Peak Mating and Breeding Period of the Humpback Whale —(Megaptera novaeangliae) in Okinawa Island, Japan

Although detailed knowledge on breeding ecology of humpback whales is required for developing effective and sustainable whale watching programs in breeding areas, the breeding ecology of this species is still poorly understood. Hence, we examine the migratory timing of humpback whales in Okinawa that is one of their breeding ground, distinguishing the reproductive status (male, female, or female with a calf), group compositions (singleton, pair, or whales more than three) and group types (singer or competitive group) in order to assess the peak period of breeding activities. A total of 1192 days of photo-identification surveys were conducted from 1991 to 2012 and a total of 7366 humpback whales were sighted during the surveys. Among them, 1284 whales were sex-determined (848 males, 147 females and 289 females with a calf), 1138 singletons, 1416 pairs and 710 groups of more than three whales were observed. Females without calves tended to occur from late January to late February, which was the beginning of the breeding season and male-female pairs were observed most frequently during this period. The peak occurrence of competitive group which was considered a mating-related behavior group, formed by females and males, was also observed during this period. These results indicated that humpback whales peak mating period in Okinawa occurred between late January and late February. Females with a calf tended to increase from mid-February toward the end of the breeding season maintaining a high sighting per unit effort (SPUE) value in late March. We, therefore, suggested that the peak time of birthing and newborn care was probably that period in Okinawa. These findings extended our knowledge on the reproductive ecology of humpback whales in Okinawan waters.

α-fetoprotein,vascular endothelial growth factor receptor-1 and early recurrence of hepatoma

AIM:To investigate whether α-fetoprotein (AFP) and vascular endothelial growth factor receptor (VEGFR)-1 correlate with early recurrence of hepatoma/hepatocel-lular carcinoma (HCC).METHODS:From 2000 to 2005,114 consecutive pa-tients with HCC underwent primary curative hepatecto-my.The mean age was 60.7 (8.7) years and 94 patients were male.The median follow-up period was 71.2 mo (range:43-100 mo).Immediately prior to commencing laparotomy,5 mL bone marrow was aspirated from thesternum and collected in citrate-coated test tubes.The initial 2 mL of bone marrow aspirate was discarded in each case.AFP mRNA and VEGFR-1 mRNA in the bone marrow and peripheral blood (BM-and PH-AFP mRNA and BM-and PH-VEGFR-1 mRNA,respectively) were measured by real-time quantitative reverse transcription polymerase chain reaction.As normal controls,VEGFR-1 mRNA in the bone marrow and peripheral blood was also measured in 11 living liver donors.These data were evaluated for any correlation with early recurrence,comparing clinical and pathological outcomes.RESULTS:The cut-off value of the BM-AFP mRNA and PH-AFP mRNA level in patients with HCC was set at 1.92 × 10-7 and zero,respectively,based on data from the controls.A total of 34 (29.8%) and six (5.4%) patients were positive for BM-AFP mRNA and PH-AFP mRNA,respectively.The BM-VEGFR-1 mRNA levels in all HCC patients were higher than those in the normal con-trols,and this was the case also for PH-VEGFR-1mRNA.The 25-percentile values for the BM-and PH-VEGFR-1 mRNA in HCC patients were used as the cut-off values for assigning the patients into two groups based on these transcript levels.The High group for BM-VEG-FR-1 mRNA contained 81 (71.1%) HCC cases and the Low group was assigned 33 (28.9%) patients.These numbers for PH-VEGFR-1mRNA were 78 (75.0%) and 26 (25.0%),respectively.HCC recurred in 80 patients;in the remnant liver in 48 cases,in the remnant liver and remote tissue in 20,and in the remote tissue alone in 12.BM-AFP mRNA-positive cases showed a signifi-cantly higher rate of early recurrence (within 1 year of surgical treatment) compared with BM-AFP mRNA-negative patients (P=0.0091).Patients were classified into four groups according to the level/status of their BM-VEGFR-1 and BM-AFP mRNA as follows:group A (n=23),BM-VEGFR-1/BM-AFP mRNA=low/negative;group B (n=57) high/negative;group C (n=10) low/positive;group D (n=24),high/positive.This classifi-cation was found to correlate with a recurrence of thisdisease within 1 year (P=0.0228).The disease-free survival curve of group A was significantly better than that of groups B,C or D (P=0.0437,P=0.0325,P=0.0225).No other classification (i.e.,PH-VEGF-R1/BM-AFP,BM-VEGF-R1/PH-AFP,and PH-VEGF-R1/PH-AFP mRNA) showed such a correlation.CONCLUSION:The evaluation of BM-AFP and BM-VEG-FR-1 mRNA in patients with HCC may be a valuable pre-dictor of disease recurrence following curative resection.