Follow-up of patients with COVID-19 by the Delta variant after hospital discharge in Guangzhou, Guandong, China

ABSTRACT The B.1.617.2 (Delta) variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has contributed to a new increment in cases across the globe. We conducted a prospective follow-up of COVID-19 cases to explore the recurrence and potential propagation risk of the Delta variant and discuss potential explanations for the infection recurrence. A prospective, non-interventional follow-up of discharged patients who had SARS-CoV-2 infections by the Delta variant in Guangdong, China, from May 2021 to June 2021 was conducted. The subjects were asked to complete a physical health examination and undergo nucleic acid testing and antibody detection for the laboratory diagnosis of COVID-19. In total, 20.33% (25/123) of patients exhibited recurrent positive results after discharge. All patients with infection recurrence were asymptomatic and showed no abnormalities in the pulmonary computed tomography. The time from discharge to the recurrent positive testing was usually between 1-33 days, with a mean time of 9.36 days. The cycle threshold from the real-time polymerase chain reaction assay that detected the recurrence of positivity ranged from 27.48 to 39.00, with an average of 35.30. The proportion of vaccination in the non-recurrent group was higher than that in the recurrently positive group (26% vs. 4%; χ2 = 7.902; P < 0.05). Two months after discharge, the most common symptom was hair loss and 59.6% of patients had no long-term symptoms at all. It is possible for the Delta variant SARS-CoV-2 patients after discharge to show recurrent positive results of nucleic acid detection; however, there is a low risk of continuous community transmission. Both, the physical and mental quality of life of discharged patients were significantly affected. Our results suggest that it makes sense to implement mass vaccination against the Delta variant of SARS-CoV-2.

Balloon-Assisted Enteroscopy and Capsule Endoscopy in Suspected Small Bowel Crohn's Disease

Inflammatory bowel diseases are idiopathic inflammatory diseases of two main types, Crohn's disease and ulcerative colitis. Crohn's disease can affect the entire gastrointestinal tract, and the distal ileum is involved in up to 70% of patients. Moreover, Crohn's disease in one-quarter to one-third of patients involves isolation of the small bowel. Due to the nonspecific symptoms and anatomical location of the disease, small bowel Crohn's disease is a phenotype that is particularly difficult to manage. Since the introduction of capsule endoscopy in 2000 and balloon-assisted enteroscopy in the 21st century, it is now possible to directly inspect for small bowel Crohn's disease. However, the new modalities still have limitations, such as capsule retention and invasiveness of balloon-assisted enteroscopy. The diagnostic yields of both capsule endoscopy and balloon-assisted enteroscopy are high for patients with suspected small bowel Crohn's disease. Therefore, earlier use of capsule endoscopy or balloon-assisted enteroscopy can help with the diagnosis and earlier treatment of these patients to avert possible disastrous outcomes.

Intestinal Stricture in Crohn's Disease

Crohn's disease (CD) is a disease with chronic inflammation of unknown etiology involving any part of the gastrointestinal tract. The incidence and prevalence of CD are increasing recently in Asia. Half of the CD patients will have intestinal complications, such as strictures or fistulas, within 20 years after diagnosis. Twenty-five percentage of CD patients have had at least one small bowel stricture and 10% have had at least one colonic stricture and lead to significant complications. Most of these patients will require at least one surgery during their lifetime. Early diagnosis and evaluation with adequate managements for the patients can prevent disability and mortality of these patient. Here, we reviewed the current incidence of CD with stricture, the etiology of stricture, and how to diagnose and manage the stricture.

Safety and Efficacy of Adalimumab for Patients With Moderate to Severe Crohn's Disease: The Taiwan Society of Inflammatory Bowel Disease (TSIBD) Study

BACKGROUND/AIMS: Only moderate to severe Crohn's Disease (CD) patients without a satisfactory conventional therapy effect are eligible to get reimbursement from the National Health Insurance of Taiwan for using adalimumab. These are more stringent criteria than in many Western countries and Japan and Korea. We aim to explore the efficacy of using adalimumab in CD patients under such stringent criteria. METHODS: A retrospective analysis was conducted in nine medical centers in Taiwan and we collected the results of CD patients receiving adalimumab from Sep 2009 to Mar 2014. The clinical characteristics, response measured by CDAI (Crohn's Disease Activity Index), adverse events and survival status were recorded and analyzed. CR-70, CR-100, and CR-150 were defined as attaining a CDAI decrease of 70, 100 or 150 points compared with baseline. RESULTS: A total of 103 CD patient records were used in this study. Sixty percent of these patients received combination therapy of adalimumab together with immunomodulators. CR-70 was 68.7%, 74.5% and 88.4% after week 4, 8 and 12 of treatment, respectively. The steroid-free rate, complications and survival were 47.6%, 9.7% and 99% of patients, respectively. In considering the mucosal healing, only 25% patients achieve mucosal healing after treatment for 6 to12 months. Surgery was still needed in 16.5% of patients. Combination treatment of adalimumab with immunomodulators further decreased the level of CDAI at week 8 when compared with the monotherapy. CONCLUSIONS: Even under the stringent criteria for using adalimumab, the response rate was comparable to those without stringent criteria.

Development of pollen mediated activation tagging system for Phalaenopsis and Doritaenopsis

In the present study, a novel plant transformation system for Doritaenopsis and Phalaenopsis has been developed. The pollen-mediated activation tagging system was established by artificial pollination. The pollens, co-cultured with Agrobacterium tumefaciens strain EHA105 harbouring an activation tagging vector (pTAG-8), were used for pollination. In order to optimize the transformation efficiency, several factors (concentration of A. tumefaciens, concentration of acetosyringone during co-cultivation and the duration of co-cultivation) known to influence Agrobacterium-mediated DNA transfer were examined. A concentration of 0.5-1 x 10(8) CFU/ml for A. tumefaciens, 0.1 mM acetosyringone, and 6 hrs of co-culture period were found to be the optimal condition for high transformation efficiency. Integration of T-DNA into the genome of putative transgenic plants was confirmed by PCR and DNA blot analyses. Single copy of the transgene was observed in all transgenic plants analyzed. Most of the transgenic plants had a morphologically normal phenotype and the overall capsule formation efficiency was similar to control plant. Our results showed a new approach of genetic transformation in orchids and this method can be employed for genetic improvement of the orchids.