Aristolochic acid I promoted clonal expansion but did not induce hepatocellular carcinoma in adult rats.

Aristolochic acid I (AAI) is a well-known nephrotoxic carcinogen, which is currently reported to be also associated with hepatocellular carcinoma (HCC). Whether AAI is a direct hepatocarcinogen remains controversial. In this study we investigated the association between AAI exposure and HCC in adult rats using a sensitive rat liver bioassay with several cofactors.

[Sporadic cutaneous infections due to nontuberculous mycobacteria: a retrospective study of 37 cases].

Objective: To study the clinical and pathological characteristics of sporadic cutaneous infections due to nontuberculous mycobacteria (NTM), and investigate the diagnostic criteria and therapeutic principal.

Methods: Totally 37 cases of sporadic cutaneous infections due to NTM were confirmed in the Department of Dermatology, Peking University People's Hospital from January 2000 to March 2014. The microbiologic and clinical data were reviewed, and their skin biopsy specimens were reassessed.

Rare earth elements activate endocytosis in plant cells.

It has long been observed that rare earth elements (REEs) regulate multiple facets of plant growth and development. However, the underlying mechanisms remain largely unclear. Here, using electron microscopic autoradiography, we show the life cycle of a light REE (lanthanum) and a heavy REE (terbium) in horseradish leaf cells.

Differential Effects of Naja naja atra Venom on Immune Activity.

Previous studies reported that Naja naja atra venom (NNAV) inhibited inflammation and adjuvant arthritis. Here we investigated the role of NNAV in regulation of immune responses in mice. Oral administration of NNAV to normal mice showed significant increase in natural killer cell activity, B lymphocyte proliferation stimulated by lipopolysaccharides, and antibody production in response to sheep red blood cells.

The Protective Effects of Cobra Venom from Naja naja atra on Acute and Chronic Nephropathy.

This study investigated the effects of Naja naja atra venom (NNAV) on acute and chronic nephropathy in rats. Rats received 6 mg/kg adriamycin (ADR) once to evoke the chronic nephropathy or 8 ml/kg 50% v/v glycerol to produce acute renal failure (ARF). The NNAV was given orally once a day starting five days prior to ADR or glycerol injection and continued to the end of experiments.

Structural basis for the decrease in the outward potassium channel current induced by lanthanum.

The current of the outward K+ channel in the cell of horseradish treated with La3+ and the direct interaction between La3+ and the K+ channel protein were investigated using the whole-cell patch-clamp technique, molecular dynamics simulation, and quantum chemistry calculation methods. It was found for the first time that La3+ decreases the current of the K+ channel in the horseradish mesophyll cell. The decrease results from the formation of a coordination bond and hydrogen bond between La3+ and the K+ channel protein in the plasma membrane.

[Detection and identification of mycobacterial gene in skin lesions and lymph nodes in patients with sarcoidosis].

Objective: To investigate the possible role of mycobacteria in the pathogenesis of sarcoidosis.

Methods: We used nested polymerase chain reaction-restriction fragment length polymorphism (nPCR-RFLP) and gene sequencing method to examine 31 formalin-fixed, paraffin-embedded specimens (including 19 skin lesions and 12 lymph nodes ) obtained from patients with sarcoidosis, 14 normal skin specimens, and 3 cutaneous tuberculosis specimens.

Results: The 65kD mycobacterial heat shock protein gene was found in 4 out of 19 (21.

Mutation of the conserved Asp122 in the linker impedes creatine kinase reactivation and refolding.

Creatine kinase (CK), a key enzyme in maintaining the intracellular energetic homeostasis, contains two domains connected by a long linker. In this research,we found that the mutations of the conserved Asp122 in the linker slightly affected CK activity, structure and stability. The hydrogen bonding and the ion pair contributed 2-5 kJ/mol to the conformational stability of CK.

The conserved Cys254 plays a crucial role in creatine kinase refolding under non-reduced conditions but not in its activity or stability.

Oxidative stress is a common factor that may affect cell survival in extreme or disease-related conditions, and it is important for the cells to develop not only redox homeostatic mechanisms, but also adequate protein-protecting mechanisms to fight against oxidative stress. In this research, we investigated the role of the conserved C254 in the refolding of creatine kinase (CK), a key cytosolic enzyme involved in intracellular energetics. It was found that the conserved C254 did not contribute to the activity, structure, stability and unfolding of CK, but played a crucial role in CK refolding under non-reduced conditions by preventing off-pathway aggregation.