The underlying mechanism of nuclear and mitochondrial DNA damages in triggering cancer incidences: Insights into proteomic and genomic sciences

The attempt of this review article is to determine the impact of nuclear and mitochondrial damages on the propagation of cancer incidences. This review has advanced our understanding to altered genes and their relevant cancerous proteins. The progressive raising effects of free reactive oxygen species ROS and toxicogenic compounds contributed to significant mutation in nuclear and mitochondrial DNA where the incidence of gastric cancer is found to be linked with down regulation of some relevant genes and mutation in some important cellular proteins such as AMP-18 and CA-11. Thereby, the resulting changes in gene mutations induced the apparition of newly polymorphisms eventually leading to unusual cellular expression to mutant proteins. Reduction of these apoptotic growth factors and nuclear damages is increasingly accepted by cell reactivation effect, enhanced cellular signaling and DNA repairs. Acetylation, glycation, pegylation and phosphorylation are among the molecular techniques used in DNA repair for rectifying mutation incidences. In addition, the molecular labeling based fluorescent materials are currently used along with the bioconjugating of signal molecules in targeting disease translocation site, particularly cancers and tumors. These strategies would help in determining relevant compounds capable in overcoming problems of down regulating genes responsible for repair mechanisms. These issues of course need interplay of both proteomic and genomic studies often in combination of molecular engineering to cible the exact expressed gene relevant to these cancerous proteins.

Watermelon (Citrullus lanatus) leaf extract attenuates biochemical and histological parameters in high-fat diet/streptozotocin-induced diabetic rats

The present research aimed to investigate the attenuative effects of watermelon (Citrullus lanatus) leaf extract on biochemical and histological parameters in a high-fat diet combined with a low-dose streptozotocin (HFD/STZ)-induced type 2 diabetes mellitus. Forty male Sprague Dawley rats were divided into five groups, including three supplemented groups: 10 mg metformin/kg BW (HFD/STZ +M), 200 mg watermelon leaf extract /kg BW (HFD/STZ + LD), and 400 mg watermelon leaf extract /kg BW (HFD/STZ + HD). The efficacy of the 6-week intervention was evaluated by measuring body weight, fasting blood sugar, serum insulin, lipid profile, superoxide dismutase, catalase, malondialdehyde, and serum liver markers. Kidneys and liver structure were defined by histopathological examination. Results revealed that intervention with watermelon leaf extract attenuated the biochemical parameters and the structural changes in kidneys and liver. In brief, the watermelon leaf extract treatment could effectively decrease complications associated with diabetes better than metformin, and that the treatment with 400 mg/kg BW is the most potent. PRACTICAL APPLICATIONS: This was the first study to investigate the antidiabetic potential of watermelon leaf extract in obese diabetic rats. Data revealed that the watermelon leaf extract significantly attenuated the HFD/STZ-induced diabetes changes, as evidenced by the biochemical and histological data. Hence, watermelon leaf could be an excellent candidate to be developed as a functional food ingredients or nutraceuticals for holistic management of diabetes mellitus and its complications.

Analytical Computation of Interleukin17A Activity in Breast Cancer Patients Using Bioinformatics Methods

Interleukin-17A (IL-17A) is a member of the Interleukin-17 family, which belongs to the pro-inflammatory cystine-knot cytokines. Recent studies on the etiology of breast cancer have focused on the role of immunity and inflammation. The pro-inflammatory cytokines IL-17A can medicate cancer-related inflammation. The present study aimed to analyze the mutation in physicochemical properties and structure of the Interleukin-17 A gene in developing breast cancer using bioinformatics methods. A total of 60 blood samples were obtained from Iraqi women aged 25 to 75 with breast cancer. Twenty blood samples were obtained from healthy women in the same age range as a control group. Deletion and missense mutations detected by BLAST in samples with breast cancer. The present study determined the physicochemical properties of IL-17A such as hydrophilic nature, alpha-helical and 3D structure. The results of this study indicated that IL-17A is considered a marker for a patient with breast cancer. Also, mutations in the IL-17A gene affect the structure and physicochemical properties of the IL-17A protein complex.

Characterization of crude 5'-phosphodiesterase from germinated adzuki (Vigna angularis L.) beans

BACKGROUND

5'-Phosphodiesterase (5'-PDE) is an enzyme that hydrolyzes RNA to form 5'-inosine monophosphate (5'-IMP) and 5'-guanosine monophosphate (5'-GMP). These 5'-nucleotides can function as flavor enhancers. Adzuki beans (Vigna angularis L.) are found to be high in 5'-PDE.

METHODS

5'-phosphodiesterase (5'-PDE) enzyme was characterized from adzuki beans, in which the optimum pH and temperature were determined. In addition, the stability of 5'-PDE was assessed at different pH and temperature. The effects of cations and EDTA were evaluated to characterize the 5'-PDE enzymes further.

RESULTS

The alkaline 5'-phosphodiesterase has an optimum pH of 8.5. This enzyme is also thermostable, with an optimum temperature of 80°C. The stability in terms of temperature and pH was also determined, and was found to be stable in the pH range of 7.0-8.5. This enzyme was found to retain more than 80% of its activity for 4 days at 60 and 65°C. In addition, the effects of 14 different metal ions, 4 types of detergents and ethylenediaminetetraacetic acid (EDTA) on 5'-PDE were studied. Ca2+, K+, Mg2+ and Li+ activated 5'-PDE while Na+, Zn2+, Ni+, Hg+, Cu2+, Pb2+, Fe2+, Al3+, Ba2+ and Co2+ were inhibitory. EDTA, Triton X-100 and sodium dodecyl sulfate (SDS) were strong inhibitors of 5'-PDE, while Tween 80 and Tween 20 were slightly inhibitory. The effects of cations and EDTA suggest that 5'-PDE from adzuki beans is a metalloenzyme.

CONCLUSIONS

Although 5'-PDE from adzuki beans has a high temperature optimum of 80°C, the enzyme is more stable at 60°C, and different cations affected the activity of the enzyme differently.

Tuberculosis infection prevention and control measures in DOTS centres in Lagos State, Nigeria

<sec id="st1"> <title>SETTING</title> Nigeria is a high tuberculosis (TB) burden country. However, there is limited evidence on implementation of tuberculous infection prevention and control (TBIC) practices in Nigeria. </sec> <sec id="st2"> <title>OBJECTIVE</title> To assess TBIC practices, and barriers to their implementation, in TB-DOTS centres in Lagos State, Nigeria. </sec> <sec id="st3"> <title>DESIGN</title> A descriptive cross-sectional study was used to assess 112 TB-DOTS centres in primary and secondary health facilities in Lagos State using mixed methods. Quantitative data comprised a survey and measurement of the air exchange rate in a subsample of centres. The qualitative aspect comprised focus-group discussions to highlight health care workers' (HCWs') perceptions of TBIC guidelines and barriers to their implementation. </sec> <sec id="st4"> <title>RESULTS</title> The majority of the DOTS centres had a dedicated TBIC officer, while a fifth (21%) had documented TBIC plans. About 57% of DOTS centres had staff that had been trained on TBIC and 37% provided some form of personal respiratory protection (face masks/tissue papers) for staff or patients. The air exchange rate was adequate in 21% of centres. The HCWs' perception of being at risk of contracting TB was reported to affect the way they relate to TB patients. The key barrier to implementing TBIC was the design of DOTS centres. </sec> <sec id="st5"> <title>CONCLUSION</title> TBIC measures at study centres were inadequate. Institutional commitment, renovation of existing and appropriate design of new DOTS centres in the future to improve TBIC implementation is recommended. </sec>.

Characterization of three varieties of Malaysian rambutan seed oil

Introduction: Rambutan seed is considered a waste by-product of fruit processing. The seed waste is usually discarded or disposed in a large amount without an economic value which has become an issue that needs to be solved.  However, the seed contains a considerable amount of crude fat. Aim: the purpose of this study was to characterize the physicochemical properties of oil of the seeds of three varieties of Malaysian rambutan fruit (R4, R7 and Serjan) for potential application. Materials and methods: In this study, colour, refractive index, viscosity, free fatty acid content, peroxide value, p-anisidine value, iodine value, saponification value, unsaponifiable matter, fatty acid composition, thermal behaviour, melting point, and solid fat content of rambutan seed oil from three varieties were used to characterise physicochemical properties of rambutan seed oil. Results: No significant differences (p > 0.05) were observed for free fatty acid content, peroxide value, p-anisidine value, saponification value, unsaponifiable matter, colour, viscosity and refractive index among three varieties. There are significant differences (p < 0.05) in the iodine value and melting point among the rambutan seed oil of three varieties. Varieties R7 and R4 seed had the highest (37.62 ± 0.10 %) and lowest (34.25 ± 0.07 %) crude fat content, respectively. Oleic (37.75-40.58 %) and arachidic (35.24-36.89 %) acids were the major fatty acids in the oil. Both melting and crystallization curves showed that the oil exhibited three distinct peaks. The complete melting and crystallization onset temperatures of the oil were 24.76–26.57°C and 21.19–22.79°C, respectively.Conclusions: This study reveals that the rambutan seed oil has potential to be used in various sectors of food industry. Therefore, rambutan seed can be fully utilized and, subsequently, the amount of waste can be minimized.

Determining the oxidative stability and quality of tiger nut (Cyperus esculentus) oil and its antioxidant activity during microwave heating

Introducción: El énfasis en los aceites vegetales con alto contenido de ácido oleico es prominente en las comunidades humanas de todo el mundo. Dicho esto, el alto nivel de este ácido graso monoinsaturado (ácido oleico) en el aceite de chufa (Cyperus esculentus) muestra que es resistente a la estabilidad oxidativa. El propósito de este estudio fue ver si el aceite de chufa puede explotarse para su uso como una fuente alternativa o suplementaria de aceite de cocina de alta calidad y nutritivo.Materiales y métodos: En este estudio se utilizó el Color, RI, viscosidad, PV, p-AV, FFA, TPC, a 233 y 269 nm, comportamiento térmico, TAG y FAC para evaluar el aceite después del calentamiento por microondas.Resultados: El PV, p-AV, FFA, TPC y extinción específica aumentaron durante el calentamiento con microondas. Se detectaron diferencias significativas (p <0,05) para el peróxido, la anisidina, el valor del ácido, los compuestos polares y la extinción específica. Durante el calentamiento con microondas, las cantidades de los valores de peróxido, anisidina y TOTOX aumentaron desde el valor inicial de 3,06, 0,72 y 6,84 para el aceite no calentado a 4,11, 10,02 y 18,25 después de 15 minutos de calentamiento respectivamente. El ácido graso libre cambió de 0,10 a 0,12% durante el calentamiento con microondas. La cantidad de ácidos grasos insaturados disminuyó significativamente durante el calentamiento. Durante el calentamiento con microondas, la actividad antioxidante disminuyó significativamente (p <0,05) de 68,60 a 19,66 (para el aceite de chufa sin calentar y después de 15 minutos de calentamiento en altas concentraciones mediante la prueba de DPPH, respectivamente).Conclusiones: Esto puede indicar que el aceite de chufa puede soportar tratamientos térmicos en métodos culinarios como la fritura y se puede concluir que el aceite de chufa es estable en los procesos de calentamiento, especialmente la fritura.

Response Surface Methodology Modelling of an Aqueous Two-Phase System for Purification of Protease from Penicillium candidum (PCA 1/TT031) under Solid State Fermentation and Its Biochemical Characterization

Penicillium candidum (PCA 1/TT031) synthesizes different types of extracellular proteases. The objective of this study is to optimize polyethylene glycol (PEG)/citrate based on an aqueous two-phase system (ATPS) and Response Surface Methodology (RSM) to purify protease from Penicillium candidum (PCA 1/TT031). The effects of different PEG molecular weights (1500–10,000 g/mol), PEG concentration (9%–20%), concentrations of NaCl (0%–10%) and the citrate buffer (8%–16%) on protease were also studied. The best protease purification could be achieved under the conditions of 9.0% (w/w) PEG 8000, 5.2% NaCl, and 15.9% sodium citrate concentration, which resulted in a one-sided protease partitioning for the bottom phase with a partition coefficient of 0.2, a 6.8-fold protease purification factor, and a yield of 93%. The response surface models displayed a significant (p ≤ 0.05) response which was fit for the variables that were studied as well as a high coefficient of determination (R²). Similarly, the predicted and observed values displayed no significant (p > 0.05) differences. In addition, our enzyme characterization study revealed that Penicillium candidum (PCA 1/TT031) produced a slight neutral protease with a molecular weight between 100 and 140 kDa. The optimal activity of the purified enzyme occurred at a pH of 6.0 and at a temperature of 50 °C. The stability between different pH and temperature ranges along with the effect of chemical metal ions and inhibitors were also studied. Our results reveal that the purified enzyme could be used in the dairy industry such as in accelerated cheese ripening.

Evaluation of commercial soy sauce koji strains of Aspergillus oryzae for γ-aminobutyric acid (GABA) production

In this study, four selected commercial strains of Aspergillus oryzae were collected from soy sauce koji. These A. oryzae strains designated as NSK, NSZ, NSJ and NST shared similar morphological characteristics with the reference strain (A. oryzae FRR 1675) which confirmed them as A. oryzae species. They were further evaluated for their ability to produce γ-aminobutyric acid (GABA) by cultivating the spore suspension in a broth medium containing 0.4 % (w/v) of glutamic acid as a substrate for GABA production. The results showed that these strains were capable of producing GABA; however, the concentrations differed significantly (P < 0.05) among themselves. Based on the A. oryzae strains, highest GABA concentration was obtained from NSK (194 mg/L) followed by NSZ (63 mg/L), NSJ (51.53 mg/L) and NST (31.66 mg/L). Therefore, A. oryzae NSK was characterized and the sequence was found to be similar to A. oryzae and A. flavus with 99 % similarity. The evolutionary distance (K nuc) between sequences of identical fungal species was calculated and a phylogenetic tree prepared from the K nuc data showed that the isolate belonged to the A. oryzae species. This finding may allow the development of GABA-rich ingredients using A. oryzae NSK as a starter culture for soy sauce production.

Green Tea Leaves Extract: Microencapsulation, Physicochemical and Storage Stability Study

Green tea polyphenols have been reported to possess many biological properties. Despite the many potential benefits of green tea extracts, their sensitivity to high temperature, pH and oxygen is a major disadvantage hindering their effective utilization in the food industry. Green tea leaves from the Cameron Highlands Malaysia were extracted using supercritical fluid extraction (SFE). To improve the stability, green tea extracts were encapsulated by spray-drying using different carrier materials including maltodextrin (MD), gum arabic (GA) and chitosan (CTS) and their combinations at different ratios. Encapsulation efficiency, total phenolic content and antioxidant capacity were determined and were found to be in the range of 71.41%–88.04%, 19.32–24.90 (g GAE/100 g), and 29.52%–38.05% respectively. Further analysis of moisture content, water activity, hygroscopicity, bulk density and mean particles size distribution of the microparticles were carried out and the results ranged from; 2.31%–5.11%, 0.28–0.36, 3.22%–4.71%, 0.22–0.28 g/cm³ and 40.43–225.64 µm respectively. The ability of the microparticles to swell in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) was determined as 142.00%–188.63% and 207.55%–231.77%, respectively. Release of catechin polyphenol from microparticles in SIF was higher comparable to that of SGF. Storage stability of encapsulated catechin extracts under different temperature conditions was remarkably improved compared to non-encapsulated extract powder. This study showed that total catechin, total phenolic content (TPC) and antioxidant activity did not decrease significantly (p ≥ 0.05) under 4 °C storage conditions. The half-life study results were in the range of 35–60, 34–65 and 231–288 weeks at storage temperatures of 40 °C, 25 °C and 4 °C respectively, therefore, for improved shelf-life stability we recommend that microparticles should be stored at temperatures below 25 °C.

Tuberculosis infection control measures in health care facilities offering tb services in Ikeja local government area, Lagos, South West, Nigeria

Background

Tuberculosis infection among health care workers is capable of worsening the existing health human resource problems of low - and middle-income countries. Tuberculosis infection control is often weakly implemented in these parts of the world therefore, understanding the reasons for poor implementation of tuberculosis infection control guidelines are important. This study was aimed at assessing tuberculosis infection control practices and barriers to its implementation in Ikeja, Nigeria.

Methods

A cross-sectional study in 20 tuberculosis care facilities (16 public and 4 private) in Ikeja, Lagos was conducted. The study included a facility survey to assess the availability of tuberculosis infection control guidelines, the adequacy of facilities to prevent transmission of tuberculosis and observations of practices to assess the implementation of tuberculosis infection control guidelines. Four focus group discussions were carried out to highlight HCWs’ perceptions on tuberculosis infection control guidelines and barriers to its implementation.

Results

The observational study showed that none of the clinics had a tuberculosis infection control plan. No clinic was consistently screening patients for cough. Twelve facilities (60 %) consistently provided masks to patients who were coughing. Ventilation in the waiting areas was assessed to be adequate in 60 % of the clinics while four clinics (20 %) possessed N-95 respirators. Findings from the focus group discussions showed weak managerial support, poor funding, under-staffing, lack of space and not wanting to be seen as stigmatizing against tuberculosis patients as barriers that hindered the implementation of TB infection control measures.

Conclusion

Tuberculosis infection control measures were not adequately implemented in health facilities in Ikeja, Nigeria. A multi-pronged approach is required to address the identified barriers to the implementation of tuberculosis infection control guidelines.

Cytotoxic effects of Mangifera indica L. kernel extract on human breast cancer (MCF-7 and MDA-MB-231 cell lines) and bioactive constituents in the crude extract

Background

Waterlily Mango (Mangifera indica L.) is thought to be antioxidant-rich, conferred by its functional phytochemicals.

Methods

The potential anticancer effects of the ethanolic kernel extract on breast cancer cells (MDA-MB-231 and MCF-7) using MTT, anti-proliferation, neutral red (NR) uptake and lactate dehydrogenase (LDH) release assays were evaluated. Cytological studies on the breast cancer cells were also conducted, and phytochemical analyses of the extract were carried out to determine the likely bioactive compounds responsible for such effects.

Results

Results showed the extract induced cytotoxicity in MDA-MB-231 cells and MCF-7 cells with IC₅₀ values of 30 and 15 μg/mL, respectively. The extract showed significant toxicity towards both cell lines, with low toxicity to normal breast cells (MCF-10A). The cytotoxic effects on the cells were further confirmed by the NR uptake, antiproliferative and LDH release assays. Bioactive analyses revealed that many bioactives were present in the extract although butylated hydroxytoluene, a potent antioxidant, was the most abundant with 44.65%.

Conclusions

M. indica extract appears to be more cytoxic to both estrogen positive and negative breast cancer cell lines than to normal breast cells. Synergistic effects of its antioxidant bioactives could have contributed to the cytotoxic effects of the extract. The extract of M. indica, therefore, has potential anticancer activity against breast cancer cells. This potential is worth studying further, and could have implications on future studies and eventually management of human breast cancers.

Anti- and pro-lipase activity of selected medicinal, herbal and aquatic plants, and structure elucidation of an anti-lipase compound

Plants that help in slowing down the digestion of triacylglycerols (TAGs) in the pancreas and small intestine of humans play an important role in the reduction of obesity. On the other hand, there may be plants or plant parts that stimulate intestinal lipolytic activity, thus contributing to greater TAG assimilation. The aim of this study was to evaluate the aqueous methanolic extracts of ninety eight (98) medicinal, herbal and aquatic plant materials from Malaysia for their effect on porcine pancreatic lipase (PPL) activity and to identify the structure of an anti-lipase compound from one of the sources. The degree of inhibition was also quantified as relative to orlistat activity against PPL (orlistat equivalents). Results revealed that while 19.4% of the extracts were found to have anti-lipase activity ≥80%, 12% were actually found to promote PPL activity. Twenty two percent (22.4%) exhibited moderate inhibition (41%-80%) and 2% were neutral toward PPL activity. The ripe fruit of Averrhoa carambola and the leaves of Archidendron jiringa (Jack) I.C Nielsen L. (jering), Cynometra cauliflora (nam-nam) and Aleurites moluccana (L.) Willd (candle nut/buah keras) had the highest (100%) anti-lipase activity and are equivalent to 0.11 µg orlistat/mL. Plants that stimulated lipase activity included Pimpinella anisum L. (aniseed/jintan manis), activating the enzyme by 186.5%. Kaempferol 3-O-rhamnoside was isolated from the ethyl acetate fraction of C. cauliflora leaves and found to be an active lipase inhibitor. The structure was elucidated using 1H-NMR, 13C-NMR and 2D-NMR analyses.

Acaricidal properties of two extracts from Guiera senegalensis J.F. Gmel. (Combrataceae) against Hyalomma anatolicum (Acari: Ixodidae)

Laboratory test were carried out on eggs, larvae, nymphs and adults of Hyalomma anatolicum to determine the acaricidal activities of petroleum ether (PE) and crude ethanolic extracts (EE) from the leaves of Guiera senegalensis J.F. Gmel. (Combrataceae) using immersion method. Stock solutions, of 300 mg/ml (30%) of the each two extract, were prepared. Six two-fold serial dilutions each with three replicates were used. Both extracts, at the highest concentration 150 mg/ml (15%), induced 100% failure of hatching of the treated eggs. The concentrations of PE and EE that induced 50% inhibition of the hatchability (IC50) were 1.71 and 0.508%, respectively. In the larval immersion test (LIT), EE at 15% concentration caused complete mortality while the same concentration of PE resulted in 96% mortality. The mortalities increased with concentrations. There was a correlation between the mortalities and increased concentrations, the values of the linear correlation coefficient (r) for PE and EE were 0.93 and 0.79, and The LC50 and LC99 were 2.08 and 14.09, and 0.787 and 11.054, respectively. At the concentrations of 3.75%, 7.5% and 15%, PE inhibited the molting of the nymphs by 40, 55 and 65%, respectively, while EE induced 46.49, 64.3 and 71.4% inhibition, respectively. The effectiveness of the treatment against unfed adult females was assessed by measuring the feeding performance and egg production using adult immersion test (AIT). Although, there was no mortality in unfed adults, PE and EE inhibited feeding and egg-laying of the survived females by 35-100% and 6.16-100%, respectively. Our results indicated that G. senegalensis is a promising biocontrol candidate as an acaricidal agent against H. anatolicum.

Current sickle cell disease management practices in Nigeria

BACKGROUND

Although Nigeria has the highest burden of sickle cell disease (SCD) worldwide, there is still variable and poor utilisation of standard-of-care practices for SCD patients in the country.

METHODS

This was a questionnaire survey of doctors in some dedicated SCD clinics in Nigeria in order to document the facilities available and common management practices.

RESULTS

There were responses from 18 clinics based in 11 institutions. The number of patients being followed in each centre ranged from 15 to approximately 11 000. All clinics provided malaria prophylaxis and folic acid routinely to their patients. Only eight clinics prescribe penicillin prophylaxis. Eight prescribe hydroxyurea to patients who can afford it when indicated. All of the centres except three have electronic cell counters, but all had access to haemoglobin electrophoresis. Three had high-performance liquid chromatography machines installed but none was being routinely used. One institution had a functioning molecular biology laboratory. There is no official newborn screening programme in the country. All had access to microbiology and chemistry laboratories. Nine institutions had CT, six had MRI and three had transcranial Doppler facilities.

CONCLUSION

The care available for SCD in Nigeria is still suboptimal and there is an urgent need for concerted effort to tackle the problem, but to make a significant impact on the burden of the disease would require more focus at the primary care level. Some steps to achieving this are outlined.

The influence of temperature and humidity on oviposition and hatchability of Amblyomma lepidum (Dönitz, 1808) (Acarina: Ixodidae) under laboratory conditions

The effect of temperature and humidity on the oviposition and hatchability of Ablyomma lepidum was studied. Above 90% of adult ticks applied on calves succeeded to attach and feed through 6-13 days. The development process was studied under three levels of temperature: 27, 35 and 40 degrees C, each level with five sets of humidity. Temperature rather than humidity affected all developmental parameters. It was found that high temperature of 40 degrees C, even at high humidity 75.5-97.8% significantly affected pre-oviposition, oviposition, pre-hatching periods, egg mass weight and egg conversion ratio (p<or=0.0001), hatching period and hatchability (p<or=0.05). The effect of humidity on the pre-hatching period and hatchability was highly significant (p<or=0.0001), while it was less significant on pre-oviposition and hatching periods (p<or=0.05). It could be concluded that the development process is influenced by the interaction of both temperature and humidity. However, humidity above 90% and temperature range of 27-35 degrees C seem to be the optimum requirements for ideal development of A. lepidum.

Development of the immature stages of Amblyomma lepidum (Acari: Ixodidae) under field conditions

According to this study, the effect of seasonality on the development of larvae and nymphs of Amblyomma lepidum was highly significant (P< or =0.001). The moulting of larvae was only possible in the rainy season, where means of 76.8 and 73.1% were recorded in the first and the second year, respectively. Nymphs, in the same period, achieved 68.8 and 71.8% moult. In winter, only 11.8 and 12.2% of nymphs succeeded to moult in the first and the second year, respectively. Males outnumbered females, but the effect of seasonality on the male/female ratio was statistically insignificant. The development of both stages in summer was unsuccessful.

Seroprevalence of tick-borne diseases among cattle in the Sudan

This study was carried out to determine the prevalence of Theileria annulata, Theileria mutans, Babesia bigemina, and Anaplasma marginale antibodies among cattle in the Sudan. A total of 600 serum samples were collected from indigenous (zebu) and crossbred cattle (zebu x Friesian) of both sex and different age groups. Indirect enzyme-linked immunosorbent assay was used to assess antibodies against tick-borne diseases in apparently healthy cattle. The overall prevalence rates of T. annulata, T. mutans, B. bigemina, and A. marginale antibodies were found to be 30.8%, 6.1%, 10.7%, and 38.9%, respectively. The highest seroprevalence of T. annulata was reported in Atbara and El Damer, Northern Sudan. There were no significant associations for the seroprevalence of all tick-borne diseases reported among different age groups. Although there were no significant differences between the two breeds of cattle examined for T. annulata, T. mutans, and B. bigemina antibodies, there was a significant difference for prevalence of antibodies against A. marginale, with highest percentages of antibodies in indigenous cattle. Six different combinations of mixed infection were detected. This is the first report in which antibodies against A. marginale among cattle in Northern Sudan is reported. The findings imply that antibodies to tick-borne infections are widely distributed in the region. The need for further investigations using more advanced techniques is recommended.

Ventilatory long-term facilitation in non-snoring subjects during NREM sleep

We hypothesized that very brief episodes of hypoxia (<1 min) would evoke long-term facilitation (LTF) in individuals free of inspiratory flow limitation (IFL). We studied 12 healthy participants who were self-reported non-snorers and confirmed the absence of IFL. We induced 15 brief episodes of hypoxia during non-REM sleep, reducing arterial oxygen saturation to 84-85%, followed by 1 min of room air. Ventilatory variables and resistance were measured during the control period, hypoxic trials, room air controls, and for 20 min following the last hypoxic episode. There was a significant increase in minute ventilation (108+/-1.3% of control, P < 0.05) and tidal volume (105+/-1.7% of control, P < 0.05) and a significant decrease in upper airway resistance (88+/-9.8% control, P < 0.05) during the recovery period. However, there were no significant changes in any variable during sham studies. We have shown for the first time that LTF can be elicited in sleeping humans free of IFL.

Endothelial Dysfunction in Renal Transplant Recipients

Endothelial dysfunction and damage are systemic processes that are recognised to play a central role in the pathogenesis of hypertension and atherosclerotic cardiovascular disease. Renal failure is associated with impaired endothelium dependent vasodilatation that is partly a consequence of increased circulating levels of asymmetric dimethyl arginine. Endothelial dysfunction persists, although it is improved, after renal transplantation. Statins appear to improve endothelial dysfunction, as does withdrawal of calcineurin inhibitors, although there is no evidence that these strategies improve patient or graft survival. The situation in transplant recipients is complicated by the fact that endothelial dysfunction (within the graft vasculature) may be a separate process contributing to chronic allograft nephropathy and to circulating levels of endothelial cells and their components, thus limiting the utility of circulating markers of endothelial damage in this population.

Genotypic and phenotypic resistance patterns of human immunodeficiency virus type 1 variants with insertions or deletions in the reverse transcriptase (RT): multicenter study of patients treated with RT inhibitors

Genomic rearrangements in the 5' part of the human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) have been involved in multidrug resistance to nucleoside RT inhibitors (NRTI). We carried out a retrospective, multicenter study to investigate the prevalence, variability, and phenotypic consequences of such rearrangements. Data concerning the HIV-1 RT genotype and the biological and clinical characteristics of NRTI-treated patients were collected from 10 virology laboratories. Sensitivities of the different HIV-1 variants to RT inhibitors were analyzed in a single-cycle recombinant virus assay. Fifty-two of 2,152 (2.4%) RT sequences had a rearrangement in the 5' part of the RT, with an extensive molecular variation. The number of codons inserted between positions 68 and 69 ranged from 1 (3 samples) or 2 (41 samples) to 5 and 11 in one case each. In four cases, codon 67 was deleted. High levels of phenotypic resistance to zidovudine (AZT), lamivudine (3TC), stavudine (d4T), abacavir (ABC), and didanosine (ddI) were found in 95, 92, 72, 62, and 15% of the 40 samples analyzed, respectively. Resistance to AZT, d4T, and ABC could be found in the absence of the T215Y/F mutations. Resistance to 3TC could develop in the absence of specific mutations. Low-level resistance to ddI was noticed in 40% of the patients. The deletions of codon 67 seemed to have little effect on NRTI sensitivity. Most of the rearrangements were shown to contribute to cross-resistance to NRTI. The results regarding susceptibility to ddI raise the question of the interpretation of the phenotypic data concerning this drug.

Didanosine dosed once daily is equivalent to twice daily dosing for patients on double or triple combination antiretroviral therapy. The AI454-147 Team

OBJECTIVE

To compare the antiviral activity, effect on CD4 cell count, and tolerability of didanosine (ddI) administered once daily and twice daily in HIV-1-infected patients receiving ddI with stavudine or zidovudine, with or without a protease inhibitor. The study was designed to demonstrate that once-daily dosing of ddI was not inferior to twice-daily dosing.

DESIGN

Randomized, open-label, multicenter, two-arm study.

PATIENTS AND METHODS

121 HIV-1-infected adults on a stable regimen including ddI (twice daily) during the previous 3 months with a stable viral load <10,000 copies/ml started therapy. Of these, 62 were randomized to switch to a combination that included ddI once daily and 59 to continue with ddI twice daily. The ddI dose was 400 mg/day (250 mg/day if body weight was <60 kg). The primary efficacy analysis compared the time-averaged difference (TAD) between the two treatment regimens in change from baseline log10 plasma HIV-1 RNA levels over 24 weeks of therapy, with an equivalence margin between the two treatment groups of <0.5 log10 copies/ml.

RESULTS

At week 24, the mean plasma HIV-1 RNA level had increased by 0.31 and 0.17 log10 copies/ml in the ddI once-daily and ddI twice-daily groups, respectively. The time-averaged difference between the two groups in change from baseline plasma HIV-1 RNA levels over 24 weeks was (0.05 log10 copies/ml (95% confidence interval, -0.21 to +0.12 log10 copies/ml), indicating that the antiviral activity of ddI once daily is similar to that of ddI twice daily. After 24 weeks of treatment, changes from baseline in CD4 cell counts were similar in the two groups. Both regimens were generally well-tolerated.

CONCLUSIONS

Once-daily and twice-daily ddI are equally effective at reducing plasma HIV-1 RNA levels when used in a combination regimen with stavudine or zidovudine, with or without a protease inhibitor.

Clinical aspects of malaria in the Asir Region, Saudi Arabia

Three hundred and thirty-four cases of confirmed malaria seen in the Asir Central Hospital, Abha, in southwestern Saudi Arabia, were studied retrospectively. Two hundred and eighty-two of these (84.4%) were Saudis and the majority (72.2%) were living in the lowlands of Tihama. Transmission was found to occur throughout the year, with peaks following the rainy season and in the summer. In Saudis, falciparum malaria is more common than vivax (97.2% vs. 2.8%), while vivax malaria is more commonly seen in expatriates (46.2%). Poor response of falciparum malaria to chloroquine was more prevalent in expatriates than in Saudis (46.4% vs. 23%). Most of the expatriates gave a history of recent travel to countries known to be endemic with resistant malaria. The possibility of the emergence of chloroquine-resistant malaria in the southwestern region of Saudi Arabia was discussed.

The southern region renal transplant program at armed forces hospital, khamis mushayt

The Southern Region renal transplant program was established in February 1989. The appointment of a transplant co-ordinator and creation of a waiting list for the Southern Region as well as tissue typing of all patients in the region were important early steps. Between February 1989 and December 1995, 155 transplants were performed on 152 patients at the Armed Forces Hospital, Southern Region (AFHSR). Of them, 52 were cadaveric donor transplants and the remaining were from living related donors. The overall five-year actuarial patient and graft survival was 93% and 78% respectively. Of the 152 patients who were transplanted, 79 patients were from other hospitals in the region and 73 were from AFHSR. Maintenance immunosuppression consisted of cyclosporin, azathioprine and prednisolone. Use of the spouse as a donor was an early feature of this program. Our results compare favorably with results published from other centers. To cope with the increasing demand of transplantation in the Southern Region, we have to look into ways of increasing our transplant numbers to match the needs.