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1.
Clin Infect Dis ; 73(9): e3106-e3109, 2021 11 02.
Article in English | MEDLINE | ID: mdl-33075138

ABSTRACT

We compared self-collected oral fluid swab specimens with and without clinician supervision, clinician-supervised self-collected anterior nasal swab specimens, and clinician-collected nasopharyngeal swab specimens for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Supervised oral fluid and nasal swab specimens performed similarly to clinician-collected nasopharyngeal swab specimens. No sample type could detect SARS-CoV-2 infections amongst all positive participants.


Subject(s)
COVID-19 , Humans , Nasopharynx , SARS-CoV-2 , Saliva , Specimen Handling
2.
Drug Dev Ind Pharm ; 45(3): 379-386, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30395722

ABSTRACT

OBJECTIVE: The aim of this study is to demonstrate the applicability of predictive stability studies to the degradation of drug substances. SIGNIFICANCE: The use of predicted stability studies during pharmaceutical development and in regulatory submissions is increasing, particularly in early phase to support an initial retest period/shelf life claim in the absence of standard stability data. These studies offer an alternative to standard stability testing and can facilitate clinical trials to be started earlier and medicines to reach patients faster. They involve a short-term stressed stability study, typically designed to degrade a drug substance or product to the specification level of the shelf life limiting attribute. The results are used to predict degradation under long-term storage conditions and enable stability understanding to be gained over a short time frame, using limited amounts of material. METHODS: In this work, Accelerated Stability Assessment Program (ASAP) studies were performed for 10 different drug substances and the predictions obtained for chemical degradation were compared to ICH compliant stability data. RESULTS: Across the studies good agreement was achieved, with the initial retest period predictions from the ASAP studies being conservative by design. When minimal degradation was observed during an ASAP study, it was demonstrated that at least a 12-month initial retest period could be supported. CONCLUSION: This comparison of ASAP predictions and ICH compliant stability data has demonstrated the ability of well-designed ASAP studies to predict the long-term chemical stability of drug substances.


Subject(s)
Drug Stability , Pharmaceutical Preparations/chemistry , Chemistry, Pharmaceutical/methods , Drug Packaging/methods , Drug Storage/methods , Humans , Technology, Pharmaceutical/methods
3.
Ann Dermatol Venereol ; 145(11): 659-664, 2018 Nov.
Article in French | MEDLINE | ID: mdl-30217682

ABSTRACT

BACKGROUND: Foreign body granuloma is an inflammatory tissue reaction to exogenous material. Classically it appears on the face after aesthetic procedures. Herein we report for the first time three cases of facial granulomatous reactions to microbeads after arterial cervico-facial embolization. PATIENTS AND METHODS: Three patients underwent embolization of the facial arteries using Embogold® microbeads in a setting of epistaxis or tumoral hemostasis. Within 10 to 45 days painful, inflammatory, subcutaneous nodules appeared on the homolateral side of the face. Histological samples showed an inflammatory response with giant cells as well as the presence of microbeads in the skin. A favorable outcome was achieved with colchicine in one patient and with surgery in another; the third patient was lost to follow-up. DISCUSSION: The embolizing microspheres produced a local inflammatory reaction, with destruction of the vascular wall and bead migration to facial tissue leading to a granulomatous reaction. The occurrence of three cases within a period of few weeks, with several different operators and batches of products, is surprising considering the long-standing use of the product. There was no common comorbidity in the patients and no suggestion of trauma. Retrospective analysis of the product batches was normal. Gold staining could play a role in severe inflammatory response to Embogold® particles. CONCLUSION: These three cases illustrate the value of discussing potential foreign body granulomatous reaction in cases of facial nodules following cervico-facial embolization. Colchicine may offer a valuable therapeutic alternative.


Subject(s)
Arteries , Embolization, Therapeutic/instrumentation , Granuloma, Foreign-Body/etiology , Microspheres , Adult , Aged , Embolization, Therapeutic/adverse effects , Epistaxis/therapy , Face/blood supply , Humans , Male , Postoperative Complications , Preoperative Care
4.
Am J Alzheimers Dis Other Demen ; 30(8): 738-45, 2015 Dec.
Article in English | MEDLINE | ID: mdl-24526759

ABSTRACT

We report the findings from a clinical trial in which a group of patients clinically diagnosed with probable Alzheimer's disease (AD) were discriminated from an age-matched group of healthy volunteers (HVs) with statistical significance (P<.001). The results from 20 patients with AD and 20 HVs were obtained by a Fluorescent Ligand Eye Scanning (FLES) technique that measures a fluorescent signature specific to an exogenous ligand bound to amyloid-ß in the lens of the eye. Sensitivity and specificity of 85% and 95%, respectively, have been achieved in predicting clinical diagnosis. Additionally, amyloid brain imaging using florbetapir F18 positron emission tomography shows significant correlation with the results obtained in the eye. Results of the study demonstrate the safety of the FLES system.


Subject(s)
Alzheimer Disease/diagnosis , Amyloid beta-Peptides/metabolism , Brain/diagnostic imaging , Lens, Crystalline/metabolism , Spectrometry, Fluorescence/methods , Aged , Aged, 80 and over , Alzheimer Disease/diagnostic imaging , Aniline Compounds , Ethylene Glycols , Female , Fluorine Radioisotopes , Humans , Male , Middle Aged , Positron-Emission Tomography , Sensitivity and Specificity
5.
Evol Dev ; 15(4): 243-56, 2013.
Article in English | MEDLINE | ID: mdl-23809699

ABSTRACT

Fossils of soft tissues provide important records of early animals and embryos, and there is substantial evidence for a role for microbes in soft tissue fossilization. We are investigating the initial events in interactions of bacteria with freshly dead tissue, using marine embryos as a model system. We previously found that microbial invasion can stabilize embryo tissue that would otherwise disintegrate in hours or days by generating a bacterial pseudomorph, a three dimensional biofilm that both replaces the tissue and replicates its morphology. In this study, we sampled seawater at different times and places near Sydney, Australia, and determined the range and frequency of different taphonomic outcomes. Although destruction was most common, bacteria in 35% of seawater samples yielded morphology­preserving biofilms. We could replicate the taphonomic pathways seen with seawater bacterial communities using single cultured strains of marine gammaproteobacteria. Each given species reproducibly generated a consistent taphonomic outcome and we identified species that yielded each of the distinct pathways produced by seawater bacterial communities. Once formed,bacterial pseudomorphs are stable for over a year and resist attack by other bacteria and destruction by proteases and other lytic enzymes. Competition studies showed that the initial action of a pseudomorphing strain can be blocked by a strain that destroys tissues. Thus embryo preservation in nature may depend on contingent interactions among bacterial species that determine if pseudomorphing occurs.We used Artemia nauplius larvae to show that bacterial biofilm replacement of tissue is not restricted to embryos, but is relevant for preservation of small multicellular organisms. We present a model for bacterial self­assembly of large­scale three­dimensional tissue pseudomorphs, based on smallscaleinteractions among individual bacterial cells to form local biofilms at structural boundaries within the tissue. Localbiofilms then conjoin to generate the pseudomorph.


Subject(s)
Bacteria/metabolism , Biofilms , Fossils , Seawater/microbiology , Aerobiosis , Anaerobiosis , Animals , Artemia/physiology , Bacterial Physiological Phenomena , Biological Evolution , Cytoplasm/metabolism , Gammaproteobacteria/metabolism , Larva , Lipids/analysis , Sea Urchins/physiology , Water Microbiology
6.
Gene Ther ; 20(10): 1022-8, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23719068

ABSTRACT

Revealing the lung tumor genome has directed the current treatment strategies toward targeted therapy. First line treatments targeting the genome of lung tumor cells have been approved and are on the market. However, they are limited by the small number of patients with the current investigated genetic mutations. Novel treatment administration modalities have been also investigated in an effort to increase the local drug deposition and disease control. In the current study, we investigated the safety of the new nonviral vector 2-diethylaminoethyl-dextran methyl methacrylate copolymer (DDMC; Ryujyu Science), which belongs to the 2-diethylaminoethyl-dextran family by aerosol administration. Thirty male BALBC mice, 2 month old, were included and divided into three groups. However, pathological findings indicated severe emphysema within three aerosol sessions. In addition, the CytoViva technique was applied for the first time to display the nonviral particles within the pulmonary tissue and emphysema lesions, and a spectral library of the nonviral vector was also established. Although our results in BALBC mice prevented us from further investigation of the DDMC nonviral vector as a vehicle for gene therapy, further investigation in animals with larger airways is warranted to properly evaluate the safety of the vector.


Subject(s)
DEAE-Dextran/toxicity , Emphysema/chemically induced , Genetic Therapy , Lung/pathology , Methylmethacrylate/toxicity , Administration, Inhalation , Animals , DEAE-Dextran/administration & dosage , Genetic Therapy/adverse effects , Genetic Therapy/methods , Lung Neoplasms/therapy , Male , Methylmethacrylate/administration & dosage , Mice , Mice, Inbred BALB C , Random Allocation
7.
Eur Ann Otorhinolaryngol Head Neck Dis ; 130(2): 55-60, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23352731

ABSTRACT

OBJECTIVES: To describe our experience in the management of vascular malformations of the parotid area. MATERIALS AND METHODS: This was a retrospective study. Among 614 parotidectomy performed between 1998 and 2008 at our institution, 10 cases (1.6%) of vascular malformations have been identified. Clinical features and management of these patients were analyzed. RESULTS: Clinical presentation was usually related to that of a benign, slow-growing and asymptomatic tumor. There was a marked female predominance (90%). In any case, the diagnosis of vascular malformation could be obtained with certainty preoperatively. Surgical excision was performed most often referred to diagnosis. Sixty percent of vascular malformations were located in the superficial lobe of the parotid gland. On the histological we found a classic look with benign vascular proliferation of endothelial cells in the walls. The vessel lumen was either the head of a congestion or thrombosis or calcification (phleboliths). CONCLUSION: Vascular malformations of the parotid gland, rare disease, are mainly venous. The terminology is based on clinical data, scalable, histological and hemodynamic as classified by the International Society of Study of Vascular Anomaly (ISSVA). Despite advances in imaging including MRI they remain difficult to diagnose. The treatment of reference is surgical excision.


Subject(s)
Parotid Neoplasms/blood supply , Parotid Region/blood supply , Vascular Malformations/surgery , Adult , Arteriovenous Malformations/pathology , Arteriovenous Malformations/surgery , Female , Humans , Magnetic Resonance Angiography , Male , Middle Aged , Parotid Neoplasms/diagnostic imaging , Parotid Neoplasms/surgery , Parotid Region/pathology , Parotid Region/surgery , Retrospective Studies , Sex Factors , Ultrasonography , Vascular Malformations/classification , Vascular Malformations/pathology , Young Adult
8.
J Laryngol Otol ; 126(8): 815-7, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22697050

ABSTRACT

OBJECTIVE: To evaluate the haemostatic efficacy and safety of the LigaSure vessel sealing system in major head and neck cancer surgery. METHODS: This two-year, prospective study included 34 patients who underwent major head and neck cancer surgery at a university hospital. The LigaSure Precise handpiece and LigaSure 8 vessel sealing system were utilised as the primary means of haemostasis, except when sealing vessels larger than 7 mm in diameter. Surgical outcomes were evaluated. In addition, in each patient the diameter of the largest vein and artery sealed (all were >2 mm) was measured before sealing. RESULTS: In all cases except one (33/34 patients), a sutureless technique was performed. Post-operative bleeding was observed in two cases. Thirty veins and 22 arteries were measured. The mean diameter of the largest sealed vein was 3.8 mm, while that of the largest sealed artery was 2.7 mm. CONCLUSION: Our experience indicates that the surgical technique described is safe and effective. The main advantages of the LigaSure system are that it simplifies the procedure and eliminates the need for clips and suture ligations.


Subject(s)
Carcinoma, Squamous Cell/surgery , Head and Neck Neoplasms/surgery , Hemostasis, Surgical/methods , Adult , Aged , Aged, 80 and over , Equipment Safety , Female , Hemostasis, Surgical/instrumentation , Humans , Ligation/instrumentation , Ligation/methods , Male , Middle Aged , Postoperative Hemorrhage/prevention & control , Prospective Studies
9.
Eur Ann Otorhinolaryngol Head Neck Dis ; 129(3): 131-5, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22626640

ABSTRACT

INTRODUCTION: The role of fine-needle aspiration cytology (FNAC) in the management of parotid tumours is still the subject of controversy. The purpose of this study was to determine the diagnostic value of FNAC in our institution in order to define its place in the diagnostic strategy. PATIENTS AND METHODS: This retrospective study was based on 249 patients who had undergone preoperative FNAC before being operated in our institution between 2001 and 2008. All examinations were performed and interpreted by the same experienced pathologist. RESULTS: Among the 249 patients included in this study, 187 (75%) had a benign tumour and 62 (25%) had a malignant tumour. No complications of FNAC were observed. Cytological findings were non-contributory in 47 patients (18%). The sensitivity of FNAC for the diagnosis of malignancy was 80% with a specificity of 89.5%. Among the 11 false-negative results, lymphomas and low-grade mucoepidermoid carcinomas were the most common histological types. Among the 16 false-positive results, Warthin's tumours, pleomorphic adenomas and lymphoepithelial lesions were the most common histological types. Accurate histological classification of the tumour was reported in 79.5% of cases (86% for benign tumours and 44% for malignant tumours). CONCLUSION: FNAC is a reliable examination providing important information to the surgeon in the preoperative diagnostic assessment.


Subject(s)
Biopsy, Fine-Needle , Parotid Diseases/pathology , Parotid Diseases/surgery , Parotid Gland/pathology , Parotid Neoplasms/pathology , Parotid Neoplasms/surgery , Diagnosis, Differential , Humans , Predictive Value of Tests , Retrospective Studies
10.
Rev Laryngol Otol Rhinol (Bord) ; 133(4-5): 183-7, 2012.
Article in French | MEDLINE | ID: mdl-24006824

ABSTRACT

INTRODUCTION: Mucoepidermoid carcinoma (MEC) is considered as the most common malignant salivary gland tumor. Its prognosis is dominated by the presence of high-grade forms involving life-threatening. The aim of our study was to evaluate the usefulness of immunohistochemistry to identify the most aggressive forms and allow better discrimination between low grade, intermediate grade and high grade tumors. MATERIALS AND METHODS: This was a retrospective study of 49 cases of mucoepidermoid carcinomas of salivary glands. Two immunohistochemical markers have mainly been studied: a marker of proliferation (Ki-67) and a growth factor receptor (EGFR). Additional analyzes were performed with other markers (p53, ACE, bcl2, CD 117 and her2). Statistical analysis investigated the existence of a correlation between the presence of these factors and the histopathological grade on one hand and survival of patients on the other hand. RESULTS: Regarding the results of immunohistochemical Ki-67 and EGFR, it was observed a better survival rate when the immunostaining was less than 10%. The expression of Ki-67 and EGFR was correlated with the histological grade, but did not, in our study, allow discrimination between low-grade, intermediate grade and high grade. Our results are consistent with data of the literature, including Ki-67, which appears to be a useful but not powerful marker of prognosis of MEC. Other markers studied (p53, ACE, bcl2, CD 117 and her2) showed no contributory results. CONCLUSION: The prognosis of MEC is appreciated satisfactorily following histological criteria: histological grade, surgical margins, perineural invasion or vascular emboli. The integration of immunohistochemistry in a therapeutic algorithm could be particularly useful for the challenging assessment of prognosis of intermediate grades.


Subject(s)
Carcinoma, Mucoepidermoid/mortality , Carcinoma, Mucoepidermoid/pathology , Salivary Gland Neoplasms/mortality , Salivary Gland Neoplasms/pathology , Adolescent , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/analysis , Carcinoma, Mucoepidermoid/surgery , Child , ErbB Receptors/analysis , Female , Humans , Immunohistochemistry , Ki-67 Antigen/analysis , Male , Middle Aged , Prognosis , Retrospective Studies , Salivary Gland Neoplasms/surgery , Young Adult
11.
Proc Biol Sci ; 279(1734): 1857-64, 2012 May 07.
Article in English | MEDLINE | ID: mdl-22158954

ABSTRACT

The Ediacaran Doushantuo biota has yielded fossils interpreted as eukaryotic organisms, either animal embryos or eukaryotes basal or distantly related to Metazoa. However, the fossils have been interpreted alternatively as giant sulphur bacteria similar to the extant Thiomargarita. To test this hypothesis, living and decayed Thiomargarita were compared with Doushantuo fossils and experimental taphonomic pathways were compared with modern embryos. In the fossils, as in eukaryotic cells, subcellular structures are distributed throughout cell volume; in Thiomargarita, a central vacuole encompasses approximately 98 per cent cell volume. Key features of the fossils, including putative lipid vesicles and nuclei, complex envelope ornament, and ornate outer vesicles are incompatible with living and decay morphologies observed in Thiomargarita. Microbial taphonomy of Thiomargarita also differed from that of embryos. Embryo tissues can be consumed and replaced by bacteria, forming a replica composed of a three-dimensional biofilm, a stable fabric for potential fossilization. Vacuolated Thiomargarita cells collapse easily and do not provide an internal substrate for bacteria. The findings do not support the hypothesis that giant sulphur bacteria are an appropriate interpretative model for the embryo-like Doushantuo fossils. However, sulphur bacteria may have mediated fossil mineralization and may provide a potential bacterial analogue for other macroscopic Precambrian remains.


Subject(s)
Embryo, Nonmammalian/ultrastructure , Eukaryotic Cells/ultrastructure , Fossils , Sulfur/metabolism , Thiotrichaceae/classification , Animals , Bacteria/classification , Bacteria/cytology , Bacteria/ultrastructure , Embryo, Nonmammalian/physiology , Eukaryotic Cells/cytology , Eukaryotic Cells/physiology , History, Ancient , Thiotrichaceae/cytology , Thiotrichaceae/ultrastructure
12.
Phys Rev Lett ; 105(13): 133002, 2010 Sep 24.
Article in English | MEDLINE | ID: mdl-21230768

ABSTRACT

Tunneling is often used to describe multiphoton ionization of rare gas atoms in infrared fields. We test the tunneling approximation and its nonadiabatic extension by measuring the unperturbed momentum distribution along the κ direction of a circularly polarized light pulse. We find substantial, but not total, agreement between our results and the predictions of the model. As predicted, the κ direction momentum distribution is Gaussian and its width increases with the square root of electric field strength. However, the width is 15% too large and we find no evidence of nonadiabatic effects as we approach the expected limits of the approximation.

13.
Science ; 325(5946): 1364-7, 2009 Sep 11.
Article in English | MEDLINE | ID: mdl-19745145

ABSTRACT

Tunneling, one of the most striking manifestations of quantum mechanics, influences the electronic structure of many molecules and solids and is responsible for radioactive decay. Much of the interaction of intense light pulses with matter commences with electrons tunneling from atoms or molecules to the continuum. Until recently, this starting point was assumed to be the highest occupied orbital of a given system. We have now observed tunneling from a lower-lying state in hydrogen chloride (HCl). Analyzing two independent experimental observables allowed us to isolate (via fragment ions), identify (via molecular frame photoelectron angular distributions), and, with the help of ab initio simulations, quantify the contribution of lower-lying orbitals to the total and angle-dependent tunneling current of the molecule. Our results bolster the emerging tenet that the coherent interaction between different orbitals--which can amplify the impact of lower orbitals--must be considered in tunneling processes.

14.
HIV Med ; 10(5): 310-7, 2009 May.
Article in English | MEDLINE | ID: mdl-19228205

ABSTRACT

OBJECTIVES: The aim of the study was to characterize the impact of the cytochrome P450 2B6 (CYP2B6), CYP3A4, CYP3A5 and ATP-binding cassette sub-family B member 1 (ABCB1) polymorphisms on nevirapine plasma concentrations. METHODS: A total of 104 patients (82% male; 26% non-Caucasian) were genotyped for eight single nucleotide polymorphisms at four loci (CYP2B6, CYP3A4, CYP3A5 and MDR1). Nevirapine plasma concentrations were determined using high-performance liquid chromatography. RESULTS: Non-Caucasian ethnicity [5609 ng/mL (n=27) for non-Caucasians vs. 3771 ng/mL (n=77) for Caucasians; P<0.0001] and CYP2B6 516G-->T [GG, 3574 ng/mL (n=50); GT, 4634 ng/mL (n=50); TT, 8170 ng/mL (n=4); P(analysis of variance (anova))=0.001] were significantly associated with a higher nevirapine trough concentration (C(trough)). The latter association was maintained with both 200 mg twice daily (bid) and 400 mg once daily (qd) dosing [GG, 3527 ng/mL (n=30); GT, 4525 ng/mL (n=32); TT, 7020 ng/mL (n=2); P(anova)=0.05 and GG, 3645 ng/mL (n=20); GT, 4861 ng/mL (n=17); TT, 9508 ng/mL (n=2); P(anova)=0.01, respectively]. In a multivariable analysis, CYP2B6 516G-->T and non-Caucasian ethnicity remained significant predictors of nevirapine C(trough) but CYP2B6 516G-->T homozygosity had the greatest effect (108% higher, 46% higher). No associations were found between nevirapine C(trough) and the remaining polymorphisms. CONCLUSION: In this population, both non-Caucasian ethnicity and carriage of the variant allele of CYP2B6 516G-->T were significant predictors of nevirapine C(trough). The association between CYP2B6 516G-->T and higher plasma nevirapine exposure was maintained at both bid and qd dosing.


Subject(s)
Cytochrome P-450 Enzyme System/genetics , HIV Infections/drug therapy , Nevirapine/blood , Reverse Transcriptase Inhibitors/blood , ATP Binding Cassette Transporter, Subfamily B , ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , Adult , Aged , Alleles , Analysis of Variance , Black People/genetics , Chromatography, High Pressure Liquid , Cohort Studies , Cytochrome P-450 CYP2B6 , Cytochrome P-450 CYP3A/genetics , Female , Genotype , HIV Infections/blood , Humans , Male , Middle Aged , Nevirapine/administration & dosage , Polymerase Chain Reaction , Polymorphism, Single Nucleotide , Reverse Transcriptase Inhibitors/administration & dosage , White People/genetics
15.
Dev Genes Evol ; 219(2): 89-101, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19189123

ABSTRACT

Adult echinoderms possess a highly diverged, pentaradial body plan. Developmental mechanisms underlying this body plan are completely unknown, but are critical in understanding how echinoderm pentamery evolved from bilateral ancestors. These mechanisms are difficult to study in indirect-developing species; in this study, we use the direct-developing sea urchin Heliocidaris erythrogramma, whose accelerated adult development can be perturbed by NiCl(2). We introduce a new nomenclature for the adult echinoderm axes to facilitate discussion of the radially symmetric body plan and the events required to pattern it. In sea urchins, the adult oral-aboral axis is often conflated with the long axes of the five rays; we identify these as distinct body axes, the proximodistal (PD). In addition, we define a circular axis, the circumoral (CO), along which the division into five sectors occurs. In NiCl(2)-treated larvae, aspects of normal PD pattern were retained, but CO pattern was abolished. Milder treatments resulted in relatively normal juveniles ranging from biradial to decaradial. NiCl(2) treatment had no effect either on mesodermal morphology or on the ectodermal gene expression response to an inductive mesodermal signal. This suggests that the mesoderm does not mediate the disruption of CO patterning by NiCl(2). In contrast, mesodermal signaling may explain the presence of PD pattern in treated larvae. However, variations in appendage pattern suggest that ectodermal signals are also required. We conclude that CO patterning in both germ layers is dependent on ectodermal events and PD patterning is controlled by mutual ectoderm-mesoderm signaling.


Subject(s)
Sea Urchins/embryology , Animals , Body Patterning , Embryo, Nonmammalian , Gene Expression Regulation, Developmental , Sea Urchins/genetics , Sea Urchins/metabolism , Signal Transduction
16.
Rev Laryngol Otol Rhinol (Bord) ; 130(3): 189-91, 2009.
Article in English | MEDLINE | ID: mdl-20345077

ABSTRACT

OBJECTIVES: We describe a case of an unusual schwannoma of the hypoglossal nerve presenting clinically as a malignant tumour of the floor of the oral cavity. CASE REPORT: A 77-year-old woman presented with a bulky tumour located between the left anterior floor of mouth and the ventricular portion of the tongue. The tumour was ulcerated, painful and presented with a necrotic aspect. Neurological examination revealed a mild left hemiparesis of the tongue. MRI and CT showed a circumscribed tumour with a broad necrotic centre. The patient underwent a transoral excision of the tumour under general anaesthesia. CONCLUSION: Schwannomas are generally managed by complete surgical excision but they can mimic primary or metastatic cancer in the head and neck, preoperative diagnosis is therefore necessary to avoid a wide excision.


Subject(s)
Cranial Nerve Neoplasms/diagnosis , Hypoglossal Nerve Diseases/diagnosis , Mouth Floor , Neurilemmoma/diagnosis , Aged , Female , Humans
17.
Proc Natl Acad Sci U S A ; 105(49): 19360-5, 2008 Dec 09.
Article in English | MEDLINE | ID: mdl-19047625

ABSTRACT

Fossilized embryos with extraordinary cellular preservation appear in the Late Neoproterozoic and Cambrian, coincident with the appearance of animal body fossils. It has been hypothesized that microbial processes are responsible for preservation and mineralization of organic tissues. However, the actions of microbes in preservation of embryos have not been demonstrated experimentally. Here, we show that bacterial biofilms assemble rapidly in dead marine embryos and form remarkable pseudomorphs in which the bacterial biofilm replaces and exquisitely models details of cellular organization and structure. The experimental model was the decay of cleavage stage embryos similar in size and morphology to fossil embryos. The data show that embryo preservation takes place in 3 distinct steps: (i) blockage of autolysis by reducing or anaerobic conditions, (ii) rapid formation of microbial biofilms that consume the embryo but form a replica that retains cell organization and morphology, and (iii) bacterially catalyzed mineralization. Major bacterial taxa in embryo decay biofilms were identified by using 16S rDNA sequencing. Decay processes were similar in different taphonomic conditions, but the composition of bacterial populations depended on specific conditions. Experimental taphonomy generates preservation states similar to those in fossil embryos. The data show how fossilization of soft tissues in sediments can be mediated by bacterial replacement and mineralization, providing a foundation for experimentally creating biofilms from defined microbial species to model fossilization as a biological process.


Subject(s)
Bacteria/growth & development , Biofilms , Biological Evolution , Embryo, Nonmammalian/microbiology , Fossils , Aerobiosis , Anaerobiosis , Animals , Anthocidaris/embryology , Autolysis , Bacteria/genetics , DNA, Bacterial , Embryo, Nonmammalian/ultrastructure , Microscopy, Electron , Minerals
18.
Cell Motil Cytoskeleton ; 65(12): 955-63, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18802936

ABSTRACT

Using Drosophila spermatogenesis as a model, we show that function of the beta-tubulin C-terminal tail (CTT) is not independent of the body of the molecule. For optimal microtubule function, the beta-tubulin CTT and body must match. beta2 is the only beta-tubulin used in meiosis and spermatid differentiation. beta1-tubulin is used in basal bodies, but beta1 cannot replace beta2. However, when beta1 is co-expressed with beta2, both beta-tubulins are equally incorporated into all microtubules, and males exhibit near wild type fertility. In contrast, co-expression of beta2beta1C and beta1beta2C, two reciprocal chimeric molecules with bodies and tails swapped, results in defects in meiosis, cytoskeletal microtubules, and axonemes; males produce few functional sperm and few or no progeny. In these experiments, all the same beta-tubulin parts are present, but unlike the co-assembled native beta-tubulins, the "trans" configuration of the co-assembled chimeras is poorly functional. Our data thus reveal essential intra-molecular interactions between the CTT and other parts of the beta-tubulin molecule, even though the CTT is a flexible surface feature of tubulin heterodimers and microtubules. In addition, we show that Drosophila sperm tail length depends on the total tubulin pool available for axoneme assembly and spermatid elongation. D. melanogaster and other Drosophila species have extraordinarily long sperm tails, the length of which is remarkably constant in wild type flies. We show that in males of experimental genotypes that express wild type tubulins but have half the amount of the normal tubulin pool size, sperm tails are substantially shorter than wild type.


Subject(s)
Axoneme/metabolism , Spermatogenesis , Spermatozoa/physiology , Tubulin/metabolism , Amino Acid Sequence , Animals , Axoneme/ultrastructure , Cytoskeleton/metabolism , Drosophila melanogaster/physiology , Male , Microscopy, Electron, Transmission , Molecular Sequence Data , Spermatogenesis/genetics , Spermatozoa/ultrastructure , Tubulin/genetics
19.
J Exp Zool B Mol Dev Evol ; 310(8): 609-22, 2008 Dec 15.
Article in English | MEDLINE | ID: mdl-18702078

ABSTRACT

To understand the role of body axes in the evolution of larval form, we use the two sea urchins in the genus Heliocidaris, which have distinctly different larval morphologies. Heliocidaris tuberculata is an indirect-developing sea urchin, which forms a pluteus larva, whereas its sister species, Heliocidaris erythrogramma, exhibits direct development and forms a nonfeeding, ovoid larva. Changes along all three larval axes underlie the differences in larval form associated with each developmental mode. Nodal signaling has recently been implicated as important in establishing the dorsal-ventral (D-V) and left-right (L-R) axes in the indirect-developing sea urchin Paracentrotus lividus. However, because of changes in morphology and timing of morphogenetic events associated with the D-V and L-R axes, respectively, in H. erythrogramma, it was unclear whether nodal played the same roles during direct development. We show that the expression patterns and functions of nodal during H. erythrogramma development are similar to its roles in indirect-developing sea urchins in both D-V and L-R axes formation. However, there are profound changes in gene expression downstream of nodal signaling along the D-V axis and major heterochronies in the execution of the function of nodal along the L-R axis. These highly modified events are linked to the dramatic modifications of larval morphology that have occurred during the evolution of direct development in H. erythrogramma.


Subject(s)
Anthocidaris/growth & development , Anthocidaris/metabolism , Biological Evolution , Gene Expression Regulation, Developmental , Nodal Protein/genetics , Nodal Protein/metabolism , Animals , Anthocidaris/genetics , Goosecoid Protein/metabolism , In Situ Hybridization , Larva/anatomy & histology , Larva/growth & development , Phenotype , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction , Time Factors
20.
Curr Biol ; 18(12): 911-4, 2008 Jun 24.
Article in English | MEDLINE | ID: mdl-18571413

ABSTRACT

Axonemes of motile eukaryotic cilia and flagella have a conserved structure of nine doublet microtubules surrounding a central pair of microtubules. Outer and inner dynein arms on the doublets mediate axoneme motility [1]. Outer dynein arms (ODAs) attach to the doublets at specific interfaces [2-5]. However, the molecular contacts of ODA-associated proteins with tubulins of the doublet microtubules are not known. We report here that attachment of ODAs requires glycine 56 in the beta-tubulin internal variable region (IVR). We show that in Drosophila spermatogenesis, a single amino acid change at this position results in sperm axonemes markedly deficient in ODAs. Moreover, we found that axonemal beta-tubulins throughout the phylogeny have invariant glycine 56 and a strongly conserved IVR, whereas nonaxonemal beta-tubulins vary widely in IVR sequences. Our data reveal a deeply conserved physical requirement for assembly of the macromolecular architecture of the motile axoneme. Amino acid 56 projects into the microtubule lumen [6]. Imaging studies of axonemes indicate that several proteins may interact with the doublet-microtubule lumen [3, 4, 7, 8]. This region of beta-tubulin may determine the conformation necessary for correct attachment of ODAs, or there may be sequence-specific interaction between beta-tubulin and a protein involved in ODA attachment or stabilization.


Subject(s)
Amino Acid Sequence , Axoneme/ultrastructure , Drosophila/physiology , Dyneins/metabolism , Spermatogenesis/physiology , Tubulin/chemistry , Animals , Axoneme/metabolism , Drosophila/metabolism , Drosophila/ultrastructure , Glycine/chemistry , Male , Molecular Sequence Data , Protein Conformation , Spermatozoa/metabolism , Spermatozoa/ultrastructure , Tomography, X-Ray Computed , Tubulin/genetics , Tubulin/metabolism
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