An FcRn-targeted mucosal vaccine against SARS-CoV-2 infection and transmission

SARS-CoV-2 is primarily transmitted through droplets and airborne aerosols, and in order to prevent infection and reduce viral spread vaccines should elicit protective immunity in the airways. The neonatal Fc receptor (FcRn) transfers IgG across epithelial barriers and can enhance mucosal delivery of antigens. Here we explore FcRn-mediated respiratory delivery of SARS-CoV-2 spike (S). A monomeric IgG Fc was fused to a stabilized spike; the resulting S-Fc bound to S-specific antibodies and FcRn. Intranasal immunization of mice with S-Fc and CpG significantly induced antibody responses compared to the vaccination with S alone or PBS. Furthermore, we intranasally immunized mice or hamsters with S-Fc. A significant reduction of virus replication in nasal turbinate, lung, and brain was observed following nasal challenges with SARS-CoV-2 and its variants. Intranasal immunization also significantly reduced viral airborne transmission in hamsters. Nasal IgA, neutralizing antibodies, lung-resident memory T cells, and bone-marrow S-specific plasma cells mediated protection. Hence, FcRn delivers an S-Fc antigen effectively into the airway and induces protection against SARS-CoV-2 infection and transmission.

Child abuse and neglect and mental health outcomes in adulthood by ethnicity: Findings from a 40-year longitudinal study in New Zealand/Aotearoa

BACKGROUND

Longitudinal studies consistently report adverse long-term outcomes of childhood maltreatment. Little is known about the impact of childhood maltreatment on mental health among a marginalized population (New Zealand Māori); therefore, we cannot assume the effects of maltreatment are the same across the population.

OBJECTIVE

Associations were examined between childhood sexual abuse (CSA), childhood physical punishment (CPP) and childhood neglect (CN) (<16 years) and mental health outcomes 18-40 years, by ethnicity (Māori/non-Māori).

PARTICIPANTS AND SETTING

Data from the Christchurch Health and Development Study, a study of a birth cohort of 1265 children born in Christchurch in 1977. By age 40, 17.8 % (n = 191) reported New Zealand Māori ethnic identity; 82.2 % (n = 883) were non-Māori.

METHODS

CSA, CPP (<16 years) were measured at 18, 21 years; CN was measured at 40 years. Major depression, anxiety disorder, suicidal ideation, alcohol abuse/dependence and cannabis abuse/dependence were measured at ages 21, 25, 30, 35 and 40 years. Childhood confounding variables controlled. Analyses were extended to include Māori ethnicity.

RESULTS

After statistical adjustment, experience of severe childhood maltreatment increased odds of mental health problems 1.8-2.6×, compared to no maltreatment; the effects of maltreatment were similar for males and females. For Māori, some higher rates of mental health problems were seen among those maltreated, no statistically significant associations were detected after Bonferroni correction (among severe maltreatment vs. no maltreatment). Limitations should be considered when interpreting results.

CONCLUSIONS

Exposure to childhood maltreatment has long-term effects into middle-age. Further research employing culturally-sensitive approaches may help clarify Māori childhood maltreatment outcomes.

Experimental demonstration of diffusion limitations on resolution and SNR in MR microscopy

PURPOSE

MR microscopy is in principle capable of producing images at cellular resolution (<10 µm), but various factors limit the quality achieved in practice. A recognized limit on the signal to noise ratio and spatial resolution is the dephasing of transverse magnetization caused by diffusion of spins in strong gradients. Such effects may be reduced by using phase encoding instead of frequency encoding read-out gradients. However, experimental demonstration of the quantitative benefits of phase encoding are lacking, and the exact conditions in which it is preferred are not clearly established. We quantify the conditions where phase encoding outperforms a readout gradient with emphasis on the detrimental effects of diffusion on SNR and resolution.

METHODS

A 15.2 T Bruker MRI scanner, with 1 T/m gradients, and micro solenoid RF coils < 1 mm in diameter, were used to quantify diffusion effects on resolution and the signal to noise ratio of frequency and phase encoded acquisitions. Frequency and phase encoding's spatial resolution and SNR per square root time were calculated and measured for images at the diffusion limited resolution. The point spread function was calculated and measured for phase and frequency encoding using additional constant time phase gradients with voxels 3-15 µm in dimension.

RESULTS

The effect of diffusion during the readout gradient on SNR was experimentally demonstrated. The achieved resolutions of frequency and phase encoded acquisitions were measured via the point-spread-function and shown to be lower than the nominal resolution. SNR per square root time and actual resolution were calculated for a wide range of maximum gradient amplitudes, diffusion coefficients, and relaxation properties. The results provide a practical guide on how to choose between phase encoding and a conventional readout. Images of excised rat spinal cord at 10 µm × 10 µm in-plane resolution demonstrate phase encoding's benefits in the form of higher measured resolution and higher SNR than the same image acquired with a conventional readout.

CONCLUSION

We provide guidelines to determine the extent to which phase encoding outperforms frequency encoding in SNR and resolution given a wide range of voxel sizes, sample, and hardware properties.

Prevalence of Anemia Among Pregnant Women in Rural Village of Sindhupalchowk District of Nepal - A Cross-Sectional Study

Background: Anemia is a global public health problem all around the world, principally the developing countries like Nepal. Anemia results in maternal mortality alongside low birth weight which contributes to an increased infant mortality rate. The prevalence of anemia ranges from 27% to 42% among pregnant women depending on geographical regions. Iron and folic acid tablets are supplied free of charge to pregnant women as part of the Nepal government's National Anemia Control Strategy and Iron Intensification Program.  Methods:  A cross-sectional study was carried out among pregnant women attending Manekharka health center for an antenatal checkup. Hemoglobin levels of pregnant women from April 2018-2020 were obtained and analyzed. Hemoglobin level was determined using the indirect cyanmethemoglobin method. Results:  We used the World Health Organization (WHO) standard classification of hemoglobin levels below 11 gm/dl to determine the prevalence of anemia in pregnant women. The result suggested that a total of 30.7%, (n=63) of the pregnant women were anemic. Among which 4.76% had moderate anemia (hemoglobin 7-9.9gm/dl) and 96.58% had mild anemia (hemoglobin ≥9.9mg/dl to <11gm/dl). Conclusion:  The study and its results suggest that the women in the age group 16-19 had a higher prevalence of anemia whereas the age group 25-29 had the lowest prevalence of anemia. Moreover, the study revealed that the prevalence of anemia in hills is substantial.

An FcRn-targeted mucosal vaccine against SARS-CoV-2 infection and transmission

SARS-CoV-2 and its variants cause COVID-19, which is primarily transmitted through droplets and airborne aerosols. To prevent viral infection and reduce viral spread, vaccine strategies must elicit protective immunity in the airways. FcRn transfers IgG across epithelial barriers; we explore FcRn-mediated respiratory delivery of SARS-CoV-2 spike (S). A monomeric IgG Fc was fused to a stabilized S protein; the resulting S-Fc bound to S-specific antibodies (Ab) and FcRn. A significant increase in Ab responses was observed following the intranasal immunization of mice with S-Fc formulated in CpG as compared to the immunization with S alone or PBS. Furthermore, we intranasally immunize adult or aged mice and hamsters with S-Fc. A significant reduction of virus replication in nasal turbinate, lung, and brain was observed following nasal challenges with SARS-CoV-2, including Delta and Omicron variants. Intranasal immunization also significantly reduced viral transmission between immunized and naive hamsters. Protection was mediated by nasal IgA, serum-neutralizing Abs, tissue-resident memory T cells, and bone marrow S-specific plasma cells. Hence FcRn delivers an S-Fc antigen effectively into the airway and induces protection against SARS-CoV-2 infection and transmission. Based on these findings, FcRn-targeted non-invasive respiratory immunizations are superior strategies for preventing highly contagious respiratory viruses from spreading.

A PSGL-1 glycomimetic reduces thrombus burden without affecting hemostasis

Events mediated by the P-selectin/PSGL-1 pathway play a critical role in the initiation and propagation of venous thrombosis by facilitating the accumulation of leukocytes and platelets within the growing thrombus. Activated platelets and endothelium express P-selectin, which binds P-selectin glycoprotein ligand-1 (PSGL-1) that is expressed on the surface of all leukocytes. We developed a pegylated glycomimetic of the N terminus of PSGL-1, PEG40-GSnP-6 (P-G6), which proved to be a highly potent P-selectin inhibitor with a favorable pharmacokinetic profile for clinical translation. P-G6 inhibits human and mouse platelet-monocyte and platelet-neutrophil aggregation in vitro and blocks microcirculatory platelet-leukocyte interactions in vivo. Administration of P-G6 reduces thrombus formation in a nonocclusive model of deep vein thrombosis with a commensurate reduction in leukocyte accumulation, but without disruption of hemostasis. P-G6 potently inhibits the P-selectin/PSGL-1 pathway and represents a promising drug candidate for the prevention of venous thrombosis without increased bleeding risk.

Cellular NADH and NADPH Conformation as a Real-Time Fluorescence-Based Metabolic Indicator under Pressurized Conditions

Cellular conformation of reduced pyridine nucleotides NADH and NADPH sensed using autofluorescence spectroscopy is presented as a real-time metabolic indicator under pressurized conditions. The approach provides information on the role of pressure in energy metabolism and antioxidant defense with applications in agriculture and food technologies. Here, we use spectral phasor analysis on UV-excited autofluorescence from Saccharomyces cerevisiae (baker's yeast) to assess the involvement of one or multiple NADH- or NADPH-linked pathways based on the presence of two-component spectral behavior during a metabolic response. To demonstrate metabolic monitoring under pressure, we first present the autofluorescence response to cyanide (a respiratory inhibitor) at 32 MPa. Although ambient and high-pressure responses remain similar, pressure itself also induces a response that is consistent with a change in cellular redox state and ROS production. Next, as an example of an autofluorescence response altered by pressurization, we investigate the response to ethanol at ambient, 12 MPa, and 30 MPa pressure. Ethanol (another respiratory inhibitor) and cyanide induce similar responses at ambient pressure. The onset of non-two-component spectral behavior upon pressurization suggests a change in the mechanism of ethanol action. Overall, results point to new avenues of investigation in piezophysiology by providing a way of visualizing metabolism and mitochondrial function under pressurized conditions.

Incidence and Diagnosis of Ampullary Carcinoma in Dhulikhel Hospital, Kathmandu University Hospital

Background Endoscopy from a suspected ampulla of vator may establish an early preoperative diagnosis of ampullary carcinoma. However, information regarding the diagnostic accuracy of this procedure is limited and variable. Objective To study the preoperative diagnostic accuracy of Endoscopic/ERCP appearance of ampullary tumors with that of endoscopic biopsy. Method Among patients who were performed endoscopy during a one year period; a suspicious ampulla of vator was seen in 44 cases. Endoscopic biopsy specimens were classified into four groups based on the degree of epithelial atypia: group 1 (no evidence of malignancy), group 2 (presence of dysplasia), group 3 (suspicious of malignancy) and group 4 (positive for malignancy). In each case comparison was made between the pre-endoscopic biopsy clinical diagnosis and endoscopic appearance. Result Endoscopic biopsy diagnosis of malignancy (group 4) were seen in 22 cases, Suspicious of malignancy (group 3) in 3 cases, dysplasia (group 2) in 9 cases and no evidence of malignancy (group 1) in 10 cases. Pre-endoscopic diagnostic accuracy of endoscopy/ ERCP was 50% compared to the diagnosis by biopsy. Conclusion Diagnostic accuracy of endoscopy/ERCP was 50% compared to the diagnosis by biopsy. A diagnosis of non malignancy in the forceps biopsy material does not rule out the presence of cancerous foci in ampullary neoplasms.

The Risk of COVID-19 in People Having a Particular Set of Gene

These risk factors of advancing age, male gender and co-existing health conditions like cancer, cardiovascular diseases, diabetes and obesity do not fully explain why some people have no or mild symptoms whereas others have severe symptoms. Genomewide association study (GWAS) identify a 3p21.31 gene cluster as a genetic susceptibility locus in patients with COVID-19 with respiratory failure. They also found a higher risk among persons with blood group A and protective effect for blood group O than among patients with other blood groups. The particular haplotype in a region of chromosome 3 is contributed to modern humans by neandertals. Another Neanderthal haplotype on chromosome 12 is associated with a 22% reduction in relative risk of becoming severely ill with COVID-19. The ApoE e4e4 homozygous genotype was found to increase the risk of severe COVID-19. Change in angiotensin converting enzyme (ACE) 2 gene was also found to be associated with increased risk of COVID-19, cardiovascular and pulmonary conditions.

Respiratory Failure in a Neonate with Pierre Robin Syndrome -A Challenging Proposition

Background Fine needle aspiration (FNA) with radiological assisted tools such as ultrasonography (USG) and computed tomography (CT) are effective in obtaining high yield aspiration of tissues located in technically difficult places such as deep-seated. It is a simple outpatient procedure with low cost as compared to surgical biopsies. Objective To study the cytomorphological features of deep-seated lesions according to the site of occurrence, and to categorize them with respect to age, sex and behavior of lesions. Method This was a descriptive cross-sectional study of 125 patients who underwent imageguided fine needle aspiration cytology of deep-seated lesions. The study was conducted in the Department of Pathology and Department of Radiodiagnosis, Dhulikhel Hospital- Kathmandu University Hospital, between January 2017 and December 2018. Under radiological guidance, aspiration was performed under negative pressure, and adequate material was obtained. Smears were stained with Giemsa and Papanicolaou stain. The prepared slides were examined under a microscope. Result Of the 125 patients who underwent USG and CT-guided fine needle aspiration cytology (FNAC), 68(54.4%) were female and 57(45.6%) were male. The age of the patients ranged from 13 to 84 years. The maximum number of patients was above 50 years. The nature of lesions was categorized as malignant 78(62.4%), followed by 23(18.4%) inflammatory and benign 1(0.8%). Conclusion Image-guided fine needle aspiration cytology is a safe diagnostic procedure, as it provides real-time visualization of tip insertion in anatomical structures. It provides high yield and a better representation of the samples.

Endometriosis of Groin Mimicking Neoplasm

Endometriosis is principally a disease of women in active reproductive life. Although it is rare, foci of endometrial tissue may be seen in the bowel, the umbilicus, abdominal surgical scars and in the lungs. Inguinal endometriosis is challenging to the clinicians and pathologist and often diagnosed accidentally. We present a case of inguinal endometriosis mimicking neoplasm. A 40 year old woman presented with a swelling in the right inguinal region associated with cyclical pain. In view of presence of atypical cells in fine needle aspiration cytology, metastatic carcinoma was rendered as diagnosis. Histopathological examination revealed endometrial glands and stroma which was further confirmed by immunohistochemistry. Diagnosis of inguinal endometriosis is difficult and often challenging because of unusual site. The clinician must have high index of suspicion with any patient who has cyclical symptoms. A good history and physical examination can guide clinical diagnosis of endometriosis.

Prevalence and Clinical Manifestations of Helicobacter Pylori with Reference to Histopathological Diagnosis

Background Helicobacter pylori infection is on a steep decline in most of the developed countries; however, in developing countries like Nepal such steep decline is not seen. This may be due to failure of treatment regimens and emergence of drug resistance. Our previous study done in 2004/2005 showed 38% prevalence of Helicobacter pylori. The present study has been conducted to review the prevalence and clinical diagnosis of Helicobacter pylori with reference to histo-pathological diagnosis. Method This was retrospective study done at Dhulikhel Hospital, Kathmandu University Hospital over a period of 13 years from January 2006 to December 2018. Helicobacter pylori proven cases were retrospectively analyzed with clinical features and endoscopy findings. The clinical picture were categorized into antral gastritis, gastroduodenits, erosive duodenitis, acid peptic disease, reflux esophagitis, hiatal hernia, polyp, ulcer (gastric and duodenal), acute abdomen, upper gastrointestinal bleeding and malignancy. Result A total of 1624 upper gastrointestinal endoscopy biopsies were taken during the study period. Helicobacter pylori infection was seen in 618 (38.0%) cases out of 1624 cases. Helicobacter pylori were seen in 349 male and 269 female patients with male to female ratio of 1.29:1. Clinically, gastritis 210 (41.4%), acid peptic disease74 (42.7%), gastroduodenitis 46 (37.7%), reflux esophagitis 38 (52.7%), gastric ulcer 48 (28.4%), duodenal ulcer 34 (53.1%) and acute abdomen 50 (42.3%) cases were seen respectively. Conclusion Most commonly Helicobacter pylori cause chronic gastritis in our context. There is no significant change in prevalence of Helicobacter pylori infection as compared to our previous study (2004/05). This needs proper management of Helicobacter pylori infection to prevent serious complication such as gastric cancer in our part of the world.

Clinical profile of pregnancy loss and placental histopathology at a University Hospital

Aims: To review the clinical features of abortion and intrauterine fetal demise with histopathological findings in their placenta Methods: A retrospective study conducted at Kathmandu University Dhulikhel Hospital from 2008 to 2018. Results: A total of 431 placentas were examined over one decade. One third of them (33.2%) had abortion. Mean age of the patients with abortion was 24.72±5.5 years and that of intrauterine fetal demise (IUFD) was 25.36±5.4 years (p=0.2288). Two thirds of patients with abortion presented with vaginal bleeding and/or lower abdominal pain; 73% of IUFD presented with decreased fetal movement. Gross anomaly was the most common comorbid condition in abortion group while pre/post term, antepartum hemorrhage and PIH were the commoner conditions in IUFD group. In this study, 17.4% abortion cases and 18.3% IUFD cases were with histopathologically proven infection. Conclusions: Placental examination helps in revealing unseen pathologies in cases of poor obstetric outcomes in the form of abortion or fetal demise. The service provider should collect and provide required clinical information before studying the placenta to establish a hidden diagnosis.

The Diagnostic Accuracy of Frozen Section Compared to Permanent Section: Single Center Study

Background Intra-operative consultation by frozen section is a procedure which plays a major role in the surgical management of patients with neoplastic and non neoplastic disease. Therefore it is critical to determine efficiency of frozen section performance periodically. Objective To evaluate the accuracy of frozen section tests at different anatomical sites by comparing the frozen section diagnosis with the histological diagnosis. Method We conducted a retrospective study in Dhulikhel Hospital, Kathmandu University Hospital, Dhulikhel, and compared the results of 47 cases of frozen section with their final permanent section diagnosis during a period of January 2017 to December 2018. Result A total of 47 cases were studied on frozen section while no case was deferred for permanent paraffin section. The indication of frozen section was for presence/ typing of neoplasm in 38 cases (80.75%), clearance of margin in eight cases (17%) and diagnosis of Hirschsprung's disease in one case (2.1%). The overall accuracy of frozen section was 91.4% (43 cases) with 8.5% (four cases) discordant with the diagnosis, reported as false negative. None of the cases were reported as false positive. Sensitivity, specificity, positive predictive value and negative predictive value of frozen section in comparison with permanent section (as gold standard) were 85.18%, 100%, 100% and 83.33% respectively. Conclusion The accuracy of frozen section diagnosis at our institute was 91.4% which can be interpreted as comparable with most national and international studies. The overall error rate is 8.5% which is higher than previously published studies. Experience and training of the pathologist reduce the error rate.

Synthesis and Stereocontrolled Equatorially Selective Glycosylation Reactions of a Pseudaminic Acid Donor: Importance of the Side-Chain Conformation and Regioselective Reduction of Azide Protecting Groups

Pseudaminic acid is an amino deoxy sialic acid whose glycosides are essential components of many pathogenic Gram-negative bacterial cell walls including those from Pseudomonas aeruginosa, Vibrio cholerae, Campylobacter jejuni, Campylobacter coli, Vibrio vulnificus, and Pseudoalteromonas distincta. The study of pseudaminic acid glycosides is however hampered by poor availability from nature and the paucity of good synthetic methods and limited to no understanding of the factors controlling stereoselectivity. Conformational analysis of the side chains of various stereoisomeric sialic acids suggested that the side chain of pseudaminic acid would take up the most electron-withdrawing trans, gauche-conformation, as opposed to the gauche, gauche conformation of N-acetyl neuraminic acid and the gauche, trans-conformtion of 7- epi N-acetyl neuraminic acid, leading to the prediction of high equatorial selectivity. This prediction is borne out by the synthesis of a suitably protected pseudaminic acid donor from N-acetyl neuraminic acid in 20 steps and 5% overall yield and by the exquisite equatorial selectivity it displays in coupling reactions with typical glycosyl acceptors. The selectivity of the glycosylation reactions is further buttressed by the development and implementation of conditions for the regioselective release of the two amines from the corresponding azides, such as required for the preparation of the lipopolysaccharides. These findings open the way to the synthesis and study of pseudaminic acid-based bacterial lipopolysaccharides and, importantly in the broader context of glycosylation reactions in general, underline the significant role played by side-chain conformation in the control of reactivity and selectivity.

Trifluoromethanesulfonate Anion as Nucleophile in Organic Chemistry

Although the triflate ion is not generally perceived as a nucleophile, many examples of its behavior as such exist in the literature. This Synopsis presents an overview of such reactions, in which triflate may be either a stoichiometric or catalytic nucleophile, leading to the suggestion that nucleophilic catalysis by triflate may be more common than generally accepted, albeit hidden by the typical reactivity of organic triflates which complicates their observation as intermediates.

Stereoselective Synthesis of the Equatorial Glycosides of Legionaminic Acid

The synthesis of a legionaminic acid donor from N-acetylneuraminic acid in 15 steps and 17% overall yield is described. Activation of the adamantanyl thioglycoside in the donor with N-iodosuccinimide and trifluoromethanesulfonic acid in dichloromethane and acetonitrile at -78 °C in the presence of primary, secondary and tertiary alcohols affords the corresponding glycosides in excellent yield and good to excellent equatorial selectivity. In particular, coupling to the 4-OH of a suitably protected neuraminic acid derivative affords a disaccharide that closely resembles the glycosidic linkage in the polylegionaminic acid from the lipopolysaccharide of the Legionella pneumophila virulence factor. A straightforward deprotection sequence enables conversion of the protected glycosides to the free N,N-diacetyllegionaminic acid glycosides.

Stereoselective Synthesis of 5-epi-α-Sialosides Related to the Pseudaminic Acid Glycosides. Reassessment of the Stereoselectivity of the 5-Azido-5-deacetamidosialyl Thioglycosides and Use of Triflate as Nucleophile in the Zbiral Deamination of Sialic Acids

With a view to the eventual synthesis of glycosyl donors for the stereocontrolled synthesis of pseudaminic acid glycosides, the stereocontrolled synthesis of a d-glycero-d-gulo sialic acid adamantanylthioglycoside carrying an axial azide at the 5-position is described. The synthesis employs levulinic acid as nucleophile in the oxidative deamination of an N-acetylneuraminic acid thioglycoside leading to the formation of a 3-deoxy-d-glycero-d-galacto-2-nonulosonic acid (KDN) derivative selectively protected as 5-O-levulinate. Replacement of the levulinate by triflate enables introduction of the axial azide and hence formation of the glycosyl donor. A shorter synthesis uses trifluoromethanesulfonate as nucleophile in the oxidative deamination step when the 5-O-triflyl KDN derivative is obtained directly. Glycosylation reactions conducted with the 5-azido-d-glycero-d-gulo-configured sialyl adamantanylthioglycoside at -78 °C are selective for the formation of the equatorial glycosides, suggesting that the synthesis of equatorial pseudaminic acid glycosides will be possible as suitable donors become available. A comparable N-acetylneuraminic acid adamantanylthioglycoside carrying an equatorial azide at the 5-position was also found to be selective for equatorial glycoside formation under the same conditions, suggesting that reinvestigation of other azide-protected NeuAc donors is merited. Glycosylation stereoselectivity in the d-glycero-d-gulo series is discussed in terms of the side-chain conformation of the donor.

ID: 44: LOCAL CONTROL OF OCULAR ADNEXAL LYMPHO-PROLIFERATIVE DISORDERS (OALD): SIMILAR OUTCOMES IN MALT AND NON-MALT HISTOLOGIES

Background

The outcomes of local radiation therapy (RT) in MALT vs. non-MALT OALD are not known. Herein we present outcomes of local therapy in MALT vs. non-MALT OALD treated at a specialized lymphoma program.

Abstract ID: 44 Table 1:

Baseine characteristics.

MALTNON-MALTTOTAL, N=11271 (63.3%)41 (36.6%)Age (median), years64 (22–84)66 (25–87)Sex, M25 (35.2%)16 (39%)Symptoms at presentation–Mass/Swelling–Visual changes–Other35 (49.2%)11 (15.4%)2 (2.8%)27 (66%)11(27%)1 (2.4%)Site of origin–Orbital–Conjunctival–Lacrimal gland–Eyelid–Other31 (43.6%)26 (36.6%)10 (14%)1 (1.4%)4 (5.6%)14 (34.1%)14 (34.1%)10 (24.3%)3 (7.3%)0Unilateral Involvement60 (86%)34 (83%)Stage at presentation–I–II–III–IV–Unknown60 (85%)01 (1.4%)8 (11.2%)2 (2.8%)24 (59%)4 (9.7%)2 (4.8%)7 (17%)4 (9.7%)

Methods

The analysis included 112 consecutive patients (pts) with OALD diagnosed at our institution between 1975–2014. Histology was reviewed by an expert hematopathologist. The primary objective of the study was to assess the failure free survival (FFS) in pts. with marginal zone lymphoma of mucosa associated lymphoid tissue (MALT) of ocular adnexa (OA) and non–MALT OA lymphomas treated with local radiation therapy. Complete remission was defined as absence of any disease by imaging. Local failure was defined as any failure within the OA; extra-orbital failure was either regional (within the radiation field) or distant (for cases with limited stage disease at presentation). FFS was defined as time from treatment to any failure (local, regional and distant). FFS was estimated using the Kaplan-Meier methods.

Results

Baseline characteristics are shown in table 1. Of 112, 71(57.7%) of the pts had ocular MALT, and 41(33.3%) had non-MALT (23 follicular, 8 diffuse large cell B cell lymphomas, 3 mantle cell, 6 small lymphocytic lymphoma and 1 T cell lymphoma). Unilateral eye involvement (83.9%) with mass/swelling (55.3%) was the most common presentation. Staging was performed with CT scan and bone marrow biopsy in select cases (n=63, 51%). PET scan was utilized in 33 (29.4%) pts. but was able to upstage in only 5 cases.

For ocular MALT, 62 (87.3%) received involved field radiation therapy (IFRT), 9 (12.6%) chemotherapy. For non-MALT, 34 (82.9%) had IFRT,7 (17%) chemotherapy. Among those who received IFRT, 55 (75%) in MALT and 21 (52%) in non-MALT had limited stage disease (I/II).

Among OALD pts treated with only IFRT, 91.7% in ocular MALT and 90.9% in non-MALT achieved complete remission. Resolution of symptoms occurred in 83.3% and 93.3% of ocular MALT and non-MALT respectively. Failure rates of IFRT in ocular MALT vs. non-MALT were as follows: local (7% vs. 12.1%), regional (9.8% vs. 7.3%), and distant (5.6% vs 2.4%). Median follow-up was 3 (1–22) years in each group. Median time to failure was 14 years for ocular MALT and 9 years for non-MALT. 3 year and 5 year failure-free survival was 88% and 81% for ocular MALT and 78% and 71% for non-MALT respectively (log rank p=0.26 for FFS) (figure 1).

Conclusions

Both the MALT and non-MALT OALD pts achieved excellent disease control with IFRT with no significant difference in local, regional and distant failure rates. 3 year and 5 year failure free survival were comparable between the two groups. PET scan resulted in upstaging in 5% of pts but did not alter treatment selection, indicating that PET had minimal utility in initial staging of OALD.

Assessing the performance characteristics and clinical forces in simulated shape memory bone staple surgical procedure: The significance of SMA material model

This work is focused on the detailed computer simulation of the key stages involved in a shape memory alloy (SMA) osteosynthesis bone stapling procedure. To this end, a recently developed three-dimensional constitutive SMA material model was characterized from test data of three simple uniaxial-isothermal-tension experiments for powder metallurgically processed nickel-rich NiTi (PM/NiTi-P) material. The calibrated model was subsequently used under the complex, thermomechanical loading conditions involved in the surgical procedure using the body-temperature-activated PM/NiTi-P bone staple. Our aim here is to assess the immediate and post-surgical performance characteristics of the stapling operation using the material model. From this study: (1) it was found that adequate compressive forces were developed by the PM/NiTi-P bone staple, with the tendency of this force to even increase under sustained thermal loading due to the intrinsic "inverse relaxation phenomena" in the SMA material, (2) the simulation results correlated well with those from experimental measurements, (3) the body-temperature-activated PM/NiTi-P staple was proved to be clinically viable, providing a stable clamping force needed for speedy coaptation of the fractured bones, and (4) these realistic assessments crucially depend on the use of suitable and comprehensive SMA material models.