Activity budget and diet of patas monkeys in Kala Maloue National Park,Cameroon: A preliminary report

A preliminary study was carried out on the feeding ecology of patas monkeys in the rainy season in Cameroon. Their daily activity rhythm revealed two active peaks. The proportion of time spent on feeding with respect to waking time was 30%. Patas monkeys largely depended on the flowers and buds of herbaceous plants and the larvae of insects for their diet as they ranged widely. Patas monkeys spent more time in feeding and travelled for a longer distance per day than the sympatric primate species, the tantalus monkey. It is considered that these findings reflected the large amount of food requirement due to the large body size, as well as the low density and high degree of dispersal of their food.     

Monocyte-derived neutrophil chemotactic factor (MDNCF/IL-8) resides in a gene cluster along with several other members of the platelet factor 4 gene superfamily

Summary Monocyte-derived neutrophil chemotactic factor (MDNCF/IL-8, suggested gene symbol IL8) is a cytokine that chemoattracts and activates neutrophils. Using a panel of human-rodent cell hybrids that preferentially segregate human chromosomes and in situ hybridization, the MDNCF/IL-8 gene was placed on the human gene map at position 4q12-q21. This is the same location where at least three other members (platelet factor 4, melanoma growth stimulatory activity, and interferon- induced factor) of the platelet factor 4 gene superfamily reside. In addition, a restriction fragment length polymorphism was identified using MDNCF as a probe in screening genomic DNA digested with HindIII from unrelated individuals.On leave from Genetics Section, Instituto Nacional do Cancer (RJ)/ Department of Genetics, Universidade Federal do Rio de Janeiro, Brazil     

Modulation-Specific and Laminar-Dependent Effects of Acetylcholine on Visual Responses in the Rat Primary Visual Cortex

Acetylcholine (ACh) is secreted from cholinergic neurons in the basal forebrain to regions throughout the cerebral cortex, including the primary visual cortex (V1), and influences neuronal activities across all six layers via a form of diffuse extrasynaptic modulation termed volume transmission. To understand this effect in V1, we performed extracellular multi-point recordings of neuronal responses to drifting sinusoidal grating stimuli from the cortical layers of V1 in anesthetized rats and examined the modulatory effects of topically administered ACh. ACh facilitated or suppressed the visual responses of individual cells with a laminar bias: response suppression prevailed in layers 2/3, whereas response facilitation prevailed in layer 5. ACh effects on the stimulus contrast-response function showed that ACh changes the response gain upward or downward in facilitated or suppressed cells, respectively. Next, ACh effects on the signal-to-noise (S/N) ratio and the grating-phase information were tested. The grating-phase information was calculated as the F1/F0 ratio, which represents the amount of temporal response modulation at the fundamental frequency (F1) of a drifting grating relative to the mean evoked response (F0). In facilitated cells, ACh improved the S/N ratio, while in suppressed cells it enhanced the F1/F0 ratio without any concurrent reduction in the S/N ratio. These effects were predominantly observed in regular-spiking cells, but not in fast-spiking cells. Electrophysiological and histological findings suggest that ACh promotes the signaling of grating-phase information to higher-order areas by a suppressive effect on supragranular layers and enhances feedback signals with a high S/N ratio to subcortical areas by a facilitatory effect on infragranular layers. Thus, ACh distinctly and finely controls visual information processing in a manner that is specific for the modulation and cell type and is also laminar dependent.     

Feeding strategies of Japanese monkeys against deterioration of habitat quality

Field observations of the feeding behaviour of Japanese monkeys were carried out from autumn to winter on Kinkazan Island which is covered with cool temperate forest. As a result, the following two points became clear: (1) the available food items were fixed for a long time; and (2) the habitat quality deteriorated monotonously because the monkeys themselves or their competitors, such as wild mice, utilized the food resources. Against the decrease in food intake caused by this deterioration of the habitat quality, the monkeys controlled the decrease in food intake by employing the following strategies: (1) they recovered their feeding speed by exploiting new food patches (patch-increase strategy); (2) they extended the time spent on feeding (time-extension strategy); and (3) they changed their food (food-change strategy). The former two strategies operated earlier than the third one.     

Genus-specific and phase-dependent effects of nitrate on a sulfate-reducing bacterial community as revealed by dsrB-based DGGE analyses of wastewater reactors

The biogenic production of hydrogen sulfide is a serious problem associated with wastewater treatment. The aim of this study was to investigate the inhibitory effect of nitrate on the dynamics of sulfate-reducing bacteria (SRB) community in a laboratory-scale wastewater reactor, originating from a denitrifying plant using activated sludge. For this purpose, denaturing gradient gel electrophoresis (DGGE) analysis targeting the dsrB (dissimilatory sulfite reductase) gene was used in combination with chemical analyses and measurement of oxidation and reduction potential (ORP). The reactors were initially dosed with 1.0 and 4.0 g/L potassium nitrate and anaerobically incubated for 490 h. Addition of 4.0 g/L nitrate to the reactor was associated with a prolonged inhibition (over 300 h, i.e., 12.5 days) of sulfate reduction and this was consistent with a rapid decrease in ORP associated with nitrate depletion. The DGGE analysis revealed that nitrate addition remarkably attenuated a distinct group of dsrB related to Desulfovibrio, whereas other dsrB groups were not influenced. Furthermore, another sulfate reduction by Syntrophobacter in the later stages of the incubation period occurred in both reactors (regardless of the nitrate concentration), suggesting that different SRB groups are associated with sulfate reduction at different stages of the wastewater treatment process.     

The AddAB helicase/nuclease forms a stable complex with its cognate chi sequence during translocation

The Bacillus subtilis AddAB enzyme possesses ATP-dependent helicase and nuclease activities, which result in the unwinding and degradation of double-stranded DNA (dsDNA) upon translocation. Similar to its functional counterpart, the Escherichia coli RecBCD enzyme, it also recognizes and responds to a specific DNA sequence, referred to as Chi (chi). Recognition of chi triggers attenuation of the 3'- to 5'-nuclease, which permits the generation of recombinogenic 3'-overhanging, single-stranded DNA (ssDNA), terminating at chi. Although the RecBCD enzyme briefly pauses at chi, no specific binding of RecBCD to chi during translocation has been documented. Here, we show that the AddAB enzyme transiently binds to its cognate chi sequence (chi(Bs): 5'-AGCGG-3') during translocation. The binding of AddAB enzyme to the 3'-end of the chi(Bs)-specific ssDNA results in protection from degradation by exonuclease I. This protection is gradually reduced with time and lost upon phenol extraction, showing that the binding is non-covalent. Addition of AddAB enzyme to processed, chi(Bs)-specific ssDNA that had been stripped of all protein does not restore nuclease protection, indicating that AddAB enzyme binds to chi(Bs) with high affinity only during translocation. Finally, protection of chi(Bs)-specific ssDNA is still observed when translocation occurs in the presence of competitor chi(Bs)-carrying ssDNA, showing that binding occurs in cis. We suggest that this transient binding of AddAB to chi(Bs) is an integral part of the AddAB-chi(Bs) interaction and propose that this molecular event underlies a general mechanism for regulating the biochemical activities and biological functions of RecBCD-like enzymes.     

Urinary liver-type fatty acid binding protein as a useful biomarker in chronic kidney disease

Background: We reported that urinary L-FABP reflected the progression of chronic kidney disease (CKD). This study is aimed to evaluate the clinical significance of urinary liver type fatty acid binding protein (L-FABP) as a biomarker for monitoring CKD. Methods: Urinary L-FABP was measured using human L-FABP ELISA kit (CMIC.Co., Ltd., Tokyo, Japan). The relations between urinary L-FABP and clinical parameters were evaluated in non-diabetic CKD (n = 48) for a year. In order to evaluate the influence of serum L-FABP derived from liver upon urinary L-FABP, both serum and urinary L-FABP were simultaneously measured in patients with CKD (n = 73). Results: For monitoring CKD, the cut-off value in urinary L-FABP was determined as 17.4 μg/g.cr. by using a receiver operating characteristics (ROC) curve. Renal function deteriorated significantly more in patients with ‘high’ urinary L-FABP (n = 36) than in those with ‘low’ L-FABP (n = 12). The decrease in creatinine clearance was accompanied by an increase in urinary L-FABP, but not in urinary protein. Serum L-FABP in patients with CKD was not correlated with urinary L-FABP. Conclusion: Urinary excretion of L-FABP increases with the deterioration of renal function. Serum L-FABP did not influence on urinary L-FABP. Urinary L-FABP may be a useful clinical biomarker for monitoring CKD.