Trends of Air Pollution and Its Present Situation in Hiroshima Prefecture

The ambient concentration of SO₂, NOx and O_x in the atmosphere of Hiroshima, Fukuyama and Fuchu city which were monitored by the prefectural monitoring stations, are examined to give a picture of the typical air pollution at these sites. Results show that the yearly concentrations of SO₂ in these areas are significantly fall from 20 to 6 ppb during 1978–1996 when the NOx concentrations having no such significant change which varies from 40 to 30 ppb. The Photo-chemical Oxidant (Ox) increases annually at the rate of 0.3 ppb to 0.6 ppb in Hiroshima city only. To know the present situation of air pollution the Differential Optical Absorption Spectroscopy (DOAS) system is used in the city of Higashi Hiroshima. The daily average concentrations of SO₂, NO₂, O₃ and HONO measured during the period of August 1999 to March 2000 ranged from 1.4 ppb to 2.8 ppb, 13 ppb to 26.9 ppb, 21 ppb to 53.6 ppb and 1 ppb to 4.3 ppb respectively. The patterns of concentrations of NO₂ and O₃ measured by DOAS look similar to the seasonal patterns of NOx and Ox by the conventional system.     

Multiloculated solitary (unicameral) bone cyst in a young dog

A 20‐month‐old female spayed Staffordshire Terrier (22.3 kg) presented to the Orthopedic Surgery Service at North Carolina State University Veterinary Teaching Hospital for evaluation of a 6‐week history of toe‐touching to nonweight‐bearing lameness in the right hind limb. Radiographs of the right stifle revealed a multiloculated lytic lesion of the distal femur, with a large open lytic zone centrally, numerous osseous septations peripherally, and focal areas of cortical thinning and loss. An aspirate of the right distal femoral lesion yielded mildly cloudy serosanguineous fluid. Cytologic examination of the fluid revealed a pleomorphic population of discrete cells that exhibited marked anisocytosis and anisokaryosis and a variable nuclear‐to‐cytoplasmic (N:C) ratio, which were interpreted as probable neoplastic cells, with few macrophages, and evidence of hemorrhage. Given the clinical signs of pain, lesion size, and concern for malignant neoplasia, amputation of the right hind limb was performed. Histologically, the lesion had undulating walls 1‐3 mm thick with a continuous outer layer of dense fibrous tissue and an inner layer composed of reactive cancellous bone with no cortical compacta remaining. Remnants of thin fibrous or fibro‐osseous septa projected from the bony wall into the cyst lumen. The final histologic diagnosis was a benign multiloculated solitary (unicameral) bone cyst of the distal right femur. Based on the histopathologic findings, it was speculated that the cells identified on cytology were a mixture of developing osteoclasts, osteoblasts, endothelial, and stromal cells. This is the first report describing the cytologic examination of a solitary bone cyst in veterinary medicine.     

RNA干扰技术和家蚕杆状病毒表达系统在纤维素酶研究中的应用前景

植物通过光合作用产生的纤维素是地球上最丰富、最廉价的可再生资源。纤维素酶是糖苷水解酶的一种,能有效地将农作物秸杆等富含纤维素的物质水解为葡萄糖,进而发酵产生生物乙醇,从而解决农业、再生能源以及环境污染等问题。随着生物化学、分子生物学以及基因工程等多种交叉学科的快速发展,获得适合工业化的高活力的纤维素酶指日可待。RNA干扰是利用双链RNA特异性地降解相应序列的mRNA,从而特异性地阻断相应基因的表达,是后基因组时代的一种强有力的调控目的基因表达的实验工具。家蚕杆状病毒表达系统是一种快速、高效表达外源基因的技术手段,目前该系统的发展和应用已经非常成熟。本文综述了纤维素酶的特性以及近年来国内外对纤维素酶、RNA干扰和家蚕杆状病毒表达系统的研究进展,并对该两种实验技术手段在今后纤维素酶研究中的应用前景作了预测和展望。     

Potential of a novel antibiotic, 2-methylheptyl isonicotinate, as a biocontrol agent against fusarial wilt of crucifers

Screening for newer bioactive compounds from microbial metabolites resulted in the isolation of a novel antibiotic from the culture filtrate, Streptomyces sp 201, of a soil. The bioactive compound, with antifungal and antibacterial activity, was identified as 2-methylheptyl isonicotinate. The antifungal activity of live culture, culture broth and the isolated bioactive compound showed marked inhibition against dominant soil-borne phytopathogens such as Fusarium oxysporum Schlect, F moniliforme Sheldon, F semitectum Berkeley & Ravenel, F solani (Martius) Sacc and Rhizoctonia solani Kuehn. The compound had no effect on seed germination and seedling development as displayed by root and stem growth of the test plant species. In pot experiments with seedlings of cruciferous plants such as Raphanus sativus L (radish), Brassica campestris L (yellow mustard), Brassica oleracea var botrytis L (cauliflower), the antibiotic compound showed promising protective activity of 92% when seeds of the test plants were treated at a dose of 50 micrograms ml-1 prior to sowing. Seed treatment with a spore suspension (3 x 10(8) spores ml-1) of the Streptomyces sp 201 displayed protective activity in the range of 56-60%. Seeds coated with 2.5% methyl cellulose-amended spores of the antagonist showed protective activity in the range of 64-72%. Further, seed treatment with the culture filtrate of the antagonist also showed promising protective activity in the range of 64-84%.     

Adherence of Actinobacillus pleuropneumoniae to porcine tracheal epithelial cells and frozen lung sections

The ability of 23 different Actinobacillus pleuropneumoniae isolates to adhere in vitro to porcine tracheal epithelial cells and to porcine frozen lung sections was examined. It was found that A. pleuropneumoniae adhered poorly to isolated tracheal epithelial cells. On the other hand, A. pleuropneumoniae adhered to frozen lung sections and marked variations were observed between and within serotypes. Adherence to lung sections did not seem related to the hemagglutinating activity of the isolate. Two noncapsulated variants adhered to lung sections in greater numbers than their capsulated parent strains. Adherence to lung sections was not inhibited by the extracellular matrix components tested namely, laminin, fibronectin, and collagen, but was inhibited by homologous serotype-specific antiserum. The data indicated that the A. pleuropneumoniae isolates tested possess the ability to adhere to porcine lung tissue, a property which did not seem to be related to the serotype and did not seem to involve the capsular material or the hemagglutinins of the isolates.     

A COMPARISON OF RADIOGRAPHY, COMPUTED TOMOGRAPHY, AND MAGNETIC RESONANCE IMAGING FOR THE DIAGNOSIS OF PALMAR PROCESS FRACTURES IN FOALS

The relative sensitivity of radiography, computed tomography, and magnetic resonance imaging for detecting palmar process fractures of the distal phalanx in foals was determined and the imaging findings were compared with histomorphologic evaluations of the palmar processes. Compared to radiography, computed tomography and magnetic resonance imaging did not improve the sensitivity for detection of palmar process fractures. Statistical agreement for palmar process fracture diagnosis was excellent among the three imaging modalities. Histomorphologic evaluations were more sensitive for diagnosis of palmar process fracture than any of the imaging modalities. Three-dimensional image reconstructions and volume measurements of distal phalanges and palmar process fracture fragments from computed tomography studies provided more complete anatomical information than radiography. Magnetic resonance imaging confirmed that the deep digital flexor tendon insertion on the distal phalanx is immediately axial to the site where palmar process fractures occur, and differentiated cartilage, bone, and soft tissue structures of the hoof.     

Some factors in the separation of polychlorobiphenyls (PCB's) from organochlorine pesticides by column chromatography combined with gas-liquid chromatography

Retention volumes for polychlorobiphenyls (PCB's) and organochlorine pesticides have been measured on “Florisi”^b and silicic acid in various activity states using petroleum spirit eluant. The majority of organochlorine pesticides can be separated from PCB's by column chromatography. The exceptions areheptachlor, aldrin and BHC (apart from the gamma-isomer), and the separation of DDE from PCB's was only achieved with highly active silicic acid. With PCB residues normally found, the separations not secured by column chromatography were obtained by gas chromatography.     

Autoecological Studies on Mottra (Clinogyne dichotomy Salisb)

Clinogyne dichotoma , Salisb, belonging to the family Marantaceae, is a perennial crop with remarkable morphological characteristic. Present study on the anatomical features revealed their adaptability in waterlogged low-lying marshy lands unsuitable for the cultivation of any other crop.