61 research outputs found
Extracellular release of acid phosphatase from blood stream forms of Trypanosoma brucei brucei .
Acid phosphatase (ACP) activity was demonstrated in blood stream form
of Trypanosoma brucei brucei harvested from infected Wister rats by
Ion Exchange DEAE Cellulose 52 chromatography. Whole parasite extract
(WPE) and Excretory Secretory Extract (ESE) were prepared and analyzed
for acid phosphatase activity. A higher ACP activity (85.5
\u3bcmol/min) was recorded in WPE compared to ESE (36.8
\u3bcmol/min). ACP activity in ESE is suggestive of the presence of a
cell rich enzyme. Phase separation of the extracts using the detergent
Triton X-114 (TX-114), resulted in protein partitioning into aqueous
and detergent phases. ACP activity was higher in the detergent phases
(56.2 \u3bcmol/min and 28.8 \u3bcmol/min) of WPE and ESE
respectively. ACP activity recorded in the aqueous phases of WPE and
EPE was 27.8 and 7.6 \u3bcmol/min respectively. On a Size Exclusion
chromatography column using Sephacryl-300, ESE emerged as five distinct
protein peaks. ACP activity of the eluted fractions showed two peaks of
relative molecular weights 195 and 325 KD. This study shows that T.
brucei releases acid phosphatase extracellularly via a yet to be
determined mechanism. Acid phosphatase activity in ESE is indicative of
a soluble enzyme within the cell matrix which may also play an
important role in the pathology of African Trypanosomiasis
Assessment of heavy metal residues in water, fish tissue and human blood from Ubeji, Warri, Delta State, Nigeria
Residual levels of lead, chromium, cadmium and zinc in water and fish
tissue from Ubeji River, Warri and blood samples from residents of
Ubeji were analysed. Control water and fish samples were obtained from
Eleyele River and blood from residents of Ibadan. All the samples
collected were digested using a modified procedure from the Association
of Official Analytical Chemists (AOAC) and were subsequently analyzed
using Atomic Absorption Spectroscopy. Levels of lead and cadmium in
Ubeji river were significantly higher than levels in Eleyele River.
Fifty fish samples from five species ( Citharinus citharus , Liza
falcipinis , Brycinus macrolepidotus , Polydactylus quadrifilis and
Tilapia zilli ) were analysed. Lead concentration (ppm) was highest in
C. citharus (76.07\ub1161.48) and least in T. zilli
(23.16\ub126.30). Chromium was not detected in B. macrolepidotus, P.
quadrifilis and T. zilli. Concentrations of all heavy metals detected,
except zinc, in the fish species were higher than WHO permissible
limit. Lead, Cadmium and Zinc concentrations in the tissues of the
control fish were significantly lower (p>0.05) than those recorded
in fish from Ubeji River. There were no statistically significant
differences in heavy metal concentration in fish gills and muscle
(p>0.05). Lead and cadmium levels in Ubeji river significantly
exceeded (p=0.0 and p=0.012) the permissible limits for aquaculture and
drinking. Levels of Chromium (1737.17\ub12996.01), Zinc and Lead
(149.35\ub1188.28 and 123.49\ub1350.85 respectively) were
significantly high (p<0.05) in the 101 human blood samples screened,
while concentrations of Cadmium was comparatively low
(10.11\ub110.71). Lower levels of cadmium, zinc and lead (8.54\ub1
7.49, 79.89\ub162.65 and 53.46\ub157.17, respectively) were
recorded for the control samples from Ibadan. This study highlights the
high levels of heavy metals in the Ubeji River and suggests the need
for interventions to stem the tide of pollution in the river. It would
also be important to assess health problems that may arise as a result
of contact and continuous use of the water. @ JASE
A study of the M235T variant of the angiotensinogen gene and hypertension in a sample population of Calabar and Uyo, Nigeria
AbstractA common molecular variant of the angiotensinogen gene had been reported to predispose some ethnic groups to hypertension. This case–control study was designed to determine the frequency and association of the angiotensinogen M235T allele with hypertension in residents of Calabar and Uyo cities, south–south Nigeria.The study involved 1308 subjects, 612 patients and 696 controls. The M235T variant was investigated using an allele specific polymerase chain reaction and enzymatic digestion to determine allele frequencies. Hypertensinogenic factors such as dietary habits, physical activity, smoking and drinking habits were assessed using questionnaires. Descriptive statistics, chi-square and multiple regression analysis were used to analyze the data obtained.The M235T allele frequency was high (0.94 for hypertensives and 0.96 for controls) though it was not associated with hypertension status. The odds ratio for hypertension was 0.64 (95% confidence interval: 0.39–1.06) there were no significant differences between the genotype frequency of hypertensives and controls. By multiple regression, Hypertension was observed to be associated with age and was a predictor for systolic blood pressure in both patient r2=0.359; p<0.05 and control groups r2=0.26.Age and body mass index were predictors for diastolic blood pressure in the control group, r2=0.28.Although the frequency of the M235T variant was high, it was not a significant risk factor for hypertension in the study population
Serum Ferritin Levels In Children With Malaria Anaemia In Ibadan
This study assessed the serum ferritin levels in plasma samples from
children (4 - 74 months old) admitted for malaria at the Adeoyo
Maternity Hospital (Beere) Ibadan, Oyo State, using a sandwich-ELISA.
These values were compared with malaria parasitemia, MSP-1 antibody
titre and packed cell volume values previously obtained through
standard methods. Statistical analyses were carried out using SPSS,
Excel and Epi-Calc software. Results showed that the serum ferritin
level in the population ranged in from 363ng/ml to 1000ng/ml, with a
mean value of 630ng/ml. There was a negative correlation between serum
ferritin levels and the packed cell volume, and malaria parasitemia in
the children; while the serum ferritin levels increased with increasing
malaria antibodies. There was no significant difference in the mean
levels of ferritin in anaemic and non-anaemic children. Serum ferritin
concentration decreased with increasing age in children with malaria.
Gender was found to have no significant association with serum ferritin
levels in children with malaria anaemia
Developmental Regulation of Genes Encoding Universal Stress Proteins in Schistosoma mansoni
The draft nuclear genome sequence of the snail-transmitted, dimorphic, parasitic, platyhelminth Schistosoma mansoni revealed eight genes encoding proteins that contain the Universal Stress Protein (USP) domain. Schistosoma mansoni is a causative agent of human schistosomiasis, a severe and debilitating Neglected Tropical Disease (NTD) of poverty, which is endemic in at least 76 countries. The availability of the genome sequences of Schistosoma species presents opportunities for bioinformatics and genomics analyses of associated gene families that could be targets for understanding schistosomiasis ecology, intervention, prevention and control. Proteins with the USP domain are known to provide bacteria, archaea, fungi, protists and plants with the ability to respond to diverse environmental stresses. In this research investigation, the functional annotations of the USP genes and predicted nucleotide and protein sequences were initially verified. Subsequently, sequence clusters and distinctive features of the sequences were determined. A total of twelve ligand binding sites were predicted based on alignment to the ATP-binding universal stress protein from Methanocaldococcus jannaschii. In addition, six USP sequences showed the presence of ATP-binding motif residues indicating that they may be regulated by ATP. Public domain gene expression data and RT-PCR assays confirmed that all the S. mansoni USP genes were transcribed in at least one of the developmental life cycle stages of the helminth. Six of these genes were up-regulated in the miracidium, a free-swimming stage that is critical for transmission to the snail intermediate host. It is possible that during the intra-snail stages, S. mansoni gene transcripts for universal stress proteins are low abundant and are induced to perform specialized functions triggered by environmental stressors such as oxidative stress due to hydrogen peroxide that is present in the snail hemocytes. This report serves to catalyze the formation of a network of researchers to understand the function and regulation of the universal stress proteins encoded in genomes of schistosomes and their snail intermediate hosts
Cellular responses to modified Plasmodium falciparum MSP119 antigens in individuals previously exposed to natural malaria infection
<p>Abstract</p> <p>Background</p> <p>MSP1 processing-inhibitory antibodies bind to epitopes on the 19 kDa C-terminal region of the <it>Plasmodium falciparum </it>merozoite surface protein 1 (MSP1<sub>19</sub>), inhibiting erythrocyte invasion. Blocking antibodies also bind to this antigen but prevent inhibitory antibodies binding, allowing invasion to proceed. Recombinant MSP1<sub>19 </sub>had been modified previously to allow inhibitory but not blocking antibodies to continue to bind. Immunization with these modified proteins, therefore, has the potential to induce more effective protective antibodies. However, it was unclear whether the modification of MSP1<sub>19 </sub>would affect critical T-cell responses to epitopes in this antigen.</p> <p>Methods</p> <p>The cellular responses to wild-type MSP1<sub>19 </sub>and a panel of modified MSP1<sub>19 </sub>antigens were measured using an <it>in-vitro </it>assay for two groups of individuals: the first were malaria-naïve and the second had been naturally exposed to <it>Plasmodium falciparum </it>infection. The cellular responses to the modified proteins were examined using cells from malaria-exposed infants and adults.</p> <p>Results</p> <p>Interestingly, stimulation indices (SI) for responses induced by some of the modified proteins were at least two-fold higher than those elicited by the wild-type MSP1<sub>19</sub>. A protein with four amino acid substitutions (Glu27→Tyr, Leu31→Arg, Tyr34→Ser and Glu43→Leu) had the highest stimulation index (SI up to 360) and induced large responses in 64% of the samples that had significant cellular responses to the modified proteins.</p> <p>Conclusion</p> <p>This study suggests that specific MSP1<sub>19 </sub>variants that have been engineered to improve their antigenicity for inhibitory antibodies, retain T-cell epitopes and the ability to induce cellular responses. These proteins are candidates for the development of MSP1-based malaria vaccines.</p
Assessment of heavy metal residues in water, fish tissue and human blood from Ubeji, Warri, Delta State, Nigeria
Residual levels of lead, chromium, cadmium and zinc in water and fish
tissue from Ubeji River, Warri and blood samples from residents of
Ubeji were analysed. Control water and fish samples were obtained from
Eleyele River and blood from residents of Ibadan. All the samples
collected were digested using a modified procedure from the Association
of Official Analytical Chemists (AOAC) and were subsequently analyzed
using Atomic Absorption Spectroscopy. Levels of lead and cadmium in
Ubeji river were significantly higher than levels in Eleyele River.
Fifty fish samples from five species ( Citharinus citharus , Liza
falcipinis , Brycinus macrolepidotus , Polydactylus quadrifilis and
Tilapia zilli ) were analysed. Lead concentration (ppm) was highest in
C. citharus (76.07±161.48) and least in T. zilli
(23.16±26.30). Chromium was not detected in B. macrolepidotus, P.
quadrifilis and T. zilli. Concentrations of all heavy metals detected,
except zinc, in the fish species were higher than WHO permissible
limit. Lead, Cadmium and Zinc concentrations in the tissues of the
control fish were significantly lower (p>0.05) than those recorded
in fish from Ubeji River. There were no statistically significant
differences in heavy metal concentration in fish gills and muscle
(p>0.05). Lead and cadmium levels in Ubeji river significantly
exceeded (p=0.0 and p=0.012) the permissible limits for aquaculture and
drinking. Levels of Chromium (1737.17±2996.01), Zinc and Lead
(149.35±188.28 and 123.49±350.85 respectively) were
significantly high (p<0.05) in the 101 human blood samples screened,
while concentrations of Cadmium was comparatively low
(10.11±10.71). Lower levels of cadmium, zinc and lead (8.54±
7.49, 79.89±62.65 and 53.46±57.17, respectively) were
recorded for the control samples from Ibadan. This study highlights the
high levels of heavy metals in the Ubeji River and suggests the need
for interventions to stem the tide of pollution in the river. It would
also be important to assess health problems that may arise as a result
of contact and continuous use of the water. @ JASE
Extracellular release of acid phosphatase from blood stream forms of Trypanosoma brucei brucei .
Acid phosphatase (ACP) activity was demonstrated in blood stream form
of Trypanosoma brucei brucei harvested from infected Wister rats by
Ion Exchange DEAE Cellulose 52 chromatography. Whole parasite extract
(WPE) and Excretory Secretory Extract (ESE) were prepared and analyzed
for acid phosphatase activity. A higher ACP activity (85.5
ÎĽmol/min) was recorded in WPE compared to ESE (36.8
ÎĽmol/min). ACP activity in ESE is suggestive of the presence of a
cell rich enzyme. Phase separation of the extracts using the detergent
Triton X-114 (TX-114), resulted in protein partitioning into aqueous
and detergent phases. ACP activity was higher in the detergent phases
(56.2 ÎĽmol/min and 28.8 ÎĽmol/min) of WPE and ESE
respectively. ACP activity recorded in the aqueous phases of WPE and
EPE was 27.8 and 7.6 ÎĽmol/min respectively. On a Size Exclusion
chromatography column using Sephacryl-300, ESE emerged as five distinct
protein peaks. ACP activity of the eluted fractions showed two peaks of
relative molecular weights 195 and 325 KD. This study shows that T.
brucei releases acid phosphatase extracellularly via a yet to be
determined mechanism. Acid phosphatase activity in ESE is indicative of
a soluble enzyme within the cell matrix which may also play an
important role in the pathology of African Trypanosomiasis
Serum Ferritin Levels In Children With Malaria Anaemia In Ibadan
This study assessed the serum ferritin levels in plasma samples from
children (4 - 74 months old) admitted for malaria at the Adeoyo
Maternity Hospital (Beere) Ibadan, Oyo State, using a sandwich-ELISA.
These values were compared with malaria parasitemia, MSP-1 antibody
titre and packed cell volume values previously obtained through
standard methods. Statistical analyses were carried out using SPSS,
Excel and Epi-Calc software. Results showed that the serum ferritin
level in the population ranged in from 363ng/ml to 1000ng/ml, with a
mean value of 630ng/ml. There was a negative correlation between serum
ferritin levels and the packed cell volume, and malaria parasitemia in
the children; while the serum ferritin levels increased with increasing
malaria antibodies. There was no significant difference in the mean
levels of ferritin in anaemic and non-anaemic children. Serum ferritin
concentration decreased with increasing age in children with malaria.
Gender was found to have no significant association with serum ferritin
levels in children with malaria anaemia
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