis of vWD types and subtypes should be first approached by using a low-resolution electrophoretic technique, where each vWF multimer appears as a single band. Low-resolution techniques differentiate type I from type II, subtype la from lb and also subtype IIA from other type II subtypes. When type II subtypes other than IIA are identified with these techniques, samples should be rerun using high resolution techniques that resolve each of the fastest migrating multimers in at least three subbands, and permit the differentiation of subtypes IIB, IIC and IID.

An Enzyme Immunoassay (ELISA) for the Quantitation of Human Factor VII

A new solid phase enzyme-linked immunosorbent assay (ELISA) was developed for the quantitation of human Factor VII antigen (F VII Ag), using a monospecific rabbit anti-F VII antiserum. Anti-F VII F(ab′)2 fragments were adsorbed to polystyrene plates. The binding of serial dilutions of control or test plasma, containing F VII, was detected by incubation with peroxidase-labeled anti- FV II IgG followed by the addition of hydrogen peroxyde and O-phenylenediamine. This ELISA is specific, sensitive (detection limit: 0.05%) and accurate (coefficient of variation: 1.5-4% for within- and 1.6-9% for between-assays). F VII coagulant activity (F VII C) and F VII Ag were determined in large populations of controls and patients. In normal plasma (n = 38), F VII Ag ranged from 83 to 117% and the correlation coefficient between F VII Ag and F VII C was 0.94. In patients with severe (F VII C inf. 1%) congenital F VII deficiency (n = 5), F VII Ag was undetectable in two cases (inf. 0.05%) and markedly reduced (0.35 to 5.6%) in the three other cases. In patients with liver cirrhosis (n = 15), F VII Ag ranged from 21 to 59% and was in good correlation with F VII C (r = 0.84). In dicoumarol treated patients (n = 15), the levels of F VII Ag ranged from 51% to 79% and a poor correlation (r = 0.52) with F VIIC was observed. In “compensated” DIC (n = 5), levels of F VII Ag varied from 60 to 186%, with significantly higher F VII C levels (from 143 to 189%). In contrast, in “decompensated” DIC (n = 7), low F VII Ag and F VII C levels were observed (from 7 to 27%). In patients with deep-vein thrombosis (n = 25), high levels of F VII Ag (from 102 to 136%) and F VII C (from 110 to 150%) were demonstrated. In surgical patients, no significant difference was observed before and one day after intervention.

Homozygous Variant of Antithrombin III : AT III Fontainebleau

A qualitative defect of antithrombin III (AT III) was demonstrated in four members of a large Tunisian family by the discrepancy between a normal amount of antigen and decreased or absent heparin cofactor activity. The propositus, a 3-year-old girl, died from massive intracardiac thrombosis despite oral anticoagulant therapy. Heparin cofactor activity measured in the presence of thrombin or F. Xa was undetectable in her plasma. Anti-F. Xa activity was also absent when using low molecular weight heparin or a synthetic pentasaccharide, representing the binding site to AT III. The lack of affinity of the propositus AT III for heparin was demonstrated by two-dimensional immunoelectrophoresis and chromatography on heparin-Sepha-rose. The parents, first cousins, and the sister of the propositus also demonstrated a qualitative abnormality of AT III, with levels of heparin cofactor activity close to 50% of the normal range. Our data support the view that the abnormal protein was present at the heterozygous state in the parents and sister and at the homozygous state in the propositus. None of the affected family members had thrombotic episodes, except for the propositus. The name of AT III Fontainebleau is proposed for this variant.

Impaired Prothrombin Consumption in Bernard-Soulier Syndrome Is Corrected In Vitro by Human Factor VIII

The Bernard-Soulier syndrome (BSS) is characterized by thrombocytopenia with giant platelets, a prolonged bleeding time with defective platelet adhesion to the subendothelium related to a defect in platelet membrane glycoprotein lb (GPIb) and a decreased prothrombin consumption. The mechanism of the latter abnormality remains unknown. In this study, we showed that this defect was corrected by the addition of purified human factor VIII (FVIII) to blood from four patients with BSS. The correction of prothrombin consumption was almost complete at concentrations between 1.5 and 3 IU/ml of FVIII procoagulant activity (VIII.'C) and partially abolished by a monoclonal antibody which neutralizes VIII:C. This correction was specific for FVIII and was not observed after addition of purified human FIX. It was obtained, in the same magnitude range, with FVIII complexed to von Willebrand factor (vWF) but not with free vWF. These data provide a new insight into the knowledge of the physiological interaction between the platelet membrane and the vWF-FVIII complex facilitating plasma coagulation activation and may lead to helpful therapeutic advances.