A radiologist's guide to median sternotomy

Median sternotomy is widely recognised as the primary incision technique in cardiac surgery. This surgical procedure involves dividing the sternum to gain access to the heart and lungs, making it invaluable in correcting congenital heart defects. Furthermore, it is frequently employed in adult patients, particularly during coronary artery bypass graft (CABG) procedures. In this imaging review, we present a comprehensive overview of the pre-procedural assessment and various post-sternotomy complications encountered within our clinical experience at a tertiary cardiothoracic centre. The focus of this review is to outline the imaging features associated with mediastinal adhesions and establish the minimal safe distance between the sternum and common mediastinal structures when considering re-sternotomy. By providing visual examples, we aim to facilitate a better understanding of these key concepts. Moreover, we delve into a detailed discussion of a spectrum of postoperative complications that may arise following median sternotomy including those related to metalwork (sternal wire fracture), bone (sternal dehiscence, non-union and osteomyelitis), and soft tissue (abscess, haematoma).

Groin Hernia Repair during the COVID-19 Pandemic-A Romanian Nationwide Analysis

Background and Objectives: Groin hernia repair surgery (GHRS) is among the most common elective interventions. The aim of this three-year nationwide study on GHRS is to provide a thorough analysis of the impact that the COVID-19 pandemic had on the Romanian Health System in regard to elective procedures. Materials and Methods: 46,795 groin hernia cases obtained between 2019 and 2021 from the DRG database using ICD-10 diagnostic codes. The data were collected from all 261 GHRS performing hospitals nationwide, including 227 public hospitals (PbH) and 34 private hospitals (PvH). The 42 variables taken into account were processed using Microsoft Excel 2021, applying Chi square, F-Test Two-Sample for variances, and Two Sample t-Test. The significance threshold considered was p < 0.001. Results: Of the grand total of cases, 96.2% were inguinal hernias, 86.8% were performed on men, 15.2% were laparoscopic procedures, and 6.88% were in PvH. Overall, due to the pandemic, the total number of GHRS decreased with 44.45% in 2020 and with 29.72% in 2021 compared to pre-pandemic year 2019. April 2020 shows the steepest decrease in GHRS (91 procedures nationwide). In the private sector, there was an opposite trend with increases in the number of cases by 12.21% and a 70.22% in both pandemic years. The mean admission period (MAP) for all procedures was 5.5 days. There was a significant difference between PbH and PvH (5.75 vs. 2.8 days, p < 0.0001). During the pandemic, the MAP in PbH decreased (6.02 in 2019, 5.82 in 2020 and 5.3 in 2021), remaining stable for PvH (2.9 days in 2019, 2.85 days in 2020 and 2.74 days in 2021). Conclusions: The COVID-19 pandemic significantly reduced the overall number of GHRS performed in Romania in 2020 and 2021, compared to 2019. However, the private sector thrived with an actual increase in the number of cases. There was a significant lower MAP in the PvH compared to PbH throughout the three-year period.

HLA class II immunogenic mutation burden predicts response to immune checkpoint blockade

BACKGROUND

Whereas human leukocyte antigen (HLA) class I mutation-associated neoantigen burden has been linked with response to immune checkpoint blockade (ICB), the role of HLA class II-restricted neoantigens in clinical responses to ICB is less studied. We used computational approaches to assess HLA class II immunogenic mutation (IMM) burden in patients with melanoma and lung cancer treated with ICB.

PATIENTS AND METHODS

We analyzed whole-exome sequence data from four cohorts of ICB-treated patients with melanoma (n = 110) and non-small-cell lung cancer (NSCLC) (n = 123). MHCnuggets, a neural network-based model, was applied to estimate HLA class II IMM burdens and cellular fractions of IMMs were calculated to assess mutation clonality. We evaluated the combined impact of HLA class II germline genetic variation and class II IMM burden on clinical outcomes. Correlations between HLA class II IMM burden and density of tumor-infiltrating lymphocytes were computed from expression data.

RESULTS

Responding tumors harbored a significantly higher HLA class II IMM burden for both melanoma and NSCLC (P ≤ 9.6e-3). HLA class II IMM burden was correlated with longer survival, particularly in the NSCLC cohort and in the context of low intratumoral IMM heterogeneity (P < 0.001). HLA class I and II IMM landscapes were largely distinct suggesting a complementary role for class II IMMs in tumor rejection. A higher HLA class II IMM burden was associated with CD4+ T-cell infiltration and programmed death-ligand 1 expression. Transcriptomic analyses revealed an inflamed tumor microenvironment for tumors harboring a high HLA class II IMM burden.

CONCLUSIONS

HLA class II IMM burden identified patients with NSCLC and melanoma that attained longer survival after ICB treatment. Our findings suggest that HLA class II IMMs may impact responses to ICB in a manner that is distinct and complementary to HLA class I-mediated responses.

Extremely long-range, high-temperature Josephson coupling across a half-metallic ferromagnet

The Josephson effect results from the coupling of two superconductors across a spacer such as an insulator, a normal metal or a ferromagnet to yield a phase coherent quantum state. However, in junctions with ferromagnetic spacers, very long-range Josephson effects have remained elusive. Here we demonstrate extremely long-range (micrometric) high-temperature (tens of kelvins) Josephson coupling across the half-metallic manganite La_0.7Sr_0.3MnO₃ combined with the superconducting cuprate YBa₂Cu₃O₇. These planar junctions, in addition to large critical currents, display the hallmarks of Josephson physics, such as critical current oscillations driven by magnetic flux quantization and quantum phase locking effects under microwave excitation (Shapiro steps). The latter display an anomalous doubling of the Josephson frequency predicted by several theories. In addition to its fundamental interest, the marriage between high-temperature, dissipationless quantum coherent transport and full spin polarization brings opportunities for the practical realization of superconducting spintronics, and opens new perspectives for quantum computing.

Morphological and genetic variation in populations of Sitana/ marudhamneydhal/ and the validity of Sitana attenboroughii/

Dewlap morphology and body ratios are two of the main morphological characters used in delimiting Sitana spp. It becomes a statistical limitation when small samples are used in species descriptions, as outliers can be picked to be described as a distinct species. Genetic data has been used to support the distinctness of a species in Sitana. However, species with shallow genetic divergence becomes a problem if not thoroughly examined. We examine and report our findings on morphological and genetic differences in two populations of Sitana marudhamneydhal and one population of S. attenboroughii. The shallow genetic divergence and overlapping morphology shows that Sitana attenboroughii is a junior synonym of Sitana marudhamneydhal.

Mycobacterium tuberculosis CysA2 is a dual sulfurtransferase with activity against thiosulfate and 3-mercaptopyruvate and interacts with mammalian cells

Cyanide is a toxic compound that is converted to the non-toxic thiocyanate by a rhodanese enzyme. Rhodaneses belong to the family of transferases (sulfurtransferases), which are largely studied. The sulfur donor defines the subfamily of these enzymes as thiosulfate:cyanide sulfurtransferases or rhodaneses (TSTs) or 3-mercaptopyruvate sulfurtransfeases (MSTs). In Mycobacterium tuberculosis, the causative agent of tuberculosis, the gene Rv0815c encodes the protein CysA2, a putative uncharacterized thiosulfate:cyanide sulfurtransferase that belongs to the essential sulfur assimilation pathway in the bacillus and is secreted during infection. In this work, we characterized the functional and structural properties of CysA2 and its kinetic parameters. The recombinant CysA2 is a α/β protein with two rhodanese-like domains that maintains the functional motifs and a catalytic cysteine. Sulfurtransferase activity was determined using thiosulfate and 3-mercaptopyruvate as sulfur donors. The assays showed Km values of 2.89 mM and 7.02 mM for thiosulfate and 3-mercaptopyruvate, respectively, indicating the protein has dual activity as TST and MST. Immunological assays revealed that CysA2 interacted with pulmonary cells, and it was capable to activate macrophages and dendritic cells, indicating the stimulation of the immune response, which is important for its use as an antigen for vaccine development and immunodiagnostic.

Size-dependent redox behavior of iron observed by in-situ single nanoparticle spectro-microscopy on well-defined model systems

Understanding the chemistry of nanoparticles is crucial in many applications. Their synthesis in a controlled manner and their characterization at the single particle level is essential to gain deeper insight into chemical mechanisms. In this work, single nanoparticle spectro-microscopy with top-down nanofabrication is demonstrated to study individual iron nanoparticles of nine different lateral dimensions from 80 nm down to 6 nm. The particles are probed simultaneously, under same conditions, during in-situ redox reaction using X-ray photoemission electron microscopy elucidating the size effect during the early stage of oxidation, yielding time-dependent evolution of iron oxides and the mechanism for the inter-conversion of oxides in nanoparticles. Fabrication of well-defined system followed by visualization and investigation of singled-out particles eliminates the ambiguities emerging from dispersed nanoparticles and reveals a significant increase in the initial rate of oxidation with decreasing size, but the reactivity per active site basis and the intrinsic chemical properties in the particles remain the same in the scale of interest. This advance of nanopatterning together with spatially-resolved single nanoparticle X-ray absorption spectroscopy will guide future discourse in understanding the impact of confinement of metal nanoparticles and pave way to solve fundamental questions in material science, chemical physics, magnetism, nanomedicine and nanocatalysis.

Sublingual immunization with the phosphate-binding-protein (PstS) reduces oral colonization by Streptococcus mutans

Bacterial ATP-binding cassette (ABC) transporters play a crucial role in the physiology and pathogenicity of different bacterial species. Components of ABC transporters have also been tested as target antigens for the development of vaccines against different bacterial species, such as those belonging to the Streptococcus genus. Streptococcus mutans is the etiological agent of dental caries, and previous studies have demonstrated that deletion of the gene encoding PstS, the substrate-binding component of the phosphate uptake system (Pst), reduced the adherence of the bacteria to abiotic surfaces. In the current study, we generated a recombinant form of the S. mutans PstS protein (rPstS) with preserved structural features, and we evaluated the induction of antibody responses in mice after sublingual mucosal immunization with a formulation containing the recombinant protein and an adjuvant derived from the heat-labile toxin from enterotoxigenic Escherichia coli strains. Mice immunized with rPstS exhibited systemic and secreted antibody responses, measured by the number of immunoglobulin A-secreting cells in draining lymph nodes. Serum antibodies raised in mice immunized with rPstS interfered with the adhesion of bacteria to the oral cavity of naive mice challenged with S. mutans. Similarly, mice actively immunized with rPstS were partially protected from oral colonization after challenge with the S. mutans NG8 strain. Therefore, our results indicate that S. mutans PstS is a potential target antigen capable of inducing specific and protective antibody responses after sublingual administration. Overall, these observations raise interesting perspectives for the development of vaccines to prevent dental caries.

Prognostic implication of the loss of TGFBR2 expression in oral carcinoma

Oral squamous cell carcinoma (OSCC) is a disease that strikes many worldwide, accounting for more than 145,000 deaths annually. This study examined the role of Transforming Growth Factor Beta (TGFβ) signalling alterations in oral carcinogenesis and also its influence on the disease prognosis. In presented study, we evaluated the protein-level alterations of core TGFβ signalling members in 20 potentially malignant oral disorders (PMDs) - leukoplakia and submucous fibrosis and 87 oral cancer samples by western blotting. Further, we analysed the association between these alterations and prognosis of oral carcinoma. For statistical analyses, univariate test like Student's 't'-test to compare expression level of various genes and logrank test has been used to compare the Kaplan-Meier survival curves. The multivariate model such as Cox's proportional hazard regression was used to verify the independent influence of each variable on the survival endpoints. A gradual decrease in the expression of TGFβ signalling members like SMAD2, SMAD4, TGFBR1 and TGFBR2 have been noted from normal to PMD in oral cancers. The bio-activeforms, SMAD2/3 also showed a similar trend. SMAD3 protein was downregulated significantly in the PMD stage itself. Thus an inverse correlation was observed between expression of TGFβ members and oral cancer progression.Furthermore, oral cancer patients showing TGFBR2 downregulation exhibited poor disease-free survival (p=0.005) and poor overall survival (p=0.012).Thus, assessing the TGFBR2 protein levels can serve as one of the prognostic marker for oral cancer.

Multidetector CT of pulmonary cavitation: filling in the holes

Pulmonary cavitation causes significant morbidity and mortality. Early diagnosis of the presence and aetiology of a cavity is therefore crucial in order to avoid further demise in both the localized pulmonary and systemic disorders that may manifest with pulmonary cavity formation. Multidetector CT has become the principal diagnostic technique for detecting pulmonary cavitation and its complications. This review provides an overview of the aetiologies and their imaging findings using this technique. Combining a literature review with case illustration, a synopsis of the different imaging features and constellations is provided, which may suggest a particular cause and aid the differentiation from diseases with similar findings.

Prognostic implication of the loss of TGFBR2 expression in oral carcinoma

Oral squamous cell carcinoma (OSCC) is a disease that strikes many worldwide, accounting for more than 145,000 deaths annually. This study examined the role of Transforming Growth Factor Beta (TGFβ) signalling alterations in oral carcinogenesis and also its influence on the disease prognosis. In presented study, we evaluated the protein-level alterations of core TGFβ signalling members in 20 potentially malignant oral disorders (PMDs) - leukoplakia and submucous fibrosis and 87 oral cancer samples by western blotting. Further, we analysed the association between these alterations and prognosis of oral carcinoma. For statistical analyses, univariate test like Student's 't'-test to compare expression level of various genes and logrank test has been used to compare the Kaplan-Meier survival curves. The multivariate model such as Cox's proportional hazard regression was used to verify the independent influence of each variable on the survival endpoints. A gradual decrease in the expression of TGFβ signalling members like SMAD2, SMAD4, TGFBR1 and TGFBR2 have been noted from normal to PMD in oral cancers. The bio-activeforms, SMAD2/3 also showed a similar trend. SMAD3 protein was downregulated significantly in the PMD stage itself. Thus an inverse correlation was observed between expression of TGFβ members and oral cancer progression.Furthermore, oral cancer patients showing TGFBR2 downregulation exhibited poor disease-free survival (p=0.005) and poor overall survival (p=0.012).Thus, assessing the TGFBR2 protein levels can serve as one of the prognostic marker for oral cancer.

Thermal fluctuations in artificial spin ice

Artificial spin ice systems have been proposed as a playground for the study of monopole-like magnetic excitations, similar to those observed in pyrochlore spin ice materials. Currents of magnetic monopole excitations have been observed, demonstrating the possibility for the realization of magnetic-charge-based circuitry. Artificial spin ice systems that support thermal fluctuations can serve as an ideal setting for observing dynamical effects such as monopole propagation and as a potential medium for magnetricity investigations. Here, we report on the transition from a frozen to a dynamic state in artificial spin ice with a square lattice. Magnetic imaging is used to determine the magnetic state of the islands in thermal equilibrium. The temperature-induced onset of magnetic fluctuations and excitation populations are shown to depend on the lattice spacing and related interaction strength between islands. The excitations are described by Boltzmann distributions with their factors in the frozen state relating to the blocking temperatures of the array. Our results provide insight into the design of thermal artificial spin ice arrays where the magnetic charge density and response to external fields can be studied in thermal equilibrium.

Mesenchymal stromal cells in the antimicrobial host response of hematopoietic stem cell recipients with graft-versus-host disease--friends or foes?

Mesenchymal stromal cells (MSCs) are multipotent cells, which exhibit broad immunosuppressive activities. Moreover, they may be administered irrespectively of human leukocyte antigen (HLA) compatibility, without inducing life-threatening immunological reactions, as they express no HLA class II and limited HLA class I antigens under resting conditions. These characteristics have made MSC an appealing candidate for cell therapy after hematopoietic stem cell transplantation (HSCT), for example, for treatment of graft-versus-host disease (GvHD) or for graft rejection prevention/treatment in allogeneic HSCT recipients. Unfortunately, information regarding the effect of MSC infusion on the host response to infectious agents is scarce, and study results on infectious complications in patients receiving MSC are conflicting. The present review focuses on the available data from in vitro studies and animal models regarding the interaction of MSC with bacterial, viral and fungal pathogens. In a clinical part, we present the current information on infectious complications in allogeneic HSCT recipients who had received MSCs as prophylaxis or treatment of GvHD disease.

Direct observation of magnetic metastability in individual iron nanoparticles

X-ray photoemission electron microscopy combined with x-ray magnetic circular dichroism is used to study the magnetic properties of individual iron nanoparticles with sizes ranging from 20 down to 8 nm. While the magnetocrystalline anisotropy of bulk iron suggests superparamagnetic behavior in this size range, ferromagnetically blocked particles are also found at all sizes. Spontaneous transitions from the blocked state to the superparamagnetic state are observed in single particles and suggest that the enhanced magnetic energy barriers in the ferromagnetic particles are due to metastable, structurally excited states with unexpected life times.

In situ magnetic and electronic investigation of the early stage oxidation of Fe nanoparticles using X-ray photo-emission electron microscopy

In situX-ray photoemission electron microscopy reveals the evolution of chemical composition and magnetism of individual iron nanoparticles during oxidation.

Direct observation of thermal relaxation in artificial spin ice

We study the thermal relaxation of artificial spin ice with photoemission electron microscopy, and are able to directly observe how such a system finds its way from an energetically excited state to the ground state. On plotting vertex-type populations as a function of time, we can characterize the relaxation, which occurs in two stages, namely a string and a domain regime. Kinetic Monte Carlo simulations agree well with the temporal evolution of the magnetic state when including disorder, and the experimental results can be explained by considering the effective interaction energy associated with the separation of pairs of vertex excitations.

Fibrous dysplasia--a 13-year retrospective radiographic analysis in a south Indian population

OBJECTIVE

The aim of this study was to examine the clinical and radiographic presentation of fibrous dysplasia through a 13-year retrospective study in patients who reported to the outpatient unit of Government Dental College, Trivandrum.

METHODS

The clinical file records and radiographs of the patients who reported to the outpatient clinic in the Department of Oral Medicine and Radiology were retrospectively reviewed for histopathologically diagnosed fibrous dysplasia. A detailed analysis of the clinical and radiographic features of the 24 cases retrieved was carried out.

RESULTS

The male-to-female ratio of incidence was approximately 1:1. Most of the patients were in the second or third decade of life. Almost all the patients presented with a complaint of swelling on the side of the face. The mandible was more frequently involved than the maxilla. The most common radiographic pattern observed was the "ground-glass" appearance. Most of the patients exhibited expansion of the involved bone and loss of lamina dura of associated teeth.

CONCLUSION

The awareness of protean features of fibrous dysplasia evident through this study is essential in the accurate diagnosis and proper treatment planning of such lesions.

Multi-technique imaging of sarcoidosis

Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology. The diagnosis is suggested on the basis of wide ranging clinical and radiological manifestations, and is supported by the histological demonstration of non-caseating granulomas in affected tissues. This review highlights the multisystem radiological features of the disease across a variety of imaging methods including multidetector computed tomography (CT), magnetic resonance imaging (MRI) as well as functional radionuclide techniques, particularly 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography/computed tomography (PET/CT). It is important for the radiologist to be aware of the varied radiological manifestations of sarcoidosis in order to recognize and suggest the diagnosis in the appropriate clinical setting.

Crystallization, data collection and data processing of maltose-binding protein (MalE) from the phytopathogen Xanthomonas axonopodis pv. citri

Maltose-binding protein is the periplasmic component of the ABC transporter responsible for the uptake of maltose/maltodextrins. The Xanthomonas axonopodis pv. citri maltose-binding protein MalE has been crystallized at 293 K using the hanging-drop vapour-diffusion method. The crystal belonged to the primitive hexagonal space group P6(1)22, with unit-cell parameters a = 123.59, b = 123.59, c = 304.20 A, and contained two molecules in the asymetric unit. It diffracted to 2.24 A resolution.

Production of the refolded oligopeptide-binding protein (OppA) encoded by the citrus pathogen Xanthomonas axonopodis pv. Citri

The oligopeptide-binding protein, OppA, binds and ushers oligopeptide substrates to the membrane-associated oligopeptide permease (Opp), a multi-component ABC-type transporter involved in the uptake of oligopeptides expressed by several bacterial species. In the present study, we report the cloning, purification, refolding and conformational analysis of a recombinant OppA protein derived from Xanthomonas axonopodis pv. citri (X. citri), the etiological agent of citrus canker. The oppA gene was expressed in Escherichia coli BL21 (DE3) strain under optimized inducing conditions and the recombinant protein remained largely insoluble. Solubilization was achieved following refolding of the denatured protein. Circular dichroism analysis indicated that the recombinant OppA protein preserved conformational features of orthologs expressed by other bacterial species. The refolded recombinant OppA represents a useful tool for structural and functional analyses of the X. citri protein.

Structural model and ligand interactions of the Xanthomonas axonopodis pv. citri oligopeptide-binding protein

The oligopeptide-binding protein, OppA, ushers oligopeptide substrates to the membrane-associated oligopeptide permease (Opp), a multi-component ABC-type transporter involved in the uptake of oligopeptides by several bacterial species. In the present study, we report a structural model and an oligopeptide docking analysis of the OppA protein expressed by Xanthomonas axonopodis pv. citri (X. citri), the etiological agent of citrus canker. The X. citri OppA structural model showed a conserved three-dimensional structure, irrespective of the low amino acid identities with previously defined structures of Bacillus subtilis and Salmonella typhimurium orthologs. Oligopeptide docking analysis carried out with the proposed model indicated that the X. citri OppA preferentially binds tri- and tetrapeptides. The present study represents the first structural analysis of an OppA ortholog expressed by a phytopathogen and contributes to the understanding of the physiology and nutritional strategies of X. citri.

The oligopeptide (opp) gene cluster of Streptococcus mutans: identification, prevalence, and characterization

INTRODUCTION

The Opp system is an ATP-binding cassette-type transporter formed by membrane-associated proteins required for the uptake of oligopeptides in bacteria. In gram-positive bacteria, the Opp system, and particularly the oligopeptide-binding protein (OppA), has been shown to be involved in different aspects of cell physiology, including intercellular communication and binding to host proteins.

METHODS

In the present study we began to investigate the Opp system of Streptococcus mutans, the main etiological agent of dental caries.

RESULTS

Five opp genes (oppABCDF) organized in a single operon were identified in the genome of the S. mutans UA159 strain. Amino acid sequence analyses showed that the S. mutans OppA is closely related to an ortholog found in Streptococcus agalactiae. Incubation of S. mutans UA159 cells with an anti-OppA-specific serum did not inhibit biofilm formation on polystyrene plates. Moreover, S. mutans UA159 derivatives carrying deletions on the oppA or oppB genes did not show significant growth impairment, increased sensitivity to aminopterin, or defective capacity to form biofilms on polystyrene wells in the presence or not of saliva. Remarkably, only two out of three laboratory strains and one out of seven clinical strains recovered from tooth decay processes harbored a copy of the oppA gene and expressed the OppA protein.

CONCLUSION

Collectively, these results indicate that, in contrast to other Streptococcus species, the S. mutans Opp system, and particularly the OppA protein, does not represent an important trait required for growth and colonization.

Crystallization, data collection and phasing of the molybdate-binding protein of the phytopathogen Xanthomonas axonopodis pv. citri

Xanthomonas axonopodis pv. citri ModA protein is the ABC periplasmic binding component responsible for the capture of molybdate. The protein was crystallized with sodium molybdate using the hanging-drop vapour-diffusion method in the presence of PEG or sulfate. X-ray diffraction data were collected to a maximum resolution of 1.7 A using synchrotron radiation. The crystal belongs to the orthorhombic space group C222(1), with unit-cell parameters a = 68.15, b = 172.14, c = 112.04 A. The crystal structure was solved by molecular-replacement methods and structure refinement is in progress.

Now you see it, now you don't: statistical and methodological considerations in fMRI

We illustrate the effects of statistical threshold, spatial clustering, voxel size, and two approaches to multiple comparison correction on fMRI results. We first analyzed fMRI images obtained from a single subject during a noun-verb matching task. Data were analyzed with Statistical Parametric Mapping (SPM) using two different voxel sizes, and results were displayed at three different levels of statistical significance. At each statistical threshold, results were first uncorrected for multiple comparisons and spatial extent and then presented using a spatial extent cluster of 20 voxels. We then statistically controlled the Type I error rate associated with multiple comparisons by using the false discovery rate and by the random field adjustment for false-positive rate used by SPM. We also examined group results from language and graphesthesia paradigms at three levels of statistical significance. In all circumstances, apparent random activations decreased as more conservative statistical approaches were employed, but activation in areas considered to be functionally significant was also reduced. These issues are important in the choice of analytic approach and interpretation of fMRI results, with clear implications for the surgical management of individual patients when fMRI results are used to delineate specific areas of eloquent cortex.

Gamma camera-mounted anatomical X-ray tomography: technology, system characteristics and first images

Scintigraphic diagnosis, based on functional image interpretation, becomes more accurate and meaningful when supported by corresponding anatomical data. In order to produce anatomical images that are inherently registered with images of emission computerised tomography acquired with a gamma camera, an X-ray transmission system was mounted on the slip-ring gantry of a GEMS Millennium VG gamma camera. The X-ray imaging system is composed of an X-ray tube and a set of detectors located on opposite sides of the gantry rotor that moves around the patient along with the nuclear detectors. A cross-sectional anatomical transmission map is acquired as the system rotates around the patient in a manner similar to a third-generation computerised tomography (CT) system. Following transmission, single-photon emission tomography (SPET) or positron emission tomography (PET) coincidence detection images are acquired and the resultant emission images are thus inherently registered to the anatomical maps. Attenuation correction of the emission images is performed with the same anatomical maps to generate transmission maps. Phantom experiments of system performance and examples of first SPET and coincidence detection patient images are presented. Despite limitations of the system when compared with a state of the art CT scanner, the transmission anatomical maps allow for precise anatomical localisation and for attenuation correction of the emission images.

Primary intraosseous carcinoma of the mandible--a case report and review of the literature

BACKGROUND

Squamous cell carcinoma arising within bone is a rare lesion and is only seen essentially in the jaw bones.

METHODS

A case of primary intraosseous carcinoma arising in the mandible is reported in a 60-year-old female patient. Twenty-eight cases of primary intraosseous carcinoma published in the literature, till date, are reviewed.

RESULTS

The mean age of the patients at the time of diagnosis was 53 years and the male: female ratio was 2.2:1. The posterior mandible was the predominant site. Fourteen of 28 patients presented with routine dental disorders, while eight patients complained of swelling, four of severe pain and three had sensory disturbances. The incidence of lymphadenopathy was 10 (34.481%) out of the 29 cases reviewed here. Wide surgical excision is accepted as the treatment of choice.

CONCLUSION

The most common presenting symptom of these tumours is swelling and persistent pain in the jaw. Hence, in making a diagnosis one is likely to consider benign dental conditions. The importance of considering intraosseous carcinoma as a possibility in all cases of persistent pain and swelling in the jaw is emphasized so that suitable treatment can be instituted early.

Effect of sentence length on the production of linguistic stress by left- and right-hemisphere-damaged patients

An acoustical/perceptual study of phonemic stress (e.g., HOTdog vs. hot DOG) was conducted to evaluate the effect of sentence length on stress production after brain damage. Productions of phonemic stress pairs were elicited in sentence contexts of increasing length from eight left-hemisphere-damaged nonfluent (LHD-NFL), fluent LHD-FL), right-hemisphere-damaged (RHD), and normal speakers (n = 32). Tape recordings of subjects' productions were presented to naïve listeners for perceptual identification of stress placement. Acoustic analysis focused on fundamental frequency, duration, and intensity of the initial and final syllables as well as pause duration between syllables. Perceptual tests indicated that regardless of sentence length, all brain-damaged groups exhibited an impairment in the production of linguistic stress when compared to normals. The LHD-NFL group experienced the greatest difficulty in signaling stress contrasts, followed in order by the LHD-FL and RHD groups. In medium-length sentences, the LHD-FL group's performance was degraded by comparison to short-length sentences. Acoustic analysis showed that pause duration was the strongest predictor of phonemic stress for all groups. Acoustic profiles of the RHD group were similar qualitatively to those of normals, but differed quantitatively in terms of magnitude of effect associated with shifts in stress patterns. Findings are brought to bear on the nature of the stress production deficit after unilateral brain damage, the role of the right hemisphere in linguistic prosody, and the concept of "subtle phonetic deficit" in fluent aphasia.

Multi-facial anomalies in mandibulofacial dysostosis. A report of three cases

Mandibulofacial dysostosis is readily recognized on the basis of a characteristic facial appearance caused by hard and soft tissue abnormalities of the face, including malformations of the ear. Generally, the abnormality is symmetrical. The psychological and social stigma associated with severe facial deformity makes this syndrome one of the most challenging reconstructive problems presented to the craniomaxillofacial surgeon.

Human papillomaviruses in 91 oral cancers from Indian betel quid chewers--high prevalence and multiplicity of infections

India has one of the world's highest incidences of oral cancer. The habit of chewing betel quid is widespread and is suspected to play a role in the etiology of this disease. Studies in many other countries have also pointed to a role for human papilloma-viruses (HPVs) in the etiology of some oral cancers. In this study we analyzed biopsies from 91 Indian oral cancer patients, most of whom were betel quid chewers, by PCR amplification and direct DNA sequencing. HPV DNA was detected in 74% of these lesions, of which 41% had multiple HPV infections. Among the lesions from different oral sites, lesions of the tongue had the highest rate (9 of 11) of HPV infection. These HPV prevalences are among the highest ever reported in oral cancers. As to individual HPV types, prevalences of HPV-6, HPV-11, HPV-16 and HPV-18 were 13%, 20%, 42% and 47%, respectively. No additional known or novel HPV types were detected. To understand the unexpectedly high prevalences of the "low-risk" types HPV-6 and HPV-11, we compared the subtypes and variants that were found in oral cancers against those from benign genital warts from the same patient population but found no differences. The high prevalence of HPV in the oral cancers of these Indian patients suggests that viral infection is an important etiological component, with betel quid probably causing additional mutagenic steps in the carcinogenic process.

Tritium labeling of a powerful methylphosphonate inhibitor of cholinesterase: synthesis and biological applications

7-(Methylethoxy phosphinyloxy)-1-methyl-quinolinium iodide (MEPQ), a powerful anti-cholinesterase methylphosphonate ester, was labeled with tritium (9 Ci/mmol) at the methylphosphonyl moiety (TCH2P(O)(OR)X) by an iodine-tritium replacement reaction. Kinetic measurements of the rate of inhibition of acetylcholinesterase (AChE) by [3H]MEPQ and its rate of hydrolysis in alkaline solution confirmed the identity of [3H]MEPQ with authentic MEPQ, which was prepared by the same reaction sequences. Gel-filtration experiments verified the radiospecificity of [3H]MEPQ. In vitro radiolabeling of both AChE and butyrylcholinesterase along with the whole-body autoradiography of [3H]MEPQ-treated mice suggests that [3H]MEPQ is a convenient marker for studying biological systems containing these esterases.

Distribution of 3H-soman in mice

3H-soman (specific activity 10 Ci/mMol), a potent irreversible cholinesterase inhibitor, was administered IV to mice in a dose of one LD-50, which corresponds to 0.25 mCi/mouse. Animals were sacrificed at 5 min, 2 h and 24 h, and whole body autoradiography was performed. High levels of radioactivity in lung and skin were observed at all time intervals after injection. The central nervous system showed very low concentrations of radioactivity, which remained so for 24 h post-injection. Considerable accumulation of 3H-soman in the urine and gall-bladder, and in the intestinal lumen, may indicate these as pathways of soman excretion. Quantitative determinations of radioactivity in various tissue samples were consistent with the above-mentioned findings. It is concluded that the nature of the persistent binding of soman to lung and skin is striking, and may indicate the existence of specific sites for soman depots.

A novel immunoassay with direct relevance to protection against organophosphate poisoning

Antiparaoxon immune sera were employed in a new immunoassay based on competition between acetylcholinesterase and antibodies for the binding of paraoxon. Unlike radioimmunoassay, the new assay described herein can be extended to predict the feasibility of antibodies to confer in vivo protection of acetylcholinesterase against organophosphate poisoning. The toxicity of paraoxon was reduced in mice which were preinjected with the immune sera.

[The infantile chronic-visceral form of niemann-Pick diseases (author's transl)]

A report was made of three patients who exhibited pronounced heptosplenomegaly at the time of hospital admission: a six-year-old girl and two brothers, 1 year 4 months and 4 years 4 months of age. As is typical for Niemann-Pick disease, foam cells were found in the bone marrow and the liver biopsy specimens for the three patients. Since, however, none of the children had syptoms involving the central nervous systems, the disease must have been the rare B form of Niemann-Pick disease, the infantile chronic-visceral form. In all three patients, laboratory findings indicated a disturbance in hepatic function. The characteristic pulmonary involvement associated with the infantile form was found only in the two brothers, and then in a follow-up examination one year later. The reduced speed of nerve conduction established in the two brothers suggested subclinical involvement of the peripheral nervous system in the disease process. Electron-microscopic examinations of liver biopsies showed various forms of lipoid storage: lipoid bodies with loose, membranous structures and bodies with dense, concentrically arranged lamellae.