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Urinary Schistosomiasis in two family populations, using school children as tracers
(1988) Anigbo, E.U.; Nwaorgu, O.C.
Two groups of families designated A and B were studied for Schistosoma haematobium infection in Amagunze, Anambra State, Nigeria. The groups were selected on the basis of a preliminary screening of schoolchildren: group A were children with negative urine samples and group B were those with positive samples. Each group contained 60 children and the families of each of these were screened for schistosomiasis. The total prevalence among the 1017 individuals examined was 48.4% and the mean egg count was 72/10 ml urine. The peak prevalence (73%) and intensity of infection (84 eggs/10 ml of urine) occurred between the ages of 5 and 14 years. The prevalence and intensity of S. haematobium infection was statistically higher in males than in females. Although water contact patterns were similar, families in group B were significantly more infected (59%) than those in group A (36%).
Photolabelling of Prostaglandin E2 receptor in cardiac sarcolemmnal vesicles
(1990) Njue, Wilson N.; Liu, H.J.; Olley, P.N.
A [3H]azidophenacyl ester of PGE2 ([3H]azido-PGE2) was synthesized and used to photoaffinity label the protein component of the high affinity PGE2 binding site in cardiac sarcolemma membrane. Photolysis of the isolated cardiac sarcolemmal vesicles in the presence of [3H]azido-PGE2 resulted in the covalent labelling of a protein component that migrated on sodium dodecyl sulfate-polyacrylamide gels with an apparent molecular weight of 100,000. Incorporation of the [3H]azido-PGE2 did not occur in the absence of photolysis. The photolabelling of the 100-kDa protein by [3H]azido-PGE2 was inhibited by excess unlabelled PGE2 and azido-PGE2. Specific binding of [3H]azido-PGE2 was displaced by excess unlabelled PGE2 or azido-PGE2, but not PGF2 alpha, 6-keto-PGF1 alpha or PGD2. These results indicate that the 100-kDa photoaffinity labelled [3H]azido-PGE2 binding protein contains the binding site for PGE2 in isolated cardiac sarcolemma membranes.
The diagnostic value of haematuria and proteinuria in Schistosoma haematobium infection in Southern Nigeria.
(1992) Nwaorgu, O.C.; Anigbo, E.U.
Haematuria and proteinuria as detected by chemical reagent strips correlated moderately (r=0·7) with prevalence and intensity of infection with Schistosoma haematobium in an area of Anambra State, Nigeria. Differences attributable to age and sex were also reflected in a similar pattern, all peaks occurring in the 5–14 year age group. The differences observed with varying levels of intensity and haematuria at both 10 and 50 erythrocytes/μl (p<0·001) and proteinuria at 0·3 g/dl (p<0·01) were statistically significant. At a proteinuria level of 1 g/dl, the observed differences were however not statistically significant (p>0·5). The percentage of specimens from children (1–14 years) positive for S. haematobium eggs and with at least traces of haematuria and proteinuria (63·4% and 95%, respectively) was higher than in adults (33·3% and 80·2%, respectively). All individuals with more than 50 eggs/10 ml of urine were correctly identified using both indices either separately or in combination. For egg counts of less than 50 egg/10 ml of urine, false diagnosis occurred in only 5% of all specimens examined. The sensitivity and specificity of haematuria and proteinuria at trace quantities was very high, hut haematuria had a higher predictive value for a positive test (PvPt) and was considered the overall better indicator. A combination of both indices did not significantly increase the PvPt. When trace haematuria and moderate proteinuria were combined, both the sensitivity, specificity and PvPt were all above 90%, giving the best overall values in all the combinations made.
Decomposition of Cassia siamea loppings in semiarid Machakos, Kenya
(1994) Mugendi, Daniel N.; Mochoge, B.O.; Coulson, C.L.; Stigter, C.J.; Sang, F.K.
The rate of decomposition of Cassia siamea Lam. prunings in an alley cropping system was investigated using litter bags in the semiarid area of the Machakos District, Kenya, during the short rains of 1988 and the long rains of 1989. Cassia siamea had been grown as the hedgerow species since 1983. Loppings were used as mulch incorporated into the soil for green manuring. Approximately 70–90% of the loppings could decompose exponentially within 60 days, a relatively low rate. Younger material decomposed faster in the long rains than older material in the short rains. Nitrogen content and C/N ratios explain this result. They also meet critical values in the literature for nitrogen availability to the crop. Position in the alleys had no significant influence on decomposition. Outside the rainy seasons, termite activity appreciably influenced diminution of decomposing material. Fungi had a role throughout, but bacteria may be supposed to be the predominant agent within the rainy seasons.
The influence of diel climatic cycle on the depth time distribution of phytoplankton and photosynthesis in a shallow equatorial lake (Lake Baringo), Kenya.
(Springer, 1995-05) Patterson, G.; Kotut, Kiplagat
Lake Baringo is a shallow equatorial lake. This paper reports a diel study of the depth-time distribution of phytoplankton and photosynthesis at one location in Lake Baringo on 10 March 1989. The water column shows a pattern of diurnal stratification probably accentuated by the high turbidity of the water and therefore rapid attenuation of solar energy. This stratified pattern breaks down at night due to atmospheric cooling and the regular onset of winds in the early evening. The phytoplankton is dominated by Microcystis aeruginosa with some associated epiphytes. It concentrates in the narrow euphotic zone during the diurnal period of stratification due to buoyancy of the Microcystis; evening breakdown of the thermocline results in the phytoplankton being mixed throughout the water column. A series of measurements of photosynthesis throughout the diurnal period gives an areal rate of 3.8 g O2 m−2 d−1. The relationship between this value and the level of fish exploitation in Lake Baringo is discussed. The diel cycle in Lake Baringo is interpreted as dominating over any seasonal limnological cycle in the lake.
Predicting decomposition patterns of tree biomass in tropical highland microregions of Kenya
(Kluwer Academic Publishers, 1997) Mugendi, Daniel N.; Nair, P.K.
Decomposition- and nitrogen-release patterns of biomass from three agroforestry multipurpose trees (Calliandra calothyrsus, Cordia africana and Grevillea robusta) were investigated in four contrasting environments (microregions) in the Kenyan tropical highlands during two cropping seasons. Dried leafy biomass was placed in 2-mm litter bags, buried at 15-cm depth and recovered after 2, 4, 7, 10, 15 and 20 weeks. Decomposition patterns were best described by first-order exponential decline curves. The decomposition rate constants ranged from 2.1 to 8.2 yr−1, and the rates of decomposition among the species were in the order: calliandra ≥ cordia > grevillea. There was a species-by-environment interaction during both seasons, but the nitrogen released did not follow such a pattern. Among the three tree species, calliandra released the highest amount of cumulative N, followed by cordia and grevillea. Using multiple regression techniques, decomposition pattern was described as a function of three groups of factors: biomass quality (N, C, lignin and polyphenol), climate (soil temperature and rainfall), and soil conditions (pH, soil organic C, total N and P). For all the species and factors combined, the adjusted R 2 values were 0.88 and 0.91 for seasons 1 and 2, respectively. Among the three groups of factors, climate and biomass quality had the most influence on decomposition rates. Climatic factors accounted for 75% of the total rate of decomposition in season 1 (‘irregular’ season with less rainfall and more soil temperature fluctuations), whereas biomass quality factors were more influential in season 2 (‘regular’ season), accounting for 65% of the total variability.
Evaluation of Leucaena leucocephala as a source of N for maize
(1997-01) Mafongoya, P.L.; Mugendi, Daniel N.; Pedereira, C.
Prunings of leucaena [Leucaena leucocephala (Lam.) De Wit] have long been regarded as a useful alternative to N fertilizer, but N use efficiency by crops is often low. The potential exists to synchronise nutrient release with crop nutrient demand through variation in the rate and placement of prunings. A 2x2x3 factorial experiment was conducted to evaluate the potential of leaves of leucaena to supply N to maize (Zea mays L.) plants grown in pots of soil (Grossarenic Paleudult) under glasshouse conditions. Factors tested were two rates of application (3 and 6 Mg ha-1), two methods of placement (surface vs incorporation), and 3 levels of N fertilizer (0, 50, and 150 kg ha-1 equivalent of urea in solution form). Surface applied prunings significantly increased maize shoot dry weight with increasing levels of N fertilizer. Although incorporation of prunings increased maize shoot dry weight, the incorporated treatments did not show any significant response to N fertilizer, indicative of adequate N supply from prunings. Both shoot and total dry weight significantly increased with increasing rates of prunings applied. Nitrogen recovery was increased by applying prunings together with N fertilizer. There was a higher N recovery with incorporation compared to surface application. Prunings applied at a rate of 3 Mg ha-1 gave higher %N recovery than 6 Mg ha-1. At the final harvest date, application of 6 Mg ha-1 of prunings produced taller plants than 3 Mg ha-1.
Effect of incorporating Cassia siamea prunings on maize yield in an alley cropping trial in semiarid Kenya
(1997) Mugendi, Daniel N.; Mochoge, B.O.; Coulson, C.L.; Stigter, C.J.; Sang, F.K.
The influence of soil-incorporated Cassia siamea prunings on nutrient status of maize leaves, grain and yield was studied in an alley cropping experiment in semiarid Machakos, Kenya, during the 1988 long and short rainy seasons. The trial was established in 1983 and in all the seasons Katumani composite B maize was sown, except in the short rains of 1988 when Hybrid 511 was planted. Plots consisted of 3 cropped alleys between cassia hedges spaced at 3.6 m apart. The hedges were lopped at the beginning of every season (on-set of rains) and the prunings incorporated into the alleys one day before maize seeds were sown. The control plots had no hedges and hence no prunings were incorporated. Incorporation of prunings into the soil increased nutrient concentration in the maize leaves, grains and soil in the treatment plots compared to the controls. Maize grain yield on a per row basis was also higher in the plots that received prunings application compared to the controls. However, on an area basis, the yield increase was insufficient to compensate for the area lost to the Cassia siamea shrubs.
Temporal changes in phytoplankton structure and composition at the Turkwel Gorge Reservoir, Kenya
(Kluwer Academic Publishers, 1998) Kotut, Kiplagat; Krienitz, L.; Muthuri, Francis M.
Temporal changes in phytoplankton chlorophyll a, composition, diversity, biomass (density and fresh weight) and primary production were investigated at the Turkwel Gorge Reservoir (Kenya) over a two year period (1994 and 1995). The phytoplankton properties investigated revealed a seasonal pattern that was very distinct in 1994 and muted in 1995. The wet season was characterized by higher levels of chlorophyll a, biomass and primary production and a lower diversity. A prominent seasonality in 1994 was found to be the result of a higher river inflow volume as compared to 1995. Chlorophyll a changes showed some positive correlation to changes in total nitrogen and total phosphorus. Diversity changes were inversely correlated to changes in total counts (R = −0.84 and −0.96 for 1994 and 1995 respectively). Individual species density changes varied from a distinct seasonal pattern to a nearly uniform density. While the diatom Achnanthes dominated the wet season in 1994, coccoid blue green algae were dominant during most of 1995. Throughout the study period, most biomass was due to the diatoms but with a lower percentage of total biomass in 1995 (40%) as compared to 1994 (88%). The wet season biomass in each year was dominated by the diatoms. Dominance of the intervening period changed irregularly between diatoms, dinoflagellates, green algae and blue green algae. The range of variation in chlorophyll a, total biomass and primary production were; 4.9 to 36.8 µg l-1, 440.14 to 11172.70 mg m-3 and 1.85 to 9.67 g O2 m-2 d-1 in 1994 and 4.9 to 11.5 µg l-1, 486.46 to 1351.39 mg l-1 and 3.08 to 5.41 g O2 m-2 d-1 in 1995 in the same order.
The Physico-chemical Conditions of Turkwel Gorge Reservoir, a New Man Made Lake in Northern Kenya
(1999) Kotut, Kiplagat; Njuguna, Stephen; Muthuri, Francis M.; Krienitz, L.
Variations in some physical, chemical, and nutrient conditions were investigated at Turkwel Gorge Reservoir and its inflowing river, Suam between 1994 and 1995. Seasonal changes in inflow volume had the greatest impact on the reservoir and river conditions investigated. A wide fluctuation in inflow volume combined with a regulated outflow independent of season resulted in a draw down of over 10 m in each year. Flood inflows during the wet season resulted in the lowest values of Secchi depth (range, 0.09-2.16 m), electrical conductivity (EC, range = 140-200 mS cm -1) and total alkalinity (TA, range = 75-111 mg 1-1) while the highest values were measured during the dry season. A functional relation between EC and TA (TA = 0.529 mg p1 EC: R ~ = 0.876) suggests a predominance of carbonates among the anions. Vertical profiles of temperature and dissolved oxygen (DO) revealed that the reservoir is monomictic with a wide variation in the depth of the daily mixed layer. High values of pH (range = 6.7-8.9) and DO (range = 4.9-9.2 mg V) were associated with periods of peak phytoplankton photosynthesis while the lowest values followed reservoir mixing. Peak total nitrogen (TN, range = 119-526 pg ki) and total phosphorus (TP, range = 8.9-71.6 pg 1-1) levels during the wet season resulted from increased river loading. Values of dissolved reactive silica (DRS, range = 0.41-9.77 mg kl) showed a wet season decline which was related to diatom depletion during the wet season. Annual reservoir areal loading rates of 27.38, 10.90 and 408.5 mg m -2 were computed for TN, TP and DRS respectively based on estimates of inflowing fiver loads in 1994. At the inflowing river Suam, low levels of EC (range =107-210 pS cm 1) and TA (range = 62-125 mg 1 -I) occurred during the wet season while the highest levels occurred shortly before the river dried up. The first flood water at the resumption of river inflow in March was characterized by very low levels of DO (range = 1.8-8.2 mg 11) and high levels of TN (range = 205-3354 pg 1 <) and TP (102-1259 pg 1-1). River pH (6.9-7.7) and DRS (range = 9.01-19.93 mg 1 -l) varied irregularly throughout the year.
Alley cropping of maize with calliandra and leucaena in the subhumid highlands of Kenya Part 2. Biomass decomposition, N mineralization, and N uptake by maize
(Kluwer Academic Publishers, 1999-06) Mugendi, Daniel N.; Nair, P.K.; Mugwe, Jayne; O'Neill, M.K.; Swift, M.J.; Woomer, P.
A major challenge in developing agroforestry approaches that utilize tree-leaf biomass for provision of N to crops is to ensure synchrony between the N released from decomposing prunings and N demand by crops. A study was conducted in the subhumid highlands of Kenya to assess the rate of decomposition and mineralization of soil-incorporated Calliandra calothyrsus Meissner (calliandra) and Leucaena leucocephala (Lam.) de Wit (leucaena) tree biomass and maize roots (Zea mays L.) both in an alley cropping and a sole cropping system. The amount of mineralized N peaked four weeks after planting (WAP) maize in all the treatments during both seasons of 1995. Cumulative mineralized N at week 20 ranged from 114 to 364 kg N ha−1 season−1, the absolute control treatment giving the lowest and the prunings-incorporated treatments giving the highest amounts in the two seasons. Total N uptake by maize, ranging from 42 to 157 kg ha−1 season−1, was lowest in the 'alley-cropped, prunings-removed' treatments, and highest in the 'non alley-cropped-prunings-incorporated' treatments. The apparent N recovery rate by maize was highest in the fertilizer applied treatments in the two seasons. Decomposition rate constants (kD) ranged from 0.07 to 0.21 week−1, and the rates among the different plant residues were as follows: leucaena < calliandra < maize roots. Nitrogen release rate constants (kN), ranging from 0.04 to 0.25 week−1, followed a similar pattern as the rate of decomposition with leucaena releasing the highest amount of N followed by calliandra and lastly by maize roots
Nitrogen recovery by alley-cropped maize and trees from 15N-labeled tree biomass in the subhumid highlands of Kenya
(Springer-Verlag, 2000-05) Mugendi, Daniel N.; Nair, P.K.; Graetz, D.A.; Mugwee, Jayne; O'Neill, M.K.
The effectiveness of tree-leaf biomass as a source of N to crops in agroforestry systems depends on the rate at which crops can obtain N from the biomass. A study was conducted to determine the fate of 15N labeled, soil-applied biomass of two hedgerow species, Calliandra calothyrsus Meissner (calliandra) and Leucaena leucocephala (Lam.) de Wit (leucaena), in the subhumid highlands of Kenya. Labeled biomass obtained from 15N fertilized trees was applied to microplots in an alley cropping field and maize planted. N uptake and recovery by maize and hedgerow trees was periodically determined over a 20-week period during the short rain (1995) and the long rain (1996) growing seasons. In maize crop from treatments that received leucaena biomass, higher N uptake and recovery were recorded than in maize from the plots that received calliandra biomass. However, N uptake and recovery were higher in calliandra tree hedges than in leucaena hedges, indicating differences in N uptake by the two tree species. The largest fraction (55–69%) of N in the applied tree biomass was left in the soil N pool, 8–13% recovered by maize, 2–3% by tree hedges, and 20–30% could not be accounted for. Some of the unaccounted for N may have been left in the wood and root portions of the tree hedges and in the bulk soil below the 20-cm depth. The study shows that only a small fraction of the N contained in the N-rich biomass that is applied to the soil is taken up by the current season's crop, suggesting that a major benefit may be in the build-up of the soil N store.
Cyanotoxin-producing bloom of Anabaena flos-aquae, Anabaena discoidea and Microcystis aeruginosa (Cyanobacteria) in Nyanza Gulf of Lake Victoria, Kenya
(2002) Krienitz, L.; Ballot, A.; Wiegand, C.; Kotut, Kiplagat; Codd, G.A.; Pflugmacher, S.
A bloom of Anabaena flos-aquae, Anabaena discoidea and Microcystis aeruginosa, was characterized in Nyanza Gulf of Lake Victoria, near Kisumu, Kenya. According to classical literature data, A. discoidea was considered to be endemic to the Great Lakes of Africa. Its morphological characteristics are described and discussed in relation to A. flos-aquae. The two samples investigated contained the cyanobacterial toxins, microcystin-LR, -RR, -LA and -LF.
Bioactive steroidal alkaloid glycosides from Selanum aculeastrum.
(2002) Wanyonyi, Alphonse W.; Chhabra, S.C.; Mkoji, G.; Eilert, Udo; Njue, Wilson N.
Solanum aculeastrum Dunal was investigated for the presence of molluscicidal compounds. This led to the isolation of solaculine A, from the root bark in addition to known steroidal alkaloids; solamargine and beta-solamarine from the berries. The structures were elucidated by spectroscopic techniques. Molluscicidal activity of the aqueous extracts of the berries and root bark, and the isolated compounds were investigated.
Identification and distribution of pathogens coinfecting with Brucella spp., Coxiella burnetii and Rift Valley fever virus in humans, livestock and wildlife
(Wiley, 2002-01) Middlebrook, Earl A.; Romero, Alicia T.; Bett, Bernard; Nthiwa, Daniel M.; Oyola, Samuel O.; Fair, Jeanne M.; Bartlow, Andrew W.
Zoonotic diseases, such as brucellosis, Q fever and Rift Valley fever (RVF) caused by Brucella spp., Coxiella burnetii and RVF virus, respectively, can have devastating effects on human, livestock, and wildlife health and cause economic hardship due to morbidity and mortality in livestock. Coinfection with multiple pathogens can lead to more severe disease outcomes and altered transmission dynamics. These three pathogens can alter host immune responses likely leading to increased morbidity, mortality and pathogen transmission during coinfection. Developing countries, such as those commonly afflicted by outbreaks of brucellosis, Q fever and RVF, have high disease burden and thus common coinfections. A literature survey provided information on case reports and studies investigating coinfections involving the three focal diseases. Fifty five studies were collected demonstrating coinfections of Brucella spp., C. burnetii or RVFV with 50 different pathogens, of which 64% were zoonotic. While the literature search criteria involved ‘coinfection’, only 24/55 studies showed coinfections with direct pathogen detection methods (microbiology, PCR and antigen test), while the rest only reported detection of antibodies against multiple pathogens, which only indicate a history of co- exposure, not concurrent infection. These studies lack the ability to test whether coinfection leads to changes in morbidity, mortality or transmission dynamics. We describe considerations and methods for identifying ongoing coinfections to address this critical blind spot in disease risk management.
Presenting Oneself as a Nurse: A Social and Professional Reality Construction
(Unisa Press, 2002-11) Ojo, A.A.; Mutea, Naomi K.; Wambui, T.; Chelagat, D.
The paper examined the historical development of nursing education and practice in two selected African countries as a background for analysing the image of nurses and nursing. Mead's (1934) Symbolic InteractionistTheof\' was employed to describe the basis of nurse;' low social and professional image which has been perpetuated by feminization of nursing, its classification as a low status occupation, its consignment as an appendage of medicine and widespread discrimination against womcn in Africa. Since reality construction is a continual creation as individuals interact in any social situation and as the social status and professional roles of nurses improve the image and self presentation will be enhanced. The submissive, accepting and passive doer-oriented critical mass of practising nurses in these countries cxplains the need for expanding degree programmcs that will facilitate collegiality in clinical relationships. It is argued that liberal university education is an important prerequisite for nurses to effectively use the concepts of assertiveness, power and influence to bring about positive change in their image and provision of quality nursing care. Recommendations made include need for nurses to convey messages of maturity, responsibility and expertise to patients, relatives and other stakeholders in health care services through their appearance, language, behaviour and performance of their professional responsibilities.
Contribution of tixic cynobacteria to massive deaths of lesser flamingoes at saline-alkaline lakes of Kenya
(2003) Krienitz, L.; Ballot, A.; Casper, P.; Codd, G.A.; Kotut, Kiplagat; Metcalf, J.S.; Morrison, L.F.; Pflugmacher, S.; Wiegand, C.
molluscicidal and antimicrobial activity of solanum aculeastrum
(2003) Wanyonyi, Alphonse W.; Chhabra, S.C.; Mkojo, G.; Njue, Wilson N.; Tarus, Paul K.
The methanolic extract of the fresh root bark and berries of Solanum aculeastrum showed significant activity against host snails of schistosomiasis. The berries extract was more potent with 100% snail kill at 50 ppm. Fractionation increased activity with 100% mortality at 20 ppm. The aqueous and methanolic extracts of the berries showed moderate antimicrobial activity, increasing by fractionation.
Heavy Metals and Pesticides in Marine Sediment, Seawater, and Seaplants Along the Kenya-Mombasa Coastline
(Taylor & Francis, 2003) Oyugi, Mildred P.; Chhabra, S.C.; Njue, Wilson N.; Kinyua, Anthony M.
Marine sediment, seawater and several species of seaplants along the Kenya- Mombasa coastal region were analyzed to determine the levels of heavy metals by AAS and EDXRF and organochlorine pesticides (OCPs) by GLC-ECD. In marine sediments, there were high levels of manganese (1100 mg/L) at Vanga, compared to other study sites. In seawater, the heavy metals were detected in levels higher than those considered as natural in the ocean and the range was 0.01–0.30 mg/L. OCPs were detected in marine sediments and in seaplants. The trend of concentration of these pollutants in ascending order in seawater, marine sediment and seaplants was observed.
In vitro antiplasmodial activity of some plants used in Kisii, Kenya against Malaria and their chloroquine potentiative effects.
(2003) Muregi, F.W.; Chhabra, S.C.; Njagi, Eliud N.; Lang’at-Thoruwa, C.; Njue, Wilson N.; Ndiege, I.O.
Fifty-five organic and aqueous extracts of 11 plants used in malaria therapy in Kisii District, Kenya were tested in vitro against chloroquine (CQ)-sensitive and resistant strains of Plasmodium falciparum. Of the plants tested, 73% were active (IC(50) < 100 microg/ml). Three plants, Vernonia lasiopus, Rhamnus prinoides and Ficus sur afforded extracts with IC(50) values ranging less than 30 microg/ml against both CQ-sensitive and resistant strains. Combination of some extracts with CQ against the multi-drug resistant P. falciparum isolate V1/S revealed some synergistic effect. The plant extracts with low IC(50) values may be used as sources for novel antimalarial compounds to be used alone or in combination with CQ.

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