Life Cycle and Transmission of Cyclospora cayetanensis: Knowns and Unknowns

Although infections with Cyclospora cayetanensis are prevalent worldwide, many aspects of this parasite’s life cycle and transmission remain unknown. Humans are the only known hosts of this parasite. Existing information on its endogenous development has been derived from histological examination of only a few biopsy specimens. Its asexual and sexual stages occur in biliary-intestinal epithelium. In histological sections, its stages are less than 10 μm, making definitive identification difficult. Asexual (schizonts) and sexual (gamonts) are located in epithelial cells. Male microgamonts have two flagella; female macrogametes contain wall-forming bodies. Oocysts are excreted in feces unsporulated. Sporulation occurs in the environment, but there are many unanswered questions concerning dissemination and survival of C. cayetanensis oocysts. Biologically and phylogenetically, C. cayetanensis closely resembles Eimeria spp. that parastize chickens; among them, E. acervulina most closely resembles C. cayetanensis in size. Here, we review known and unknown aspects of its life cycle and transmission and discuss the appropriateness of surrogates best capable of hastening progress in understanding its biology and developing mitigating strategies.

Influence of Heterologous and Homologous Vaccines, and Their Components, on the Host Immune Response and Protection Against Experimental Caprine Paratuberculosis

Vaccination against paratuberculosis, a chronic disease of ruminants caused by Mycobacterium avium subsp. paratuberculosis (Map), has been considered as the most effective control method. However, protection is incomplete, and the mechanisms operating in the response of the animals to vaccination are not fully understood. Therefore, this study analyzed the immune response and the effects on protection against Map infection, elicited by paratuberculosis (Silirum®) and tuberculosis (heat-inactivated M. bovis [HIMB]) vaccines and their components in a caprine experimental model. Fifty goat kids were divided into 10 groups (n = 5) according to their vaccination (Silirum®, HIMB and nonvaccinated), immunization (inactivated bacteria or adjuvant), and/or infection. Oral challenge with Map was performed 45 days postvaccination/immunization (dpv), and animals were euthanized at 190 dpv. Peripheral immune response and proportion of lymphocyte subpopulations were assessed monthly by enzyme-linked immunosorbent assay and flow cytometry analysis, respectively. Local immune response, proportion of tissue lymphocyte subpopulations, Map detection (polymerase chain reaction), and histological examination were conducted in gut-associated lymphoid tissues. All infected groups developed paratuberculosis granulomatous lesions despite vaccination or immunization. The Silirum® and HIMB-vaccinated groups showed a considerable lesion reduction consistent with a significant peripheral cellular and humoral immune response. Besides, a lower number of granulomas were observed in groups immunized with inactivated bacteria and adjuvants in comparison to nonvaccinated and infected group. However, despite not being significant, this reduction was even higher in adjuvant immunized groups, which developed milder granulomatous lesion with no detectable peripheral immune responses associated with immunization. No changes in the peripheral and local proportion of lymphocyte subsets or local immune response were detected in relation to either vaccination/immunization or infection. Despite that paratuberculosis and tuberculosis vaccination showed a partial and cross-protection against Map infection, respectively, only histological examination could assess the progression of infection in these animals. In addition, the pattern observed in the reduction of the lesions in adjuvant immunized groups suggests the possible involvement of a nonspecific immune response that reduces the development of granulomatous lesions.

Case Report: An Eyelid Nodule Caused by Candidatus Dirofilaria hongkongensis Diagnosed by Mitochondrial 12S rRNA Sequence

ABSTRACT. A 59-year-old female living in Rayong Province, eastern Thailand, presented with painless, right upper eyelid nodule for 3 months. Upon removal of the eyelid mass, a well-circumscribed, firm globular mass with diameter about 1 cm was found. Histopathological examination revealed an immature female dirofilarial worm reminiscent of Dirofilaria repens, characterized by prominent sharp longitudinal ridges at external surface of the cuticle. Analysis of the mitochondrial 12S rRNA sequence showed that the worm belongs to Candidatus Dirofilaria hongkongensis. It is likely that some infections previously reported as D. repens based on histological examination may have actually been due to Candidatus D. hongkongensis.

Dermoscopy of pilomatricoma: A case report with a review of the literature

Pilomatricoma is a benign tumor originating from hair follicle matrix cells and characterized by the presence of cutaneous and subcutaneous nodules up to 3.0 cm in diameter, usually on the head, neck, and upper extremities, rarely on the trunk and lower extremities. An eleven-year-old female with a painless, erythematous-purplish tumor of the back. A dermoscopic examination revealed irregular linear vessels, white structures, and structureless grayish-blue areas. Histological examination after excision confirmed the diagnosis of pilomatricoma. Dermoscopy may be a useful tool for improving the clinical recognition of pilomatricoma.

Diagnostic yield of image-guided biopsy in patients with suspected infectious spondylodiscitis

Aims The aims of this study were to determine the diagnostic yield of image-guided biopsy in providing a final diagnosis in patients with suspected infectious spondylodiscitis, to report the diagnostic accuracy of various microbiological tests and histological examinations in these patients, and to report the epidemiology of infectious spondylodiscitis from a country where tuberculosis (TB) is endemic, including the incidence of drug-resistant TB. Methods A total of 284 patients with clinically and radiologically suspected infectious spondylodiscitis were prospectively recruited into the study. Image-guided biopsy of the vertebral lesion was performed and specimens were sent for various microbiological tests and histological examinations. The final diagnosis was determined using a composite reference standard based on clinical, radiological, serological, microbiological, and histological findings. The overall diagnostic yield of the biopsy, and that for each test, was calculated in light of the final diagnosis. Results The final diagnosis was tuberculous spondylodiscitis in 250 patients (88%) and pyogenic spondylodiscitis in 22 (7.8%). Six (2.1%) had a noninfectious condition-mimicking infectious spondylodiscitis, and six (2.1%) had no definite diagnosis and improved without specific treatment. The diagnosis was made by image-guided biopsy in 152 patients (56%) with infectious spondylodiscitis. Biopsy was contributory in identifying 132/250 patients (53%) with tuberculous spondylodiscitis, and 20/22 patients (91%) with pyogenic spondylodiscitis. Histological examination was the most sensitive diagnostic modality, followed by Xpert MTB/RIF assay. Conclusion Image-guided biopsy has a reasonably high diagnostic yield in patients with suspected infectious spondylodiscitis. A combination of histological examination, Xpert MTB/RIF assay, bacterial culture, and sensitivity provides high diagnostic accuracy in a country in which TB is endemic. Cite this article: Bone Joint J 2022;104-B(1):120–126.

Scar Sarcoidosis as Presenting Finding in Pembrolizumab Induced Systemic Sarcoidosis in Stage III Melanoma: A Case Report

Immune checkpoint blockade using inhibition of Programmed Cell Death-1 (PD-1) improves both progression-free and overall survival in patients with advanced melanoma, but is associated with a unique set of toxicities termed immune-related Adverse Events (irAEs). We present a case of a man with stage IIIc melanoma who was treated with pembrolizumab (anti PD-1). Two months after initiation of the therapy, the patient developed subcutaneous nodules on his upper lip and right knee, both in a pre-existing scar. Histological examination showed non-necrotising granuloma, most consistent with sarcoidosis. PET-CT showed hypermetabolic mediastinal and hilar adenopathies as well as lung lesions and some cutaneous and subcutaneous metabolic hot spots. Bronchoscopy with biopsy of a lymph node confirmed the diagnosis of sarcoidosis. Pembrolizumab was withheld, whereby a gradual decrease and near spontaneous resolution of all lesions was seen over a period of approximately 6 months. The patient is currently in follow up with no evidence of disease recurrence.Our case shows a unique presentation of sarcoidosis in old scar tissue as presenting symptom of pembrolizumab-related systemic sarcoidosis and demonstrates the importance of histological examination of new lesions occurring during checkpoint inhibitor therapy in order to avoid misdiagnosis of melanoma progression.

Histological examination of cranial synchondroses as functionally significant elements in the cranial osteopathic concept

Introduction. In recent decades, medical science has accumulated convincing evidence of the fact that the normal activity of a human brain depends on the functional integration of its vascular system, a circulation system of cerebrospinal fluid and biomechanical features of a skull, forming a single structural and functional system.The aim of the study is to research the histological structure of functionally significant cranial synchondroses in the middle and elderly age group, to find possible points of osteopathic influence application in their structure. Materials and methods. The study was performed on cadaver material of 27 persons (7 men — 26 %, 20 women — 74 %) who died at the age from 49 to 66 years (57,5±5,3 years) from various somatic pathologies, but had no history of craniocerebral injuries with fractures of osseous structures. Small bone fragments with sutures of interest/synchondroses (spheno-occipital synchondrosis, petro-jugular synchondrosis, sphenopetrosal synchondrosis) were subjected to standard histological processing followed by microscopy.Results. Evaluating histological specimens of spheno-occipital synchondrosis, we observed the similar pattern: highly mineralized tissues at the edges of the bodies of the sphenoid and occipital bones were connected without elements of cartilagi-nous or connective tissue. In all cases, no fibrous or nerve tissue elements were found during the in situ immunohistochemical reactions. Reactions with the CD34 antibody mark multiple vessels of the Volkmann's or Haversian canals. Evaluating histological specimens of petro-jugular and sphenopetrosal synchondroses, we found the presence of cartilage tissue in the suture in the form of small islands of various sizes (from 20 to 120 microns) with signs of degeneration and a small number of remained chondrocytes. When evaluating specimens with immunohistochemical reactions with antibodies against the S100 protein, no elements of the nervous tissue were detected.Conclusion. Spheno-occipital synchondrosis has a temporary nature. With age, its cartilaginous tissue is replaced by osseous one. According to the histological structure, sphenobasilar synchondrosis demonstrates the complete absence of a cartilaginous component in the middle and elderly age groups. Petro-jugular and sphenopetrosal synchondroses retain the cartilaginous component in their suture throughout lifetime. During histological examination of the petro-jugular and sphenopetrosal synchondroses, the cartilaginous component is represented by variety of small islands. In all synchondroses, there is an absence of vascular and nervous components. At the same time, we revealed the presence of a prominent vascular bed in the bone tissue. The fact requires emphasizing the importance of liquid potency and elastic component in cartilaginous and osseous tissues as an application point for osteopathic techniques.

Experimental justification for prompt neutralization of traumatic action of thermal exo- and endogenous damage factors (morphological features)

Objective: morphological substantiation of efficiency of prompt neutralization of traumatic action of exogenous and endogenous damage factors in burn injuries in experimental conditions. After simulating the burns on 60 rats, the traumatic hyperthermic damage factors in the main group were immediately neutralized by a gauze napkin soaked in water. Depending on its duration, the animals were divided into subgroups. Such applications were not performed on the control group. The study involved histological examination of tissues. Animals of the main groups had the presence of histologically confirmed skin appendages with a formed scar of connective tissue without signs of inflammation. In animals of the control group there were no skin appendages, which indicates a deeper thermal damage to tissues and the impossibility of self-epithelialization of wounds. These results confirm the importance and necessity of prompt neutralization of the traumatic effect of damage factors as the main elements of burn depth formation.

Bentall–De Bono procedure for aortic regurgitation and intraoperative rupture of moderately dilated ascending aorta: A case report

<p>We herein present a clinical case of root and ascending aortic replacement in a patient with borderline enlargement of the ascending aorta and aortic valve insufficiency. A 65-year-old man was admitted to our clinic with signs of heart failure. Subsequent echocardiography and contrast-enhanced computed tomography revealed hemodynamically significant aortic insufficiency, as well as expansion of the ascending aorta. Diameter at the levels of the sinuses of Valsalva, sinotubular junction and tubular portion of the ascending aorta were 48, 47 and 44 mm, respectively. Based on the aforementioned data, indications for isolated aortic valve replacement were determined. Although the main portion of the surgery was unremarkable, at its final stage, a rupture of a section of the ascending aorta occurred. The results of intraoperative express histological examination of the enlarged aorta revealed connective tissue dysplasia and cystic median necrosis. Replacement of the ascending aorta was performed using the modified Bentall–De Bono technique. This case demonstrated that a borderline aortic dilatation of 40–50 mm at the ascending aorta was associated with pathological changes in its wall, which can cause fatal complications (rupture and dissection) and may require a more aggressive approach during surgical correction. Intraoperative express histological examination of the wall of the ascending aorta in ambiguous situations can help determine the scope of the intervention.</p><p>Received 16 March 2021. Revised 14 September 2021. Accepted 15 September 2021.</p><p><strong>Funding:</strong> The study did not have sponsorship.</p><p><strong>Conflict of interest:</strong> The authors declare no conflict of interest.</p><p><strong>Contribution of the authors<br /> </strong>Literature review: S.Yu. Boldyrev, M.A. Marukyan<br /> Drafting the article: S.Yu. Boldyrev, M.A. Marukyan, V.N. Suslova<br /> Critical revision of the article: S.Yu. Boldyrev, V.A. Porkhanov<br /> Surgical treatment: S.Yu. Boldyrev, M.A. Marukyan<br /> Final approval of the version to be published: S.Yu. Boldyrev, M.A. Marukyan, V.N. Suslova, K.O. Barbukhatti, V.A. Porkhanov</p>