Genomic epidemiology of the first epidemic wave of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Palestine

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the novel coronavirus responsible for the COVID-19 pandemic, continues to cause a significant public-health burden and disruption globally. Genomic epidemiology approaches point to most countries in the world having experienced many independent introductions of SARS-CoV-2 during the early stages of the pandemic. However, this situation may change with local lockdown policies and restrictions on travel, leading to the emergence of more geographically structured viral populations and lineages transmitting locally. Here, we report the first SARS-CoV-2 genomes from Palestine sampled from early March 2020, when the first cases were observed, through to August of 2020. SARS-CoV-2 genomes from Palestine fall across the diversity of the global phylogeny, consistent with at least nine independent introductions into the region. We identify one locally predominant lineage in circulation represented by 50 Palestinian SARS-CoV-2, grouping with genomes generated from Israel and the UK. We estimate the age of introduction of this lineage to 05/02/2020 (16/01/2020-19/02/2020), suggesting SARS-CoV-2 was already in circulation in Palestine predating its first detection in Bethlehem in early March. Our work highlights the value of ongoing genomic surveillance and monitoring to reconstruct the epidemiology of COVID-19 at both local and global scales.

[Mechanisms of damage to metal-on-polyethylene articulating surfaces of total hip prostheses: influence of intra-articulate migration of metallic debris]

PURPOSE OF THE STUDY

The objective of this work was to identify the mechanisms leading to deterioration of the polyethylene acetabular surface in total hip prostheses.

MATERIAL AND METHODS

We conducted an in vivo analysis of damage caused to articulating surfaces of metal-on-polyethylene total hip prostheses. This analysis was performed on three of the 45 explants of Harris-Galante prostheses available to use from our series of 1480 implantations performed between 1985 and 1996. These three pieces were selected because large-sized fibers of metallic debris were identified on the polyethylene surface and because the explants had been performed for reasons other than loosening in aseptic patients. Macroscopic examination was combined with scan electron microscopy to analyze morphological changes.

RESULTS

We found that identical damage could be observed on the polyethylene explants despite the different sizes of the metallic heads and different metal-on-polyethylene combinations. Our analysis confirmed the deleterious effect of metallic foreign bodies trapped in contact with the articulate surfaces. These foreign bodies resulted in one case from rupture of a multifilament wire used for the trochanteric fixation and in two cases from the surfacing of the non-cemented Harris-Galante cups. The microscopic analysis demonstrated several successive localizations of the foreign bodies on the polyethylene surface before becoming deeply encrusted in the polyethylene where they deteriorated the femoral head surface (rough) and wore the polyethylene surface (abrasion). When the fibers came from the surfacing of the Harris-Galante cups, the metallic debris remained unrecognized during the revision procedure and were only identified later during the systematic examination of prosthetic explants.

DISCUSSION AND CONCLUSION

These findings emphasize the importance of quality surface treatments for non-cemented prostheses and argue in favor of particular precautions during operative manipulation of these components. A systematic analysis of the prosthetic explants is advisable, particularly for components explanted because of wear or unexplained osteolysis. Use of multifilament trochanteric wires should be avoided because rupture raises the risk of intra-articulate migration of metallic debris. If the prosthesis involves a polyethylene acetabular surface, ceramic heads should be preferred to improve resistance to abrasion, particularly to limit the deleterious effect of a third body.

Cells producing cathepsins D, B, and L in human breast carcinoma and their association with prognosis

Lysosomal proteinases, cathepsins D, B, and L have been associated with malignant tumor progression and with prognosis in various human carcinomas. In the current study, the immunohistochemical localization of cathepsins in tumor cells was correlated with cathepsin protein concentration in breast carcinoma cytosols from 77 patients. Significant correlation was found for cathepsin D (P < .041) and borderline correlation for cathepsin B (P < .055) but not for cathepsin L. We hypothesize that the poor correlation of cysteine cathepsins was attributable to the fact that they were present not only in malignant epithelial cells, but also in infiltrating macrophages and stromal fibroblasts. In addition, tumor-surrounding myoepithelial cells (42% of tumors) and myofibroblasts (26% of tumors) as well as endothelial cells of neovasculature (10% of tumors) all stained specifically for cathepsin B. Two thirds of tumors co-expressed cathepsins B and L in tumor cells, whereas only 17% of tumors co-expressed all 3 cathepsins. Intense immunostaining for cathepsin D of tumor cells was observed in tumors at high TNM stage and tumors having positive lymph nodes. The expression of cathepsin B was independent of established prognostic factors, whereas intense cathepsin L staining in tumor cells was associated with high histological grade. With respect to prognosis of patient survival, only tumor cell-associated cathepsin D (P = .042) and myoepithelial cell-associated cathepsin B (P = .061) showed borderline significance. Cathepsins B and L immunostaining in tumor cells was not prognostic. In contrast, cytosolic levels of cathepsin B correlated with higher rate of relapse. Taken together, these results show the diversity in the cellular distribution of cathepsins in human breast carcinoma, presumably reflecting specific regulation and function of each of the cathepsins during tumor progression.

Intramedullary plasmacytoma in an unusual location in a renal transplant patient

Transplant patients have increased risk for developing neoplasia. This is due to the use of more potent and long-term immunosuppression. We report a case of a 46-year-old man with a cadaver renal transplant who developed an intramedullary plasmacytoma in an unusual location. The patient had a total right elbow replacement and received 4 weeks of local radiotherapy. The pain completely resolved and the low-dose immunosuppression was continued.

Mycotic aneurysm of the descending thoracic aorta: the role of transesophageal echocardiography

Mycotic aneurysms of the aorta are prone to rupture. Thus rapid and accurate diagnosis is essential so that surgical repair can be undertaken. We report a case of mycotic aortic aneurysm caused by mitral valve endocarditis. The aneurysm situated at the junction of the thoracoabdominal aorta was readily detected by transesophageal echocardiography. Computed tomography and aortography were complementary to transesophageal echocardiography in establishing the diagnosis. The patient underwent successful repair and acute inflammation of the aneurysm was present at histologic examination.

Mediastinal bronchogenic cyst. A cause of upper airway obstruction

Although bronchogenic cysts may involve the mediastinum, they have rarely been responsible for significant upper airway obstruction. We describe a young man who had a rapidly expanding cervical mass due to the migration of a mediastinal bronchogenic cyst. Flow-volume loops confirmed the presence of a variable intrathoracic obstruction. The patient rapidly developed respiratory failure requiring urgent intubation and surgical resection.

Palpable abnormalities of the breast not requiring excisional biopsy

The evaluation of a patient with a palpable abnormality of the breast typically includes physical examination, mammography and fine needle aspiration biopsy (FNAB) with cytologic interpretation of the aspirate. If the findings of these three diagnostic modalities are negative for malignancy, the current standard of care is to proceed to surgical biopsy to confirm the benign nature of the lesion. The current study was done to identify a subset of patients who could be safely observed without surgical (histologic) biopsy. These patients fulfilled specified criteria on physical examination, mammogram and needle sensation when the FNAB needle entered the lesion. Results of the cytologic studies of the FNAB were used as a corroborative rather than as a diagnostic test. Of 305 patients with mammary abnormalities, 106 were identified with "subsuspicious" lesions. Seven of the latter patients underwent surgical biopsy, four because the results of cytologic studies of FNAB revealed cytologic atypia. One of the four patients had infiltrating ductal carcinoma. All other patients have had follow-up evaluation for a mean of 61 months (range of 43 to 74 months). No carcinomas have developed at the subsuspicious site. The current study is the first to clearly define a subset of patients with palpable abnormalities of the breast who do not require surgical biopsy.