Morphological and Molecular Identification of Spirometra Tapeworms (Cestoda: Diphyllobothriidae) from Carnivorous Mammals in the Serengeti and Selous Ecosystems of Tanzania

Spirometra tapeworms (Cestoda: Diphyllobothriidae) collected from carnivorous mammals in Tanzania were identified by the DNA sequence analysis of the mitochondrial cytochrome c oxidase subunit 1 (cox1) and internal transcribed spacer 1 (ITS1), and by morphological characteristics. A total of 15 adult worms were collected from stool samples and carcasses of Panthera leo, Panthera pardus, and Crocuta crocuta in the Serengeti and Selous ecosystems of Tanzania. Three Spirometra species: S. theileri, S. ranarum and S. erinaceieuropaei were identified based on morphological features. Partial cox1 sequences (400 bp) of 10 specimens were revealed. Eight specimens showed 99.5% similarity with Spirometra theileri ({"type":"entrez-nucleotide","attrs":{"text":"MK955901","term_id":"1796114604","term_text":"MK955901"}}MK955901), 1 specimen showed 99.5% similarity with the Korean S. erinaceieuropaei and 1 specimen had 99.5% similarity with Myanmar S. ranarum. Sequence homology estimates for the ITS1 region of S. theileri were 89.8% with S. erinaceieuropaei, 82.5% with S. decipiens, and 78.3% with S. ranarum; and 94.4% homology was observed between S. decipiens and S. ranarum. Phylogenetic analyses were performed with 4 species of Spirometra and 2 species of Dibothriocephalus (=Diphyllobothrium). By both ML and BI methods, cox1 and ITS1 gave well supported, congruent trees topology of S. erinaceieuropaei and S. theileri with S. decipiens and S. ranarum forming a clade. The Dibothriocephalus species were sisters of each other and collectively forming successive outgroups. Our findings confirmed that 3 Spirometra species (S. theileri, S. ranarum, and S. erinaceieuropaei) are distributed in the Serengeti and Selous ecosystems of Tanzania.     

Partial Characterization of Small Plasmids fromCorynebacterium renale

A naphthalene-degrading strain of corynebacteria, Corynebacterium renale, harbors multiple small plasmids designated pCR1, pCR2, pCR3, and pCR4 with sizes of 1.4, 3.2, 4.4, and 5.7 kb, respectively. Plasmid pCR1 of 1.4 kb is the smallest plasmid reported in this group of bacteria and is present in high copy number. Attempts to clone whole pCR1 in Escherichia coli were unsuccessful but two of its fragments (750 and 650 bp) could be separately cloned in it. The 4.4-kb plasmid, pCR3, bears considerable restriction pattern similarity to a 4.4-kb plasmid belonging to the pBL1 group of cryptic plasmid of corynebacteria but has no sequence homology, suggesting that pCR3 represents a new member of the 4.4-kb group of corynebacterial plasmids.     

Macromolecular synthesis in organ cultures of neonatal rat lung

Organ cultures of newborn rat lungs synthesize and accumulate DNA, RNA, collagen and noncollagenous proteins almost at a linear rate for at least 5 days. During this period the synthesis of collagen consistently exceeds the synthesis of noncollagenous proteins in a pattern similar to neonatal lung growth in vivo. Although some morphological characteristics of lung architecture are distorted after culture, fundamental structural similarities to lungs growing in intact animals are retained. When these cultures are maintained in atmospheres rich in oxygen, increased collagen synthesis is observed, a response similar to that of lungs in intact animals exposed to high oxygen concentrations in vivo. Our studies suggest that lung organ cultures may be a suitable system for investigating the biochemical aspects of lung tissue-environmental interaction. These studies were supported in parts by NIH Grant HL-19668, a contract (68-03-2005) from the U.S. Environmental Protection Agency, and grants from the California Lung Association.     

Palaeocommunity Dynamics and Behavioral Analysis of Conichnus: Bhuj Formation (Lower Cretaceous),Kachchh-India

A palaeocommunity of large Conichnus conicus, a conical, cone-in-cone shaped burrow, created by sea anemones, occurs in medium-grained, crossbedded, well-sorted sandstone in the middle part of the Cretaceous Guneri Member of the Bhuj Formation in India. The trace fossil Conichnus is considered to be a common element of the Skolithos ichnofacies and is interpreted to reflect equilibrium movement in response to substrate aggradation. In the present study, three different varieties of Conichnus conicus are distinguished based on morphology and internal fabric. Community dynamics and burrowing behavior are revealed by inter-burrow relationships, burrow initiation levels and sedimentology. Three types of behavior are envisaged: retrusive equilibrium, protrusive equilibrium response, and escape behavior. Palaeocommunity dynamics show that the tracemakers consisted of only adult organisms that initiated burrows during neap tides and are adapted to feed effectively during weak flow conditions. The occurrence of Conichnus palaeocommunity in the Guneri Member indicates the tidal conditions in a fully marine setting. Results presented herein may aid in the understanding of palaeocommunity dynamics in other shallow marine sequences.     

Effect of cadmium on tissue glutathione and glutathione peroxidase in rats: influence of selenium supplementation.

Administration of cadmium (2.5 mg/kg, sc on alternate days for 3 weeks) to male albino rats led to significant accumulation of cadmium and metallothionein in the liver and kidneys. The activity of glutathione peroxidase was significantly decreased whereas, the concentration of glutathione was increased in these organs. Glycine-l-14C incorporation studies showed enhanced synthesis of glutathione in kidney but not in the liver. Selenium supplementation (1 mg/kg/day orally) failed to prevent these cadmium-induced changes, although it resulted in very high accumulation of selenium in these organs indicating the formation of cadmium-selenium complex.     

Effect of cyanophage N-1 infection on the synthesis and stability ofNostoc muscorum nitrate reductase

The control operative on the nitrate reductase enzyme system of host cyanobacteriumNostoc muscorum was studied after being infected with the cyanophage N-1. Phage infection lifted the host nitrate reductase activity level via accelerating the enzyme synthesis. It was found that the phage-mediated increase in the molybdenum cofactor synthesis was a major contributing factor for apparent elevated nitrate reductase level of the host. This process was inhibited in the presence of erythromycin and tungsten, the inhibitors of protein synthesis and new nitrate reductase synthesis respectively. While the preformed nitrate reductase of healthy cyanobacterium was inhibited by hydrogen peroxide, an oxidizing photosynthetic product, the same enzyme of infected cells remained virtually insensitive to this inhibitor. These data suggest involvement of new nitrate reductase synthesis and its resistance to oxidative inactivation as joint factors controlling the characteristic high enzyme level of host cyanobacterium.     

NADPH production from NADP+ with a glucose dehydrogenase system involving whole cells and immobilized cells of Gluconobacter suboxydans

Summary A convenient and efficient method of NADPH production from NADP⁺ has been established using a glucose dehydrogenase system involving whole cells and immobilized cells of Gluconobacter suboxydans IFO 3172. Using airdried cells of the bacterium, the optimum conditions for NADPH production were examined, including the cell and glucose concentrations, NADP⁺ concentration, pH, buffer and reaction temperature. Under suitable conditions, the conversion ratio and the amount of NADPH accumulated reached about 100% and 73 mg/ml of the reaction mixture, respectively, after 1-h reaction. Intact cells of the bacterium also showed high NADPH production even in the reaction mixture without a surfactant. The addition of Triton X-100 to the reaction mixture and freeze-thawing treatment of intact cells enhanced the production. The NADPH production method was further improved by using cells of the bacterium immobilized by entrapment in a -carrageenan gel lattice. The immobilized cells had almost the same enzymatic properties as the air-dried cells. The conditions for the continuous production of NADPH with an immobilized cell column were also investigated. NADPH was produced in a good yield (about 95%) with this continuous process.