Fluorescence-Activated Cell-Sorting Analysis of Fibronectin Peptides Binding to Trypanosoma cruzi Trypomastigotes1

ABSTRACT. The binding of synthetic peptides modeled from the sequence of the cell attachment site of fibronectin to T. cruzi trypomastigote surface receptors was investigated by fluorescence-activated cell-sorting analysis using fluorescein-labeled peptides. Peptides with the sequence Arg-Gly-Asp-Ser bound to the parasite surface. A low percentage of fresh parasites recently liberated from infected fibroblasts had the capacity to bind the peptide. In contrast, these parasites showed a time-dependent several-fold increase in their ability to bind the Arg-Gly-Asp-Ser-containing peptides during extracellular incubation. From these observations, it appears that the expression of surface receptors on a particular, mature stage of the parasite parallels its ability to adhere to and infect host cells.     

CHEMICAL COMMUNICATION IN INSECT COMMUNITIES: A GUIDE TO INSECT PHEROMONES WITH SPECIAL EMPHASIS ON SOCIAL INSECTS

• 1 Chemical communication plays an important part in the lives of insects, and particularly in lives of those that live in groups or social organizations.
• 2 Chemicals which are used in communication in the general sense are called semiochemicals, and there are a number of subdivisions recognized under this title.
• 3 Pheromones are a category of semiochemicals which are used for communication between individuals of the same species.
• 4 Pheromones are in turn subdivided into primer and releaser pheromones. The former produce a relatively long-lasting physiological change in the receiver, and the latter stimulate the receiver to some immediate behavioural response.
• 5 Far more is known about releaser pheromones at present because they are easier to study.
• 6 Nine categories of releaser pheromone are recognized here, used by both social and non-social insects.
• 7 Sex pheromones are widely used to bring the sexes together for mating, and they have been extensively studied in Lepidoptera.
• 8 Invitation pheromones, encouraging the species to feed or oviposit at an explored site, are not extensively known.
• 9 Aggregation pheromones are designed to bring individuals together into groups which may be temporary in sub-social insects, or permanent in social insects.
• 10 Dispersal or spacing pheromones are used by other species to reduce intraspecific competition for scarce resources.
• 11 Alarm pheromones are a broad and sometimes unclearly defined group which communicate alarm or attack, chiefly in colonial species.
• 12 Trail pheromones, applied to a surface by an individual, to be followed by another, are confined to Hymenoptera, Isoptera and a few Lepidoptera as far as is known.
• 13 Territorial and home range pheromones may be widely distributed, but as yet few of them have been recognized.
• 14 Surface and funeral pheromones are even less well known. Surface pheromones may play a large part in species or colony recognition.
• 15 We can expect the number and complexity of pheromones to be much greater in social insects, a part of the subject which until now has received relatively less attention.
• 16 As our understanding of the subject grows we may expect other categories to be added to this list.

     

Cybrids and tetrad sterility for developing true potato seed hybrids

Potato cybrids result from the fusion between cytoplasm and nuclear gene donors. Such genetic materials are an alternative means to broaden the breeding pool by non‐sexual gene transfer. Tetrad pollen sterility provides also another source of male sterility with some potential for true potato seed breeding. The objective of this research was to investigate cybrid‐derived offspring for both agronomic and reproductive characteristics in two contrasting Peruvian locations, and to examine new exotic germplasm for tetrad sterility, with the aim of broadening the breeding pool available at the Centro Internacional de la Papa (CIP). The cybrids were derived from fusions between Y‐245.7, a clone with tetrad sterility, and Atzimba. These cybrids were crossed with selected male parents from the CIP breeding population, and their hybrid offspring were tested in La Molina (coastal desert) and Huancayo (cool highlands). In addition, other clones with tetrad sterility were also crossed with selected testers to determine their breeding value. There were significant differences for tuber yield, style length, and berry number among the hybrid offspring, and the genotype by environment interaction was significant for tuber yield and berry number. The top 25% highest yielding cybrid‐derived offspring across both locations showed the same tuber yield although they were significantly different for some of the reproductive characteristics. With the exception of one cybrid, the others did not exhibit segregation for tetrad sterility in their hybrid offspring, which were male fertile. However, the offspring derived from crosses between other sources of tetrad sterility and the same testers all showed tetrad sterility, and some of them had outstanding tuber yield at La Molina. The lack of segregation for tetrad sterility in these new crosses suggests that the non‐cybrid, male sterile, female parents are triplex or quadriplex for the Tr nuclear locus, which interacts with a sensitive cytoplasm (e.g. Trs from S. verrucosum or S. stoloniferum) to produce tetrad sterility in potato.     

Quest for Novel Preventive and Therapeutic Options Against Multidrug-Resistant Pseudomonas aeruginosa

International Journal of Peptide Research and Therapeutics - Pseudomonas aeruginosa (P. aeruginosa) is a critical healthcare challenge due to its ability to cause persistent infections and the...     

Effect of host plant on cornucopia of mango fruit flies (Diptera: Tephritidae) and their triumphant management in context of climate change

A study was performed to assess the preference of fourteen mango cultivars for fruit flies and their management by bagging. So the choice of Tephritid flies to mango cultivars during fruiting phase is crucial. Fourteen different cultivars of mango viz., ‘Dusehri’, ‘Malda’, ‘Langra’ early cultivars, ‘Chaunsa’, ‘Fajri Klan’, ‘Sensation’ medium whereas ‘Sanglakhi’, ‘Retaul-12’, ‘Mehmood Khan’, ‘Tukhmi’, ‘Kala Chaunsa’, ‘Chitta Chaunsa’, ‘Dai Wala’ and ‘Sobey De Ting’ late cultivars were assessed for their suitability for fruit flies. The results indicate that the population density of fruit flies was higher on late cultivars like ‘Sanglakhi’ (20.61 percent), ‘Mehmood Khan’ (20.22 percent) and ‘Reutal-12’ (19.92 percent) were proved to be highly susceptible to fruit flies. Among these the cultivar ‘Reutal-12’ was selected being commercial and future cultivar for the management of fruit flies through bagging. The results reported that the attack of tephritid fruit flies and other insect pests were zero in bagged fruits as compared with control. It was further recorded that the bagged fruits has maximum average fruit weight i.e. 203.50 and 197.83 g per fruit was noted in those treatments where butter paper bag and brown paper bag was wrapped with better coloration as compared with un-bagged fruit with 159.5 g per fruit. Similarly, on an average fruit length were more i.e. 90.17, 91.33 mm in bagged fruit and 85.33 in un-bagged fruits. Furthermore, bagged fruits have zero incidence of disease with reduced fruit crack, fruit sunburn, mechanical damage, bird damage, fruit blemished and agrochemical residues on the fruit. So, it is concluded that the special attention should be given on ‘Reutal-12’ for the management of fruit flies when devising an IPM program for the control of fruit flies. Further, bagging has proved to be the good agricultural practices for the production of quality mango.     

Therapeutic effects of Typha elephantina leave’s extract against paracetamol induced renal injury in rabbits

Present study focuses on ameliorative potential of Typha elephantina leave’s aqueous (TE.AQ) extract against Paracetamol (PCM) induced toxicity in rabbits. We fed the male rabbits with 300 mg PCM in alone and in combination with TE.AQ at different doses i.e. (100, 200 and 300 mg/kg body weight) or silymarin (100 mg/kg) daily for 21 days. PCM in alone significantly (P < 0.5) increased serum urea, uric acid, creatinine, total protein, albumin, globulin and blood urea nitrogen. Serum sodium, potassium and magnesium level were high. The glutathione, radical scavenging activity and Thiobarbituric acid reactive substances were significantly reduced. Treatment with TE.AQ at dose rate 300 mg/kg body weight and Silymarin significantly ameliorated all the parameters when compared with PCM administered group. The 100 and 200 mg of TE.AQ showed no significant effects. The histopathological examination confirmed the therapeutic potential of TE.AQ. These results established the presence of natural antioxidants in Typha elephantina leaves.     

Farmers’ knowledge,perception and management of mango mealy bug,Drosicha mangiferae Green (Hemiptera: Monophlebidae), on Mangifera indica in Punjab,Pakistan

In 2004–05, during the December to February about 141 mango farmers were interviewed during peak activity of mango mealy bug in southern Punjab, Pakistan. The objective was to know the farmers’ knowledge, perceptions and practices in the management of mango mealy bug. Most of the farmers (94.33%) reported that Chaunsa variety (king of all mango varieties) was susceptible to mango and irrigation water was the major source of flare up of this pest. Basudin and Supracide were the most commonly used insecticides as 72.92 and 51.77 percent farmers gave positive response and grease bands were applied for the control of mango mealy bug by the majority of the respondents. Hundred percent yield losses was told by 22.7 percent respondents whereas 75 percent, 50 percent and 25 percent losses were reported by 39.7, 31.9 and 14.2 insecticidal spray did not show satisfaction to the respondents for the control of fertilized females of mango mealy bug coming down from the trees. Lack of knowledge about the pest, lack of money, adulterated and shortage of pesticides, lack of unity amongst farmers Further the growers’ views were tested in the field for confirmation and small land holdings were the main constraints for the control of mango mealy bug.     

Association of polymorphisms in genes involved in enamel formation,taste preference and immune response with early childhood caries in Saudi pre-school children

Dental caries is primarily elicited by modifiable factors such as inadequate oral hygiene, poor dietary practices and deficient fluoride exposure. However, there is a growing body of evidence suggesting the profound influence of genetic factors in dental caries susceptibility. The present study aimed to evaluate the association between single nucleotide polymorphisms (SNPs) in ENAM (rs12640848), MMP20 (rs1784418), TAS2R38 (rs713598), and LTF (rs4547741) genes and early childhood caries (ECC) in Saudi preschool children. This case-control study enrolled 360 Saudi preschool children (262 with ECC and 98 caries-free). Data on environmental factors were collected through a questionnaire. However, caries experience and oral hygiene data were obtained during clinical examination. Buccal swab samples were collected for DNA extraction and SNPs were genotyped using PCR and DNA sequencing. Children with ECC were compared to caries free children (control), then they were categorized into two categories based on ECC severity as follows; non-severe ECC (NS-ECC), and severe-ECC (S-ECC). Association between the SNPs, ECC, NS-ECC, and S-ECC was reported as an odds ratio (OR) with a 95% confidence interval (CI). The majority of the children (72.8%) exhibited ECC (31.7% NS-ECC and 41.1% S-ECC) with mean dmft of 4.20 ± 4.05. Multivariate analyses of environmental factors showed that nocturnal feeding was a risk factor for ECC (P = 0.008). Poor oral hygiene was also a risk factor for both NS-ECC and S-ECC (ECC: P < 0.0001, NS-ECC: P = 0.032 and S-ECC: P < 0.0001). Univariate analysis showed that the AG genotype of rs1784418 of MMP20 gene was protective against ECC (OR = 0.532; 95% CI = 0.316–0.897, P = 0.018) and against NS-ECC (OR = 0.436; 95% CI = 0.238–0.798, P = 0.007). When environmental risk factors for ECC were included as covariates during multivariate analysis, AG variant in rs1784418 of MMP20 gene remained less frequent in NS-ECC cases compared to controls with borderline significance (OR = 0.542; 95% CI = 0.285–1.033, P = 0.063). Our findings concluded that MMP20 rs1784418 SNP might be associated with protection against ECC in Saudi preschool children.