The Hormonal Control of Uterine Luminal Fluid Secretion and Absorption

GABA_A receptors composed of α, β and γ subunits display a significantly higher single-channel conductance than receptors comprised of only α and β subunits. The pore of GABA_A receptors is lined by the second transmembrane region from each of its five subunits and includes conserved threonines at the 6′, 10′ and 13′ positions. At the 2′ position, however, a polar residue is present in the γ subunit but not the α or β subunits. As residues at the 2′, 6′ and 10′ positions are exposed in the open channel and as such polar channel-lining residues may interact with permeant ions by substituting for water interactions, we compared both the single-channel conductance and the kinetic properties of wild-type α1β1 and α1β1γ2S receptors with two mutant receptors, αβγ(S2′A) and αβγ(S2′V). We found that the single-channel conductance of both mutant αβγ receptors was significantly decreased with respect to wild-type αβγ, with the presence of the larger valine side chain having the greatest effect. However, the conductance of the mutant αβγ receptors remained larger than wild-type αβ channels. This reduction in the conductance of mutant αβγ receptors was observed at depolarized potentials only (E_Cl = −1.8 mV), which revealed an asymmetry in the ion conduction pathway mediated by the γ2′ residue. The substitutions at the γ2′ serine residue also altered the gating properties of the channel in addition to the effects on the conductance with the open probability of the mutant channels being decreased while the mean open time increased. The data presented in this study show that residues at the 2′ position in M2 of the γ subunit affects both single-channel conductance and receptor kinetics.     

Protein-alginate gel for enzyme immobilisation

Summary Propylene glycol alginate forms strong, covalently bonded gel when mixed with certain proteins in alkaline conditions. Enzymes can be immobilised onto the alginate ester before gelating with protein to form the above gel. Some data on the immobilisation of -glucosidase are presented.     

16S rRNA metagenomic analysis of the symbiotic community structures of bacteria in foregut,midgut, and hindgut of the wood-feeding termite <Emphasis Type="Italic">Bulbitermes</Emphasis> sp.

The termite gut is a highly structured microhabitat with physicochemically distinct regions. It is generally separated into the foregut, midgut and hindgut. The distribution of gut microbiota is greatly influenced by varying physicochemical conditions within the gut. Thus, each gut compartment has a unique microbial population structure. In this study, the bacterial communities of foregut, midgut and hindgut of wood-feeding higher termite, Bulbitermes sp. were analyzed in detail via metagenomic sequencing of the 16S rRNA V3-V4 region. While the microbiomes of the foregut and midgut shared a similar taxonomic pattern, the hindgut possessed more diverse bacterial phylotypes. The communities in the foregut and midgut were dominated by members of the group Bacilli and Clostridia (Firmicutes) as well as taxon Actinomycetales (Actinobacteria). The main bacterial lineage found in hindgut was Spirochaetaceae (Spirochaetes). The significant difference among the three guts was the relative abundance of the potential lignin-degrading bacteria, Actinomycetales, in both the foregut and midgut. This suggests that lignin modification was probably held in the anterior part of termite gut. Predictive functional profiles of the metagenomes using 16S rRNA marker gene showed that cell motility, energy metabolism and metabolism of cofactors and vitamins were found predominantly in hindgut microbiota, whereas xenobiotics degradation and metabolism mostly occurred in the foregut segment. This was compatible with our 16S rRNA metagenomic results showing that the lignocellulose degradation process was initiated by lignin disruption, increasing the accessibility of celluloses and hemicelluloses.     

Nodamura virus B2 amino terminal domain sensitivity to small interfering RNA

Nodamura virus (NoV) B2, a suppressor of RNA interference, binds double stranded RNAs (dsRNAs) and small interfering RNAs (siRNAs) corresponding to Dicer substrates and products. Here, we report that the amino terminal domain of NoV B2 (NoV B2 79) specifically binds siRNAs but not dsRNAs. NoV B2 79 oligomerizes on binding to 27 nucleotide siRNA. Mutation of the residues phenylalanine49 and alanine60 to cysteine and methionine, respectively enhances the RNA binding affinity of NoV B2 79. Circular dichroism spectra demonstrated that the wild type and mutant NoV B2 79 have similar secondary structure conformations.     

Taxonomic rearrangement of the genus Ulkenia sensu lato based on morphology, chemotaxonomical characteristics, and 18S rRNA gene phylogeny (Thraustochytriaceae, Labyrinthulomycetes): emendation for Ulkenia and erection of Botryochytrium, Parietichytrium, and Sicyoidochytrium gen. nov.

The genus Ulkenia is characterized by the naked protoplast stage within its life cycle. However, the 18S rRNA gene tree clearly shows that this genus is not a natural taxon, because our own isolates and reported strains separately form four well-supported monophyletic groups. These four groups are clearly distinguishable by their profiles of polyunsaturated fatty acids and carotenoid pigments and cell and colony morphology, e.g., persistence of sporangial wall, manner of the cell cleavage at the zoospore formation, and development of the ectoplasmic nets. Therefore, the four groups are assigned to four genera including three new genera, i.e., Ulkenia sensu stricto, Botryochytrium, Parietichytrium, and Sicyoidochytrium gen. nov.     

Isolation of the crude oil degrading marine Acinetobacter sp. E11

The Acinetobacter sp. E11, isolated from Port Dickson Beach, Malaysia, was able to grow in media containing crude oil as the sole carbon and energy source. Substrate specificity studies showed that the bacterium exhibited substrate preference as growth was observed only in media containing aliphatic hydrocarbons, while aromatic and cyclic hydrocarbons inhibited growth. With the aliphatic hydrocarbons, growth was seen only in the long-chain alkanes tested (pentadecane, dodecane and hexadecane). No growth was recorded in the short-chain alkanes (pentane, hexane and heptane) tested. With complex hydrocarbons, only crude oil and 4T SHELL engine oil supported growth. No growth was observed in kerosene and PETRONAS gasoline. The isolate could grow in up to 10% and 20% [v/v] of the crude oil and alkanes tested, respectively. Among the long-chain alkanes tested, hexadecane was the most preferred, followed by pentadecane and dodecane. Nitrogen and phosphorous supplements were essential for growth and the best growth was achieved with 3% nitrogen/phosphorous additions. Microscopic observation revealed that the bacterium adhered to the hexadecane and crude oil droplets. GC analysis showed that the bacterium was able to degrade more than 60% of the hydrocarbons in the crude oil in 15 days at 37°C compared to the uninoculated media.     

Study of sexual behaviours with different types of estrus synchronization protocols in Boer goats

There is still a lack of information on estrus synchronization in goats. Understanding the estrus synchronization protocols and the subsequent effects is important to improve the efficiency of assisted reproductive technologies (ARTs) and subsequently would improve the breeding procedures. This study will help in determining the most suitable estrus synchronization protocol and understand better the effect on the sexual behaviour and hormonal effects in goats. A total of 127 Boer does were used and divided into three groups with different duration of CIDR insertion intravaginally either for 14 (two groups) or 9 days (one group). Approximately 0.5 ml Estrumate^® (PG) was administered intramuscularly to all groups at CIDR removal, and only groups PMSG14 and PMSG9 were administered with 200IU of Pregnant Mare Serum Gonadotropin (PMSG) intramuscularly. Estrus signs were observed at 4 h intervals and blood samples were collected for progesterone and luteinizing hormone determination. The percentage of does in estrus within 24 to 72 h post CIDR removal was significantly higher (P<0.05) in groups with PMSG compared to the group without the PMSG. The numbers of does display estrus signs within 24 to 28 h post CIDR removal were significantly higher (P<0.05) in group shorter period (9 days) compared to groups with 14 days CIDR. The P4 concentrations at 24 hours post CIDR removals and LH concentration was not significantly different (P>0.05) in all groups. The time of the LH peak in the group without the PMSG was significantly delayed (P<0.05) when compared to group 9 days CIDR and administered with PMSG. It is recommended to use the treatment for 9 days CIDR since the estrous cycle can be shortened.     

Glibenclamide or metformin combined with honey improves glycemic control in streptozotocin-induced diabetic rats

Diabetes mellitus is associated with deterioration of glycemic control and progressive metabolic derangements. This study investigated the effect of honey as an adjunct to glibenclamide or metformin on glycemic control in streptozotocin-induced diabetic rats. Diabetes was induced in rats by streptozotocin. The diabetic rats were randomized into six groups and administered distilled water, honey, glibenclamide, glibenclamide and honey, metformin or metformin and honey. The animals were treated orally once daily for four weeks. The diabetic control rats showed hypoinsulinemia (0.27 ± 0.01 ng/ml), hyperglycemia (22.4 ± 1.0 mmol/L) and increased fructosamine (360.0 ± 15.6 μmol/L). Honey significantly increased insulin (0.41 ± 0.06 ng/ml), decreased hyperglycemia (12.3 ± 3.1 mmol/L) and fructosamine (304.5 ± 10.1 μmol/L). Although glibenclamide or metformin alone significantly (p < 0.05) reduced hyperglycemia, glibenclamide or metformin combined with honey produced significantly much lower blood glucose (8.8 ± 2.9 or 9.9 ± 3.3 mmol/L, respectively) compared to glibenclamide or metformin alone (13.9 ± 3.4 or 13.2 ± 2.9 mmol/L, respectively). Similarly, glibenclamide or metformin combined with honey produced significantly (p < 0.05) lower fructosamine levels (301.3 ± 19.5 or 285.8 ± 22.6 μmol/L, respectively) whereas glibenclamide or metformin alone did not decrease fructosamine (330.0 ± 29.9 or 314.6 ± 17.9 μmol/L, respectively). Besides, these drugs or their combination with honey increased insulin levels. Glibenclamide or metformin combined with honey also significantly reduced the elevated levels of creatinine, bilirubin, triglycerides, and VLDL cholesterol. These results indicate that combination of glibenclamide or metformin with honey improves glycemic control, and provides additional metabolic benefits, not achieved with either glibenclamide or metformin alone.     

Detection and identification of antibiotic biosynthesis genes in Bacillus subtilis strains

Two Bacillus subtilis strains L10 and G1, previously isolated from fermented pickles, were tested for antibacterial activity against Vibrio harveyi using a well-diffusion agar assay. Antibiotic biosynthesis genes were then detected in both bacterial strains and included the following genes: bacA, bacB and bacD genes for bacilysin production, ppsE/fenB gene for plipastatin/fengycin production, albF and albA genes for subtilosin production, and srfAB and sfP genes for surfactin production. Based on these results, two B. subtilis strains could be considered as potential biological control agents in aquaculture.     

Molecular Dynamics Study of the Structure,Flexibility and Dynamics of Thermostable L1 Lipase at High Temperatures

Molecular Dynamics (MD) simulations have been used to understand how protein structure, dynamics, and flexibility are affected by adaptation to high temperature for several years. We report here the results of the high temperature MD simulations of Bacillus stearothermophilus L1 (L1 lipase). We found that the N-terminal moiety of the enzyme showed a high flexibility and dynamics during high temperature simulations which preceded and followed by clear structural changes in two specific regions; the small domain and the main catalytic domain or core domain of the enzyme. These two domains interact with each other through a Zn²⁺-binding coordination with Asp-61 and Asp-238 from the core domain and His-81 and His-87 from the small domain. Interestingly, the His-81 and His-87 were among the highly fluctuated and mobile residues at high temperatures. The results appear to suggest that tight interactions of Zn²⁺-binding coordination with specified residues became weak at high temperature which suggests the contribution of this region to the thermostability of the enzyme. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.