A spin-label study of the effect of gamma radiation on erythrocyte membrane. Influence of lipid peroxidation on membrane structure.

Gamma-irradiation of bovine erythrocyte membranes (0.1-4 Mrad) resulted in a decrease in the degree of order of membrane lipids, as measured by spin-labelled fatty acid esters, at the depth of C12 but not at the depth of C5. Dose dependence of this phenomenon corresponded to dose dependence of malondialdehyde formation in the membranes. On this basis a mechanism for the effect of lipid peroxidation on the membrance structure is proposed. Membrane proteins underwent radiation-induced conformational transitions revealed by maleimide spin label which could be also connected with lipid peroxidation.     

Induced ovulation in Atlantic croaker (Sciaenidae) using hCG and an LHRH analog: A preliminary study

A single dose of LHRHa (D-Ala(6), des Gly(10)- LHRH-ethylamide; 100 mug/kg body weight); administered by intramuscular injection, effectively induced ovulation in the Atlantic croaker (Micropogonias undulatus ); 37 of 40 (92%) females were successfully hand-stripped and there was no mortality. A single dose of human chorionic gonadotropin (hCG; 500 IU/kg body weight) was successful in inducing oocyte hydration. However, only 16 of 30 (53%) females ovulated successfully and could be hand-stripped. Another 8 females became extremely bloated and died. Thus LHRHa was shown to be the more reliable method of inducing ovulation in the Atlantic croaker. The response interval between hormone treatment and ovulation at different water temperatures was also determined.     

Spermatozoal ultrastructures of two marine perciform teleost fishes, the goatfish, Paraupeneus spilurus (Mullidae) and the rabbitfish, Siganus fuscescens (Siganidae) from Taiwan

Mature spermatozoa of two perciform teleost fishes, Paraupeneus spilurus (Mullidae) and Siganus fuscescens (Siganidae) from Taiwan were examined using transmission and scanning electron microscopy. Despite the fact that spermatozoa of both species are of the primitive type, the results of the present study highlight the potential application of spermatozoal morphology in studies of fish phylogenetic relationships. To our knowledge, the flattened nucleus observed in P. spilurus spermatozoa is reported for the first time. Several features common to Sigandae spermatozoa-the unusual almost parallel situation of the centrioles, the arrangement of mitochondria and the near absence of shallow nuclear fossa-are significantly different from other common teleost sperm types. These unique features may be synapomorphies for the Siganidae and Mullidae and evidently contribute to the study of phylogenetic relationships in teleosts.     

Ethyl pyruvate attenuates ventilation‐induced diaphragm dysfunction through high‐mobility group box‐1 in a murine endotoxaemia model

Mechanical ventilation (MV) can save the lives of patients with sepsis. However, MV in both animal and human studies has resulted in ventilator‐induced diaphragm dysfunction (VIDD). Sepsis may promote skeletal muscle atrophy in critically ill patients. Elevated high‐mobility group box‐1 (HMGB1) levels are associated with patients requiring long‐term MV. Ethyl pyruvate (EP) has been demonstrated to lengthen survival in patients with severe sepsis. We hypothesized that the administration of HMGB1 inhibitor EP or anti‐HMGB1 antibody could attenuate sepsis‐exacerbated VIDD by repressing HMGB1 signalling. Male C57BL/6 mice with or without endotoxaemia were exposed to MV (10 mL/kg) for 8 hours after administrating either 100 mg/kg of EP or 100 mg/kg of anti‐HMGB1 antibody. Mice exposed to MV with endotoxaemia experienced augmented VIDD, as indicated by elevated proteolytic, apoptotic and autophagic parameters. Additionally, disarrayed myofibrils and disrupted mitochondrial ultrastructures, as well as increased HMGB1 mRNA and protein expression, and plasminogen activator inhibitor‐1 protein, oxidative stress, autophagosomes and myonuclear apoptosis were also observed. However, MV suppressed mitochondrial cytochrome C and diaphragm contractility in mice with endotoxaemia (P < 0.05). These deleterious effects were alleviated by pharmacologic inhibition with EP or anti‐HMGB1 antibody (P < 0.05). Our data suggest that EP attenuates endotoxin‐enhanced VIDD by inhibiting HMGB1 signalling pathway.     

Cost-Effectiveness of Aspirin Adjuvant Therapy in Early Stage Colorectal Cancer in Older Patients

Background & Aims

Recent observational studies showed that post-operative aspirin use reduces cancer relapse and death in the earliest stages of colorectal cancer. We sought to evaluate the cost-effectiveness of aspirin as an adjuvant therapy in Stage I and II colorectal cancer patients aged 65 years and older.

Methods

Two five-state Markov models were constructed separately for Stage I and II colorectal cancer using TreeAge Pro 2014. Two hypothetical cohorts of 10,000 individuals at a starting age of 65 years and with colorectal cancer in remission were put through the models separately. Cost-effectiveness of aspirin was evaluated against no treatment (Stage I and II) and capecitabine (Stage II) over a 20-year period from the United States societal perspective. Extensive one-way sensitivity analyses and multivariable Probabilistic Sensitivity Analyses (PSA) were performed.

Results

In the base case analyses, aspirin was cheaper and more effective compared to other comparators in both stages. Sensitivity analyses showed that no treatment and capecitabine (Stage II only) can be cost-effective alternatives if the utility of taking aspirin is below 0.909, aspirin’s annual fatal adverse event probability exceeds 0.57%, aspirin’s relative risk of disease progression is 0.997 or more, or when capecitabine’s relative risk of disease progression is less than 0.228. Probabilistic Sensitivity Analyses (PSA) further showed that aspirin could be cost-effective 50% to 80% of the time when the willingness-to-pay threshold was varied from USD20,000 to USD100,000.

Conclusion

Even with a modest treatment benefit, aspirin is likely to be cost-effective in Stage I and II colorectal cancer, thus suggesting a potential unique role in secondary prevention in this group of patients.     

Cryopreservation of Atlantic croaker spermatozoa: evaluation of morphological changes.

The spermatozoon of the Atlantic croaker (Micropogonias undulatus) is a primitive type in that it lacks an acrosome. The kidney-shaped head has a diameter of about 1.5 microns and is occupied by a granular and electron-dense nucleus. The short midpiece contains 3 spherical mitochondria and encircles the basal body of the flagellum but is separated from it. The flagellum consists of the typical 9 + 2 axoneme and surrounding plasma membrane but lacks a lateral ridge. Spermatozoa of Atlantic croaker diluted in either NaCl or sodium citrate solutions with or without DMSO were examined with the electron microscope before freezing in liquid nitrogen and after thawing. Damage following cryopreservation appeared to be greater to the mitochondria, plasma membrane, and 9 + 2 axoneme than to the nucleus. The incidence of postthaw damage in spermatozoa diluted with NaCl solutions containing DMSO was remarkably lower than that with either pure NaCl solutions, pure sodium citrate solutions, or sodium citrate solutions containing DMSO.     

Ultrastructure of the spermatozoon of the teleost fish Acanthopagrus schlegeli (Perciformes: Sparidae)

Ultrastructurally the spermatozoon of Acanthopagrus schlegeli (Sparidae) has a spherical, homogeneously electron-dense nucleus with a deep axial nuclear fossa, and an unusual notch, shaped like a bowtie, in the nuclear region. The short midpiece contains four spherical mitochondria and encircles the basal body of the flagellum. It is concluded that the spermatozoon is of a primitive type, although it is characterized by several unique features which may provide useful systematic characters. © 1993 Wiley-Liss, Inc.     

Cystic fibrosis: II. Altered microviscosity of erythrocyte membrane

Erythrocyte membrane fluidity alterations in cystic fibrosis are described. The relative flexibility of the membrane was studied using lipid spin label, i.e. methyl-5-doxylpalmitate (M5DP), and pyrene as a fluorescence probe. It was found that there was a decrease of membrane fluidity in the hydrophobic midzone of the membrane, probed by pyrene, as well as at the hydrophilic surface region, probed by M5DP.     

Phylogeography of a salmonid fish,masu salmon Oncorhynchus masou subspecies-complex,with disjunct distributions across the temperate northern Pacific

1. Climate oscillations during the Pleistocene had profound effects on the evolutionary history of freshwater fishes now distributed across northern temperate regions. The extent of continental glaciation on the western side of the North Pacific, including areas of East Asia, was more limited as compared with regions of North America, Europe and high-latitude areas of the North Pacific. Therefore, the effects of climate oscillations might have influenced species in dissimilar ways depending on the species' distribution.
2. We used mitochondrial DNA (mtDNA) and microsatellite DNA (msDNA) markers to clarify the evolutionary history of masu salmon Oncorhynchus masou subspecies-complex (family Salmonidae) distributed in historically non-glaciated regions in the western North Pacific.
3. No marked regional or subspecies-specific mtDNA haplotype associations were recognised, except for O. masou subsp., a lacustrine form endemic to Lake Biwa, an ancient lake in central Honshu. The landlocked subspecies O. masou formosanus, with a disjunct distribution on Taiwan Island, exhibited no diagnostic population features differing from the other subspecies, in either mtDNA or msDNA markers. Mismatch distribution and Bayesian skyline plot analyses indicated relatively recent range expansion and rapid population growth for masu salmon during the last glacial period (c. 0.1–0.15 Ma).
4. Contrary to the mtDNA genealogy, Bayesian clustering using msDNA showed two main genetic clusters, mainly northern populations of the subspecies O. m. masou and populations of the subspecies O. m. ishikawae in southern areas of the Japanese Archipelago. Notably, O. m. formosanus on Taiwan Island was included in the O. m. masou group, and O. masou subsp. was included in the O. m. ishikawae group.
5. Our results suggest that the masu salmon subspecies-complex in historically non-glaciated regions of the Temperate Northern Pacific is characterised by weak population structuring and shallow genetic differentiation among the subspecies, except for O. masou subsp. owing to its long isolation in Lake Biwa. Incomplete lineage sorting and historical inter-subspecies hybridisation, possibly due to secondary contact, seem to be plausible explanations for discrepancies in the mitochondrial DNA genealogy and nuclear DNA genetic structure.