Continuous production of galacto-oligosaccharides from lactose using immobilized β-galactosidase from Bacillus circulans

Summary -Galactosidase-2 (-d-galactoside galactohydrolase, EC 3.2.1.23) from Bacillus circulans was purified using hydroxyapatite gel chromatography and immobilized onto Duolite ES-762 (phenolformaldehyde resin) and Merckogel (controlled pore silica gel) for continuous production of galacto-oligosaccharides using lactose as the substrate. The maximum amount of ologosaccharides produced by the immobilized enzyme was 35–40% of the total sugar during hydrolysis of 4.56% lactose. Partially purified -galactosidase from B. circulans was also immobilized onto various supports for the same purpose. The stability of the immobilized -galactosidase-2 or partially purified enzyme during a continuous reaction depended on their supports and specific activity. Of the supports tested, Merckogel was best for operational stability. With this support, the enzyme was quite stable with specific activity up to 15 units/g of wet gel; it was reversibly inactivated with more.     

A new species of coccinellid feeding on scale insects in West Pakistan

Résumé Les auteurs décriventPseudoscymnus simmondsi, espèce nouvelle deCoccinellidae prédatrice dePinnaspis strachani (Cooley) surFicus palmata au Pakistan occidental. Les autres espèces du genre sont connues seulement de l'Extrême-Orient.

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This research has been financed in part by a grant made by the United States Department of Agriculture, Agricultural Research Service.     

Note on breeding the argentine stem weevilHyperodes bonariensis [Col.: Curculionidae] and its egg parasitePatasson atomarius [Hym.: Mymaridae]

Hyperodes bonariensis Kuschel underwent ovarial diapause from March to August in the Bariloche area in Argentina. Feeding on germinating seedlings ofTriticum aestivum L. andPoa annua L. in continuous dark induced the weevil for oviposition in 24 and 32 days, respectively. Breeding techniques are described forH. bonariensis and its parasitePatasson atomarius (Brethes).     

Salinity induced changes in the reproductive physiology of wheat plants

The effect of salinity on reproductive physiology of wheat wasinvestigated. One set of wheat plants was subjected to increasingsalt levels up to a certain concentration, whereas another setwas given the same concentration in a single application. Theformer was called "gradual" and latter "shock" treatment. Theireffects on pollen viability, germination and activity of starchsynthetase were studied. Gradual treatment seemed to reducethe toxic effects of salts on the viability of pollen grainsand their germination. Seeds obtained from the two sets weregerminated in the same salinities in which their plants hadbeen growing, and the results were compared with those of seedsobtained from control plants growing in a non-saline medium.The seeds of plants from the gradual treatment were better suitedfor germination on a saline medium than those from the shocktreatment or the control group. Salt treatment also increasedthe activity of starch synthetase at the midmilky stage in developinggrains. This phenomenon was considered essential for synthesisof starch in a saline environment. The increase in Na⁺ and Cl^– and decrease in K⁺ contentsof wheat grains in both treatments suggest that the effect ofsalinity on the physiological phenomenon studied is due to changesin the ionic content of the plants. ¹ In partial fulfilment of a Ph.D. degree from the Universityof Karachi, Pakistan. ² Professor of Botany, Director of Research Projects, Head,Plant Physiology Section, University of Karachi, Pakistan. (Received July 11, 1977; )     

The Cerebral Neurosecretory System,Secretory End-Foot System and Infracerebral Gland—a Probable Neuroendocrine Complex in Nephtys (Annelida; Polychaeta)

Abstract The brain of Nephtys contains four neurosecretory cell types with distinctive cytoplasmic inclusions, a cells are located uniquely in a single pair of ganglionic nuclei and b cells are represented by a single pair of cells, whereas c cells and d cells have a scattered distribution. Their axons form two types of secretory release structure. First, possible axon collaterals synapse upon slender “dentritic twigs” in the core of the brain. Secondly, two tracts descend to the brain floor to form a “neurosecretory neuropile” (or storage and release complex) in contact with the inner surface of the brain capsule. Other neurosecretory fibres penetrate through the capsule, branch extensively, and terminate in contact with its ventral surface in close association with the “infracerebral gland”. The gland is derived from the pericapsular epithelium and exhibits signs of specialization for glandular function. In contrast to certain other polychaetes, it does not contain secretory neuron perikarya. The secretory end-foot system is poorly developed. Its terminals are located adjacent to the neurosecretory neuropile, which they encircle. The cell bodies are probably represented by four e cells which, like the terminals, contain many mitochondria.     

The outcome of radiation therapy as a primary treatment in orbital lymphoma: a systematic review

BackgroundThe extranodal marginal-zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) is the most common orbital and adnexal lymphomas. Radiotherapy is one of the most preferred treatment options for orbital lymphomas since they are localized and radiation sensitive. The objective of this study is to evaluate how radiation therapy affected the outcome of orbital MALT lymphoma.Materials and methodsPRISMA guideline was used to conduct this systematic review of electronic databases (PubMed, EMBASE and Cochrane Library), then we assessed the quality of evidence of each paper.ResultsTwenty-five studies were finally included. 94% studies were intended for definitive therapy and almost all of the studies used external radiation sources. The total doses given to the tumor bed ranged from 4 Gy to 55 Gy and were divided into three groups: ultra-low dose (4–6 Gy), standard-dose (24–30.6 Gy), and high-dose (> 30.6 Gy). 75–90% patients showed CR and local relapse was only reported at 3.5–5%. Higher 5-year PFS was reported in the patients group with lens shielding (90.1% vs. 82.1%) and an increase in Meiboscore after RT courses. Toxicities, including dry eye and cataract, were reported in several patients. Acute toxicities subsided gradually over a few months with artificial tears. The risk of early cataract formation increases in patients who received > 30 Gy and lower in the IMRT group.ConclusionRT is a successful primary definitive therapy for low-grade orbital MALT lymphoma, with a high survival rate, low recurrence rate, and typically acceptable toxicity.     

Pandemic strains of O3:K6 Vibrio parahaemolyticus in the aquatic environment of Bangladesh

A total of 1500 environmental strains of Vibrio parahaemolyticus, isolated from the aquatic environment of Bangladesh, were screened for the presence of a major V. parahaemolyticus virulence factor, the thermostable direct haemolysin (tdh) gene, by the colony blot hybridization method using a digoxigenin-labeled tdh gene probe. Of 1500 strains, 5 carried the tdh sequence, which was further confirmed by PCR using primers specific for the tdh gene. Examination by PCR confirmed that the 5 strains were V. parahaemolyticus and lacked the thermostable direct haemolysin-related haemolysin (trh) gene, the alternative major virulence gene known to be absent in pandemic strains. All 5 strains gave positive Kanagawa phenomenon reaction with characteristic beta-haemolysis on Wagatsuma agar medium. Southern blot analysis of the HindIII-digested chromosomal DNA demonstrated, in all 5 strains, the presence of 2 tdh genes common to strains positive for Kanagawa phenomenon. However, the 5 strains were found to belong to 3 different serotypes (O3:K29, O4:K37, and O3:K6). The 2 with pandemic serotype O3:K6 gave positive results in group-specific PCR and ORF8 PCR assays, characteristics unique to the pandemic clone. Clonal variations among the 5 isolates were analyzed by comparing RAPD and ribotyping patterns. Results showed different patterns for the 3 serotypes, but the pattern was identical among the O3:K6 strains. This is the first report on the isolation of pandemic O3:K6 strains of V. parahaemolyticus from the aquatic environment of Bangladesh.     

Isolation and molecular characterization of toxigenic Vibrio parahaemolyticus from the Kii Channel, Japan

Studies were conducted on the ecology of potentially pathogenic Vibrio parahaemolyticus in three coastal areas of Kii Channel, Tokushima, Japan. Seawater and seaweed samples were collected seasonally between June 2003 and May 2004. Total and toxigenic strains of V. parahaemolyticus were isolated using most probable number culture and colony blot hybridization. Toxigenic strains were serotyped and further characterized by random amplified polymorphic DNA (RAPD) and ribotyping. Six thousand strains of V. parahaemolyticus were isolated and 18 were found positive for tdh. V. parahaemolyticus were detected in all samples during summer and autumn, and from some samples during winter and spring. Among the toxigenic strains seven serotypes, five ribotypes and RAPD patterns were observed. Seven strains belonged to O3:K6 clone with identical ribotypes and RAPD patterns to that of a pandemic reference strain. The presence of toxigenic V. parahaemolyticus with pandemic potential might indicate a human health risk due to consumption of marine food sources.