L-Kynurenine, an amino acid identified as a sex pheromone in the urine of ovulated female masu salmon

Many animals employ sex pheromones to find mating partners during their reproductive seasons. However, most sex pheromones of vertebrates remain to be identified. Over the past 20 years, steroids and prostaglandins have been identified as sex pheromones in several fishes. These pheromones are broadly termed "hormonal pheromones" because they or their precursors act as hormones in these fishes. Hitherto, no other type of sex pheromone has been unambiguously identified in teleost fish. Here we report the identification of a "nonhormonal pheromone" in teleost fish. The urine of the reproductively mature female masu salmon (Oncorhynchus masou) contains a male-attracting pheromone. Bioassay-guided fractionation yielded an active compound that was identical to L-kynurenine in spectral and chromatographic properties. L-Kynurenine is a major metabolite of L-tryptophan in vertebrates. This pheromone elicits a male-specific behavior at even picomolar concentrations; its electrophysiological threshold is 10(-14) M. L-Kynurenine is a reasonable substance for female masu salmon to advertise their readiness for mating.     

Adult T-cell leukemia/lymphoma in a 21-year-old man

Adult T-cell leukemia/lymphoma (ATL) is malignancy of mature T cells that caused by infection with human T-cell leukemia virus type I (HTLV-I). Leukemogenesis of ATL cells considered to involve a multistep oncogenic process, resulting in a very long latency period. But, we report here the case of a 21-year-old man having suffered from recurrent stomatititis who has already developed acute-type ATL. ATL generally occurs after a long latency period, and the present case in a young man is thus very rare.     

A 90-day oral toxicity study of nisin A,an anti-microbial peptide derived from Lactococcus lactis subsp. lactis,in F344 rats

This study was designed to evaluate and characterize any adverse effect of nisin A, when administered to both sexes of F344/DuCrlCrlj rats (10 males and 10 females in each group) at dietary levels of 0%, 0.2%, 1.0% and 5.0% for 90 days. Animals given NaCl at a dietary level of 3.712% (equivalent to the NaCl content in 5.0% nisin A diet) served as a reference material treated group.There were no deaths, and the treatment had no toxicologically significant effects on clinical signs, body weights, food consumption, ophthalmology, hematology, or gross pathology.Statistically significant increases of water consumption, urine volume, and urinary sodium and chlorine, and decreases of urinary potassium and serum sodium, along with increases of absolute and relative kidney weight, and incidences of minimal squamous cell hyperplasia of limiting ridge in the forestomach, were found in nisin A-treated groups. It was considered that these changes were related to NaCl, since they were also noted in rats given diet containing the reference substance.Thus, no toxicologically significant changes were apparent in both sexes of F344/DuCrlCrlj rats fed diet containing 0%, 0.2%, 1.0% and 5.0% nisin A for 90 days. Therefore, the no-observed-adverse-effect level (NOAEL) for nisin A was concluded to be a dietary level of 5.0% (2996 mg/kg/day for males and 3187 mg/kg/day for females).     

Thoracoscopic resection of congenital cystic adenomatoid malformation in an adolescent

Congenital cystic adenomatoid malformation (CCAM) in adolescents or adults is extremely rare. In this case study, a 17‐year‐old boy was admitted to our clinic for the treatment of a giant bulla in the lower lobe of the right lung. Preoperative imaging studies led to the diagnosis of cystic lung disease. The patient underwent wedge resection of the right lower lobe with VATS, and histological examination confirmed the presentation of type 1 CCAM. A thoracoscopic lobectomy was performed after the second surgery because of postoperative air leakage.Herein, we report a case of CCAM in an adolescent. VATS was a suitable procedure for the operation. Between the parenchyma‐saving resection and lobectomy for CCAM, we believe that the lobectomy is the better treatment option when the extent of the disease cannot be determined clearly or it is extremely large. Therefore, strategies for deciding between parenchyma‐saving resection and lobectomy for the treatment of CCAM should be developed.     

Ethanol-induced apoptosis in human liver adenocarcinoma cells (SK-Hep1): Fas- and mitochondria-mediated pathways and interaction with MAPK signaling system

For studying molecular mechanisms regulating the fate of ethanol-treated hepatocytes, involvement of Fas in ethanol-induced apoptosis was examined in human liver adenocarcinoma (SK-Hep1) cells in which the function of Fas-associated death domain (FADD) protein was knocked down by transfection. In FADD-knocked down cells, while ethanol-induced increase in generation of reactive oxygen species (ROS) was unaffected, apoptosis was significantly suppressed, demonstrating the involvement of Fas in ethanol-induced hepatocyte apoptosis more directly than in the past reports. On the other hand, effects of mitogen-activated protein kinase (MAPK), which is well known to determine the fate of various cells, on ethanol-induced apoptosis have not been examined in SK-Hep1 cells. Of three major MAPKs, only p38 MAPK and JNK were found activated by 200 mM ethanol treatment. When cells were incubated with inhibitors of p38 MAPK and JNK, ethanol-induced apoptosis was decreased while ROS generation was unaffected, and examination of pro-apoptotic Bax and anti-apoptotic Bcl-2 levels showed decrease of the former and increase of the latter. We concluded that oxidative stress inflicted by ROS triggered Fas-mediated and mitochondria-mediated apoptotic pathways in ethanol-treated SK-Hep1 cells, and that p38 MAPK and JNK were promoting mitochondrial pathway, suggesting interaction between apoptosis and MAPK signaling systems.     

Usefulness of a colorimetric method for testing antifungal drug susceptibilities of Aspergillus species to voriconazole

 The usefulness of a colorimetric method using Alamar Blue (Alamar Blue method) for susceptibility testing of Aspergillus species to voriconazole and three existing antifungal agents, itraconazole (ITCZ), flucytosine (5-FC), and amphotericin B (AMPH-B), was studied using four ATCC strains of three species, including two strains of A. fumigatus and one each of A. flavus and A. niger. For comparison, the broth microdilution method for antifungal susceptibility testing of filamentous fungi proposed by the National Committee for Clinical Laboratory Standards (NCCLS method M38-P) was also used. Minimun inhibitory concentration (MIC) endpoints were read spectrophotometrically for the Alamar Blue method and visually for the NCCLS method after 46–50 h. Like the NCCLS method, Alamar Blue produced highly reproducible results for all the drugs and strains tested; most MIC values obtained by nine tests were within the range of 2 twofold dilutions for each strain. Voriconazole and ITCZ susceptibility testing with the Alamar Blue method and the NCCLS method yielded comparable results in 94% of the tests, meaning that the endpoints obtained were identical or differed by no more than 2 twofold dilutions. On the other hand, susceptibility testing for 5-FC and AMPH-B yielded scores of 25% and 64%, respectively. Our study suggests the potential value of the Alamar Blue method as a convenient alternative to the NCCLS M38-P method for routine testing of Aspergillus species susceptibility to at least voriconazole and ITCZ. Received: April 22, 2002 / Accepted: July 23, 2002