Purification and characterization of three isoforms of chrysophsin, a novel antimicrobial peptide in the gills of the red sea bream, Chrysophrys major.

We report here the isolation of three isoforms of a novel C-terminally amidated peptide from the gills of red sea bream, Chrysophrys (Pagrus) major. Peptide sequences were determined by a combination of Edman degradation, MS and HPLC analysis of native and synthetic peptides. Three peptides, named chrysophsin-1, chrysophsin-2, and chrysophsin-3, consist of 25, 25, and 20 amino acids, respectively, and are highly cationic, containing an unusual C-terminal RRRH sequence. The alpha-helical structures of the three chrysophsin peptides were predicted from their secondary structures and were confirmed by CD spectroscopy. The synthetic peptides displayed broad-spectrum bactericidal activity against Gram-negative and Gram-positive bacteria including Escherichia coli, Bacillus subtilis, and fish and crustacean pathogens. The three peptides were also hemolytic. Immunohistochemical analysis showed that chrysophsins were localized in certain epithelial cells lining the surface of secondary lamellae and eosinophilic granule cell-like cells at the base of the secondary lamellae in red sea bream gills. Their broad ranging bactericidal activities, combined with their localization in certain cells and eosinophilic granule cell-like cells in the gills, suggest that chrysophsins play a significant role in the innate defense system of red sea bream gills.     

Possible participation of intracellular platelet-activating factor in NF-κB activation in rat peritoneal macrophages

As we had found previously that thapsigargin, an endomembrane Ca²⁺-ATPase inhibitor, induces production of intracellular platelet-activating factor (PAF) [Br. J. Pharmacol. 116 (1995) 2141], we decided to investigate the possible roles of intracellular PAF in nuclear factor (NF)-κB activation of thapsigargin-stimulated rat peritoneal macrophages. When rat peritoneal macrophages were stimulated with thapsigargin, the level of inhibitory protein of NF-κB-α (IκB-α) was decreased and the nuclear translocation of NF-κB was increased. The thapsigargin-induced activation of NF-κB was inhibited by the PAF synthesis inhibitor SK&F 98625 and the PAF antagonist E6123. Structurally unrelated PAF antagonists such as E5880 and L-652,731 also inhibited the thapsigargin-induced activation of NF-κB. Lipopolysaccharide (LPS)-induced activation of NF-κB was also suppressed by these drugs. In a culture of rat peritoneal macrophages, exogenously added PAF did not induce degradation of IκB-α. These findings suggest that the intracellular PAF produced by the stimulation with thapsigargin or LPS is involved in activation of the NF-κB pathway.     

Effects of low-intensity resistance exercise with slow movement and tonic force generation on muscular function in young men.

We investigated the acute and long-term effects of low-intensity resistance exercise (knee extension) with slow movement and tonic force generation on muscular size and strength. This type of exercise was expected to enhance the intramuscular hypoxic environment that might be a factor for muscular hypertrophy. Twenty-four healthy young men without experience of regular exercise training were assigned into three groups (n = 8 for each) and performed the following resistance exercise regimens: low-intensity [ approximately 50% of one-repetition maximum (1RM)] with slow movement and tonic force generation (3 s for eccentric and concentric actions, 1-s pause, and no relaxing phase; LST); high-intensity ( approximately 80% 1RM) with normal speed (1 s for concentric and eccentric actions, 1 s for relaxing; HN); low-intensity with normal speed (same intensity as for LST and same speed as for HN; LN). In LST and HN, the mean repetition maximum was 8RM. In LN, both intensity and amount of work were matched with those for LST. Each exercise session consisting of three sets was performed three times a week for 12 wk. In LST and HN, exercise training caused significant (P < 0.05) increases in cross-sectional area determined with MRI and isometric strength (maximal voluntary contraction) of the knee extensors, whereas no significant changes were seen in LN. Electromyographic and near-infrared spectroscopic analyses showed that one bout of LST causes sustained muscular activity and the largest muscle deoxygenation among the three types of exercise. The results suggest that intramuscular oxygen environment is important for exercise-induced muscular hypertrophy.     

Heat coma and its relationship to ocean dynamics in the oceanic sea skaters of Halobates (Heteroptera: Gerridae) inhabiting Indian and Pacific Oceans

This study was performed to clarify how weather and current dynamics affect the resistance to temperature change in the oceanic sea skaters, Halobates. Heat coma temperature (HCT) was measured for the adults and 5th instar larvae of four Halobates species collected from a fixed sampling location (12°00′N, 135°00′E ) in western tropical Pacific Ocean and from 13 locations in the eastern area of the India Ocean ranging from 08°00′N-06°00′S and 86°00-76°00′E. Both the gap temperature for heat coma (GTHC, mean±SD: 7.83±1.86 °C, n=32) and the heat coma temperature (HCP, 35.03±1.80 °C, n=32) of individuals collected from the Pacific Ocean, during the first half (10 days) of the sampling period at the fixed sampling point, were significantly higher than those during the second half (GTHC: 5.10±2.05 °C, n=63; HCP: 34.03±2.02 °C, n=63). The reduction in heat tolerance shown in the second half of the 20 day period may have been caused by a decrease in air temperature due to rainfall that occurred around the sampling point accompanied with the arrival of Typhoon No. 6.In the study of individuals collected from the Indian Ocean, significantly higher average GTHCs of >8 °C were recorded for the adult H. micans collected at 02°00′S and 06°00′S (89°00′E) than those at 0°00-8°00′N in the eastern Indian Ocean. Dynamic mixture of water from northern and southern currents occurs at 02°00-6°00′S of the Indian Ocean and might relate to such high heat tolerance.Temperature dynamics in the ocean habitat might directly affect the temperature resistance of the oceanic sea skaters.     

Distribution and Numbers of Pygmies in Central African Forests

Pygmy populations occupy a vast territory extending west-to-east along the central African belt from the Congo Basin to Lake Victoria. However, their numbers and actual distribution is not known precisely. Here, we undertake this task by using locational data and population sizes for an unprecedented number of known Pygmy camps and settlements (n = 654) in five of the nine countries where currently distributed. With these data we develop spatial distribution models based on the favourability function, which distinguish areas with favourable environmental conditions from those less suitable for Pygmy presence. Highly favourable areas were significantly explained by presence of tropical forests, and by lower human pressure variables. For documented Pygmy settlements, we use the relationship between observed population sizes and predicted favourability values to estimate the total Pygmy population throughout Central Africa. We estimate that around 920,000 Pygmies (over 60% in DRC) is possible within favourable forest areas in Central Africa. We argue that fragmentation of the existing Pygmy populations, alongside pressure from extractive industries and sometimes conflict with conservation areas, endanger their future. There is an urgent need to inform policies that can mitigate against future external threats to these indigenous peoples’ culture and lifestyles.     

Effects of LPA1 and LPA6 on the regulation of colony formation activity in colon cancer cells treated with anticancer drugs

Lysophosphatidic acid (LPA) is a simple physiological lipid and exhibits a variety of cellular responses via the activation of G protein-coupled transmembrane LPA receptors (LPA receptor-1 (LPA₁) to LPA₆). The aim of our study was to investigate effects of LPA receptors on soft agar colony formation in colon cancer cells treated with anticancer drugs. DLD1 cells were treated with fluorouracil (5-FU) or cisplatin (CDDP) for at least six months (DLD-5FU and DLD-CDDP cells, respectively). LPAR1 gene expression was markedly elevated in DLD-5FU cells. In contrast, DLD-CDDP cells showed the high expression of LPAR6 gene. In colony formation assay, DLD-5FU cells formed markedly large-sized colonies, while no colony formation was observed in DLD1 and DLD-CDDP cells. The large-sized colonies formed in DLD-5FU cells were suppressed by LPA₁ knockdown. In contrast, LPA₆ knockdown increased the size of colonies. In addition, DLD-5FU cells were further treated with CDDP for three months (DLD-C-F cells). DLD-CDDP cells were also treated with 5-FU (DLD-F-C cells). DLD-C-F cells formed large-sized colonies, but not DLD-F-C cells, correlating with LPAR1 and LPAR6 gene expression levels. These results suggest that LPA₁ and LPA₆ may regulate the colony formation activity in DLD1 cells treated with anticancer drugs.     

Pulmonary carcinosarcoma showing an obvious response to pazopanib: a case report

Background

Pulmonary carcinosarcoma (PCS) is a rare primary lung malignancy and has a poor prognosis among lung tumor histological subtypes. However, an appropriate treatment strategy has not been developed for unresectable PCS.

Case presentation

A 65-year-old man who was diagnosed with PCS was treated by surgical removal of the primary lung lesion, followed by six cycles of adjuvant chemotherapy with cisplatin plus irinotecan. Following the chemotherapy, he experienced a relapse with brain metastasis, which induced the rapid onset of left leg paralysis. Radical surgical resection and stereotactic radiosurgery to the resection cavity were performed. However, meningeal dissemination and new lung metastases occurred after a year and half. To control these multiple metastatic lesions, the patient was treated with the multiple kinase inhibitor pazopanib. No change was observed in the meningeal dissemination, while the metastatic lung lesions were prominently reduced in size following treatment with pazopanib. Consequently, the patient showed a partial response to pazopanib treatment, although the dose of pazopanib was reduced by half as a result of thrombocytopenia.

Conclusion

This is the first report of metastatic PCS showing an evident therapeutic response to tumor-targeted therapy. We suggest that pazopanib may be a therapeutic option for patients with metastatic PCS.