胰腺内分泌肿瘤胃肠多肽受体的表达

目的：研究胰腺内分泌肿瘤的胃肠多肽受体表达状况。方法：采用储磷放射自显影技术显示和定量分析胰泌素、蛙皮素、肠血管活性多肽、胆囊收缩素、生长抑素受体在胰腺内分泌肿瘤的表达特征。结果：胃泌素瘤表达蛙皮素、生长抑素受体，胰泌素和肠血管活性多肽受体，其中生长抑素受体亲和力及结合能力显高于其它受体。肠血管活性多肽瘤表达生长抑素，肠血管活性多肽和B型胆囊收缩素受体，以B型胆囊收缩素受体亲和力及结合能力最高。胃泌素瘤或VIP瘤所表达的胰泌素、蛙皮素、肠血管活性多肽、胆囊收缩素和生长抑素受体均呈高亲和力、单结合位点特征。生长抑素瘤和胰高糖素瘤未能测得上述5种胃肠多肽受体。结论：除生长抑素受体外，胃泌素瘤和肠血管活性多肽瘤还表达胰泌素、蛙皮素、肠血管活性多肽受体。     

Near full-length genome characterization of an HIV type 1 CRF25_cpx strain from Cameroon

Recombinant forms of HIV-1 contribute significantly to the ongoing epidemic. In the present study, we characterized the near full-length genome of one candidate HIV-1 CRF25_cpx strain originating in Cameroon, 06CM-BA-040. Viral RNA was extracted from plasma, and the genome was obtained using RT-PCR amplification to generate 10 overlapping fragments. Bootscanning, recombination breakpoint analysis, and phylogenetic trees confirmed that 06CM-BA-040 had a genomic structure consistent with two available CRF25_cpx reference sequences. The CRF25_cpx mosaic composition consisted of nine segments derived from subtypes A and G as well as unclassified (U) regions. Subtype G and CRF25_cpx clusters diverged from each other with long branch lengths but were distinct from other known subtypes with high bootstrap support (94%). The epidemiological significance of CRF25_cpx strains is unknown; however, the availability of additional genomic sequences will improve our understanding of the overall genetic diversity within this recombinant form of HIV-1.     

Epidermal growth factor regulation of DNA synthesis in human colonic lamina propria lymphocytes

Epidermal growth factor (EGF) is a potent growth factor for many tissues including the gastrointestinal tract. EGF is present in the gut lumen and is absorbed through the mucosa in the developing animals. In addition, EGF has been found to alter the immune system. In this study, we investigated thein vitro effect of EGF on normal colonic lamina propria lymphocyte DNA synthesis and ornithine decarboxylase activity. Human colonic lamina propria lymphocytes were isolated by collagenase-EDTA digestion. The effect of EGF on Con A-stimulated lymphocyte thymidine incorporation was tested. We observed that EGF suppressed DNA synthesis and ornithine decarboxylase (ODC) activity in lamina propria lymphocytes. EGF did not alter the time course of thymidine incorporation into LPL stimulated by the combination of phorbol 12,13-dibutyrate (PDB) and ionomycin. Our data suggest that (1) EGF suppresses DNA synthesis in human colonic lamina propria lymphocytes as well as ODC activity and (2) this inhibition may be mediated through protein kinase C or calcium flux. We postulate that EGF may have a role in modulating the human gut immune system.This work was supported in part by grant CA43280 from the National Institutes of Health.     

Synergistic Inhibition on Acetylcholinesterase by the Combination of Berberine and Palmatine Originally Isolated from Chinese Medicinal Herbs

Alzheimer’s disease is a multi-factorial neurodegenerative disorder devastatingly affecting the aged population worldwide. Previous studies have shown that medicinal herbs used in traditional Chinese medicine might be benefit to Alzheimer’s disease patients. Berberine and palmatine, two isoquinoline alkaloids found in several medicinal herbs, were used for memory enhancement in China. In this study, the inhibitory effects of combined berberine and palmatine on acetylcholinesteras were evaluated using recombinant human acetylcholinesterase. Our results showed that the combination of berberine and palmatine inhibited acetylcholinesterase in a mixed competitive pattern. By the median-effect principle, the calculated combination index of the combination was less than 1, suggesting that berberine and plamatine inhibited acetylcholinesterase synergistically. Furthermore, the drug-reducing index of berberine and palmatine were 2.98 and 2.66, respectively. Taken together, the results showed that the combination of the two alkaloids might potentially be developed as a more effective therapeutic strategy for Alzheimer’s disease patients.     

Characterizations of Cholinesterases in Golden Apple Snail (Pomacea canaliculata)

Cholinesterases (ChEs) have been identified in vertebrates and invertebrates. Inhibition of ChE activity in invertebrates, such as bivalve molluscs, has been used to evaluate the exposure of organophosphates, carbamate pesticides, and heavy metals in the marine system. The golden apple snail (Pomacea canaliculata) is considered as one of the worst invasive alien species harmful to rice and other crops. The ChE(s) in this animal, which has been found recently, but poorly characterized thus far, could serve as biomarker(s) for environmental surveillance as well as a potential target for the pest control. In this study, the tissue distribution, substrate preference, sensitivity to ChE inhibitors, and molecular species of ChEs in P. canaliculata were investigated. It was found that the activities of both AChE and BChE were present in all test tissues. The intestine had the most abundant ChE activities. Both enzymes had fair activities in the head, kidney, and gills. The BChE activity was more sensitive to tetra-isopropylpyrophosphoramide (iso-OMPA) than the AChE. Only one BChE molecular species, 5.8S, was found in the intestine and head, whereas two AChE species, 5.8S and 11.6S, were found there. We propose that intestine ChEs of this snail may be potential biomarkers for manipulating pollutions.     

Report on a case of fibrogenesis imperfecta ossium and a possible new treatment option

Fibrogenesis imperfecta is an extremely rare acquired progressive bone disorder of unknown etiology. In its course, normal bone architecture is replaced at sites by structurally unsound collagen-deficient tissue resulting in a disorganized bone structure and a skeleton that is radically susceptible to deformity and fracture. Herein, we report the case of a patient who had experienced constant bone pain and several spontaneous fractures since 1997. In 10 years’ time with the sole exception of his skull, the disease affected the entire skeleton causing a significant decrease in height and progressive disablement. Laboratory findings included elevation of serum alkaline phosphatase and C-terminal telopeptide of type 1 collagen, with normal serum calcium, phosphate, 25-hydroxy-vitamin-D, and parathyroid hormone concentrations. Monoclonal gammopathy was present with no pathological plasma cells in bone marrow. Radiological and histological results were inconclusive suggesting either osteoporosis, osteomalacia, or Paget’s disease and later on osteosclerosis. Treatment administered for the abovementioned conditions has proven to be of no effect. The findings eventually raised the possibility of fibrogenesis imperfecta ossium, which was confirmed by polarized light microscopy as well as transmission electron microscopy. The suggested therapy for the disease is melphalan that could not be initiated due to legal restrictions. Steroid monotherapy also reported to be moderately successful in one case resulted in no improvement. Paraproteinemia had been suggested not only to be a characteristic feature but also a possible etiological factor in this condition. In 2012, plasmapheresis was initiated monthly at the beginning, later on biweekly. In response, the patient’s symptoms improved dramatically supporting the abovementioned theory.