Search

Lipomembranous fat necrosis (LFN) is an uncommon but distinct form of fat necrosis, which is characterized by eosinophilic, crenulated and/or serpiginous membranes. LFN exhibits macrocystic, microcystic and/or crushed features. LFN is routinely detectable on hematoxylin and eosin (HE)-stained sections, and is present both in the acute phase and in the later or fibrous stage of necrotic fatty lesions. Smaller crushed LFN embedded within fibrous tissues may be difficult to recognize on HE-stained sections, but can be highlighted by some staining techniques, including Masson trichrome, periodic acid-Schiff, orcein, long Ziehl-Neelsen stain, silver impregnation, phosphotungstic acid-hematoxylin and luxol fast blue staining. LFN was initially considered a specific feature of Nasu-Hakola disease, but has since been identified in various subcutaneous or intraabdominal lesions related to ischemic conditions or venous insufficiency. In addition, LFN is detectable in intra-articular loose bodies and aortic valves with or without dysfunction, suggesting that LFN is also associated with ischemia-like hypoxic conditions or malnutrition. LFN is considered to be a histological hallmark of hidden ischemic or hypoxic/malnourished conditions in various diseases; however, the exact mechanisms of LFN remain poorly understood. The present review described the clinicopathological features of this interesting, but poorly characterized, condition.

Background Non-parasitic splenic cysts are associated with elevated serum carbohydrate antigen (CA) 19–9 levels. We report a case in which a 23-year-old female exhibited a large ruptured splenic cyst and an elevated serum CA19–9 level. Case presentation The patient, who experienced postprandial abdominal pain and vomiting, was transferred to our hospital and was found to have a large splenic cyst during an abdominal computed tomography (CT) scan. On physical examination, her vital signs were stable, and she demonstrated rebound tenderness in the epigastric region. An abdominal CT scan revealed abdominal fluid and a low-density region (12 × 12 × 8 cm) with enhanced margins in the spleen. The patient’s serum levels of CA19–9 and CA125 were elevated to 17,580 U/mL and 909 U/mL, respectively. A cytological examination of the ascitic fluid resulted in it being categorized as class II. Finally, we made a diagnosis of a ruptured splenic epidermoid cyst and performed laparoscopic splenic fenestration. The patient’s postoperative course was uneventful, and she was discharged on postoperative day 5. The cystic lesion was histopathologically diagnosed as a true cyst, and the epithelial cells were positive for CA19–9. Follow-up laboratory tests performed at 4 postoperative months showed normal CA19–9 (24.6 U/L) and CA125 (26.8 U/L) levels. No recurrence of the splenic cyst was detected during the 6 months after surgery. Conclusion Laparoscopic fenestration of a ruptured splenic cyst was performed to preserve the spleen, after the results of abdominal fluid cytology and MRI were negative for malignancy.

To identify the characteristic magnetic resonance imaging (MRI) findings in angioleiomyoma and to clarify its relationship with histopathological findings. We retrospectively analyzed the MRI findings and pathological subtypes in 25 patients with subcutaneous angioleiomyoma of the extremities. Based on the previous reports, MRI findings that could be characteristic of angioleiomyoma were extracted. According to the World Health Organization classification, all cases were classified into three pathological subtypes: solid, venous, and cavernous. The relationship between MRI findings and pathological subtypes was analyzed. The pathological subtypes were solid (n = 10), venous (n = 11), and cavernous (n = 4). The following MRI findings were observed: (a) hypo- or iso-intense linear and/or branching structures on a T2-weighted image (positive total/solid/venous/cavernous: 19/5/10/4, respectively), which we defined as “dark reticular sign”; (b) peripheral hypointense rim on a T2-weighted image (positive total/solid/venous/cavernous: 19/7/8/4, respectively); and (c) presence of any adjacent vascular structures (positive total/solid/venous/cavernous: 6/3/3/0, respectively). Chi-square test showed a significant relationship between dark reticular sign and pathological subtypes (p = 0.0426). The dark reticular sign was found more frequently in the venous and cavernous types than in the solid type. The other MRI findings did not reveal a significant relationship between pathological subtypes. We present the largest case series exploring MRI findings in angioleiomyoma. The dark reticular sign was a characteristic MRI finding of angioleiomyoma and was seen in most of the venous and cavernous types, which may facilitate preoperative diagnosis.

We expressed luciferase (RLuc) from Renilla reniformis in Escherichia coli RLuc was purified using a Ni-NTA column and subsequently characterized. It was unstable in acidic solutions and at 30°C. To increase the stability of RLuc, the Rluc gene was randomly mutated using error-prone polymerase chain reaction. E. coli harboring the mutated gene was screened by detecting luminescence on a plate containing the substrate coelenterazine at 34°C. Three mutants, i.e. N264SS287P, N178D and F116LI137V, were obtained. The solubilities and specific activities of these mutants were higher than those of the wild type. Furthermore, the N264SS287P mutant maintained stability at a temperature approximately 5°C higher than that of the wild type, while denaturation of the F116LI137V mutant started at a temperature that was 5°C lower than the wild type, and ended at a temperature that was 7°C higher. We examined the obtained mutations using thermal shift assays and a computer program Coot in this study.

We expressed luciferase (RLuc) from Renilla reniformis in Escherichia coli RLuc was purified using a Ni-NTA column and subsequently characterized. It was unstable in acidic solutions and at 30°C. To increase the stability of RLuc, the Rluc gene was randomly mutated using error-prone polymerase chain reaction. E. coli harboring the mutated gene was screened by detecting luminescence on a plate containing the substrate coelenterazine at 34°C. Three mutants, i.e. N264SS287P, N178D and F116LI137V, were obtained. The solubilities and specific activities of these mutants were higher than those of the wild type. Furthermore, the N264SS287P mutant maintained stability at a temperature approximately 5°C higher than that of the wild type, while denaturation of the F116LI137V mutant started at a temperature that was 5°C lower than the wild type, and ended at a temperature that was 7°C higher. We examined the obtained mutations using thermal shift assays and a computer program Coot in this study.