Assessment of natural radioactivity levels in soil samples from Dejen district, Ethiopia.

Gamma ray spectrometry was used to determine the activity concentrations of naturally occurring radionuclides in 12 soil samples collected at random from Dejen district, Ethiopia. In agricultural soils, the calculated mean activity concentrations of 226Ra, 232Th and 40K were 33.44 ± 2.01, 66.02 ± 4.54 and 214.16 ± 8.90 Bq kg-1, respectively, and in virgin soils, they were 38.05 ± 2.48, 61.78 ± 4.76 and 240.32 ± 10.79 Bq kg-1, respectively. The findings were discussed and compared to other studies' findings. The mean values of absorbed dose rate, annual effective dose rate and radium equivalent activity in agricultural land soils are 67.24 nGyh-1, 0.083 mSvy-1 and 144.57 Bq kg-1, and in virgin land soils are 67.53 nGyh-1, 0.082 mSvy-1 and 144.90 Bq kg-1, respectively. These findings were discussed and compared to the internationally recommended value. As a result, it is possible to conclude that the soil samples are safe for residents and those involved in agricultural activities.

Computed Dosimeter Dose Index on a 16-Slice Computed Tomography Scanner.

A computed tomography dose index can be used to quantify the radiation dose received during a CT scan and it is an indicator of the radiation dose to the polymetaylenmetaAcrylate (PMMA) standardized phantom. The objective of this study was 2-fold. The first was to measure the computed tomography (CT) radiation dose for the head and body polymetaylelenmetaAcrylate (PMMA) phantoms and to determine the accuracy of the CT radiation dose parameter displayed on the CT scanner console; these were measured in this investigation and compared with the dose displayed on the CT scanner console. The dose was calculated using the formalism described in the American Association of Physics in Medicine (AAPM) Report 96. The second was to compare the dosimetric results of the head and body polymetaylelenmetaAcrylate (PMMA) phantoms with dose reference levels published in international journals, as well as to measure the central cumulative dose (DL' (0)), as recommended by the American Association of Physics in Medicine (AAPM) report 111. This is a new, cutting-edge methodology for estimating the CT radiation dosage provided by the abdomen, thorax, and head of a PMMA phantom. We used a Philips Big Bore CT scanner with 16 slices. A CT dosimeter head phantom with a diameter of 16 cm, a CT dosimeter body phantom with a diameter of 32 cm, a 100 mm pencil chamber (PC), and a 20 mm short chamber (SC) were employed. These were coupled to an electrometer and a dosimetric readout device. The measured volume computed tomography dose index (CTDIvol) values were in good agreement with the CT radiation dose displayed on the corresponding CT scanner console. The percentage disagreement was less than 10%, with a maximal difference of 1.7% and 5.5% for the body and head phantom, respectively. The central cumulative dose (DL (0)) measurements (for L' = 100 mm) also matched nominal or the corresponding computed tomography dose index (CT) scanner console volume computed tomography dose index (CTDIvol) values. In this case, the agreement is always below 3% for abdomen scans and 1.0% for head examinations. This result implies that the radiation dose supplied by the 16-slice computed tomography (CT) system was in good agreement with the international dose reference level and we observed something different.

Development and validation of a delayed presenting clubfoot score to predict the response to Ponseti casting for children aged 2-10.

The aim of the study was to develop a simple and reliable clinical scoring system for delayed presenting clubfeet and assess how this score predicts the response to Ponseti casting. We measured all elements of the Diméglio and the Pirani scoring systems. To determine which aspects were useful in assessing children with delayed presenting clubfeet, 4 assessors examined 42 feet (28 patients) between the ages of 2-10 years. Selected variables demonstrating good agreement were combined to make a novel score and were assessed prospectively on a separate consecutive cohort of children with clubfeet aged 2-10, comprising 100 clubfeet (64 patients). Inter-observer and intra-observer agreement was found to be greatest using the following clinically measured angles of the deformities. These were plantaris, adductus, varus, equinus of the ankle and rotation around the talar head in the frontal plane (PAVER). Measured angles of 1-20, 21-45 and > 45 degrees scored 1, 2 and 3 points, respectively. The PAVER score was derived from both the sum of points derived from measured angles and a multiplier according to age. The sum of the points was multiplied with 1, 1.5 or 2 for ages 2-4, 5-7 and 8-10, respectively. This demonstrated a good association with the total number of casts to achieve a full correction (tau = 0.71). A score greater than 18 out of 30 indicated a cast-resistant clubfoot. The score could be used clinically for prognosis and treatment, and for research purposes to compare the severity of clubfoot deformities.

N-Glycan synthesis in the apical and basolateral secretory pathway of epithelial MDCK cells and the influence of a glycosaminoglycan domain.

Different classes of glycans are implicated as mediators of apical protein sorting in the secretory pathway of epithelial cells, but recent research indicates that sorting to the apical and basolateral surfaces may occur before completion of glycan synthesis. We have previously shown that a proteoglycan (PG) core protein can obtain different glycosaminoglycan (GAG) structures in the apical and basolateral secretory routes (Tveit H, Dick G, Skibeli V, Prydz K. 2005. A proteoglycan undergoes different modifications en route to the apical and basolateral surfaces of Madin-Darby canine kidney cells. J Biol Chem. 280:29596-29603) of epithelial Madin-Darby canine kidney (MDCK) cells. We have now also determined the detailed N-glycan structures acquired by a single glycoprotein species in the same apical and basolateral secretory pathways. For this purpose, rat growth hormone (rGH) with two N-glycan sites (rGH-2N) inserted into the rGH portion (NAS and NFT) was fused to green fluorescent protein (GFP) and expressed in MDCK cells. Immunoisolated rGH variants were analyzed for site occupancy and N-glycan structure by mass spectrometry. The extent of NAS and NFT site occupancy was different, but comparable for rGH-2N secreted apically and basolaterally. Microheterogeneity existed for the glycans attached to each N-glycan site, but no major differences were observed in the apical and basolateral pathways. Transfer of the GAG modification domain from the PG serglycin to the fusion site of rGH-2N and GFP allowed polymerization of GAG chains onto the novel protein variant and influenced the microheterogeneity of the N-glycans toward more acidic glycans, but did not alter the relative site occupancy. In conclusion, no major differences were observed for N-glycan structures obtained by the expressed model proteins in the apical and basolateral secretory pathways of epithelial MDCK cells, but insertion of a GAG attachment domain shifted the N-glycans to more acidic structures.

Isoform-specific regulation of immune cell reactivity by the catalytic subunit of protein kinase A (PKA).

There are two major genes encoding the catalytic subunits of protein kinase A, Calpha and Cbeta. The functional significance of these isoforms is enigmatic. Lymphoid cells of the immune system express both Calpha and Cbeta. In this study we tested the role of Calpha and Cbeta in regulating immune cell reactivity to antigens using mice carrying a targeted disruption of the Calpha and Cbeta gene respectively. Calpha and Cbeta ablation both resulted in a 50% reduction in PKA-specific kinase activity and the level of PKA type I but not PKA type II. Moreover, despite that C subunit ablation did not affect immune cell development and homeostasis, Calpha but not Cbeta ablation augmented expression of the activation marker CD69 on lymphocytes. CD69 induction coincided with immune cell hyperresponsiveness and was associated with reduced sensitivity to cAMP-mediated inhibition of anti-CD3 induced T cell proliferation. Our results imply that Calpha is required for normal immune cell reactivity and demonstrates isoform-specific effects and non-redundant functions of C subunit isoforms expressed in the same cell.

Inactive forms of the catalytic subunit of protein kinase A are expressed in the brain of higher primates.

It is well documented that the beta-gene of the catalytic (C) subunit of protein kinase A encodes a number of splice variants. These splice variants are equipped with a variable N-terminal end encoded by alternative use of several exons located 5' to exon 2 in the human, bovine and mouse Cbeta gene. In the present study, we demonstrate the expression of six novel human Cbeta mRNAs that lack 99 bp due to loss of exon 4. The novel splice variants, designated CbetaDelta4, were identified in low amounts at the mRNA level in NTera2-N cells. We developed a method to detect CbetaDelta4 mRNAs in various cells and demonstrated that these variants were expressed in human and Rhesus monkey brain. Transient expression and characterization of the CbetaDelta4 variants demonstrated that they are catalytically inactive both in vitro against typical protein kinase A substrates such as kemptide and histone, and in vivo against the cAMP-responsive element binding protein. Furthermore, co-expression of CbetaDelta4 with the regulatory subunit (R) followed by kinase activity assay with increasing concentrations of cAMP and immunoprecipitation with extensive washes with cAMP (1 mm) and immunoblotting demonstrated that the CbetaDelta4 variants associate with both RI and RII in a cAMP-independent fashion. Expression of inactive C subunits which associate irreversibly with R may imply that CbetaDelta4 can modulate local cAMP effects in the brain by permanent association with R subunits even at saturating concentrations of cAMP.

Identification, cloning and characterization of a novel 47 kDa murine PKA C subunit homologous to human and bovine Cbeta2.

BACKGROUND: Two main genes encoding the catalytic subunits Calpha and Cbeta of cyclic AMP dependent protein kinase (PKA) have been identified in all vertebrates examined. The murine, bovine and human Cbeta genes encode several splice variants, including the splice variant Cbeta2. In mouse Cbeta2 has a relative molecular mass of 38 kDa and is only expressed in the brain. In human and bovine Cbeta2 has a relative molecular mass of 47 kDa and is mainly expressed in lymphoid tissues. RESULTS: We identified a novel 47 kDa splice variant encoded by the mouse Cbeta gene that is highly expressed in lymphoid cells. Cloning, expression, and production of a sequence-specific antiserum and characterization of PKA catalytic subunit activities demonstrated the 47 kDa protein to be a catalytically active murine homologue of human and bovine Cbeta2. Based on the present results and the existence of a human brain-specifically expressed Cbeta splice variant designated Cbeta4 that is identical to the former mouse Cbeta2 splice variant, the mouse splice variant has now been renamed mouse Cbeta4. CONCLUSION: Murine lymphoid tissues express a protein that is a homologue of human and bovine Cbeta2. The murine Cbeta gene encodes the splice variants Cbeta1, Cbeta2, Cbeta3 and Cbeta4, as is the case with the human Cbeta gene.

Distribution of lymphocyte subsets in healthy human immunodeficiency virus-negative adult Ethiopians from two geographic locales.

Immunological values for 562 factory workers from Wonji, Ethiopia, a sugar estate 114 km southeast of the capital city, Addis Ababa, Ethiopia, were compared to values for 218 subjects from Akaki, Ethiopia, a suburb of Addis Ababa, for whom partial data were previously published. The following markers were measured: lymphocytes, T cells, B cells, NK cells, CD4(+) T cells, and CD8(+) T cells. A more in depth comparison was also made between Akaki and Wonji subjects. For this purpose, various differentiation and activation marker (CD45RA, CD27, HLA-DR, and CD38) expressions on CD4(+) and CD8(+) T cells were studied in 60 male, human immunodeficiency virus-negative subjects (30 from each site). Data were also compared with Dutch blood donor control values. The results confirmed that Ethiopians have significantly decreased CD4(+) T-cell counts and highly activated immune status, independent of the geographic locale studied. They also showed that male subjects from Akaki have significantly higher CD8(+) T-cell counts, resulting in a proportional increase in each of the CD8(+) T-cell compartments studied: naïve (CD45RA(+)CD27(+)), memory (CD45RA(-)CD27(+)), cytotoxic effector (CD45RA(+)CD27(-)), memory/effector (CD45RA(-)CD27(-)), activated (HLA-DR(+)CD38(+)), and resting (HLA-DR(-)CD38(-)). No expansion of a specific functional subset was observed. Endemic infection or higher immune activation is thus not a likely cause of the higher CD8 counts in the Akaki subjects. The data confirm and extend earlier observations and suggest that, although most lymphocyte subsets are comparable between the two geographical locales, there are also differences. Thus, care should be taken in extrapolating immunological reference values from one population group to another.

Immunohematological reference ranges for adult Ethiopians.

A cross-sectional survey was carried out with 485 healthy working adult Ethiopians who are participating in a cohort study on the progression of human immunodeficiency virus type 1 (HIV-1) infection to establish hematological reference ranges for adult HIV-negative Ethiopians. In addition, enumeration of absolute numbers and percentages of leukocyte subsets was performed for 142 randomly selected HIV-negative individuals. Immunological results were compared to those of 1,356 healthy HIV-negative Dutch blood donor controls. Immunohematological mean values, medians, and 95th percentile reference ranges were established. Mean values were as follows: leukocyte (WBC) counts, 6.1 x 10(9)/liter (both genders); erythrocyte counts, 5.1 x 10(12)/liter (males) and 4.5 x 10(12)/liter (females); hemoglobin, 16.1 (male) and 14.3 (female) g/dl; hematocrit, 48.3% (male) and 42.0% (female); platelets, 205 x 10(9)/liter (both genders); monocytes, 343/microl; granulocytes, 3, 057/microl; lymphocytes, 1,857/microl; CD4 T cells, 775/microl; CD8 T cells, 747/microl; CD4/CD8 T-cell ratio, 1.2; T cells, 1, 555/microl; B cells, 191/microl; and NK cells, 250/microl. The major conclusions follow. (i) The WBC and platelet values of healthy HIV-negative Ethiopians are lower than the adopted reference values of Ethiopia. (ii) The absolute CD4 T-cell counts of healthy HIV-negative Ethiopians are considerably lower than those of the Dutch controls, while the opposite is true for the absolute CD8 T-cell counts. This results in a significantly reduced CD4/CD8 T-cell ratio for healthy Ethiopians, compared to the ratio for Dutch controls.

Decline of Glossina morsitans ugadensis in Gambella, Ethiopia.

Gambella is the only area where sleeping sickness is endemic in Ethiopia. Four species of Glossina had been reported from Gambella out of the five species found in the country in surveys made before 1985. These are Glossina morsitans ugadensis, G. pallidipes, G. fuscipes and G. tachinoides. A tsetse fly survey was carried out in parts of Gambella owing to the fact that the area is undergoing ecological changes due to massive deforestation (because of resettlement and development programmes), poaching, and introduction of domestic animals into tsetse infested parts of Gambella after 1985. Tsetse populations were sampled for one year, March 1993-April 1994, using biconical traps and hand catches. The survey has reported all Glossina spp which were previously reported except G. morsitans ugadensis. It seems that a combination of factors, such as, lack of host and increase in human population have forced G. morsitans ugadensis to decline. This study has consolidated the fact that tsetse flies of the morsitans group specially G. morsitans, are easily affected by human interference while the palpalis group is resistant to this factor. In addition, this study has also indicated, villagization and rural development could be practised where G. morsitans is the only species in a certain area to alleviate pressure on already impoverished land in parts of Africa.