Challenges and responses of elective orthopaedic surgery during the second wave of COVID-19.

BACKGROUND: Elective orthopaedic surgery has been severely curtailed because of coronavirus disease, 2019. There is scant scientific evidence to guide surgeons in assessing the protocols that must be implemented before resuming elective orthopaedic surgery safely after the second wave of the coronavirus disease, 2019. METHODS: A retrospective review of elective orthopaedic surgeries performed between May 15, 2020, and November 20, 2020, was conducted. A screening questionnaire was used, and reverse transcription-polymerase chain reaction and severe acute respiratory syndrome coronavirus-2 immunoglobulin G and IgM antibodies testing were assessed in all admitted patients. Screening and testing data for coronavirus disease was reviewed for all patients. RESULTS: Of 592 patients tested for severe acute respiratory syndrome coronavirus-2 during the study period, 21 (3.5%) tested positive. There were 2 patients (0.3%) with positive reverse transcription-polymerase chain reaction tests, 3 (0.5%) with positive IgG and IgM antibodies, 13 (2.2%) with positive IgG antibodies, and 10 (1.7%) with positive IgM antibodies. Among these 21 patients, 20 (95.2%) were asymptomatic. CONCLUSIONS: Our findings suggest that most elective orthopaedic surgery patients with severe acute respiratory syndrome coronavirus-2 are asymptomatic. In the second wave of coronavirus disease, 2019, universal testing of all patients should be strongly considered as an important measure to prevent clusters of in-hospital transmission of the disease.

Chromosomal circularization of the model Streptomyces species, Streptomyces coelicolor A3(2).

Streptomyces linear chromosomes frequently cause deletions at both ends spontaneously or by various mutagenic treatments, leading to chromosomal circularization and arm replacement. However, chromosomal circularization has not been confirmed at a sequence level in the model species, Streptomyces coelicolor A3(2). In this work, we have cloned and sequenced a fusion junction of a circularized chromosome in an S. coelicolor A3(2) mutant and found a 6-bp overlap between the left and right deletion ends. This result shows that chromosomal circularization occurred by nonhomologous recombination of the deletion ends in this species, too. At the end of the study, we discuss on stability and evolution of Streptomyces chromosomes.

Incidence of synchronous and metachronous pancreatic carcinoma in 168 patients with branch duct intraductal papillary mucinous neoplasm.

BACKGROUND/AIMS: Although branch duct intraductal papillary mucinous neoplasms of the pancreas (BD-IPMN) are being diagnosed with increasing frequency, the incidence of concomitant pancreatic carcinoma (PC) is not well known. We investigated the incidence and clinical features of synchronous and metachronous PC in patients with BD-IPMN. METHODS: We studied 168 BD-IPMN patients diagnosed by various imaging modalities, including endoscopic retrograde pancreatography, between 1990 and 2008. We reviewed the medical records and clinical features in both patients developing and not developing PC. The diagnosis of PC was histologically verified in all patients. RESULTS: PC was observed in 9 (5.4%) of 168 patients. Five were synchronously detected at the time of BD-IPMN diagnosis, whereas four were metachronously identified during the follow-up period. All PCs occurred in regions separate from the BD-IPMN lesion. All PCs represented histologically invasive ductal adenocarcinomas, whereas the BD-IPMN lesion was diagnosed as adenoma. Patients developing PC were significantly older than patients not developing PC (p = 0.017). The diameters of the BD-IPMN lesions and main pancreatic ducts were significantly smaller in patients developing PC than patients not developing PC (p = 0.013 and p < 0.001, respectively). CONCLUSIONS: It was not infrequent for PC to occur in the pancreas with BD-IPMN. Particular attention should therefore be paid to the development of PC, even in low-risk BD-IPMN, as well as to changes in BD-IPMN.

[A case of pancreatic carcinoma presenting as pancreaticopleural fistula with pancreatic pleural effusion].

A 63-year-old man was admitted with left pleural effusion, and an amylase level of 30994IU/l. A diagnosis of pancreaticopleural fistula was made, based on the findings of magnetic resonance cholangiopancreatography and endoscopic retrograde pancreatography (ERP). After the placement of an endoscopic naso-pancreatic drainage tube, the pleural effusion markedly reduced. When ERP was performed for internal drainage, the main pancreatic duct and stricture were biopsied and showed pancreatic ductal adenocarcinoma histologically. CT revealed a mass in the head of the pancreas. He underwent pylorus-preserving pancreaticoduodenectomy. To the best of our knowledge this is the first case of pancreatic carcinoma presenting as pancreaticopleural fistula with pancreatic pleural effusion. Clinicians should pay attention to the possible presence of cancer and pancreaticopleural fistula in patients with pancreatic pleural effusion.

Pancreatic ductal adenocarcinomas in long-term follow-up patients with branch duct intraductal papillary mucinous neoplasms.

OBJECTIVE: Although branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) are slow-growing tumors with a favorable prognosis, the synchronous occurrence of pancreatic ductal adenocarcinomas (PDAs) in patients with BD-IPMNs has been reported. This study was aimed to elucidate the development of PDAs in long-term follow-up patients with BD-IPMNs. METHODS: We investigated 89 BD-IPMN patients who had no mural nodules and followed them up conservatively at least 2 years (median follow-up, 64 months; range, 25-158 months). All subjects underwent examinations by imaging modalities including endoscopic retrograde pancreatography. We calculated the standardized incidence ratio (SIR) from the vital statistics compiled by the Ministry of Health, Labor, and Welfare of Japan. RESULTS: Among the 89 patients, 4 cases of PDAs distant from BD-IPMN were observed in 552 patient-years of follow-up (7.2 per 1000 patient-years). The expected number was 0.25, and the SIR of PDAs was 15.8 (95% confidence interval [CI], 4.3-40.4; P = 0.00014). Subgroup analyses showed that the incidence of PDAs was significantly increased in patients 70 years or older (SIR 16.7; 95% CI, 3.4-48.7; P = 0.0008) and in women (SIR 22.5; 95% CI, 2.7-81.1; P = 0.0037). CONCLUSIONS: Patients with BD-IPMNs are at a high risk for PDAs. During the follow-up, careful examination is required to detect the development of PDAs in patients with BD-IPMNs.

[Gemcitabine in combination with S-1 or UFT in patients with advanced pancreatic cancer].

The present retrospective study aimed to evaluate the anti-tumor activity and toxicity of combination chemotherapy with gemcitabine (GEM) and oral S-1 or UFT in patients with advanced or metastatic pancreatic cancer. Ninety-four patients received chemotherapy. Among them, sixty-three were treated with GEM alone, twenty-two with UFT and GEM (UFT/GEM), and nine with S-1 and GEM(S-1/GEM). The median survival time was 8.7 months with GEM, 7.3 months with UFT/GEM, and 23.3 months with S-1/GEM. The overall response rate was 11.1%, 10.0%, and 22.2%, respectively. The 1-year survival rate was 29.5%, 36.4%, and 85.7%, respectively. Although the treatment-related adverse effects were not infrequent in patients treated with S-1/GEM, they were moderate in intensity. The combination chemotherapy with S-1/GEM was well tolerated and yielded a high response rate in patients with pancreatic cancer.

Sonic hedgehog derived from human pancreatic cancer cells augments angiogenic function of endothelial progenitor cells.

Hedgehog signaling is important in the pathogenesis of pancreatic cancer. Several recent observations suggest the involvement of sonic hedgehog (SHH) in postnatal neovascularization. We identified a novel role for SHH in tumor-associated angiogenesis in pancreatic cancer. Immunohistochemical analysis revealed that patched homolog 1 (PTCH1), both a receptor for and transcriptional target of hedgehog signaling, was expressed in a small fraction of endothelial cells within pancreatic cancer, but not in normal pancreatic tissue. When endothelial progenitor cells (EPC) isolated from human peripheral blood were cultured with supernatant from SHH-transfected 293 cells or pancreatic cancer cells, mRNA levels of vascular endothelial growth factor (VEGF), stromal cell-derived factor-1 and angiopoietin-1 were significantly increased, whereas no such induction was observed in human umbilical vein endothelial cell (HUVEC) and human dermal microvascular endothelial cell (HMVEC). HUVEC tube formation was stimulated when cocultured with EPC, and preconditioning EPC with supernatant from KP-1 N pancreatic cancer cells highly expressing SHH significantly enhanced the effect. The effect was partially attenuated by specific inhibition of SHH with cyclopamine or a neutralizing antibody. These findings suggest that tumor-derived SHH can induce angiogenesis, and this is mediated by its effects on EPC specifically. Targeting SHH would be a novel therapeutic approach that can inhibit not only proliferation of cancer cells but also EPC-mediated angiogenesis.