Robustness and resilience of supply chains during the COVID-19 pandemic.

Using a unique firm-level data set from Asia, this study examines what determined the robustness and resilience of supply chain links, that is, the ability of maintaining links and recovering disrupted links by substitution, respectively, when firms faced economic shocks due to the spread of the coronavirus disease (COVID-19). We find that a supply chain link was likely to be robust if the link was between a foreign-owned firm and a firm located in the foreign-owned firm's home country, implying that homophily on a certain dimension generates strong ties and thus supply chain robustness. We also find that firms with geographic diversity of customers and suppliers tended to increase their transaction volume with one partner while decreasing the volume with others. This evidence shows that firms with diversified customers and suppliers are resilient, mitigating the damage from supply chain disruption through the substitution of partners. Furthermore, the robustness and resilience of supply chains are found to have led to higher performance.

Microbially cleaved immunoglobulins are sensed by the innate immune receptor LILRA2.

Microbial proteases degrade a variety of host proteins(1-3). However, it has remained largely unknown why microorganisms have evolved to acquire such proteases and how the host responds to microbially degraded products. Here, we have found that immunoglobulins disrupted by microbial pathogens are specifically detected by leukocyte immunoglobulin-like receptor A2 (LILRA2), an orphan activating receptor expressed on human myeloid cells. Proteases from Mycoplasma hyorhinis, Legionella pneumophila, Streptococcus pneumonia and Candida albicans cleaved the N-terminus of immunoglobulins. Identification of the immunoglobulin-cleaving protease from L. pneumophila revealed that the protease is conserved across some bacteria including Vibrio spp. and Pseudomonas aeruginosa. These microbially cleaved immunoglobulins but not normal immunoglobulins stimulated human neutrophils via LILRA2. In addition, stimulation of primary monocytes via LILRA2 inhibited the growth of L. pneumophila. When mice were infected with L. pneumophila, immunoglobulins were cleaved and recognized by LILRA2. More importantly, cleaved immunoglobulins were detected in patients with bacterial infections and stimulated LILRA2-expressing cells. Our findings demonstrate that LILRA2 is a type of innate immune receptor in the host immune system that detects immunoglobulin abnormalities caused by microbial pathogens.

Preoperative staging and surgical approaches for sinonasal inverted papilloma.

OBJECTIVES: We sought to determine the value of preoperative staging by magnetic resonance imaging (MRI) assessment in the surgical management of sinonasal inverted papillomas (IPs). METHODS: Preoperative MRI staging was used to assess 22 patients with IPs. In addition to the Krouse staging system, T3 cases were categorized as subgroup T3-B if tumors extended into the frontal sinus or the supraorbital recess; otherwise, they were categorized as T3-A. Standard endoscopic sinus surgery (ESS) was the first choice for T1 and T2 cases. Endoscopic approaches, including ESS combined with endoscope-assisted transantral approach and endoscopic medial maxillectomy, were considered in T3-A cases, and external approaches were considered in T3-B cases. Patients were followed for a minimum of 1 year after surgery. RESULTS: Preoperative MRI staging and postoperative staging were coincident in 21 of the 22 patients (95%). All 8 T2 cases were treated by an endoscopic approach. Of 10 T3-A cases, 9 (90%) were treated by an endoscopic approach and 1 (residual case) was treated by an external approach. All 3 of the T3-B cases underwent an external approach. One T4 case with malignant transformation underwent an external approach followed by radiotherapy. After a median follow-up period of 22 months, none of the 22 patients had had a recurrence. No major complications were observed after endoscopic approaches, but epiphora or hemorrhage requiring transfusion occurred in 3 of the 5 patients (60%) who underwent external approaches. CONCLUSIONS: Preoperative staging of IP by MRI is useful for selecting cases that can be managed by endoscopic approaches, resulting in lower rates of tumor recurrence and morbidity.

Clinical and pathological analysis of recurrent inverted papilloma.

OBJECTIVES: We analyzed the clinical characteristics, pathological findings, and treatment outcomes of patients with recurrent sinonasal inverted papilloma (IP). METHODS: This retrospective study consisted of 13 patients with recurrent IP. Patient data were collected on prior treatment, sites of recurrence, surgical procedures, pathological findings, and postoperative time to recurrence. RESULTS: Eleven of the 13 patients (85%) had recurrence in the ethmoid sinus, particularly at the lamina papyracea (n = 8; 62%). Inverted papilloma with severe dysplasia (SD) was observed in 4 patients, 3 of whom showed malignant transformation of the recurrent tumor. Craniofacial resection was performed in 2 of the 4 patients, resulting in no further recurrence. However, the tumor was not managed in the remaining 2 patients. In the 9 patients without SD, lateral rhinotomy was performed in 6 patients and endoscopic sinus surgery was selected in 3 patients who had a small tumor without scar formation. No further recurrence was observed in the 9 patients. CONCLUSIONS: Careful management of IP around the lamina papyracea is essential during initial surgery. Recurrent IP without SD can be successfully managed by lateral rhinotomy in most cases, and by endoscopic sinus surgery in selected cases. However, more aggressive treatment, including craniofacial resection, should be considered in IP with SD, which is associated with a high rate of recurrence and malignant transformation.

Preoperative staging of sinonasal inverted papilloma by magnetic resonance imaging.

OBJECTIVES/HYPOTHESIS: Sinonasal inverted papilloma is a rare but locally aggressive benign tumor. Inverted papilloma tends to recur after surgical resection and is occasionally associated with squamous cell carcinoma. Radical en bloc resection by lateral rhinotomy and medial maxillectomy has been recommended for initial management; however, endoscopic sinus surgery is effective in selected cases. To determine adequate surgical approaches, a staging system for inverted papilloma based on extent and location of the tumor has been advocated. The study investigated whether preoperative assessment by magnetic resonance imaging (MRI) accurately predicts the extent of inverted papilloma. STUDY DESIGN: Magnetic resonance imaging was retrospectively reviewed in 21 cases of inverted papilloma without knowledge of the surgical and pathological findings. METHODS: Patients were categorized into stages based on MRI findings, according to the staging system proposed by Krouse. The involvement of inverted papilloma in each sinus was also assessed. RESULTS: Stages graded by MRI were coincident with postoperative staging verified by surgical and pathological findings in 18 of the 21 cases (86%), which included 1 case of stage T1, 3 cases of stage T2, and 14 cases of stage T3. Two cases of stage T2 were judged as T3, and one case of T3 was judged as T2 by MRI. Positive predictive value of MRI diagnosis for tumor involvement was 68% to 89% in each sinus, and negative predictive value was more than 93%. CONCLUSION: In most cases, MRI assessment of inverted papilloma can accurately predict the extent of tumor involvement. Preoperative staging of inverted papilloma by MRI may be useful for planning an appropriate surgical approach.