Seasonality and vertical structure of light-attracted insect communities in a dipterocarp forest in Sarawak

Nocturnal flying insects were collected monthly for 13 months using ultra violet light-traps set at various vertical levels in a weakly-seasonal, tropical lowland dipterocarp forest in Sarawak, Malaysia. Abundance, faunal composition, size distribution and guild structure of these samples were analyzed with respect to temperal and vertical distributions. The nocturnal flying insect community in the canopy level was highly dominated by fig wasps (84%) in individual number, and by scarabaeid beetles (28%) in weight. A principal component analysis on monthly catches detected non-random, seasonal trends of insect abundance. The first two principal trends were an alternation of wetter (September to January) and less wet seasons (February to August) and an alternation between the least wet (January to March) and the other seasons. Many insect groups were less abundant in the least wet season than the other seasons, whilst inverse patterns were found in Scarabaeidae and Tenebrionidae. Significantly positive and negative correlations between monthly catch and rainfall were detected only in ovule-feeders and in phloem-feeders, respectively. Delayed, significant negative correlations between monthly catch and 1–3 month preceding rainfall were more frequently detected in phytophages, phloem-feeders, seed-feeders, wood-borers and scavengers. The peak in abundance along vertical levels were found at the canopy level (35 m) for phloem-, ovule-, seed-, root-, fungal-feeders and nectar collectors, at an upper subcanopy level (25 m) for scavengers and aquatic predators, and at a middle subcanopy level (17 m) for ants. Catches at the emergent level (45 m) did not exceed those at the canopy level.     

Synchronisation of oestrus of goats treated with progestagen-impregnated intravaginal sponges and PMSG,and reproductive performance following natural mating or A.I. with frozen semen

Oestrus was synchronised in 88 goats using progestagen-impregnated intravaginal sponges (60 mg Repromap; Upjohn) left in place for 17 days, followed by intramuscular injection of PMSG (300 i.u.) at sponge withdrawal. The percentages of does that came into oestrus in 0–24, 25–48, 49–72 and 73–96 h periods were 42, 30.5, 10.5 and 6.5 (cumulative 89.5%). The time of onset of oestrus ranged from 16 to 40 h. Breeding at the synchronised oestrus using intact bucks (24–96 h) or artificial insemination with frozen-thawed semen, at fixed times of 24, 48, 72 and 96 h, resulted in 71% and 81% conceptions respectively. Intrauterine deposition of semen was possible in 31.3%, 62.5%, 87.5% and 6.3% of cases at 24, 48, 72 and 96 h respectively. Twinning percentages were 54.5% and 56% for natural mating and artificial insemination. Kidding was spread over a 14-day period with mean gestation lengths of 149 days for singletons and 147 days for twins. The results indicate that use of progestagen-impregnated sponges with PMSG is an efficient method of synchronisation of oestrus and may result in increased fertility in goats and, if used with A.I. with frozen semen, may contribute to increased breeding efficiency and rate of genetic improvement of goats in Asia.     

R54C Mutation of NOTCH3 Gene in the First Rungus Family with CADASIL

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a rare hereditary stroke caused by mutations in NOTCH3 gene. We report the first case of CADASIL in an indigenous Rungus (Kadazan-Dusun) family in Kudat, Sabah, Malaysia confirmed by a R54C (c.160C>T, p.Arg54Cys) mutation in the NOTCH3. This mutation was previously reported in a Caucasian and two Korean cases of CADASIL. We recruited two generations of the affected Rungus family (n = 9) and found a missense mutation (c.160C>T) in exon 2 of NOTCH3 in three siblings. Two of the three siblings had severe white matter abnormalities in their brain MRI (Scheltens score 33 and 50 respectively), one of whom had a young stroke at the age of 38. The remaining sibling, however, did not show any clinical features of CADASIL and had only minimal changes in her brain MRI (Scheltens score 17). This further emphasized the phenotype variability among family members with the same mutation in CADASIL. This is the first reported family with CADASIL in Rungus subtribe of Kadazan-Dusun ethnicity with a known mutation at exon 2 of NOTCH3. The penetrance of this mutation was not complete during the course of this study.     

Value of human amniotic epithelial cells in tissue engineering for cornea

Human amniotic epithelial cells (hAECs) are potentially one of the key players in tissue engineering due to their easy availability. The aim of the present study was to develop an optimal isolation and transportation technique, as well as to determine the immunophenotype and epithelial gene expression of hAECs. Amnion was mechanically peeled off from the chorion and digested with trypsin-ethylenediaminetetraacetic acid. The isolated hAECs were cultured in medium containing 10 ng/mL epidermal growth factor until P4. The epithelial gene expression, cell surface antigen and protein expression of hAECs were analyzed by quantitative polymerase chain reaction, flow cytometry and immunocytochemistry. hAECs were also cultured in adipogenic, osteogenic and neurogenic induction media. The best cell yield of hAECs was seen in the digestion of 15 pieces of amnion (2 × 2 cm) and isolated 30 min after digestion with trypsin. F12:Dulbecco's modified eagle medium was the best medium for short term storage at 4 °C. hAECs expressed CD9, CD44, CD73 and CD90, and negligibly expressed CD31, CD34, CD45 and CD117. After serial passage, CK3, CK19 and involucrin gene expressions were upregulated, while p63, CK1 and CK14 gene expressions were downregulated. Sustained gene expressions of integrin β1 and CK18 were observed. At initial culture, these cells might have stem-like properties. However, they differentiated after serial passage. Nonetheless, hAECs have epithelial stem cell characteristics and have the potential to differentiate into corneal epithelial cells. Further investigations are still needed to elucidate the mechanism of differentiation involved and to optimize the culture condition for long term in vitro culture.     

cMyc is a principal upstream driver of beta-cell proliferation in rat insulinoma cell lines and is an effective mediator of human beta-cell replication

Adult human β-cells replicate slowly. Also, despite the abundance of rodent β-cell lines, there are no human β-cell lines for diabetes research or therapy. Prior studies in four commonly studied rodent β-cell lines revealed that all four lines displayed an unusual, but strongly reproducible, cell cycle signature: an increase in seven G(1)/S molecules, i.e. cyclins A, D3, and E, and cdk1, -2, -4, and -6. Here, we explore the upstream mechanism(s) that drive these cell cycle changes. Using biochemical, pharmacological and molecular approaches, we surveyed potential upstream mitogenic signaling pathways in Ins 1 and RIN cells. We used both underexpression and overexpression to assess effects on rat and human β-cell proliferation, survival and cell cycle control. Our results indicate that cMyc is: 1) uniquely up-regulated among other candidates; 2) principally responsible for the increase in the seven G(1)/S molecules; and, 3) largely responsible for proliferation in rat β-cell lines. Importantly, cMyc expression in β-cell lines, although some 5- to 7-fold higher than normal rat β-cells, is far below the levels (75- to 150-fold) previously associated with β-cell death and dedifferentiation. Notably, modest overexpression of cMyc is able to drive proliferation without cell death in normal rat and human β-cells. We conclude that cMyc is an important driver of replication in the two most commonly employed rat β-cell lines. These studies reverse the current paradigm in which cMyc overexpression is inevitably associated with β-cell death and dedifferentiation. The cMyc pathway provides potential approaches, targets, and tools for driving and sustaining human β-cell replication.     

Stimulation of human endothelium with IL-3 induces selective basophil accumulation in vitro

Basophils have been shown to accumulate in allergic airways and other extravascular sites. Mechanisms responsible for the selective recruitment of basophils from the blood into tissue sites remain poorly characterized. In this study, we characterized human basophil rolling and adhesion on HUVECs under physiological shear flow conditions. Interestingly, treatment of endothelial cells with the basophil-specific cytokine IL-3 (0.01-10 ng/ml) promoted basophil and eosinophil, but not neutrophil, rolling and exclusively promoted basophil adhesion. Preincubation of HUVECs with an IL-3R-blocking Ab (CD123) before the addition of IL-3 inhibited basophil rolling and adhesion, implicating IL-3R activation on endothelial cells. Incubation of basophils with neuraminidase completely abolished both rolling and adhesion, indicating the involvement of sialylated structures in the process. Abs to the beta(1) integrins, CD49d and CD49e, as well as to P-selectin and P-selectin glycoprotein ligand 1, inhibited basophil rolling and adhesion. Furthermore, blocking chemokine receptors expressed by basophils, such as CCR2, CCR3, and CCR7, demonstrated that CCR7 was involved in the observed recruitment of basophils. These data provide novel insights into how IL-3, acting directly on endothelium, can cause basophils to preferentially interact with blood vessels under physiological flow conditions and be selectively recruited to sites of inflammation.     

Anti-amoebic properties of a Malaysian marine sponge <Emphasis Type="Italic">Aaptos</Emphasis> sp<Emphasis Type="Italic">.</Emphasis> on <Emphasis Type="Italic">Acanthamoeba castellanii</Emphasis>

Crude methanol extracts of a marine sponge, Aaptos aaptos, collected from three different localities namely Kapas, Perhentian and Redang Islands, Terengganu, Malaysia, were tested in vitro on a pathogenic Acanthamoeba castellanii (IMR isolate) to examine their anti-amoebic potential. The examination of anti-Acanthamoebic activity of the extracts was conducted in 24 well plates for 72 h at 30 °C. All extracts possessed anti-amoebic activity with their IC₅₀ values ranging from 0.615 to 0.876 mg/mL. The effect of the methanol extracts on the surface morphology of A. castellanii was analysed under scanning electron microscopy. The ability of the extracts to disrupt the amoeba cell membrane was indicated by extensive cell’s blebbing, changes in the surface morphology, reduced in cell size and with cystic appearance of extract-treated Acanthamoeba. Number of acanthapodia and food cup was also reduced in this Acanthamoeba. Morphological criteria of apoptosis in Acanthamoeba following treatment with the sponge’s extracts was determined by acridine orange-propidium iodide staining and observed by fluorescence microscopy. By this technique, apoptotic and necrotic cells can be visualized and quantified. The genotoxic potential of the methanol extracts was performed by the alkaline comet assay. All methanol extracts used were significantly induced DNA damage compared to untreated Acanthamoeba by having high percentage of scores 1, 2, and 3 of the DNA damage. Results from cytotoxicity and genotoxicity studies carried out in the present study suggest that all methanol extracts of A. aaptos have anti-amoebic properties against A. castellanii.