Optical Flow Methods for Lung Nodule Segmentation on LIDC-IDRI Images.

Lung nodule segmentation is an essential step in any CAD system for lung cancer detection and diagnosis. Traditional approaches for image segmentation are mainly morphology based or intensity based. Motion-based segmentation techniques tend to use the temporal information along with the morphology and intensity information to perform segmentation of regions of interest in videos. CT scans comprise of a sequence of dicom 2-D image slices similar to videos which also comprise of a sequence of image frames ordered on a timeline. In this work, Farneback, Horn-Schunck and Lucas-Kanade optical flow methods have been used for processing the dicom slices. The novelty of this work lies in the usage of optical flow methods, generally used in motion-based segmentation tasks, for the segmentation of nodules from CT images. Since thin-sliced CT scans are the imaging modality considered, they closely approximate the motion videos and are the primary motivation for using optical flow for lung nodule segmentation. This paper also provides a detailed comparative analysis and validates the effectiveness of using optical flow methods for segmentation. Finally, we propose methods to further improve the efficiency of segmentation using optical flow methods on CT scans.

Impact of COVID-19 on the Utilization of Maternal and Child Health Services at a Regional Referral Hospital in Kenya.

Background and Objective: Pandemics, like COVID-19, disrupt healthcare, potentially reversing progress in various disease areas. The impact on maternal and child health (MCH) services in Kenya during the pandemic is yet to be determined. Recognizing this impact is crucial for formulating policies and programs that minimize disruptions in reproductive health services during future health crises. The purpose of this study was to determine the effect of COVID-19 on the uptake of MCH services at Thika Level V Hospital, a regional referral hospital in Kenya. Methods: In this cross-sectional mixed methods study, we reviewed antenatal clinic (ANC), MCH, and family planning (FP) registers for data on the uptake of the various services during the COVID-19 pandemic (July to October 2020) compared to a year before the COVID-19 pandemic (July to October 2019). MCH clients (N = 60) and healthcare workers (N = 19) were interviewed about the impact of the pandemic on MCH services at the hospital. Differences in clinic attendance before and during the pandemic were compared using the student t-test. Thematic analysis was conducted on the interview responses. Results: The number of MCH/FP clients dropped from 12,915 pre-pandemic to 7,429 during the pandemic. Significant differences were noted in ANC revisits (p = 0.026) and those completing the World Health Organization recommended minimum of four ANC visits (p<0.001) during the COVID-19 pandemic. The number of revisits at the child welfare clinic was also significantly lower (p = 0.004) during the COVID-19 lockdown period. MCH clients stated that the decline in the uptake of MCH services was attributable to the fear of contracting disease, financial difficulties, and strain on the healthcare workforce. Conclusion and Global Health Implications: This study found a decline in access to MCH/FP services during the COVID-19 crisis with the potential to reverse gains made in securing the safety of the pregnant mother and unborn baby.

A survey and taxonomy of 2.5D approaches for lung segmentation and nodule detection in CT images.

CAD systems for lung cancer diagnosis and detection can significantly offer unbiased, infatiguable diagnostics with minimal variance, decreasing the mortality rate and the five-year survival rate. Lung segmentation and lung nodule detection are critical steps in the lung cancer CAD system pipeline. Literature on lung segmentation and lung nodule detection mostly comprises techniques that process 3-D volumes or 2-D slices and surveys. However, surveys that highlight 2.5D techniques for lung segmentation and lung nodule detection still need to be included. This paper presents a background and discussion on 2.5D methods to fill this gap. Further, this paper also gives a taxonomy of 2.5D approaches and a detailed description of the 2.5D approaches. Based on the taxonomy, various 2.5D techniques for lung segmentation and lung nodule detection are clustered into these 2.5D approaches, which is followed by possible future work in this direction.

Selective depletion of myelin-reactive T cells with the anti-OX-40 antibody ameliorates autoimmune encephalomyelitis.

The OX-40 protein was selectively upregulated on encephalitogenic myelin basic protein (MBP)-specific T cells at the site of inflammation during the onset of experimental autoimmune encephalomyelitis (EAE). An OX-40 immunotoxin was used to target and eliminate MBP-specific T cells within the central nervous system without affecting peripheral T cells. When injected in vivo, the OX-40 immunotoxin bound exclusively to myelin-reactive T cells isolated from the CNS, which resulted in amelioration of EAE. Expression of the human OX-40 antigen was also found in peripheral blood of patients with acute graft-versus-host disease and the synovia of patients with rheumatoid arthritis during active disease. The unique expression of the OX-40 molecule may provide a novel therapeutic strategy for eliminating autoreactive CD4+T cells that does not require prior knowledge of the pathogenic autoantigen.

Identification of a human OX-40 ligand, a costimulator of CD4+ T cells with homology to tumor necrosis factor.

The human OX-40 cell surface antigen is a CD4+ T cell activation marker that acts as a costimulatory receptor and is a member of the nerve growth factor receptor/tumor necrosis factor (TNF) receptor family. Using a soluble form of the receptor, the extracellular region fused with human immunoglobulin Fc, we expression cloned the human OX-40 ligand cDNA from a library derived from an activated B lymphoblastoid cell line MSAB. The encoded protein is identified as gp34, a type II transmembrane antigen previously known to be expressed only by human T cell lymphotropic virus 1-infected cells. We describe gp34 as a new member of the TNF family, and find that the recombinant ligand expressed in COS cells costimulates phorbol myristate acetate, phytohemagglutinin, and anti-CD3-induced CD4+ T cell proliferation.

The clinical effectiveness of central venous catheters treated with anti-infective agents in preventing catheter-related bloodstream infections: a systematic review.

OBJECTIVES: To assess the clinical effectiveness of central venous catheters (CVCs) treated with anti-infective agents (AI-CVCs) in preventing catheter-related bloodstream infections (CRBSI). DATA SOURCES: MEDLINE (OVID), EMBASE, SCI//Web of Science, SCI/ISI Proceedings, and the Cochrane Library. STUDY SELECTION: A systematic review of the literature was conducted using internationally recognized methodology. All included articles were reports of randomized controlled trials comparing the clinical effectiveness of CVCs treated with AI-CVCs with either standard CVCs or another anti-infective treated catheter. Articles requiring in-house preparation of catheters or that only reported interim data were excluded. DATA EXTRACTION: Data extraction was carried out independently and crosschecked by two reviewers using a pretested data extraction form. DATA SYNTHESIS: Meta-analyses were conducted to assess the effectiveness of AI-CVCs in preventing CRBSI, compared with standard CVCs. Results are presented in forest plots with 95% confidence intervals. RESULTS: Thirty-eight randomized controlled trials met the inclusion criteria. Methodologic quality was generally poor. Meta-analyses of data from 27 trials assessing CRBSI showed a strong treatment effect in favor of AI-CVCs (odds ratio 0.49 (95% confidence interval 0.37-0.64) fixed effects, test for heterogeneity, chi-square = 28.78, df = 26, p = 0.321, I = 9.7). Results subgrouped by the different types of anti-infective treatments generally demonstrated treatment effects favoring the treated catheters. Sensitivity analyses investigating the effects of methodologic differences showed no differences to the overall conclusions of the primary analysis. CONCLUSION: AI-CVCs appear to be effective in reducing CRBSI compared with standard CVCs. However, it is important to establish whether this effect remains in settings where infection-prevention bundles of care are established as routine practice. This review does not address this question and further research is required.

In vivo development of heterogeneous glycopeptide-intermediate Staphylococcus aureus (hGISA), GISA and daptomycin resistance in a patient with meticillin-resistant S. aureus endocarditis.

We report a patient who developed a meticillin-resistant Staphylococcus aureus (MRSA) central venous catheter infection complicated by infective endocarditis. The patient was initially treated with glycopeptides, which led to the development of heterogeneous glycopeptide resistance, the detection of which required the use of a macro Etest screening test. Subsequently, the causative strain, confirmed by PFGE as a UK epidemic MRSA-15, was treated with daptomycin, and again resistance developed in vivo. The development in vivo of resistance to both these agents suggests that the resistance mechanisms may be associated. We suggest that the clinician managing MRSA infection should anticipate daptomycin resistance when reduced glycopeptide susceptibility is detected.

The anatomy of an antigen molecule: functional subregions of L-tyrosine-p-azobenzenearsonate.

The structural components of antigen molecules that interact with class II major histocompability complex (MHC) molecules on antigen-presenting cells (APCs) (agretopes) and with antigen receptors of T-lymphocytes (epitopes) in class II restricted T-cell responses have not been precisely defined. This issue was addressed here using murine T-cell clones specific for the simple immunogen L-tyrosine-p-azobenzenearsonate (ABA-tyr) and a series of analogs of the homologous antigen. Two experimental approaches were used. First, APCs were pulsed with analogs and used to stimulate T-cell proliferation. The patterns of stimulation segregated the clones into two specificity groups and indicated that the epitope recognized by the T-cell included the arsonate group and elements in the side chain of tyrosine. Furthermore, the clones manifest different sensitivities to antigen. Second, non-stimulatory analogs were used to block the presentation of ABA-tyr in an effort to define the agretope. Compounds containing the azophenyl group blocked presentation of ABA-tyr in a dose-dependent fashion, whereas p-arsanilic acid and L-tyrosine were ineffective. The blocking was specific inasmuch as the compounds had no effect on the antigen-induced proliferative responses of giant keyhole limpet hemocyanin (KLH) or hen egg white lysozyme (HEL)-reactive T-cell clones. The blocking pattern indicated that the feature required for productive association with the APC centered on the planar structure of the azo-linked aromatic rings, with little or no contribution from either the arsonate moiety or the tyrosyl side chain. We propose that this structure forms an agretope for this family of compounds.

Primary aberrant oculomotor regeneration due to intracranial aneurysm.

Two elderly patients had unilateral ophthalmoparesis and retrobulbar pain. Both had subtle lid signs of aberrant regeneration of the third nerve without proceding acute oculomotor paralysis, and both were found to have intracranial aneurysms. Although primary aberrant oculomotor regeneration has been reported previously in patients with aneurysms and meningiomas, the diagnostic importance of this sign in the elderly has not been emphasized. The presence of lid elevation on downgaze associated with slowly progressive ophthalmoplegia in patients aged 65 or older suggests aneurysm in or near the cavernous sinus.

Mycobacterium fortuitum infection: evidence of bactericidal defect due to hyperactive antigen-specific suppressor cells. Correction in vitro and in vivo by cholinergic agonist and indomethacin.

Immunologic studies in a patient with long-standing Mycobacterium fortuitum infection revealed normal numbers of T cells, T inducers, T suppressors, B cells, and monocytes, significant in vitro proliferative response to M. fortuitum antigen, and poor bactericidal activity against M. fortuitum but not against Escherhicia coli. M. fortuitum antigen-activated suppressor cells contributed to the bactericidal defect. The activity of these suppressor cells could be eliminated by the in vitro treatment of blood mononuclear cells with a combination of a cholinergic agonist and indomethacin, but not with either alone. Administration of the two drugs to the patient resulted in reversal of the bactericidal defect and dramatic clinical improvement. Systemic atypical (nontuberculous) mycobacterial infection may activate specific suppressor cells that could compromise the host's phagocytic cell function. Modulation of those suppressor cells by a combination of a cholinergic agonist and prostaglandin synthetase inhibitor could reverse this abnormality and may be beneficial to the patient.

Childhood sarcoidosis manifesting as juvenile rheumatoid arthritis.

Sarcoidosis in childhood may manifest primarily as arthropathy and uveitis, mimicking juvenile rheumatoid arthritis. The characteristic appearance and course of the inflammation at these sites, particularly the uveitis, is often a major clue to correct diagnosis. These children generally do not have the fulminant systemic manifestations such as pulmonary disease usually ascribed to sarcoidosis.

Association of presumed ocular histoplasmosis with HLA-B7.

Thirty-one white patients who fulfilled the clinical criteria of the syndrome recognized as presumed ocular higtoplasmosis were typed for common histocompatibility antigens. These clinical criteria included the presence of multiple peripheral punched out choroidal atrophic scars, compatible macular disciform lesion in at least one eye, and clear vitreous. Seventeen out of 31 patients were found to have HLA-B7, which is statistically significant at the P less than .005 level when compared to a normal population. More patients should be tested to establish this correlation more firmly. Though this is statistically significant, other factors must be involved as there still remain many patients who fulfill the clinical criteria but do not demonstrate a common histocompatibility antigen.

Complications of chronic cyclitis.

Follow-up examinations, ranging from four to more than 20 years, were performed on 100 patients with chronic cyclitis whose ages at onset were from 4 to 58 years. Cataracts were found in 42% of eyes and macular disease secondary to macular edema in 28% of eyes. Band keratopathy, glaucoma, retinal detachment, retinoschisis, vitreous hemorrhage, retinal hemorrhage, and vessels leaving the disk margin were also noted. The complications resulting in decreased vision in chronic cyclitis were macular edema in active cases and macular degenerative changes in the late inactive stages. Of all eyes with final visual acuity of 6/12 (20/40) or less, 74% had permanent, late macular changes secondary to earlier cystoid macular edema. Vitreous opacities or cells, or both, caused decreased visual acuity in the early active stages of chronic cyclitis but were not major factors in the ultimate visual prognosis in the late inactive stages. At the final examination, vitreous opacities caused a visual loss in only 9% of the eyes that had visual acuity of 6/12 (20/40) or less. It was difficult to determine whether corticosteroids caused cataract formation and glaucoma.

HLA-B7 in presumed ocular histoplasmosis maculopathy.

Sixty-four patients that fulfill the clinical criteria of the presumed ocular histoplasmosis syndrome were typed for common histocompatibility antigens. The clinical criteria included the presence of multiple peripheral punched out choroidal atropic scars, a clear vitreous, and compatible macular disciform lesions in at least one eye. Thirty-four patients were found to have HLA-B7, which is statistically significant at the p less than 0.005 level when compared to a normal population. Though this is statistically significant, other factors must be involved, as there still remain many patients with this clinical picture who do not demonstrate a common histocompatibility antigen.

Characterization of the choroidal mast cell.

The experimental studies performed on nonpigmented rat choroids and the review of the important literature covered in this thesis seem to justify the following statements: 1. Mast cells are present in the choroid in significant numbers. 2. Mast cell numbers vary considerably from one individual to another and from one location in the choroid to another. 3. The major concentration of mast cells in the uvea is in the posterior choroid. 4. The mast cells of the choroid have a preferential location along arterial vessels. 5. Choroidal mast cell population density apparently decreases with senescence. 6. Mast cell products are present in sufficient quantity to exert substantial effects on physiologic, immunologic, and inflammatory responses in the choroid. 7. Choroidal mast cell products are released with appropriate stimulation and share some properties with the connective-tissue mast cell. 8. Choroidal mast cell demonstrate enough differences to suggest that a local differentiation may be present and may represent a locally controlled modulating effect for choroidal physiologic, immunologic, and inflammatory reactions.