This review largely deals with the peptide toxins elaborated by marine cone snails of the genus Conus . Each species of Conus contains in its venom 50 to 200 different peptides directed at different macromolecular targts. These include competitive antagonists of postsynaptic nicotinic receptors (a-conotoxins), blockers selective for Na+ channels in skeletal muscle (u- conotoxins), blockers of presynaptic of antagonists of postsynaptic Ca2+ channels (w-conotoxins), activators of Na+ channels (s-conotoxins), blockers of K+ channels (k-conotoxins), blockers of nicotinic receptor channels (u-conotoxins) and antagonists of NMDA receptors (cono-sleeper).The small size of the peptides (13 to 30 residues is typical) has facilitated synthesis of many of them. A very attractive feature is the highly cross-linked conserved 2 to 3 disulfide bonds which make conotoxins conformationally rigid, some of conotoxins, however, are stabilized by r-carboxyglutamates. The Structure-Activity Relationships of conotoxins and a brief perspective have been reviewed in the paper.

A 9-year-old boy presented with pruritic erythema and erosions of the scalp for 1 month, which spread all over the body for 1 week. Histopathological examination of the skin lesions showed blisters forming under the granular layer of the epidermis, a large number of acantholytic cells in the blisters, and perivascular infiltration of lymphocytes and eosinophils in the superficial dermis. Direct immunofluorescence study showed reticular deposition of IgG and complement C3 between epidermal cells, and negative staining for IgM and IgA. Enzyme-linked immunosorbent assay showed the presence of serum anti-Dsg1 antibody (157.00 U/ml) . The patient was diagnosed with pemphigus foliaceus. After admission, the patient showed poor response to the treatment with prednisone at a dose of 40 mg/d. After the treatment with low-dose rituximab (100 mg per week, 4 weeks) combined with prednisone (20 mg/d) , her condition was well controlled. The dosage of prednisone gradually decreased to 7.5 mg/d for maintenance treatment, and no recurrence was observed during 24-month follow-up.

OBJECTIVETo compare the effects of different approaches to establishing rat models of acute liver failure (ALF).

METHODSSixty-eight Sprague-Dawley rats were randomly divided into 3 groups for establishing ALF models using 3 different approaches, namely conventional hepatectomy for resecting 90% liver tissue as described by Higgins and Anderson, modified bloodless hepatectomy for resecting 90% liver tissue, and intraperitoneal injections of 700 mg/kg D-galactosamine (D-gal) and 5 µg/kg lipopolysaccharide (LPS). The mortality of the rats due to postoperative bleeding and survival rate at 7 days after the surgery were recorded. The levels of alanine aminotransferase (ALT), total bilimbin (Tbil), albumin (ALB), NH3, glucose (Glu) and prothrombin time (PT) were monitored, and histopathologies of the liver were examined at 24 and 72 h after the surgery.

RESULTSThe mortality rate due to postoperative bleeding was higher in conventional hepatectomy group than in the modified surgical group (15% vs 0). The survival rate at 7 days was 25%, 0%, 15% in conventional surgical group, modified surgical group and drug injection group, respectively. In the latter two groups, significant changes of ALT, Tbil, ALB, NH3, Glu, and PT were recorded at 24 and 72 h after the modeling (P<0.05), and these changes were the most obvious at 24 h in modified surgical group and at 72 h in the drug injection group; ALB in both groups declined to the lowest at 7 days and then increased gradually. Liver cell degeneration and necrosis were found in modified surgical group and drug injection group at 24 h and 72 h after the modeling.

CONCLUSIONBoth the modified 90% bloodless hepatectomy and injections of D-gal and LPS can be used to establish ideal rat models of ALF to suit different ALF-related researches.

Animals ; Disease Models, Animal ; Galactosamine ; adverse effects ; Hepatectomy ; Injections, Intraperitoneal ; Lipopolysaccharides ; adverse effects ; Liver Failure, Acute ; chemically induced ; pathology ; Rats ; Rats, Sprague-Dawley

BACKGROUNDChronic exposure to n-hexane can lead to peripheral neuropathy that no effective treatment regimen could be applied presently. This study investigated whether myelin protein zero (P0) protein and its antibody could be used to distinguish n-hexane intoxication and protect workers from peripheral neuropathy.

METHODSWe compared P0 protein and its antibody among three levels of n-hexane-exposed groups, which included 18 patients with n-hexane-induced peripheral neuropathy as case group, 120 n-hexane-exposed workers as n-hexaneexposed control group, and 147 non-hexane-exposed participants used as control group. ELISA method was applied to detect P0 protein and its antibody.

RESULTSP0 protein in serum was significantly higher in the case group and n-hexane-exposed control group in comparison with the control group (P < 0.01). Compared with the n-hexane-exposed control group, the case group also had significant increase of P0 protein (P < 0.01). After 6 months therapy, P0 protein was observed to decrease significantly in the case group (P < 0.01). The P0 antibody in serum was significantly higher in the n-hexane-exposed control group than in the control group (P < 0.01), but not significantly different between cases and controls.

CONCLUSIONSP0 antibodies in serum may be a short-term effect biomarker for n-hexane exposure. P0 protein in serum may be an early effective biomarker for peripheral nerve neuropathy and its biological limit value needs investigation in the future study.

Adult ; Antibodies ; blood ; immunology ; Cross-Sectional Studies ; Female ; Hexanes ; toxicity ; Humans ; Male ; Myelin P0 Protein ; blood ; immunology ; Peripheral Nervous System Diseases ; blood ; chemically induced ; immunology ; Young Adult