H. N. Nyambaka

Expression of metallothionein and α-tubulin in heavy metal-tolerant Anopheles gambiae sensu stricto (Diptera: Culicidae)

Anopheles mosquitoes have been shown to adapt to heavy metals in their natural habitats. In this study we explored the possibility of using Anopheles gambiae sensu stricto as bio-reporters for environmental heavy metal pollution through expressions of their metal-responsive metallothionein and alpha-tubulin genes. The study was undertaken with third instar larvae after selection by cadmium, copper, or lead at LC(30) through five successive generations. Expression levels were determined in the 5th generation by semi-quantitative RT-PCR on the experimental and control populations. The data were analyzed using one-way ANOVA. The highest metallothionein (F(3,11)=4.574, P=0.038) and alpha-tubulin (F(3,11)=12.961, P=0.002) responses were observed in cadmium-tolerant treatments. There was significantly higher expression of metallothionein in cadmium or copper treatments relative to the control (P=0.012), and in cadmium than in lead treatments (P=0.044). Expressions of alpha-tubulin were significantly higher in cadmium than in control treatments (P=0.008). These results demonstrate the capacity of An. gambiae s.s. to develop tolerance to increased levels of heavy metal challenge. The results also confirm the potential of heavy metal-responsive genes in mosquitoes as possible bio-indicators of heavy metal environmental pollution. How the tolerance and expressions relate to An. gambiae s.s. fitness and vectorial capacity in the environment remains to be elucidated.

Multivariate analysis of the sensory changes in the dehydrated cowpea leaves

Processing of foods, especially dehydration is known to result in alteration of sensory and nutritional qualities. Cowpea leaves is one of the common leafy vegetables consumed in Kenya that contain high levels of pro-vitamin A compounds and has good carotene retention during processing. A tasting panel was trained using a quantitative descriptive analysis (QDA) test that was developed and used to characterize the sensory properties of dehydrated cowpea leaves. The panel identified sensory attributes in dehydrated cowpea leaves that were important in discriminating the dehydrated samples from the fresh material. Principal component analysis (PCA) was used to analyze the QDA scores. The first principal component (PC1) which accounted for 85% of the variance was an index of the interrelationship among variables in differentiating the samples while PC2, which accounted for the remaining variance measured the attributes influence in discriminating samples. The results of the sensory attributes mean scores showed that aroma, texture and appearance had high influence in discriminating between the fresh, the sun-dried and the solar-dried samples. The solar dried products were close to the fresh material, which was characterized, as soft and tender with an appealing dark green color, than the sun dried product. The sun dried products differed from the other products more on appearance.

Differential Induction of Proteins in Anopheles gambiae sensu stricto (Diptera: Cullicidae) Larvae in Response to Heavy Metal Selection

Investigations were conducted to establish the magnitude and pattern of differential expression of proteins due to generational selection of third instar Anopheles gambiae s.S. Giles larvae by cadmium, copper and lead heavy metals, the three possible common urban pollutants. A susceptible strain of A. gambiae s.S. third instar larvae was separately placed under selection pressure with cadmium, copper and lead at LC30 and controls through five generations. First, third and fifth generation selection survivors were screened for differentially expressed proteins relative to non-exposed control by twodimensional gel electrophoresis. Distribution patterns of the spots were analyzed by χ or Fishers’ exact test and variations in expressions between and within generations by ANOVA. Most differentially expressed spots were acidic and of low molecular weight among all metals and generations. Type of heavy metal and generation were the main indicators of variations in differential expressions. Variation between generations was most significant among cadmium-selected populations of which the most number of spots were induced in the fifth generation. Most spots were induced in the copper-selected population in the third generation. The induced protein spots may be the products from respective genes that respond to heavy metals and counter their toxicity, thus building A. gambiae s.S. tolerance to these pollutants. The differential pattern and magnitude of expressed spots have potential application as molecular markers for assessment of anopheline adaptation status to heavy metals, and provide insight into the extent of environmental pollution.RésuméDes études ont été menées afin d’estimer l’incidence de l’effet génération sur l’importance et les modalités d’expression différentielle des protéines sur des larves de 3ème stade d’Anophèles gambiae s.s. Giles élevées avec du cadmium, du cuivre et du plomb, qui sont des métaux lourds polluants, fréquemment rencontrés dans les zones urbaines. On a élevé pendant cinq générations une souche sensible de larves de 3ème stade d’A. gambiae séparément avec du cadmium, du cuivre et du plomb, à la dose DL30. Les survivants de la 1ème, 3ème et 5ème génération ont été testés par rapport aux témoins pour leur expression différentielle des protéines à l’aide d’une électrophorèse sur gel bidimensionnelle. Le mode de distribution des tâches a été analysé à l’aide des tests du χ2 et de Fisher et les variations de l’expression intra- et inter générations à l’aide d’une ANOVA. La plupart des tâches correspondent à des acides de faibles poids moléculaires pour tous les métaux et quelle que soit la génération. L’expression différentielle est fortement déterminée par le type de métal lourd et la génération. Les différences entre générations ont été les plus prononcées sur la population élevée avec du cadmium avec un plus grand nombre de tâches à la 5ème génération. La plupart des tâches ont été induites dès la 3ème génération pour la population élevée avec du cuivre. Les tâches de protéines induites peuvent être le résultat de l’expression de gènes spécifiques en réponse aux métaux lourds afin de contrecarrer leur toxicité, ce qui favorise la sélection de larves d’A. gambiae tolérantes aux polluants. Les modalités d’expression et l’importance des tâches ont une application potentielle comme marqueurs moléculaires pour l’estimation des capacités d’adaptation des anophèles aux métaux lourds. Elles permettent en outre d’apprécier l’étendue de la pollution environnementale.

Use of Low Cost Soil Amendments Reduces Uptake of Cadmium and Lead by Tobacco (Nicotiana tabacum) Grown in Medially Polluted Soils

The study explored the use of low cost soil amendments in reducing lead and cadmium uptake in tobacco. High levels of these metals in tobacco are of concern because of their toxicity and cumulative nature in tobacco consumers. Tobacco was planted in soils amended with cow manure and hydroxyapatite (HA), and non-amended sandy-loamy soil containing 60.57±3.74 μg/g lead and 33.95±0.49 μg/g cadmium in field and pot experiments. Tobacco leaves harvested after 75 days were dried, acid digested and their metal contents determined using atomic absorption spectroscopy (AAS). Cow manure reduced cadmium uptake by 67.20% and 71.75% in field and pot experiments while 1.5% HA reduced lead uptake by 39.69% in field experiments. Pot experiments had higher metals uptake than field experiments while fertilizer treatments recorded highest uptake. However, the levels were within WHO/FAO limits, indicating that amending medially polluted soils with cow manure and HA results in safe harvests of tobacco.

Use of indigenous food formulation in the management of HIV and AIDS patients in Kenya

F many years now, scientists have understood that the onset of breast cancer is a gradual and stepwise process. Chemoprevention researches in recent days are focused on finding substances or components of natural sources that can prevent or inhibit carcinogenesis. Targeted cancer therapies using natural bioactive compounds in combination with chemoprevention drugs are also used to target specific characteristics of cancer cells, such as a gene or protein that allows the cancer cells to grow in a rapid or abnormal way. Therefore, chemoprevention of breast cancer, the attempt to use natural and synthetic compounds to intervene in the early precancerous stages of carcinogenesis before invasion begins, is undertaken as a measure to reduce breast cancer risk for women at high risk. A number of bioactive dietary components are of particular interest in the field of breast cancer. One such compound known as the sub-group of vitamin-E family, the tocotrienols display anticancer properties and may play a role in cancer prevention. To date, there are many studies, which show that tocotrienols can inhibit proliferation of human breast cancer cells in vitro. The inhibitory effects of four isoforms of tocotrienols on the human breast cancer cells appear to be different. The γ and δ-tocotrienols have been shown to have a more potent inhibitory effect on cell growth compared to α and β-tocotrienols. In this study, the effect of tocotrienol isomers (γ and δ) were used to postulate the mechanism of action of these compounds using an in vitro model. The integration of omics methodologies provided insights into functions and the mechanisms of tocotrienols action in breast cancer cellular and molecular environment.Introduction: Type-1 diabetes mellitus patients are at a risk for developing eating disorders because of their intense diet consciousness which is imbibed at an early age. The main objectives of this study were to screen for the risk of developing of eating disorders amongst young adults with and without type-1 diabetes mellitus and study its associations with metabolic control in type-1 diabetes mellitus patients.I recent decades, obesity has become a major health problem. So far, several studies have showed that physical activity is related to creating negative energy balance and changes in appetite directly. However, few of the studies examined the effect of exercise time during the day on these factors. The main aim of the present study was demonstrating the effect of 6 weeks morning and evening aerobic exercise on appetite and anthropometric indices. Forty eight overweight females were recruited in this clinical trial. By the time of exercise, they were divided into two groups (morning or evening) and performed 6 weeks of aerobic exercise with the target heart rate on the ventilatory threshold. Appetite change, calorie intake and anthropometric indices were assessed. All of the variables were compared between two groups and within groups at baseline in the third and sixth week. Some parameters of appetite indices were changed significantly in morning and evening exercise groups in time point’s measurements. However, consistent changes in the appetite scores were not found along the 6 weeks (P>0.05). Calorie consumption of the morning group decreased along the 6 weeks significantly greater than evening group (P=0.02). In addition, significant changes in weight, BMI, abdominal skin fold thickness and abdominal circumference were seen in the morning group (P<0.05). It seems that moderate to high intensity aerobic exercise in the morning along 6 weeks could be considered as a more effective program than evening exercise on appetite control, calorie intake and weight loss.P of chronic health conditions such as diabetes and cardiovascular diseases has not been decreased but rather increased in UK, one of most developed countries in which huge amount of effort have been implemented by government and health care professionals. The statistic possibly indicates that ordinary nutritional instruction such as ‘eat less, move more’ has not worked appropriately, therefore, we may need to turn our perspective toward newly emerging care paradigm such as person centered care in order to provision of quality nutrition care. The person centered care has emerged alongside four themes such as ‘care with dignity, compassion, respect’ ‘coordinated care’ ‘personalized care’ and ‘enable care’. The objective of this review was firstly to elicit gaps alongside those four themes of person centered care from scientific surveys that had conducted inside the UK. Secondly, in order to respond questions such as how to resolve the gaps as well as to clarify health care professional’s roles and responsibilities, recommendations from government and non-government stakeholders were reviewed; as a results of the finding, a few elements including liaison, training and education and awareness should be undertaken by all health care professionals. Doctors should perform specific activities such as detection and solving nutritional problem, whilst nurses should aware their legal limits and consult when required. Dietitians should develop nutritional training packages as well as provide talks and lectures for all health care professionals.G is one of the nutritional factors that involves in developing of obesity and type 2 diabetes in human. The studies indicated that enterocyte cells on intestine might play a role in dietary glucose sensing during obesity. Obese people are consumed high amount of dietary glucose and enterocyte cells consequently are exposed to high glucose. Thus, we aimed to find relevant physiological pathways and genome-wide mRNA expression profiles that can be regulated by glucose in fully differentiated human intestinal epithelial (CaCo-2). The cells were maintained two different glucose levels (5.5 mM for control, 25 mM for high glucose) at least three passages. The cells were grown on transwell system for 21 days to mimic human intestine system. Transepithelial electrical resistances (TEER) were measured to control monolayer formation and polarization. RNA isolation was performed and whole genome mRNA expression profile was determined following gene ontology analysis to find affected molecular pathways. Compared to control relative glucose level was found high in basolateral site of CaCo-2 cells that were under high glucose condition without effecting TEER. GLUT2, SGLT1, GLUT5 mRNA levels were significantly reduced during elevated glucose levels which is consistent with literature. Significant fold change analysis showed that 351 genes up-regulated and 468 genes under high glucose condition. We found high glucose significantly leads changes of molecular pathways (down-regulated; insulin signaling, focal adhesion, inositol phosphate, fructose/mannose, glycolysis and up-regulated; ubiquitin-mediated proteolysis, spliceosome, protein export). These results provide us better understanding and open new window for glucose metabolism of enterocytes during obesity.T close to 1.2 billion people, approximately a fifth of the world’s population continues to live in conditions of abject poverty and almost 800 million people in the developing world are chronically hungry. A basic right to adequate and nutritious food, which most people take for granted, remains a distant dream for those who struggle with food shortages every day of their lives. The presence of extreme poverty and hunger on such a vast scale in a world of apparent opulence is a moral outrage. Evidence-based strategies for nutrition intervention commonly address direct determinants such as food/nutrient intake, whereas community-based intervention tends to take more holistic approach resulting in greater efficacy when combined with other proximal determinants such as women’s economic and social empowerment. We need to address not simply the immediate causes of malnutrition, but also their underlying and basic factors if we are to achieve nutritional well-being and reach full potential for functional and productive capacity in a population. It is thus imperative that food and nutrition programs succeed and that success is sustained. In the case of Bukoba rural, Republic of Tanzania identified direct determinants of undernutrition were lack of availability, accessibility and utilization of food whereas identified proximal determinants were women’s lack of sustainable purchasing power, decision making power, business acumen and horticultural and technical assistance. The proximal determinants imply the lack of women person and social empowerment in their family and community context. These data lead to a cooperative farming project creating a collective way to cultivate soybean crops to improve the quality of the existing diet (direct determinants) and an infrastructure to effect the women’s economic sustainability and empowerment (proximal determinants). The success of ongoing programs suggests when feeding programs and food-based safety nets are supplied from local production, there is a double benefit; not only are the hungry fed but local markets for food expand, opening income-earning and employment opportunities for the poor thereby creating sustainability. The body of evidence clearly suggests that nutrition interventions work best when it is designed with long-term sustainability as an explicit goal.