RNA interference knockdown of aminopeptidase N genes decrease the susceptibility of Chilo suppressalis larvae to Cry1Ab/Cry1Ac and Cry1Ca-expressing transgenic rice.

Transgenic rice expressing Bacillus thuringiensis (Bt) Cry toxins are resistant to lepidopteran pests, such as Chilo suppressalis, a major insect pest of rice in Asia. Understanding how these toxins interact with their hosts is crucial to understanding their insecticidal action. In this study, knockdown of two aminopeptidase N genes (APN1 and APN2) by RNA interference resulted in decreased susceptibility of C. suppressalis larvae to the Bt rice varieties TT51 (Cry1Ab and Cry1Ac fusion genes) and T1C-19 (Cry1Ca), but not T2A-1 (Cry2Aa). This suggests that APN1 and APN2 are receptors for Cry1A and Cry1C toxins in C. suppressalis.

Asymptomatic low-grade appendiceal mucinous neoplasm: A case report.

BACKGROUND: Low-grade appendiceal neoplasms (LAMN) are characterized by low incidence and atypical clinical presentations, often leading to misdiagnosis as acute or chronic appendicitis before surgery. The primary diagnostic tool for LAMN is abdominal computed tomography (CT) imaging. Surgical resection remains the cornerstone of LAMN management, necessitating en bloc tumor excision to minimize the risk of iatrogenic rupture. Laparoscopy, known for its minimal invasiveness, reduced postoperative discomfort, and expedited recovery, is a safe and reliable approach for LAMN treatment. Despite the possibility of pseudomyxoma peritonei development, appendectomy and partial appendectomy generally result in negative tumor margins and favorable outcomes, which can be attributed to the disease's slow growth and lower malignancy. CASE SUMMARY: A 71-year-old male patient was admitted to our hospital with a pelvic space-occupying lesion detected 1 mo prior. Physical examination showed a soft abdomen without tenderness or rebound and no palpable masses. No shifting dullness was noted, and digital rectal examination revealed no palpable mass. Enteroscopy revealed a raised, smooth-surfaced mass measuring 3.0 cm in the cecum. Abdominal contrast-enhanced CT showed a markedly thickened and dilated appendix with visible cystic shadows. Laparoscopic surgery was performed and revealed a significantly dilated appendix, leading to laparoscopic resection of the appendix and part of the cecum. Post-surgical pathologic analysis confirmed LAMN. The patient received symptomatic and supportive post-operative care and was discharged on postoperative day 4 without complications such as abdominal bleeding, intestinal obstruction, or incision infection. No tumor recurrence was observed during a 7-mo follow-up period. CONCLUSION: LAMN is a rare disease that lacks specific clinical manifestations. Abdominal CT plays a crucial role in diagnosing LAMN, and laparoscopic surgery is a safe and effective diagnostic and therapeutic approach.

Neurofibromatosis type 1 with multiple gastrointestinal stromal tumors: A case report.

BACKGROUND: Neurofibromatosis type 1 (NF1) is characterized by café-au-lait patches on the skin and the presence of neurofibromas. Gastrointestinal stromal tumor (GIST) is the most common non-neurological tumor in NF1 patients. In NF1-associated GIST, KIT and PDGFRA mutations are frequently absent and imatinib is ineffective. Surgical resection is first-line treatment. CASE SUMMARY: A 56-year-old woman with NF1 was hospitalized because of an incidental pelvic mass. Physical examination was notable for multiple café-au-lait patches and numerous subcutaneous soft nodular masses of the skin of the head, face, trunk, and limbs. Her abdomen was soft and nontender. No masses were palpated. Digital rectal examination was unremarkable. Abdominal computed tomography was suspicious for GIST or solitary fibrous tumor. Laparoscopy was performed, which identified eight well-demarcated masses in the jejunum. All were resected and pathologically diagnosed as GISTs. The patient was discharged on day 7 after surgery without complications. No tumor recurrence was evident at the 6-mo follow-up. CONCLUSION: Laparoscopy is effective for both diagnosis and treatment of NF1-associated GIST.

De Garengeot hernia with avascular necrosis of the appendix: A case report.

BACKGROUND: An incarcerated hernia is a common cause of acute abdominal pain. There are various types of incarcerated hernias, including incarcerated hernias of the appendix. These hernias are often complicated by appendiceal inflammation, necrosis, and suppuration, which affect the outcome of surgical repair. A De Garengeot hernia is a femoral hernia that contains the appendix. This type of hernia has a low incidence. When a De Garengeot hernia is clinically suspected, emergency surgical treatment should be performed as soon as possible. CASE SUMMARY: A 59-year-old man was admitted to the hospital with a painful right inguinal mass that had suddenly developed 6 hours earlier. Physical examination revealed a 4 cm × 2 cm palpable mass in the right groin. The mass was hard and could not be reduced due to tenderness. It did not descend into the scrotum. B-ultrasound revealed an incarcerated hernia. During surgery, the hernia was found to contain the appendix, which exhibited distal avascular necrosis. A De Garengeot hernia was diagnosed according to the classification criteria of this type of inguinal hernia. Laparoscopic reduction of the incarcerated hernia, appendectomy, and small-incision femoral hernia repair were performed in the emergency department, and cefuroxime was administered as anti-infection therapy for 2 d postoperatively. After treatment, the patient had no abdominal pain or infection and was discharged on postoperative day 4. He had no recurrence of the inguinal hernia after 16 months of follow-up. CONCLUSION: De Garengeot hernias have a low incidence and are difficult to diagnose. Laparoscopy is useful for their diagnosis and treatment.

Knockdown of the MAPK p38 pathway increases the susceptibility of Chilo suppressalis larvae to Bacillus thuringiensis Cry1Ca toxin.

The bacterium Bacillus thuringiensis (Bt) produces a wide range of toxins that are effective against a number of insect pests. Identifying the mechanisms responsible for resistance to Bt toxin will improve both our ability to control important insect pests and our understanding of bacterial toxicology. In this study, we investigated the role of MAPK pathways in resistance against Cry1Ca toxin in Chilo suppressalis, an important lepidopteran pest of rice crops. We first cloned the full-length of C. suppressalis mitogen-activated protein kinase (MAPK) p38, ERK1, and ERK2, and a partial sequence of JNK (hereafter Csp38, CsERK1, CsERK2 and CsJNK). We could then measure the up-regulation of these MAPK genes in larvae at different times after ingestion of Cry1Ca toxin. Using RNA interference to knockdown Csp38, CsJNK, CsERK1 and CsERK2 showed that only knockdown of Csp38 significantly increased the mortality of larvae to Cry1Ca toxin ingested in either an artificial diet, or after feeding on transgenic rice expressed Cry1Ca. These results suggest that MAPK p38 is responsible for the resistance of C. suppressalis larvae to Bt Cry1Ca toxin.