Erythemal UV radiation across Nigeria: where do we stand?

The deleterious effects of solar ultraviolet (UV) radiation on humans are of public health concern which demands constant global monitoring and intervention. This study analysed the latitudinal variations in mean daily and multi-year erythemal ultraviolet radiation (EUVR) across 7 states in Nigeria using satellite data from the Total Ozone Mapping Spectrophotometer (TOMS) and Ozone Mapping Instrument (OMI). The latitudes studied were 13° N, 8° N, 6° N and 4° N respectively, using 37 years of data obtained from phases: 1979-1988, 1989-1998, 1999-2008 and 2009-2020. The data obtained were statistically analysed using Ms Excel and MATLAB. The results of this study show that the mean daily EUVR at the selected latitudes ranges from 32.97 to 390 (mW/m2). The results show that Borno State located at latitude 13° N had the highest EUVR, while Rivers State recorded the least EUVR at latitude 4° N. Comparative analysis of all the locations studied indicates latitudinal and longitudinal variations because the eastern axis recorded higher values than its western counterpart on the same latitude. Box and whisker plots in this study summarized the latitudinal variance in the mean multi-year EUVR in each phase. Box and whisker plots from 2009-2020 showed that there was a drastic reduction in mean multi-year EUVR in this phase unlike in the other phases. The findings of this study when compared to the UV index show that the 37 years mean EUVR obtained across Nigeria ranged from 8-10 which is on the "very high" category. This study recommends the implementation of WHO suggestions in preventing the biological effects of solar UV radiation. Furthermore, the Nigerian government should curb ignorance among its citizens by heightening public awareness of the effects of EUVR.

First Malian series of surgery for rheumatic valve disease: opening of the centre, clinical features and peri-operative realities.

INTRODUCTION: Over the past two decades, the incidence of acute rheumatic fever (ARF) and chronic rheumatic heart disease (RHD) have dramatically declined in wealthier regions of the world as a result of preventative programmes, improved living standards and access to cardiac surgery. Nevertheless, ARF and RHD are still public health problems in less-developed regions of the world such as Oceania, south Asia and sub-Saharan Africa. AIM: We report on clinical, therapeutic and prognostic aspects as well as the difficulties encountered during this first series of surgery for rheumatic valve disease in Mali. METHODS: This was a prospective, descriptive study conducted at the Andre Festoc Cardiac Surgery Centre from September 2018 to August 2019. RESULTS: The frequency of patients having been operated on for rheumatic valve disease was 44.73% (68 patients). The mean age of the patients was 18 ± 10 years with extremes of five and 60 years. The gender ratio was 0.7. The delay to treatment was between one and three years for 39.7% of the patients. The main diagnoses found were: mitral regurgitation in 50% of patients, mitral stenosis in 16.2% and aortic regurgitation in 10.3%. Pulmonary artery systolic pressure was 35-50 mmHg in 19.1% of patients and more than 50 mmHg in 25%. The median cardiopulmonary bypass time was 132 minutes (60-276) and median extubation time was three hours (0-96). The main complications were cardiac, renal, neurological, respiratory, gastrointestinal and infectious. In the immediate postoperative period, we recorded three deaths, which is a mortality rate of 4.4%. CONCLUSIONS: Humanitarian efforts have led non-governmental organisations (NGOs) to launch surgical programmes in low-and middle-income countries in an attempt to fill the gap in these fragile healthcare systems. Cardiac surgery requires much expertise from the medical staff, as well as many material and financial resources. Empowerment of the local team is a challenge that is being realised since taking these essential steps of companionship with the NGO la Chaine de l'Espoir.

Mathematical modeling of bone marrow--peripheral blood dynamics in the disease state based on current emerging paradigms, part I.

Stemming from current emerging paradigms related to the cancer stem cell hypothesis, an existing mathematical model is expanded and used to study cell interaction dynamics in the bone marrow and peripheral blood. The proposed mathematical model is described by a system of nonlinear differential equations with delay, to quantify the dynamics in abnormal hematopoiesis. The steady states of the model are analytically and numerically obtained. Some conditions for the local asymptotic stability of such states are investigated. Model analyses suggest that malignancy may be irreversible once it evolves from a nonmalignant state into a malignant one and no intervention takes place. This leads to the proposition that a great deal of emphasis be placed on cancer prevention. Nevertheless, should malignancy arise, treatment programs for its containment or curtailment may have to include a maximum and extensive level of effort to protect normal cells from eventual destruction. Further model analyses and simulations predict that in the untreated disease state, there is an evolution towards a situation in which malignant cells dominate the entire bone marrow - peripheral blood system. Arguments are then advanced regarding requirements for quantitatively understanding cancer stem cell behavior. Among the suggested requirements are, mathematical frameworks for describing the dynamics of cancer initiation and progression, the response to treatment, the evolution of resistance, and malignancy prevention dynamics within the bone marrow - peripheral blood architecture.

Investigation of differences in sensitivity between 3 strains of Daphnia magna (crustacean Cladocera) exposed to malathion (organophosphorous pesticide).

Acute and chronic ecotoxic effects of organophosphorous insecticide malathion (Fyfanon 50 EC 500 g L(-1)) were investigated on three strains of Daphnia magna. The nominal effective concentrations immobilizing 50% (EC50) of Daphnia after 24 and 48 h were 0.53 and 0.36 µg L(-1), 0.70 and 0.44 µg L(-1), and 0.75 and 0.46 µg L(-1) for the strains 1, 2, and 3 respectively. There was an increase in malathion ecotoxicity with time of exposure as confirmed by chronic studies. In fact, after 21 days of exposure, significant effects on survival (lowest observed effect concentration or LOECs) were recorded at malathion concentrations of 22, 220 and 230 ng L(-1) for strains 1, 2 and 3 respectively. Other endpoints were also examined, including reproduction (with different parameters), body length and embryo toxicity. ICs10 and ICs20 were calculated for these different parameters. ICs10 ranged from 4.7 to more than 220 ng L(-1) for the three tested strains. The most sensitive parameter was the number of neonates per adult (ICs10 = 4.7 and 10.8 ng L(-1) for strains 1 and 2 respectively) or the number of broods (IC10 = 10 ng L(-1) for strain 3). Moreover, an increase in embryo development abnormalities was observed at the two highest tested malathion concentrations. Abnormalities comprised undeveloped second antennae, curved or unextended shell spines, and curved post-abdomen spines in live neonates. Results suggest that malathion could act as an endocrine disruptor in D. magna as it interferes with development. It also induces a significant decrease in acetylcholinesterase (AChE) activities for the three strains. Both strains 2 and 3 seemed more sensitive (LOECs = 60 ng L(-1)) than strain 1 (LOEC = 120 ng L(-1)). Our results suggest that the AChE activity response can also be used as a biomarker of inter-strain (or inter-clonal) susceptibility (i.e. strain (or clone)-specific response).

Morphological changes in the liver after the administration of piroxicam and its complexes with Bio-Ions Cu (II), Co (II), Zn (II) to the rats.

In this research we present the results of the liver histopathological examinations after the administration of the Piroxicam (Pirox) and its complex combinations with metal bio-ions Cu (II), Co (II), Zn (II) to rats (White Wistar, 150-180 gr.). The results of the histological investigations are presented separately for each compound revealing the modifications after 24 hours and after 7 days. The hepatic lesions are noted in the case of Zn-Pirox after 24 hours and after 7 days, as well. The complexes Cu-Pirox and Co-Pirox don't produce hepatic modifications either after 24 hours or after 7 days according to our histological investigations.

A comparative study regarding the morphological alteration on the gastric level after the administration of piroxicam and complexes with bio-ions Cu(II), Co(II), Zn(II) to rats.

The complex combinations of Piroxicam (Pirox) with the metallic bio-ions: Cu(II), Co(II), Zn(II) have been obtained and defined in a previous stage by physical-chemical methods (IR, X, SM, CSS-UV, DTA, DTG), an toxicological and biochemical aspect. In this research are presented the results of the histological examinations at the level of stomach, for each compound, at 24 hours and at 7 days after the administration of the Piroxicam and of its complexes to rats. The tissues histo-pathological investigation has pointed out lesions the glandular stomach level (necrosis, ulcers) especially after the administration of the Piroxicam and of the Zn-Pirox complex. Name of these have been present after the administration of Cu-Pirox, Co-Pirox.

Functional proteomics of receptor-Ck in the developmental stages of human atherosclerotic arterial wall.

BACKGROUND: The study was undertaken to understand the relationship between the functional proteomics of receptor-Ck and developmental stages of human atherosclerotic aortic wall. METHODS AND RESULTS: Gene expression study of 25 aortas was undertaken and the results revealed a gradual increase in receptor-Ck gene expression paralleled by the regulatory response of its effector genes coding for sterol response element-binding protein, p27, cyclin D, interleukin-6 and CD40 from a normal to atherosclerotic arterial wall (viz. fatty streak and fibrofatty/fibrous plaque). CONCLUSIONS: Based upon this and our earlier studies, we propose that cholesterol-specific receptor-Ck-dependent gene regulation may be of crucial importance in atherogenesis.

A novel C1-using denitrifier alcaligenes sp. STC1 and its genes for copper-containing nitrite reductase and azurin.

A novel denitrifier Alcaligenes sp. STC1 was identified. The strain efficiently denitrifies under an atmosphere of 10% oxygen (O2) where Paracoccus denitrificans, one of the most studied aerobic denitrifiers, had less denitrifying activity, indicating that the strain has an O2-torelant denitrifying system. It denitrified by using C1-carbon sources such as formate and methanol as well as glucose, glycerol, and succinate. The genes for the copper-containing nitrite reductase and azurin of this C1-using denitrifier were cloned. Their predicted products of them were similar to those of their counterparts and the maximum similarities were 90% and 92%, respectively.

Involvement of deregulated epiregulin expression in tumorigenesis in vivo through activated Ki-Ras signaling pathway in human colon cancer cells.

To identify the genes located downstream of the activated Ki-Ras signaling pathways in human colon cancer cells, a PCR-based cDNA subtraction library was constructed between HCT116 cells and HCT116-derived activated Ki-ras-disrupted cells (HKe3). One of the genes in HCT116 that was evidently up-regulated was epiregulin, a member of the epidermal growth factor family that is expressed in many kinds of human cancer cells. HKe3-stable transfectants expressing activated Ki-Ras regained over-expression of epiregulin. To further elucidate the biochemical structure and significance of epiregulin expression in tumorigenesis, HKe3-stable transfectants expressing epiregulin (e3-pSE cells) were established. Epiregulin existed as highly glycosylated membrane-bound forms, and TPA rapidly induced ectodomain shedding of epiregulin. Furthermore, the conditioned medium of e3-pSE cells showed more DNA synthesis for 32D cells expressing epidermal growth factor receptor (DER) cells than that of HKe3. Although anchorage-independent growth in soft agar was not observed for e3-pSE cells, tumorigenicity in nude mice was observed evidently, and their growth rate was correlated with each amount of exogenous epiregulin expression. These results suggested that activated Ki-Ras will be one of the factors contributing to the overexpression of epiregulin in human colon cancer cells, and that epiregulin will play a critical role in human tumorigenesis in vivo.

Bis[N,N-bis(2-hydroxyethyl)dithiocarbamato]dimethyltin(IV).

The title compound, [Sn(CH(3))(2)(C(5)H(10)NO(2)S(2))(2)], has crystallographic mirror symmetry (C-Sn-C on mirror plane) and the coordination polyhedron around the Sn atom is a tetrahedron [C-Sn-C 139.3 (2) degrees and S-Sn-S 82.3 (1) degrees ] distorted towards a skew-trapezoidal bipyramid owing to an intramolecular Sn.S contact [3.0427 (6) A]. The molecules are linked into a linear chain by intermolecular O-H.O hydrogen bonds [O.O 2.646 (3) A].

Denitrification by actinomycetes and purification of dissimilatory nitrite reductase and azurin from Streptomyces thioluteus.

Many actinomycete strains are able to convert nitrate or nitrite to nitrous oxide (N2O). As a representative of actinomycete denitrification systems, the system of Streptomyces thioluteus was investigated in detail. S. thioluteus attained distinct cell growth upon anaerobic incubation with nitrate or nitrite with concomitant and stoichiometric conversion of nitrate or nitrite to N2O, suggesting that the denitrification acts as anaerobic respiration. Furthermore, a copper-containing, dissimilatory nitrite reductase (CuNir) and its physiological electron donor, azurin, were isolated. This is the first report to show that denitrification generally occurs among actinomycetes.

Induction of cytokine-induced neutrophil chemoattractant in response to various stresses in rat C6 glioma cells.

The effect of stress on the production of cytokine-induced neutrophil chemoattractant (CINC) was examined in rat C6 glioma cells. We studied the production of CINC, an interleukin-8 (IL-8) family protein, with bacterial endotoxin, H2O2, and tumor necrosis factor-alpha (TNF-alpha). Each stress induced CINC mRNA in a concentration-dependent manner. Since stress activates the protein kinases regulating nuclear transcription factors, we examined the effects of protein kinase inhibitors and the over-expression of dominant-negative Ras on CINC mRNA expression. Neither over-expression of dominant-negative Ras nor pretreatment with PD98059 (MEK-1 inhibitor), SB203580 (p38MAPK inhibitor), or GF109203X (protein kinase C (PKC) inhibitor) altered stress-induced CINC mRNA expression. This suggests that the Ras-MAPK, p38MAPK, and PKC pathways are not involved in CINC mRNA expression in glial cells. On the other hand, pretreatment with herbimycin A, a potent tyrosine kinase inhibitor, or Ro31-8220, a non-selective serine/threonine kinase inhibitor, suppressed stress-induced CINC mRNA expression. This indicates that stress-induced CINC mRNA expression is mediated by herbimycin A-, or Ro31-8220-sensitive kinases in glial cells. Since stress activates NF-kappaB and NF-IL6, we examined that the effect of herbimycin A, which suppresses CINC mRNA expression, on NF-kappaB and NF-IL6 activation. Herbimycin A suppressed NF-kappaB but not NF-IL6. These results suggest that in rat glial cells, the factors that induce CINC mRNA expression are mediated by herbimycin A-sensitive NF-kappaB activation, but not through the PKC, Ras-MAPK or p38 MAPK pathways.

[A comparative analysis of the results of using different methods of helium-neon laser therapy in patients with stable stenocardia]. / Porivnial'nyi analiz rezul'tativ vykorystannia riznykh sposobiv heliievo-neonovoï lazeroterapiï u khvorykh na stabil'nu stenokardiiu.

Based on the findings from the examination of 133 patients with stable angina pectoris, it was shown that He-Ne laser therapy with the irradiation being applied to the liver projection area in combination with the prolonged-action nitrates is superior to similar application of irradiation to the precordial region and Head's zones or intravenous irradiation of blood. Revealed in the examination of the above patients was a reaction of antiproteolytic enzymes to He-Ne laser therapy, which appeared to be varying with methods of laser therapy. It is suggested that a reaction of the realization of the components of proteolysis might be involved in the realization of therapeutic effect of the He-Ne laser energy in patients with ischemic heart disease.

Regulatory Effect of Cell Density on the Platelet-aggregating Activity of Human Melanoma Cell Line.

Human melanoma cell Line, HMV-I, has been shown to induce platelet aggregation without thrombin generation. The platelet-aggregating activity of HMV-I cells increased with increasing culture periods of the cells. However, data indicate that the platelet-aggregating activity of HMV-I cells is dependent upon the cell density of the culture and does not result from the culture periods- nor cell cycle-dependent regulation. It is suggested that this effect of cell density is referred to as density-induced upregulation of platelet-aggregating activity.

Characterization of platelet aggregation induced by the human melanoma cell line HMV-I: roles of heparin, plasma adhesive proteins, and tumor cell membrane proteins.

We investigated the in vitro mechanism of platelet aggregation induced by HMV-I human melanoma cells. HMV-I cells, in the absence of exogenous plasma proteins, induced platelet aggregation, followed by the release reaction. Heparin at an anticoagulant concentration had no effect on the aggregation. Calcium ion was essential for this tumor cell-platelet interaction and could not be replaced by magnesium. Among the adhesive proteins containing RGD sequences that have been reported to enhance experimental metastasis, fibrinogen and thrombospondin significantly enhanced the aggregation induced by HMV-I cells, fibronectin and von Willebrand factor inhibited it, and vitronectin had no effect. To identify the platelet-aggregating factor(s) of the tumor cells, we have developed a monoclonal antibody against HMV-I cells that can inhibit HMV-I cell-induced platelet aggregation. Immunoprecipitation analysis revealed that this antibody recognized an Mr 71,000 membrane protein. These results suggest that the association between the tumor cells and platelets is mediated by the Mr 71,000 membrane protein recognized by this monoclonal antibody.

[A well differentiated fibrosarcoma arising in left neck region].

The frequency of a fibrosarcoma, based on current criteria, is less than 10% of soft tissue sarcomas. It is most common in the region of extremities and the trunk and relatively rare in the head and neck region. Therefore, of interest is a case of a well differentiated fibrosarcoma arising in left neck region of a 69-year-old woman that is reported. The excised tumor consisted of a firm, partially lobulated mass with a fibrous capsule that measured 8 cm at its greatest diameter. Histologically, the tumor tissue was rather uniform and often had a fasciculated growth pattern consisting of spindle shaped cells and interwoven collagenous fiber in a parallel fashion. To achieve a diagnosis, it was necessary to differentiate this type of fibrosarcoma from aggressive fibromatosis and myogenic tumor (leiomyoma or leiomyosarcoma).