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PubMed1989

Immune-mediated agranulocytosis related to drugs and their metabolites: mode of sensitization and heterogeneity of antibodies.

Two major unresolved problems in drug-related immune agranulocytosis are understanding the mechanism by which sensitization takes place in vivo, and verification of the diagnosis. Using a sensitive, competitive enzyme-linked immunoassay (ELISA) we were able to characterize the causative antibodies in 13 patients with drug-related agranulocytosis [metamizole (n = 5), penicillin (n = 5), dimethylaminophenazone (n = 1), propyphenazone (n = 1) and diclofenac (n = 1)]. Irrespective of the causative drug, the majority of patients appear to have developed autoantibodies (aab) in addition to drug-dependent antibodies (ddab) of the IgG and/or IgM classes. In all cases related to metamizole, and in the single case related to diclofenac, the ddab appeared to recognize only metabolites of the drug since they were reactive in the presence of ex vivo antigens (urine from individuals receiving therapeutic levels of the drugs), but not the native drugs. Only a few ddab were reactive with granulocytes pretreated with the drug (cell-drug complexes); the majority of ddab could not be detected unless the drug or ex vivo antigen was added to the incubation mixture as well as the solution used for subsequent washes. Our results indicate that drugs and/or their metabolites interact with target cells and thereby directly function as immunogenic haptens, even when the drugs do not bind tightly to the cells.

Adolescent↗

PubMed2004

Minimizing factor requirements for surgery without increased risk.

The most common type of surgical procedure in patients with haemophilia is orthopaedic surgery on the lower limb. These procedures are of great importance for the improvement of the function and quality of life of patients with haemophilia, but in many countries resources are lacking to provide the factor concentrates needed for these operations. We have attempted to reduce the level of replacement during and after total hip or total knee replacement without jeopardizing the outcome of the procedures. The results from 30 operations in 27 patients are presented. Steady-state levels down to 0.5 IU mL(-1) did not appear to increase the amount of blood loss or cause an increased incidence of complications, compared with higher levels. In addition, we review the possibilities to reduce the amount of factor concentrate by performing a combination of orthopaedic procedures and using local haemostatic agents or antifibrinolytic agents.

Aged↗

PubMedDate not supplied

p53, WAF1/CIP1 and mdm2 expression in skin lesions associated with human papillomavirus and human immunodeficiency virus.

Human papillomaviruses (HPVs) express various gene products, such as E6 protein which complexes with the p53 tumor suppressor protein and therefore diminishes p53-related regulatory mechanisms. This interaction is assumed to be HPV type-specific as "high risk" or oncogenic HPV types have more affinity for p53 binding than their "low risk" or non-oncogenic counterparts. Furthermore, HIV infection is believed to activate latent HPV infection and transcription via direct and indirect interaction with HPVs as well as cellular genes and functions. Accordingly, we carried out experiments on biopsies which originated from condylomas ("low risk" HPVs), HIV-positive condylomas (infection with multiple "low risk" and "high risk" HPVs) and anogenital squamous cell carcinomas (SCCs, "high risk" HPV infection). Using reverse transcription PCR (RT-PCR) and western immunoblotting, mRNA and protein levels of p53 and genes regulated by p53, such as mdm2 and WAF1/CIP1 were determined. We found that the presence of HPV can diminish p53 and increase WAF1/CIP1 and mdm2 protein levels. There were no significant differences in this regulation between "low risk" and "high risk" lesions. Our data suggest that these HPV-mediated cellular effects are not type-specific, and they might be part of a viral-cell interaction or represent a cellular defense mechanism against the virus. However, HIV-seropositivity renders HPV lesions containing both "low risk" and "high risk" significantly different. This may be due to the alteration of HPV-controlling cellular pathways by HIV tat and/or activation of cellular pathways different from HIV-negative counterparts. Either possibility is of great interest and needs further verification.

Carcinoma, Squamous Cell↗

PubMed2007

Sandwich-like compounds based on the all-metal aromatic unit Al(4)2- and the main-group metals M (M=Li, Na, K, Be, Mg, Ca).

Inspired by the pioneering experimental characterisation of the all-metal aromatic unit Al(4)2- in the bimetallic molecules MAl4- (M=Li, Na, Cu) and by the very recent theoretical design of sandwich-type transition-metal complexes [Al4MAl4]q- (q=0-2; M=Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W), we used density functional theory (DFT) calculations (B3LYP/6-311+G(d) to design a series of novel non-transition-metal sandwich complexes based on the all-metal aromatic unit Al4(2-) and the main-group metals M (M=Li, Na, K, Be, Mg, Ca). The traditional homo-decked sandwich compounds [Al4MAl4]q- (without counterions) and (nM)q+[Al4MAl4]q- (with counterions M) (q=2-3, M=Li, Na, K, Be, Mg, Ca), although some of them are truly energy minima, have a much higher energy than many fused isomers. We thus concluded that it seems unlikely for Al4(2-) to sandwich the main-group metal atoms in the homo-decked sandwich form. Alternatively, we proposed a new type of sandwich complex, namely hetero-decked sandwich compounds [CpMAl4]q-, that are the ground-state structures for each M both with and without counterions. It was shown that with the rigid Cp- partner, the all-metal aromatic unit Al(4)2- might indeed act as a "superatom". These new types of all-metal aromatic unit-based sandwich complexes await future experimental verification.

Journal Article↗

PubMed2004

When proteome meets genome: the alpha helix and the beta strand of proteins are eschewed by mRNA splice junctions and may define the minimal indivisible modules of protein architecture.

The significance of the intron-exon structure of genes is a mystery. As eukaryotic proteins are made up of modular functional domains, each exon was suspected to encode some form of module; however, the definition of a module remained vague. Comparison of pre-mRNA splice junctions with the three-dimensional architecture of its protein product from different eukaryotes revealed that the junctions were far less likely to occur inside the alpha-helices and beta-strands of proteins than within the more flexible linker regions ('turns' and 'loops') connecting them. The splice junctions were equally distributed in the different types of linkers and throughout the linker sequence, although a slight preference for the central region of the linker was observed. The avoidance of the alpha-helix and the beta-strand by splice junctions suggests the existence of a selection pressure against their disruption, perhaps underscoring the investment made by nature in building these intricate secondary structures. A corollary is that the helix and the strand are the smallest integral architectural units of a protein and represent the minimal modules in the evolution of protein structure. These results should find use in comparative genomics, designing of cloning strategies, and in the mutual verification of genome sequences with protein structures.

Alternative Splicing↗

PubMed1998

SCP-ECG and Vital Signs Information Representation--two examples of successful transcontinental cooperation in medical informatics standardization.

During the past 2-3 decades, development work on Medical Devices focused on improving their functionality (device control, signal analysis, pattern recognition and classification). At present, the dominant user requirement is information integration. This requires interconnectivity and interoperability of devices and device systems. Today, due to all major manufacturers operating globally, this requirement can only be met if standards with global relevance are developed. The first standard discussed is the Standard Communications Protocol for Computerized Electrocardiography (SCP ECG). The rapid finalization of the standards document itself was possible due to some of the experts being involved on basic problems for greater than 10 years. Their knowledge and long standing cooperation contributed significantly to a fast consensus finding process as well as quick implementation. The second standard discussed in this paper deals with Vital Signs Information Representation. Before starting to write the document, an International inventory workshop was held to document the state of the technology and of user requirements. This common base of problem understanding makes consensus finding less difficult. Continuous cooperation between the IEEE P1073 group and the CEN/TC251 WG5 project team also ensures early harmonization of the related standards. Finally, early implementation projects in Europe and the US allow verification and modifications based on feed-back from practical experience.

Electrocardiography↗

PubMed2000

A method to check the accuracy of dose computation using quality index: application to scatter contribution in high energy photon beams.

Computerized dose calculation verification is a relevant component of radiotherapy treatment planning quality assurance. The usual procedure is to compare measurements to computations for several standard situations. As cases become more complex, special test phantoms and beam arrangements must be used, and an experimental procedure must be carefully established. In this paper we follow a new methodology to prepare a set of reference data that may be used to verify the accuracy of dose calculations involving changes in the scatter component of photon beams. The advantage of this methodology is that local measurements are not required. A quantitative evaluation of dose modifications was performed by means of correction factors (CF). For this purpose, three geometrical configurations were designed (asymmetric, symmetric, and reference) where the primary component was kept constant and the scatter component was varied by changing the height (h) of lateral columns. Measurements were performed in polystyrene phantoms for seven photon beam energies. CF were derived as the ratio of the absolute dose measured at the point of interest to the absolute dose for the reference configuration, for the asymmetric and symmetric configurations, respectively. They were expressed as a function of beam quality (QI). We have verified that, for all configurations studied, CF decrease with QI. For h = 15 cm, CF remain practically constant, whatever machine technology is used [the mean values of CF for the asymmetric and symmetric cases are CFa= 1.028 (0.2% 1 s.d.) and CFs= 1.058 (0.4% 1 s.d.)]. We have developed a test protocol and we have chosen those configurations corresponding to h = 15 cm because they both present greater values of the CF and lower standard deviations. The direct application of the method is straightforward. The user can reproduce on his local TPS the three experimental configurations described in the test protocol, and then compute CF which can be compared to our reference data set for any beam quality.

Biophysical Phenomena↗

PubMed1997

Use of OKT3 is associated with early and severe recurrence of hepatitis C after liver transplantation.

OBJECTIVE: To determine whether increased immunosuppression is a contributor to poor outcome in hepatitis C-infected orthotopic liver transplant (OLT) recipients, we retrospectively analyzed the consequences of using OKT3 in our program for steroid-resistant rejection (SRR). METHODS: We compared the histological recurrence of HCV in two contemporary cohorts of OLT recipients. Group 1 consisted of HCV-positive patients who received OKT3 for SRR (n = 19). Group 2 (n = 33) consisted of age-, gender-, and initial immunosuppression-matched HCV-positive controls who were treated with at least one steroid pulse for acute cellular rejection but who did not require treatment with OKT3. Liver biopsies were obtained per protocol within the first month and as necessary to evaluate abnormalities in serum liver chemistries. RESULTS: Mean and median follow-up were comparable for the two groups. Recurrence of HCV was diagnosed by histological verification and was documented in 16 of 19 (84.2%) group 1 patients versus 17 of 33 (51.5%) group 2 patients (p = 0.03). The interval to recurrence was significantly shorter in patients who received OKT3 (p = 0.028). Logistic regression identified OKT3 as a significant risk factor for the recurrence of HCV within the first year post-OLT (p = 0.0004). The histological severity score, based on the most recent liver biopsy at long-term follow-up or the explant biopsy if the patient required retransplantation, was significantly higher in group 1. Moreover, cirrhosis was demonstrable in a greater proportion of allografts in patients who had received OKT3 at some point (26.3% vs. 6%, p = 0.028). Long-term follow-up revealed a trend toward higher alanine aminotransferase levels (p = 0.05) and total bilirubin (p = 0.08) in group 1 patients. CONCLUSIONS: Our data suggest that allograft hepatitis in patients with preexisting HCV occurs earlier and with greater severity in patients treated with OKT3 for SRR, compared with age-, gender-, and initial immunosuppression-matched contemporary controls. Treatment of SRR with OKT3 may jeopardize long-term allograft function and survival in HCV-infected recipients by enhancing viral hepatitis recurrence. Clearly, the recognition of recurrent HCV and differentiation from acute cellular rejection remains a crucial issue in managing the OLT recipient with HCV.

Acute Disease↗

PubMed2004

Behavioral sensitization to intermittent morphine in mice is accompanied by reduced adrenocorticotropine but not corticosterone responses.

The present study was aimed to test the hypothesis that behavioral sensitization to intermittent administration of morphine is accompanied by sensitization of adrenocorticotropine (ACTH) and corticosterone responses and with signs of hyperactivity of the hypothalamic-pituitary-adrenocortical function in mice. Male mice were injected subcutaneously with 40 mg/kg morphine or saline every 72 h for 16 days (in total, six injections were performed) and the effects were compared to those after single drug injection. Hormones were investigated 60 min after the last (6th) morphine or saline injection, i.e. 3 days after the 5th injection of intermittent treatments. Locomotor sensitization was confirmed in a separate series. ACTH levels in response to the last morphine injection of the repeated dosage regimen were found to be lower compared to those in acutely morphine-treated mice. Morphine administration was followed by increases in plasma corticosterone, but no significant differences between the acutely and repeatedly treated groups were observed. The body weight of morphine-treated mice showed a characteristic pattern with decreases measured the day after morphine administration. No statistically significant differences in adrenal and thymus weights were found. In conclusion, behavioral sensitization to morphine in mice is accompanied by a blunted rather than an enhanced ACTH response to drug injection. Unchanged levels of plasma corticosterone demonstrate an absence of tolerance and possible involvement of ACTH unrelated mechanisms needs further verification. Intermittent administration of morphine for 2 weeks failed to induce marked signs of glucocorticoid overexposure.

Adrenocorticotropic Hormone↗

PubMed2005

The visual basis of category effects in object identification: evidence from the visual hemifield paradigm.

The basis for the category specific living things advantage in object recognition (i.e., faster and more accurate identification of living compared to nonliving things) was investigated in two experiments. It was hypothesised that the global shape of living things on average provides more information about their basic level identity than the global shape of nonliving things. In two experiments subjects performed name-picture or picture-name verification tasks, in which blurred or clear images of living and nonliving things were presented in either the right or the left visual hemifield. With blurred images, recognition performance was worst for nonliving things presented to the right visual field/left hemisphere, indicating that the lack of visual detail in the stimulus combined with a left hemisphere bias toward processing high frequency visual elements proved detrimental for processing nonliving stimuli in this condition. In addition, an overall living things advantage was observed in both experiments. This advantage was considerably larger with blurred images than with clear. These results are compatible with the global shape hypothesis and converge with evidence using other paradigms.

Adult↗

PubMed1999

Ultrastructural verification of anchoring role of lamina fibroreticularis of dental basement membrane in odontogenesis.

In a previous study of the developing tooth a characteristic fibrillar layer associated with the basement membrane of the inner enamel epithelium was found to be a highly specialized lamina fibroreticularis of the basement membrane which is unusually rich in basotubules, 10 nm wide microfibril-like structures. In this study this layer was further examined in detail in the hope of ultrastructurally elucidating its role in odontogenesis. Tooth germs of the monkey (Macaca fuscata) were processed for thin section observations. Dental papilla cell processes were inserted into the lamina fibroreticularis and their surface was closely associated with numerous parallel basotubules. With high-resolution observations the space between the surface and nearest basotubules as well as the spaces between neighbouring basotubules were bridged by 1.5-3 nm wide filaments running perpendicular to the axis of basotubules. These results indicate that the processes of dental papilla cells are linked to groups of basotubules by means of 1.5-3 nm wide filaments. Immunoperoxidase staining showed the presence of fibronectin along basotubules as well as within the space between the process and basotubule. This result, together with the comparison of these filaments with microfibril-associated 1.2-3 nm wide fibronectin filaments and the reported abundance of fibronectin in the basement membrane area during odontogenesis, indicates that these 1.5-3 nm wide filaments are composed of fibronectin. After immunostaining for amyloid P component, done with the rat tissue because of the nature of an available antiserum, basotubules in the lamina fibroreticularis were positively stained, as has been shown in basotubules/microfibrils in other locations. Microfibrils function as anchoring rods by interlinking connective tissue components to one another and to the cells. Basotubules, thought to be basement membrane-incorporated microfibrils, in the lamina fibroreticularis in this study are also likely to function as an anchoring device to immobilize dental papilla cells along the basement membrane. Such an arrangement of mesenchymal cells is known to be crucial for the successful differentiation of odontoblasts in the developing tooth.

Animals↗

PubMed1998

Radiotherapy of bladder cancer: relevance of bladder volume changes in planning boost treatment.

PURPOSE: This study aims to evaluate tumor motion with controlled changes of the bladder volume, and to assess the reproducibility of bladder (and tumor) position using a urinary catheter balloon as an immobilization device. METHODS AND MATERIALS: First, three patients with tumor growths in three different bladder regions (trigone, left lateral wall, anterior wall) were evaluated. Three-dimensional CT-based reconstructed images were used to measure the displacement of the tumors when 100 cc were removed from a bladder originally filled with 170 cc of contrast. The 3D calculated boost beam arrangements and field sizes for the three tumors in the partially emptied bladders were used to simulate treatment of the same tumors in the maximally filled bladders. Dose-volume histograms were obtained. Second, verification of an ellipsoid model for bladder volume changes was undertaken in 41 patients. Third, in eight additional patients a urinary catheter balloon filled with 80-cc sterile saline solution was used in an attempt to reproduce the shape and spatial coordinates of the bladder during the boost treatment. A pair of orthogonal films with the 80-cc balloon filled with contrast material were taken at simulation and repeated twice at weekly intervals during radiotherapy. The reproducibility was quantified by sequentially calculating the common surface of the bladder images in each orthogonal view. RESULTS: Target motion, especially in the craniocaudal axis, appeared to be more relevant for tumors arising in the bladder walls (15 mm) than in the trigone (5 mm). Underdosage (<95% of the prescribed dose to the target volume) was observed in 20, 20, and 50% (with 1 cm margins around the tumor) and in 10, 10, and 15% (with 1.5 cm margins around the tumor) of the tumors arising in the trigone, left lateral wall, and anterior wall, respectively. The ellipsoidal model was validated with a strong correlation coefficient allowing to establish a predictive model for bladder wall displacements as a function of bladder volume. In the balloon reproducibility study, mean reproducibility factors of 0.84 (+/-0.06) and 0.82 (+/-0.07) were obtained for both anteroposterior and lateral views, respectively. CONCLUSIONS: Changes in bladder volume and shape related to bladder filling can result in clinically significant displacements of the target volume. A minimum of 2-cm margins around the target may compensate for extreme bladder volume changes during boost treatment. An ellipsoidal model for the bladder is consistent with these observations. Although an 80-cc urinary catheter balloon helped to immobilize the bladder, reproducibility was less than perfect.

Humans↗

PubMed1998

The characterization of a commercial MOSFET dosimeter system for use in diagnostic x ray.

A commercial patient dose verification system utilizing non-invasive metal oxide semiconductor field effect transistor (MOSFET) dosimeters originally designed for radiotherapy applications has been evaluated for use at diagnostic energy levels. The system features multiple dosimeters that may be used to monitor entrance or exit skin dose and intracavity doses in phantoms in real time. We have characterized both the standard MOSFET dosimeter designed for radiotherapy dose verification and a newly developed "high sensitivity" MOSFET dosimeter designed for lower dose measurements. The sensitivity, linearity, angular response, post-exposure response, and physical characteristics were evaluated. The average sensitivity (free in air, including backscatter) of the radiotherapy MOSFET dosimeters ranged from 3.55 x 10(4) mV per C kg(-1) (9.2 mV R(-1)) to 4.87 x 10(4) mV per C kg(-1) (12.6 mV R(-1)) depending on the energy of the x-ray field. The sensitivity of the "high sensitivity" MOSFET dosimeters ranged from 1.15 x 10(5) mV per C kg(-1) (29.7 mV R(-1)) to 1.38 x 10(5) mV per C kg(-1) (35.7 mV R(-1)) depending on the energy of the x-ray field. The high sensitivity dosimeters demonstrated excellent linearity at high energies (90 and 120 kVp) and acceptable linearity at lower energies (60 kVp). The angular response was significant for free-in-air exposures, as illustrated by the sensitivity differences between the two sides of the dosimeter, but was excellent for measurements within a tissue equivalent cylinder. The post-exposure drift response is a complicated but reproducible function of time. Real-time monitoring requires little if any corrections for the post-exposure drift response. The MOSFET dosimeter system brings some unique capabilities to diagnostic radiology dosimetry including small size, real-time capabilities, nondestructive measurement, good linearity, and a predictable angular response.

Health Physics↗

PubMed1997

Discrimination between normal wildtype and carriers of coagulation factor V Leiden mutation by the activated protein C resistance test in the presence of factor V deficient plasma.

Blood samples from 104 patients with clinically suspected thrombophilia were analyzed for coagulation factor V Leiden mutation (1691, G-->A) by allele-specific polymerase chain reaction. In 86 individuals (82.7%), the mutation was not detectable, whereas 15 patients (14.4%) were heterozygous and three patients (2.9%) were homozygous for factor V Leiden mutation. Plasma samples from these individuals were also tested for functional resistance of coagulation factor V to activated protein C (activated protein C resistance). This test was performed on a Schnitger-Gross coagulometer using an activated partial thromboplastin time-based activated protein C resistance test modified by applying a 1 : 5 dilution with factor V-deficiency plasma. All the individuals negative for factor V Leiden mutation were also negative in the functional activated protein C resistance test. On the other hand, all patients carrying the mutation revealed pathologic results in the activated protein C resistance test. The cutoff value for the activated protein C resistance index (> or = 1.7 = negative) was determined by testing 31 male and female blood donors. One of them was heterozygous for factor V Leiden mutation and had an activated protein C resistance index of 1.4, whereas those without factor V Leiden mutation had an activated protein C resistance index of 1.9 +/- 0.1 (mean +/- SD). Patients with clinically suspected thrombophilia without factor V Leiden mutation had an activated protein C resistance index of 2.1 +/- 0.2 (mean +/- SD), whereas patients heterozygous for the mutation had an index of 1.5 +/- 0.1 (mean +/- SD). Within the group of patients carrying the mutation, the activated protein C resistance test even distinguished between heterozygous and three homozygous (activated protein C resistance 1.0 to 1.2) carriers. The data demonstrate that the activated protein C resistance test in the presence of factor V-deficiency plasma provides a clear-cut discrimination between normal wildtype and carriers of factor V Leiden mutation with a sensitivity and specificity of 100%. Verification of positive activated protein C resistance tests can be performed easily with a simple and reliable polymerase chain reaction protocol for the 1691, G-->A mutation.

Base Sequence↗

PubMed1984

The use of synthetic peptides for defining the specificity of tyrosine protein kinases.

The tyrosine protein kinases are a large family of enzymes that may be involved in regulating cell growth and differentiation. An important property of these enzymes is their substrate specificity. Defining the specificity of these enzymes will contribute to a greater understanding of their biological functions. Synthetic peptides provide a useful means for studying the specificities of protein kinases. The utility of synthetic peptides for specificity studies is exemplified by the results obtained with the cyclic nucleotide-dependent protein kinases. A large number of synthetic peptides have been tested as substrates for these enzymes. There are three important conclusions from this work. First, in terms of primary sequence, the two cyclic nucleotide-dependent protein kinases both require the presence of a pair of basic residues on the N-terminal side of the phosphorylatable residue. Second, recognition of a specific secondary structure in the substrate is an equally important factor in the substrate specificities of these enzymes. Third, the specificities of the two cyclic nucleotide-dependent protein kinases are remarkably similar in terms of both primary and secondary structure recognition. Sequences at the sites of tyrosine phosphorylation often show the presence of numerous acidic residues on the N-terminal side of the tyrosine. This result led to the suggestion that these acidic residues might be important for the recognition of these sites by the tyrosine protein kinases. Specificity studies using synthetic peptides have provided some experimental verification of this concept. In the case of four tyrosine protein kinases, LSTRA cell tyrosine protein kinase, epidermal growth factor receptor kinase, insulin receptor kinase and pp60gag-yes tyrosine protein kinase, the presence of acidic residues on the N-terminal side of the tyrosine in a synthetic peptide was a favorable determinant. In the case of a fifth member of the tyrosine protein kinase family, namely pp60src kinase, the data are less clear that the presence of acidic residues is involved in substrate recognition. This enzyme readily phosphorylated several peptides that did not have acidic residues on the N-terminal side of the tyrosine. Although there is some indication that the presence of acidic residues on the N-terminal side of the tyrosine is a factor in substrate recognition by several of the tyrosine protein kinases, the changes in kinetic parameters with the various peptide substrates were rather small. In addition, some sites phosphorylated in proteins do not have any acidic residues on the N-terminal side of the phosphorylated tyrosine residue.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗

PubMed2025

Developing a disease-specific accessible transcriptional signature as a biomarker for ataxia with oculomotor apraxia type 2.

BACKGROUND: Genetic ataxias are clinically heterogenous neurodegenerative conditions often involving rare or private mutations and it is often difficult to assign pathogenicity to rare gene variants solely based on DNA sequencing. An effective functional assay from an easy-to-obtain biospecimen would aid this assessment and be of high clinical value. SETX encodes a ubiquitous DNA/RNA helicase crucial for resolving R-loops and maintaining genome stability. Loss-of-function mutations cause a recessive disorder, Ataxia with Oculomotor Apraxia Type 2 (AOA2). METHODS: Here we utilize Weighted Gene Co-expression Network Analysis (WGCNA) from patient blood to construct an AOA2-specific transcriptomic signature as a biomarker to evaluate SETX variants in patients clinically suspected of having AOA2. RESULTS: WGCNA from peripheral blood RNA of 11 AOA2 patients from 7 families initially identified a single gene module that was modestly effective in distinguishing individuals with AOA2 from controls (sensitivity 73%, specificity 97%) and was able to robustly differentiate AOA2 patients from those with genetically distinct, yet phenotypically similar, neurological disorders (sensitivity 100%, specificity 100%). An independent derivation of the transcriptional biomarker identified a dual module model that was able to better distinguish individuals with AOA2 from controls (sensitivity 100%, specificity 97%). As validation, we examined a second cohort of 21 patients from 13 families and demonstrate that this dual module transcriptional biomarker could discriminate patients clinically suspected of AOA2 from controls (57%, 95%CI: 34%-78%). Overall, the transcriptional biomarker was able to separate AOA2 subjects (n = 32) from controls (n = 35) with 72% sensitivity and 97% specificity. Notably, this transcriptomic biomarker enabled verification of the first pathogenic SETX mutation found in a non-canonical transcript, expanding the spectrum of mutations that contribute to AOA2. CONCLUSIONS: Our study identified a transcriptional biomarker that was able to differentiate AOA2 from controls and from other related neurological disorders, consequently expanding the spectrum of known pathogenic mutations. This proof-of-concept study illustrates that transcriptional biomarkers may be used to validate variants of uncertain significance in known genetic diseases.

Humans↗

PubMedDate not supplied

Development of a new transvenous patent ductus arteriosus occlusion technique using a shape memory polymer.

A novel percutaneous patent ductus arteriosus (PDA) occlusion technique, without the potential problems associated with conventional techniques, has been long awaited. The development of a novel transvenous PDA occlusion technique using a temperature-shape changeable occluder device, and the verification of its in vitro performance, were demonstrated in this study. The principles of this technique are: 1) the bar form device was inserted into the PDA transvenously by a guide wire and a pushing catheter, 2) the device was dashed with hot water through catheters, 3) the device was expanded by hot water in the PDA, and the PDA was occluded. The occluder device, made of a shape memory polymer (polynorbornene), was designed to have the monobloc configuration of a thin disk with a hole for a guide wire in the center and a cone. The barlike device by hot press was fully expanded within 10 sec upon immersion into 45 degrees C water. The mock-circulation test with the "great arteries" and a specially designed "PDA" showed 1) the introduction of hot water (45 degrees C) through the catheters caused expansion of the device which stayed in the "PDA" without any support, 2) the "aortic" pressure and the distal "aortic" flow increased rapidly, and the "pulmonary" flow reduced promptly. This resulted in a drastically reduced shunt ratio at the PDA from 68% to 30%. Thus, the novel PDA occlusion technique developed here functioned well to occlude the PDA in a great arteries model.

Cardiac Catheterization↗

PubMed1992

Primary structure and cellular localization of chicken brain myosin-V (p190), an unconventional myosin with calmodulin light chains.

Recent biochemical studies of p190, a calmodulin (CM)-binding protein purified from vertebrate brain, have demonstrated that this protein, purified as a complex with bound CM, shares a number of properties with myosins (Espindola, F. S., E. M. Espreafico, M. V. Coelho, A. R. Martins, F. R. C. Costa, M. S. Mooseker, and R. E. Larson. 1992. J. Cell Biol. 118:359-368). To determine whether or not p190 was a member of the myosin family of proteins, a set of overlapping cDNAs encoding the full-length protein sequence of chicken brain p190 was isolated and sequenced. Verification that the deduced primary structure was that of p190 was demonstrated through microsequence analysis of a cyanogen bromide peptide generated from chick brain p190. The deduced primary structure of chicken brain p190 revealed that this 1,830-amino acid (aa) 212,509-D) protein is a member of a novel structural class of unconventional myosins that includes the gene products encoded by the dilute locus of mouse and the MYO2 gene of Saccharomyces cerevisiae. We have named the p190-CM complex "myosin-V" based on the results of a detailed sequence comparison of the head domains of 29 myosin heavy chains (hc), which has revealed that this myosin, based on head structure, is the fifth of six distinct structural classes of myosin to be described thus far. Like the presumed products of the mouse dilute and yeast MYO2 genes, the head domain of chicken myosin-V hc (aa 1-764) is linked to a "neck" domain (aa 765-909) consisting of six tandem repeats of an approximately 23-aa "IQ-motif." All known myosins contain at least one such motif at their head-tail junctions; these IQ-motifs may function as calmodulin or light chain binding sites. The tail domain of chicken myosin-V consists of an initial 511 aa predicted to form several segments of coiled-coil alpha helix followed by a terminal 410-aa globular domain (aa, 1,421-1,830). Interestingly, a portion of the tail domain (aa, 1,094-1,830) shares 58% amino acid sequence identity with a 723-aa protein from mouse brain reported to be a glutamic acid decarboxylase. The neck region of chicken myosin-V, which contains the IQ-motifs, was demonstrated to contain the binding sites for CM by analyzing CM binding to bacterially expressed fusion proteins containing the head, neck, and tail domains. Immunolocalization of myosin-V in brain and in cultured cells revealed an unusual distribution for this myosin in both neurons and nonneuronal cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗