ABA INSENSITIVE 2 promotes flowering by inhibiting OST1/ABI5-dependent FLOWERING LOCUS C transcription in Arabidopsis

The plant hormone abscisic acid (ABA) is an important regulator of plant growth and development and plays a crucial role in both biotic and abiotic stress responses. ABA modulates flowering time, but the precise molecular mechanism remains poorly understood. Here we report that ABA INSENSITIVE 2 (ABI2) is the only phosphatase from the ABA-signaling core that positively regulates the transition to flowering in Arabidopsis. Loss-of-function abi2-2 mutant shows significantly delayed flowering both under long day and short day conditions. Expression of floral repressor genes such as FLOWERING LOCUS C (FLC) and CYCLING DOF FACTOR 1 (CDF1) was significantly up-regulated in abi2-2 plants while expression of the flowering promoting genes FLOWERING LOCUS T (FT) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) was down-regulated. Through genetic interactions we further found that ost1-3 and abi5-1 mutations are epistatic to abi2-2, as both of them individually rescued the late flowering phenotype of abi2-2. Interestingly, phosphorylation and protein stability of ABA INSENSITIVE 5 (ABI5) were enhanced in abi2-2 plants suggesting that ABI2 dephosphorylates ABI5, thereby reducing protein stability and the capacity to induce FLC expression. Our findings uncovered the unexpected role of ABI2 in promoting flowering by inhibiting ABI5-mediated FLC expression in Arabidopsis.

Aeroelastic tailoring for aerospace applications

This study presents a brief account of the seminal works on aeroelastic tailoring for aerospace applications. Tailoring using advanced composites is a revolutionary process in the ever-evolving realm of aerospace design. The rapid growth in scientific knowledge and research necessitates the consolidation of the latest research and technological advancements every few years. The current work is part of this process. The major portion of the study covers the latest developments and state-of-the-art research in this century, with a special focus on the last ten years. However, a brief account of the historical background, the theoretical foundation, and a few seminal works from the later part of the previous century and the early part of this century have also been included to form a comprehensive starting point for new researchers entering the field of aeroelastic tailoring and to assist them in identifying the directions of their future endeavours. A critical evaluation of different research contributions, including their advantages, limitations, and prospects for future work, has been presented. Emphasis has been laid on flutter mitigation and aeroelastic optimization for passive aeroelastic control. New material and structural technologies (like curvilinear fibres, tow steering, functional grading, thickness distributions, selective reinforcing, additive manufacturing, and unconventional structural configurations), and novel tailoring optimization techniques (like lamination parameters, blending constraints, active aeroelastic wing design, shape functions, surrogate modelling, reduced order modelling, uncertainty quantification, matrix perturbation theory, modal-strain-energy analyses, and multiple indigenous optimization algorithms) have been identified as active research areas and prospective enabling tools for future work. The challenges faced in the full-scale employment of aeroelastic tailoring include quick, robust, and cost-effective optimization to cater for all design variables and constraints, experimental validation of new methodologies, certification of new material and structural configurations through relevant bodies and standards and gaining the confidence of industrialists for investment in technologies with a few highly focused areas of applications.

Culturally adapted psychosocial interventions (CaPSI) for early psychosis in a low-resource setting: study protocol for a large multi-center RCT

BACKGROUND

Psychosis treatment guidelines recommend cognitive behaviour therapy (CBT) and family intervention (FI), for all patients with first episode psychosis (FEP), though guidance borrows heavily from literature in adults from high income countries. To our knowledge, there are few randomized controlled trials (RCTs) examining the comparative effect of these commonly endorsed psychosocial interventions in individuals with early psychosis from high-income countries and no such trials from low and middle-income countries (LMICs). The present study aims to confirm the clinical-efficacy and cost-effectiveness of delivering culturally adapted CBT (CaCBT) and culturally adapted FI (CulFI) to individuals with FEP in Pakistan.

METHOD

A multi-centre, three-arm RCT of CaCBT, CulFI, and treatment as usual (TAU) for individuals with FEP (n = 390), recruited from major centres across Pakistan. Reducing overall symptoms of FEP will be the primary outcome. Additional aims will include improving patient and carer outcomes and estimating the economic impact of delivering culturally appropriate psychosocial interventions in low-resource settings. This trial will assess the clinical-efficacy and cost-effectiveness of CaCBT and CulFI compared with TAU in improving patient (positive and negative symptoms of psychosis, general psychopathology, depressive symptoms, quality of life, cognition, general functioning, and insight) and carer related outcomes (carer experience, wellbeing, illness attitudes and symptoms of depression and anxiety).

CONCLUSIONS

A successful trial may inform the rapid scale up of these interventions not only in Pakistan but other low-resource settings, to improve clinical outcomes, social and occupational functioning, and quality of life in South Asian and other minority groups with FEP.

TRIAL REGISTRATION

NCT05814913.

Negative regulation of floral transition in Arabidopsis by HOS15-PWR-HDA9 complex

Arabidopsis HOS15/PWR/HDA9 repressor complex, which is similar to the TBL1/NcoR1/HDAC complex in animals, plays a well-known role in epigenetic regulation. PWR and HDA9 have been reported to interact with each other and modulate the flowering time by repressing AGL19 expression, whereas HOS15 and HDA9, together with the photoperiodic evening complex, regulate flowering time through repression of GI transcription. However, the role of the HOS15/PWR/HDA9 core repressor complex as a functional unit in the regulation of flowering time is yet to be explored. In this study, we reported that the loss-of-function hos15-2/pwr/hda9 triple mutant accumulates higher transcript levels of AGL19 and exhibits an early flowering phenotype similar to those of hos15, pwr, and hda9 single mutants. Interestingly, the accumulation of HOS15 in the nucleus was drastically reduced in pwr and hda9 mutants. As a result, HOS15 could not perform its role in histone deacetylation or interaction with H3 in the nucleus. Furthermore, HOS15 is also associated with the same region of the AGL19 promoter known for PWR-HDA9 binding. The acetylation level of the AGL19 promoter was increased in the hos15-2 mutant, similar to the pwr and hda9 mutants. Therefore, our findings reveal that the HOS15/PWR/HDA9 repressor complex deacetylates the promoter region of AGL19, thereby negatively regulating AGL19 transcription, which leads to early flowering in Arabidopsis.

Multidimensional characterization of noble metal alloy nanoparticles by multiwavelength analytical ultracentrifugation

In this study, we introduce a method for the simultaneous retrieval of two-dimensional size-composition distributions of noble metal Ag-Au alloy nanoparticles utilizing an analytical ultracentrifuge equipped with a multiwavelength extinction detector (MWL-AUC). MWL-AUC is used to measure coupled optical and sedimentation properties of the particles. The optical response of the nanoparticles is calculated using Mie's theory, where the particles' complex refractive index is corrected due to the effect of reduced mean free path of electrons. Using a combined analysis of the hydrodynamic and spectral data captured by MWL-AUC, the size and composition of the alloy particles is retrieved. Our method is validated through the analysis of synthetic data and by the very good agreement between experimental scanning transmission electron microscopy and our AUC data. The presented comprehensive characterization approach contributes to improved synthesis, scale-up and production of particulate systems as it provides a simple, fast and direct method to determine noble metal alloy nanoparticle size and composition distributions simultaneously.

Non-Expresser of PR-Genes 1 Positively Regulates Abscisic Acid Signaling in Arabidopsis thaliana

The plant hormone, abscisic acid (ABA), is not only important for promoting abiotic stress responses but also plays a versatile and crucial role in plant immunity. The pathogen infection-induced dynamic accumulation of ABA mediates the degradation of non-expresser of PR genes 1 (NPR1) through the CUL3^NPR3NPR4 proteasome pathway. However, the functional significance of NPR1 degradation by other E3 ligases in response to ABA remains unclear. Here, we report that NPR1 is induced transcriptionally by ABA and that npr1-1 mutation results in ABA insensitivity during seed germination and seedling growth. Mutants lacking NPR1 downregulate the expression of ABA-responsive transcription factors ABA INSENSITIVE4 (ABI4) and ABA INSENSITIVE5 (ABI5), and that of their downstream targets EM6, RAB18, RD26, and RD29B. The npr1-1 mutation also affects the transcriptional activity of WRKY18, which activates WRKY60 in the presence of ABA. Furthermore, NPR1 directly interacts with and is degraded by HOS15, a substrate receptor for the DDB1-CUL4 ubiquitin E3 ligase complex. Collectively, our findings demonstrate that NPR1 acts as a positive regulator of ABA-responsive genes, whereas HOS15 promotes NPR1 degradation in a proteasome-dependent manner.

Therapeutic potential of stem cell and melatonin on the reduction of CCl4-induced liver fibrosis in experimental mice model

Liver fibrosis is initial stage of any chronic liver disease and its end stage is develops into cirrhosis. Chronic liver diseases are a crucial global health issue and the cause of approximately 2 million deaths per year worldwide. Cirrhosis is currently the 11th most common cause of death globally. Mesenchymal stem cell (MSCs) treatment is the best way to treat acute and chronic liver disease. The aim of this study is to improve the therapeutic potential of MSCs combined with melatonin (MLT) to overcome CCl4-induced liver fibrosis and also investigate the individual impact of melatonin and MSCs against CCl4-induced liver impairment in animal model. Female BALB/c mice were used as CCL4-induced liver fibrotic animal model. Five groups of animal model were made; negative control, Positive control, CCl4+MSCs treated group, CCl4+MLT treated group and CCl4+MSCs+MLT treated group. Cultured MSCs from mice bone marrow were transplanted to CCl4-induced liver injured mice model, individually as well as together with melatonin. Two weeks after MSCs and MLT administration, all groups of mice were sacrificed for examination. Morphological and Histopathological results showed that combined therapy of MSCs+MLT showed substantial beneficial impact on CCl4-induced liver injured model, compared with MSCs and MLT individually. Biochemically, considerable reduction was observed in serum bilirubin and ALT levels of MLT+MSC treated mice, compared to other groups. PCR results shown down-regulation of Bax and up-regulation of Bcl-xl and Albumin, confirm a significant therapeutic effect of MSCs+MLT on CCI4-induced liver fibrosis. From the results, it is concluded that combined therapy of MSCs and MLT show strong therapeutic effect on CCL4-induced liver fibrosis, compared with MSCs and MLT individually.

The Transcriptional Corepressor HOS15 Mediates Dark-Induced Leaf Senescence in Arabidopsis

Multiple endogenous and environmental signals regulate the intricate and highly complex processes driving leaf senescence in plants. A number of genes have been identified in a variety of plant species, including Arabidopsis, which influence leaf senescence. Previously, we have shown that HOS15 is a multifunctional protein that regulates several physiological processes, including plant growth and development under adverse environmental conditions. HOS15 has also been reported to form a chromatin remodeling complex with PWR and HDA9 and to regulate the chromatin structure of numerous genes. However, unlike PWR and HDA9, the involvement of HOS15 in leaf senescence is yet to be identified. Here, we report that HOS15, together with PWR and HDA9, promotes leaf senescence via transcriptional regulation of SAG12/29, senescence marker genes, and CAB1/RCBS1A, photosynthesis-related genes. The expression of ORE1, SAG12, and SAG29 was downregulated in hos15-2 plants, whereas the expression of photosynthesis-related genes, CAB1 and RCBS1A, was upregulated. HOS15 also promoted senescence through dark stress, as its mutation led to a much greener phenotype than that of the WT. Phenotypes of double and triple mutants of HOS15 with PWR and HDA9 produced phenotypes similar to those of a single hos15-2. In line with this observation, the expression levels of NPX1, APG9, and WRKY57 were significantly elevated in hos15-2 and hos15/pwr, hos15/hda9, and hos15/pwr/hda9 mutants compared to those in the WT. Surprisingly, the total H3 acetylation level decreased in age-dependent manner and under dark stress in WT; however, it remained the same in hos15-2 plants regardless of dark stress, suggesting that dark-induced deacetylation requires functional HOS15. More interestingly, the promoters of APG9, NPX1, and WRKY57 were hyperacetylated in hos15-2 plants compared to those in WT plants. Our data reveal that HOS15 acts as a positive regulator and works in the same repressor complex with PWR and HDA9 to promote leaf senescence through aging and dark stress by repressing NPX1, APG9, and WRKY57 acetylation.

PWR/HDA9/ABI4 Complex Epigenetically Regulates ABA Dependent Drought Stress Tolerance in Arabidopsis

Drought stress adversely affects plant growth and development and significantly reduces crop productivity and yields. The phytohormone abscisic acid (ABA) rapidly accumulates in response to drought stress and mediates the expression of stress-responsive genes that help the plant to survive dehydration. The protein Powerdress (PWR), which interacts with Histone Deacetylase 9 (HDA9), has been identified as a critical component regulating plant growth and development, flowering time, floral determinacy, and leaf senescence. However, the role and function of PWR and HDA9 in abiotic stress response had remained elusive. Here we report that a complex of PWR and HDA9 interacts with ABI4 and epigenetically regulates drought signaling in plants. T-DNA insertion mutants of PWR and HDA9 are insensitive to ABA and hypersensitive to dehydration. Furthermore, the expression of ABA-responsive genes (RD29A, RD29B, and COR15A) is also downregulated in pwr and hda9 mutants. Yeast two-hybrid assays showed that PWR and HDA9 interact with ABI4. Transcript levels of genes that are normally repressed by ABI4, such as CYP707A1, AOX1a and ACS4, are increased in pwr. More importantly, during dehydration stress, PWR and HDA9 regulate the acetylation status of the CYP707A1, which encodes a major enzyme of ABA catabolism. Taken together, our results indicate that PWR, in association with HDA9 and ABI4, regulates the chromatin modification of genes responsible for regulation of both the ABA-signaling and ABA-catabolism pathways in response to ABA and drought stress.

Radiomodifying action, Pharmacokinetic and Biodistribution of Ethyl 3, 4, 5-trihydroxybenzoate-Implication in development of radiomitigator

Ethyl 3, 4, 5-trihydroxybenzoate (GAE) is a major bioactive constituent of Hippophae Rhamnoides L. leaves and extract prepared from H. rhamnoides leaves exhibited radioprotective and pharmacological activity. Radiomodifying properties of polyphenol compounds through free radical neutralizing have been reported earlier. However, to date pharmacokinetic (PK) and biodistribution of polyphenol compounds post 60Co-γ-irradiation (5 Gy) exposure have not been studied yet. The study aims to investigate the radio modifying and inflammatory action, PK and biodistribution of GAE at a radioprotective dose and changes, if any, induced after irradiation. Male C 57 BL/6 mice (28-30 g) were administered GAE (200 mg/kg b.wt) orally 15 minutes post to irradiation. Mice were sacrificed at 15, 30 min, 1,2,4,8 and 24 h. PK and biodistribution of GAE in plasma and tissues were studied. The radiomodifying potential was assessed in terms of mitigating NF-kB activity and SGOT, SGPT, urea and creatinine levels in liver and kidney post irradiation. Our study suggested the potential use of GAE as radiomodifying agent inhibits NF-kB expression and maintains the SGOT 24.10 ± 2.4, SGPT 36.01 ± 6.1 U/l, urea18.16 ± 0.003, and creatinine 1.05 ± 0.04 mg/dL upto 8 h in comparison to irradiated mice. Moreover, in biodistribution studies, showed that GAE crosses the blood-brain barrier and is found in brain tissue. Plasma level of GAE peaked at about 15 min, with Cmax 4390.85 ± 285.20 in GAE and in 3391.78 ± 78.13 ng/mL in radiation + GAE-treated animals, Biodistribution resulted in the highest concentration to be found in liver and kidney. These radiomodifying and pharmacokinetic result may be useful for study of the bioactive mechanism associated with radiation injury and to develop a potent formulation of GAE for clinical application.

Feeding ecology of blue rock pigeon (Columba livia) in the three districts of Punjab, Pakistan

Present paper provides information on the feeding regimens of the two genders of the blue-rock pigeon (Columba livia Linn.) in the sampled habitats of the three districts viz. Rawalpindi, Faisalabad and Bahawalpur of the Punjab province, Pakistan. This feral pigeon, considered ubiquitous species, inhabits both the grasslands and clumped environments to establish their roosts and nests. The study explored about comparable feeding proportions from three major habitats of the pigeons which were captured with medium sized mist-nets. For Rawalpindi in the winter season, the Zea mays was one of the predominant food item (30.6%) for males, and other ranked major food contents were (26.7%, 22.4% and 20.2%), and fairly similar feeding proportions were also recorded for the females (50.4%, 33.3%, 36.4% and 23.9%) for Carthamus oxyacantha, Hordeum vulgare, Triticum aestivum and Zea mays respectively. Evidently, no significant deviations in the existing food crops for the three sites for the feral pigeon were detected, which strongly suggested that the, modes of feeding habits among the sustainable roosts and nests which were closely located to food crops, exerted negligible impacts during intermittent pigeon foraging movements in the diurnal conditions.

Rheostatic Control of ABA Signaling through HOS15-Mediated OST1 Degradation

Dehydrating stresses trigger the accumulation of abscisic acid (ABA), a key plant stress-signaling hormone that activates Snf1-Related Kinases (SnRK2s) to mount adaptive responses. However, the regulatory circuits that terminate the SnRK2s signal relay after acclimation or post-stress conditions remain to be defined. Here, we show that the desensitization of the ABA signal is achieved by the regulation of OST1 (SnRK2.6) protein stability via the E3-ubiquitin ligase HOS15. Upon ABA signal, HOS15-induced degradation of OST1 is inhibited and stabilized OST1 promotes the stress response. When the ABA signal terminates, protein phosphatases ABI1/2 promote rapid degradation of OST1 via HOS15. Notably, we found that even in the presence of ABA, OST1 levels are also depleted within hours of ABA signal onset. The unexpected dynamics of OST1 abundance are then resolved by systematic mathematical modeling, demonstrating a desensitizing feedback loop by which OST1-induced upregulation of ABI1/2 leads to the degradation of OST1. This model illustrates the complex rheostat dynamics underlying the ABA-induced stress response and desensitization.

Potential risk factors for dental caries in Type 2 diabetic patients

BACKGROUND

Diabetic patients are known to be at higher risk for dental caries. However, the role of potential risk factors such as blood glucose, salivary glucose and glycaemic control in the occurrence of dental caries in type 2 diabetes (T2D) is not clearly understood so far, and therefore, it was evaluated in this study.

MATERIALS AND METHODS

This cross-sectional study was conducted on 100 T2D patients from Saudi Arabia. The caries risk assessment was evaluated using the guidelines of Caries Management by Risk Assessment (CAMBRA). Cariogenic bacteria load in saliva was determined by a chair-side test kit. The levels of fasting blood glucose (FBG), salivary glucose and HbA1c were analysed.

RESULTS

Majority of the patients had dental caries (84%), exposed root surfaces (92%) and heavy plaque (73%), whereas 66% of patients suffered from xerostomia. The frequency of patients with high counts of Streptococcus mutans and Lactobacilli (LB) were 78% and 42%, respectively. There were significant associations between dental caries risk and FBG, HbA1c and salivary glucose. After categorizing the patients into 3 categories of glycaemic control, we observed a significant association between glycaemic control and dental caries risk.

CONCLUSION

Type 2 diabetes patients are at high risk for dental caries, which is directly associated with FBG, HbA1c and salivary glucose. This is the first study measuring dental caries and its risk factors in T2D patients from Saudi Arabia.

The High-Affinity Potassium Transporter EpHKT1;2 From the Extremophile Eutrema parvula Mediates Salt Tolerance

To survive salt stress, plants must maintain a balance between sodium and potassium ions. High-affinity potassium transporters (HKTs) play a key role in reducing Na+ toxicity through K+ uptake. Eutrema parvula (formerly known as Thellungiella parvula), a halophyte closely related to Arabidopsis, has two HKT1 genes that encode EpHKT1;1 and EpHKT1;2. In response to high salinity, the EpHKT1;2 transcript level increased rapidly; by contrast, the EpHKT1;1 transcript increased more slowly in response to salt treatment. Yeast cells expressing EpHKT1;2 were able to tolerate high concentrations of NaCl, whereas EpHKT1;1-expressing yeast cells remained sensitive to NaCl. Amino acid sequence alignment with other plant HKTs showed that EpHKT1;1 contains an asparagine residue (Asn-213) in the second pore-loop domain, but EpHKT1;2 contains an aspartic acid residue (Asp-205) at the same position. Yeast cells expressing EpHKT1;1, in which Asn-213 was substituted with Asp, were able to tolerate high concentrations of NaCl. In contrast, substitution of Asp-205 by Asn in EpHKT1;2 did not enhance salt tolerance and rather resulted in a similar function to that of AtHKT1 (Na+ influx but no K+ influx), indicating that the presence of Asn or Asp determines the mode of cation selectivity of the HKT1-type transporters. Moreover, Arabidopsis plants (Col-gl) overexpressing EpHKT1;2 showed significantly higher tolerance to salt stress and accumulated less Na+ and more K+ compared to those overexpressing EpHKT1;1 or AtHKT1. Taken together, these results suggest that EpHKT1;2 mediates tolerance to Na+ ion toxicity in E. parvula and is a major contributor to its halophytic nature.

Effect of Androctonus bicolor scorpion venom on serum electrolytes in rats: A 24-h time-course study

Black fat-tailed scorpion (Androctonus bicolor) belongs to the family Buthidae and is one of the most venomous scorpions in the world. The effects of A. bicolor venom on serum electrolytes were not known and therefore investigated in this study. Adult male Wistar rats were randomly divided into seven groups with five animals in each group. One of the groups served as control and received vehicle only. The animals in the remaining groups received a single subcutaneous injection of crude A. bicolor venom (200 μg/kg bodyweight) and were killed at different time intervals including 30 min, 1 h, 2 h, 4 h, 8 h, and 24 h after venom injection. The results showed that scorpion venom caused significant increase in serum sodium levels within 30 min after injection which slightly subsided after 1 h and then persisted over 24 h. Serum potassium levels continued to significantly increase until 4 h and then slightly subsided. There were significant decreases in serum magnesium (Mg(+)) levels following scorpion venom injection, at all the time points during the course of study. Serum calcium levels were significantly increased during the entire course of study, whereas serum chloride was significantly decreased. In conclusion, A. bicolor envenomation in rats caused severe and persistent hypomagnesemia with accompanied hypernatremia, hyperkalemia, and hypercalcemia. It is important to measure serum Mg(+) levels in victims of scorpion envenomation, and patients with severe Mg(+) deficiency should be treated accordingly.

Transient increase in IL-1β, IL-6 and TNF-α gene expression in rat liver exposed to gold nanoparticles

Most studies have used in vitro systems to test inflammatory responses of nanoparticles; these may not reflect the real biological response of body organs. In fact, certain nanoparticles have provoked opposite effects under in vitro and in vivo conditions. Current understanding of the biocompatibility of gold nanoparticles is controversial. We studied the acute (1 day) and sub-chronic (5 days) effects of gold nanoparticles (10 and 50 nm in diameter) on expression of interleukin-1 beta (IL-1β), IL-6 and tumor necrosis factor alpha (TNF-α) in rat liver. Real-time PCR analysis showed that gold nanoparticles of both sizes significantly increased cytokine gene expression on day 1; this had subsided by day 5. The 50-nm gold nanoparticle produced more severe inflammation than the smaller gold nanoparticle. These findings indicate a possible biocompatibility of medium-sized gold nanoparticles, as they caused only a transient increase in proinflammatory cytokines, followed by normalization during sub-chronic repeated exposure.

A study on the distribution of different carnitine fractions in various tissues of bovine eye

The aim of the present investigation was to study the distribution of various carnitine fractions in different bovine ocular tissues. Different ocular tissues were homogenized and their carnitine content was determined. The carnitine fractions studied include short chain carnitine, long chain carnitine, acyl carnitine and free carnitine. All the four carnitine fractions were found to be present in all the ocular tissues studied. Iris contained the highest concentration short chain, long chain and acyl carnitine. However significant (p < 0.05) differences existed in long chain and acyl carnitine between iris and other tissues. Free carnitine was found in highest concentration in ciliary body which was significantly higher when compared to lens nucleus (p < 0.05). There was no significant difference in the carnitine fractions between aqueous and vitreous humor. These results show differential distribution of carnitine in bovine ocular tissues which may be involved in various functions besides fatty acid oxidation.

DNA barcoding of arid wild plants using rbcL gene sequences

DNA barcoding is currently gaining popularity due to its simplicity and high accuracy as compared to the complexity and subjective biases associated with morphology-based identification of taxa. The standard chloroplast DNA barcode for land plants recommended by the Consortium for the Barcode of Life (CBOL) plant working group needs to be evaluated for a wide range of plant species. We therefore tested the potential of the rbcL marker for the identification of wild plants belonging to diverse families of arid regions. Maximum likelihood tree analysis was performed to evaluate the discriminatory power of the rbcL gene. Our findings showed that using rbcL gene sequences enabled identification of the majority of the samples (92%) to genus level and only 17% to species level.

Limited efficiency of universal mini-barcode primers for DNA amplification from desert reptiles, birds and mammals

In recent years, DNA barcoding has emerged as a powerful tool for species identification. We report an extended validation of a universal DNA mini-barcode for amplification of 130-bp COI segments from 23 specimens collected from a desert environment, including 11 reptiles, five mammals and seven birds. Besides the standard double-annealing protocol, we also tested a more stringent single-annealing protocol. The PCR success rate for the amplification of the mini-barcode region was: mammals (4/5), reptiles (5/11) and birds (4/7). These findings demonstrate the limited utility of universal primers for mini-barcoding, at least for these vertebrate taxa that we collected from the Saudi Arabian desert.

Cytochrome c oxidase subunit I barcoding of the green bee-eater (Merops orientalis)

DNA barcoding using mitochondrial cytochrome c oxidase subunit I (COI) is regarded as a standard method for species identification. Recent reports have also shown extended applications of COI gene analysis in phylogeny and molecular diversity studies. The bee-eaters are a group of near passerine birds in the family Meropidae. There are 26 species worldwide; five of them are found in Saudi Arabia. Until now, GenBank included a COI barcode for only one species of bee-eater, the European bee-eater (Merops apiaster). We sequenced the 694-bp segment of the COI gene of the green bee-eater M. orientalis and compared the sequences with those of M. apiaster. Pairwise sequence comparison showed 66 variable sites across all the eight sequences from both species, with an interspecific genetic distance of 0.0362. Two and one within-species variable sites were found, with genetic distances of 0.0005 and 0.0003 for M. apiaster and M. orientalis, respectively. This is the first study reporting barcodes for M. orientalis.

Extensive visceral calcification demonstrated on Tc-99m MDP bone scan in patient with sphenoidal sinus carcinoma and hypercalcaemia of malignancy: a bad prognostic sign

Sphenoidal sinus carcinoma is a rare cause of hypercalcemia of malignancy. We report on a 37-year-old male with sphenoidal sinus carcinoma with intracranial extension who developed hypercalcemia of malignancy with progressing disease and demonstrated diffuse metastatic visceral calcifications of lungs, myocardium, stomach, kidneys and thyroid on follow-up 99mTc-methylene diphosphonate bone scan. In the absence of extensive skeletal metastases, bone scan help confirm humoral nature of hypercalcaeimia.

Application of RAPD for molecular characterization of plant species of medicinal value from an arid environment

The use of highly discriminatory methods for the identification and characterization of genotypes is essential for plant protection and appropriate use. We utilized the RAPD method for the genetic fingerprinting of 11 plant species of desert origin (seven with known medicinal value). Andrachne telephioides, Zilla spinosa, Caylusea hexagyna, Achillea fragrantissima, Lycium shawii, Moricandia sinaica, Rumex vesicarius, Bassia eriophora, Zygophyllum propinquum subsp migahidii, Withania somnifera, and Sonchus oleraceus were collected from various areas of Saudi Arabia. The five primers used were able to amplify the DNA from all the plant species. The amplified products of the RAPD profiles ranged from 307 to 1772 bp. A total of 164 bands were observed for 11 plant species, using five primers. The number of well-defined and major bands for a single plant species for a single primer ranged from 1 to 10. The highest pair-wise similarities (0.32) were observed between A. fragrantissima and L. shawii, when five primers were combined. The lowest similarities (0) were observed between A. telephioides and Z. spinosa; Z. spinosa and B. eriophora; B. eriophora and Z. propinquum. In conclusion, the RAPD method successfully discriminates among all the plant species, therefore providing an easy and rapid tool for identification, conservation and sustainable use of these plants.

Interpretation of electrophoretograms of seven microsatellite loci to determine the genetic diversity of the Arabian Oryx

Microsatellite markers are commonly used for examining population structure, especially inbreeding, outbreeding and gene flow. An array of microsatellite loci, preferably with multiallelic presentation, is preferable for ensuring accurate results. However, artifact peaks or stutters in the electrophoretograms significantly hamper the reliable interpretation of genotypes. We interpreted electrophoretograms of seven microsatellite loci to determine the genetic diversity of the Arabian Oryx. All the alleles of different loci exhibited good peak resolutions and hence were clearly identified. Moreover, none of the stutter peaks impaired the recognition or differentiation between homozygote and heterozygote. Our findings suggest that correct identification of alleles in the presence of co-amplified nonspecific fragments is important for reliable interpretation of microsatellite data.

Application of 16S rRNA, cytochrome b and control region sequences for understanding the phylogenetic relationships in Oryx species

The present study reports the application of mitochondrial markers for the molecular phylogeny of Oryx species, including the Arabian oryx (AO), scimitar-horned oryx (SHO) and plains oryx (PO), using the Addax as an outgroup. Sequences of three molecular markers, 16S rRNA, cytochrome b and a control region, for the above four taxa were aligned and the topologies of respective phylogenetic trees were compared. All these markers clearly differentiated the genus Addax from Oryx. However, for species-level grouping, while 16S rRNA and cytochrome b produced similar phylogeny (SHO grouped with PO), the control region grouped SHO with AO. Further studies are warranted to generate more sequencing data, apply multiple bioinformatics tools and to include relevant nuclear markers for phylogenetic analysis of Oryx species.

Phylogenetic analysis of oryx species using partial sequences of mitochondrial rRNA genes

We conducted a comparative evaluation of 12S rRNA and 16S rRNA genes of the mitochondrial genome for molecular differentiation among three oryx species (Oryx leucoryx, Oryx dammah and Oryx gazella) with respect to two closely related outgroups, addax and roan. Our findings showed the failure of 12S rRNA gene to differentiate between the genus Oryx and addax, whereas a 342-bp partial sequence of 16S rRNA accurately grouped all five taxa studied, suggesting the utility of 16S rRNA segment for molecular phylogeny of oryx at the genus and possibly species levels.

Association between glycaemic control and serum lipids profile in type 2 diabetic patients: HbA1c predicts dyslipidaemia

Impaired lipid metabolism resulting from uncontrolled hyperglycaemia has been implicated in cardiovascular complications in diabetes patients. The aim of this study was to examine the impact of glycaemic control on the lipid profile of diabetic patients. We also determined the ability of glycated haemoglobin (HbA(1c)) as an indirect marker of dyslipidaemia. A total of 1011 type 2 diabetic patients (males, 574; females, 437; mean age, 59.76 years) were included in this study. Venous blood samples were collected from all the subjects after at least 8 h fasting. The sera were analysed for HbA(1c), fasting blood glucose (FBG), total cholesterol, triglycerides (TG), high-density lipoprotein cholesterol (HDL) and low-density lipoprotein cholesterol (LDL). The levels of HbA(1c), FBG and LDL did not differ significantly between males and females. Female patients showed significantly higher serum cholesterol and HDL but significantly lower TG levels as compared to males. There was a highly significant correlation between HbA(1c) and FBG. Both HbA(1c) and FBG exhibited direct correlations with cholesterol, TG and LDL and inverse correlation with HDL; the magnitude of significance for all these lipid parameters being greater with HbA(1c) than FBG. There was a linear relationship between HbA(1c) and dyslipidaemia. The levels of serum cholesterol and TG were significantly higher and of HDL significantly lower in patients with worse glycaemic control as compared to patients with good glycaemic control. The findings of this study clearly indicate that HbA(1c) is not only a useful biomarker of long-term glycaemic control but also a good predictor of lipid profile. Thus, monitoring of glycaemic control using HbA(1c) could have additional benefits of identifying diabetic patients who are at a greater risk of cardiovascular complications.

Fluctuations in fasting blood glucose and serum fructosamine in pregnant women monitored on successive antenatal visits

Fasting blood glucose (FBG) and serum fructosamine are simple and commonly used tests for monitoring diabetes mellitus. Unfortunately, both these parameters are associated with high error rates and therefore used with caution in high-risk populations. Setting high cut-off values for these parameters increases the sensitivity but at the cost of poor specificity (more false positives). Continued efforts have been made to evaluate the efficacy of FBG and fructosamine, singly or in combination, in avoiding a large number of unnecessary oral glucose tolerance tests (OGTT). Therefore, to better understand their time-course trends, we analysed FBG and c-fructosamine in 211 blood samples from 51 Saudi pregnant women during their multiple (> or =3) antenatal visits. The mean+/-standard deviation of FBG and c-fructosamine were 5.22+/-1.07 and 2.22+/-0.25 mmol/l respectively with a significant correlation between their individual values. Using the FBG cut-off >5.3 mmol/l, 19 subjects were classified as hyperglycaemic; this frequency was reduced to 1 when a FBG cut-off of >7.0 mmol/l was used. Combined values of FBG (>5.3 mmol/l) and c-fructosamine (>2.5 mmol/l) filtered 6 high-risk subjects with a prediction of gestational diabetes mellitus (GDM). Analysis of variance revealed high within-group variance for FBG. These fluctuations were also confirmed by higher coefficient of variations (CVs) for FBG (13.27%) as compared to c-fructosamine (5.49%). The CVs of FBG were not correlated with those of corresponding CVs of c-fructosamine (R = 0.007, P = 0.962), indicating that the fluctuations in FBG were independent of fluctuations in c-fructosamine. These findings clearly suggest that the paired values of FBG and c-fructosamine would be more advantageous than their individual values in filtering high-risk patients on whom OGTT should be performed.

Modulatory effect of cadmium exposure on deltamethrin-induced oxidative stress in Channa punctata Bloch

The modulatory effect of cadmium pretreatment (0.2 mg/kg b.w. i.p.) on deltamethrin-induced oxidative stress and alterations of antioxidants was studied in freshwater fish Channa punctata Bloch. Lipid peroxidation (LPO) was measured as one of the indicators of oxidative stress. Activities of glutathione peroxidase, glutathione reductase, and glutathione-S-transferase were also studied in liver, kidney, and gills. Levels of reduced glutathione (GSH) were measured in various tissues. Fish pretreated with cadmium and subsequently exposed to deltamethrin showed significantly reduced LPO values when compared with deltamethrin-exposed fish. Conversely, in the kidney, a potentiation response was observed. Deltamethrin exposure in fish resulted in significant alteration in activities of glutathione-dependent antioxidant enzymes. In the cadmium preexposed fish, which were subsequently exposed to deltamethrin, antioxidant enzymes showed a tendency toward normalization over deltamethrin-only exposed fish in liver and gills. GSH also showed a similar pattern in liver and gills but in kidney it remained elevated. Cadmium alone had no significant effect on various parameters at the concentration used in this study. When metallothionein (MT) induction was studied, only liver showed an MT-like protein band in sodium dodecylsulfate-polyacrylamide gel electrophoresis analysis. These results demonstrate a modulatory role of cadmium on the oxidative stress and other related parameters in liver and gills. These findings are important in the context of exposure to a mixture of pollutants in aquatic environment.

Sodium benzoate attenuates iminodipropionitrile-induced behavioral syndrome in rats

This study reports the effects of the antioxidant sodium benzoate (SB) on iminodipropionitrile (IDPN)-induced excitation with choreiform and circling (ECC) syndrome in adult female Wistar rats. Rats in four different groups (n=8) received i.p. injections of SB (0, 50, 100 and 200 mg/kg) daily for 10 days. IDPN (100 mg/kg, i.p.) was administered daily 30 min before SB for the first 8 days. Two additional groups served as control (vehicle) and SB alone (200 mg/kg) groups. The animals were observed daily for neurobehavioral abnormalities, including dyskinetic head movements, circling, tail hanging, righting reflex and contact inhibition of the righting reflex, characterized as the ECC syndrome. In the IDPN-alone treated group, the onset of ECC syndrome occurred on day 9 (2 out of 8 rats), whereas none of the animals treated with IDPN plus SB (100 or 200 mg/kg) showed any signs of ECC syndrome on that day. All the animals in the IDPN-alone group developed severe dyskinesia on day 11. Treatment of rats with SB significantly and dose-dependently attenuated IDPN-induced behavioral deficits.

Serum calcitonin in renal transplant patients

We obtained blood samples from 60 renal transplant patients from our transplant clinic and from control subjects for biochemical analyses. Cyclosporin levels were measured in whole blood. Serum levels of calcitonin, calcium, phosphate, albumin, urea, creatinine, and activity of alkaline phosphatase were determined. Serum calcitonin levels were significantly higher in renal transplant patients. There was no correlation between serum calcitonin levels and activity of serum alkaline phosphatase, or levels of serum calcium, phosphate, albumin, urea, creatinine or cyclosporin. Serum calcitonin also showed no correlation with patient age or transplant age.

Protective effect of quinacrine on striatal dopamine levels in 6-OHDA and MPTP models of Parkinsonism in rodents

Recent studies provide evidence that phospholipase A2 (PLA2) may play a role in the development of experimental parkinsonism. In this investigation an attempt was made to determine a possible protective effect of quinacrine (QNC), a PLA2 inhibitor on MPTP as well as 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in rodents. For MPTP studies, adult male mice (C57 BL) were treated with MPTP (30 mg/kg, i.p.) daily for 5 days. QNC was injected i.p. in the doses of 0, 10, 30 and 60 mg/kg daily 30 min before MPTP in four different groups. Two other groups of mice received either vehicle (control) or a high dose of QNC (60 mg/kg). Two hours after the last injection of MPTP, striata were collected for the analysis of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and glutathione (GSH). For the 6-OHDA study, male Wistar rats were infused with 6-OHDA (60 microg) in the right striatum under chloral hydrate anesthesia. The rats in different groups were treated with 0, 5, 15 and 30 mg/kg QNC (i.p.) for 4 days, while first injection was given 30 min before 6-OHDA. On day 5, rats were sacrificed and striata were stored at -80 degrees C. Administration of MPTP or 6-OHDA significantly reduced striatal DA, which was significantly attenuated by QNC. Concomitant treatment with QNC also protected animals against MPTP or 6-OHDA-induced depletion of striatal GSH. Our findings clearly suggest the role of PLA2 in MPTP and 6-OHDA induced neurotoxicity and oxidative stress. However, further studies are warranted to explore the therapeutic potential of PLA2 inhibitors for the treatment of Parkinson's disease.

Exacerbation of iminodipropionitrile-induced behavioral toxicity, oxidative stress, and vestibular hair cell degeneration by gentamicin in rats

This study describes the effect of gentamicin, an aminoglycoside antibiotic on iminodipropionitrile (IDPN)-induced abnormal neurobehavioral syndrome in female Sprague-Dawley rats. The animals were exposed to IDPN in the dose of 100 mg/kg/day intraperitoneally for 7 days. Gentamicin (GM) was administered intraperitoneally daily 1 h before IDPN in the doses of 10, 40, and 80 mg/kg body weight in three different groups of rats. One more group of animals received gentamicin alone (80 mg/kg) and served as the gentamicin-alone group. The intensity of IDPN induced characteristic excitation with choreiform, and the circling movement (ECC) syndrome was examined using an observational test battery including dyskinetic head movements, circling, tail hanging, air righting reflex, and contact inhibition of the righting reflex on days 6, 8, 10, 12, 19, 26, and 33. The animals for histopathological observation were sacrificed on day 10, whereas the remaining animals that were used for long-term behavioral studies were sacrificed on day 35 for biochemical observations. The blood and brain samples were collected for the analysis of blood urea nitrogen (BUN), serum creatinine, cerebral malondialdehyde (MDA), conjugated dienes, and lipid hydroperoxides, whereas temporal bones were collected for inner ear histopathology. Our results showed that gentamicin significantly and dose dependently exacerbated the incidence and the severity of the IDPN-induced behavioral syndrome. The histopathology of the inner ear demonstrated more severe loss of sensory hair cells in the crista ampullaris of the rats treated with IDPN plus gentamicin compared to the IDPN-alone treated animals. Concomitant treatment with gentamicin also potentiated IDPN-induced increase in free radical indices, suggesting a possible role of oxidative stress in gentamicin-induced aggravation of IDPN toxicity. Further studies are warranted to determine the role of aminoglycosides in nitrile toxicity and drug-induced movement disorders.

Nitric oxide synthase inhibitor aminoguanidine potentiates iminodipropionitrile-induced neurotoxicity in rats

This investigation was undertaken to study the effect of nitric oxide synthase inhibitor, aminoguanidine on iminodipropionitrile (IDPN)-induced neurobehavioral and vestibular toxicity in rats. The dyskinetic syndrome was produced in male Wistar rats by i.p. injections of IDPN (100 mg/kg) for 6 days. Aminoguanidine was administered orally in the doses of 50, 150 and 300 mg/kg, 60 min before IDPN in three different groups. Control rats received vehicle only, whereas another group was treated with 300 mg/kg of aminoguanidine alone (without IDPN). Our results showed that aminoguanidine significantly and dose dependently exacerbated the incidence and intensity of IDPN-induced dyskinetic head movements. Aminoguanidine potentiated IDPN-induced loss of air righting reflex. The histopathological examination of inner ear showed aggravation of IDPN-induced degeneration of sensory hair cells in the crista ampullaris by aminoguanidine. These results suggest the role of nitric oxide in IDPN-induced neurobehavioral and vestibular toxicity.

Protection by 2-deoxy-D-glucose against beta,beta'-iminodipropionitrile-induced neurobehavioral toxicity in mice

This investigation was undertaken to study the effect of 2-deoxy-D-glucose (2-DG) on beta, beta'-iminodipropionitrile (IDPN)-induced neurobehavioral toxicity in mice. Animals were divided into five groups of nine animals each. One of the groups served as control and received vehicle only, whereas the remaining four groups were treated with IDPN (250 mg/kg, i.p.) daily for 11 days. 2-DG was injected intraperitoneally in the doses of 0 (vehicle only), 100, 300, and 600 mg/kg daily 30 min before IDPN administration. The animals were observed for dyskinetic behavior including vertical (retrocollis) and horizontal (laterocollis) head movements and circling. Twenty-four hours after the last dose of IDPN, the animals were sacrificed by decapitation and striata were isolated from the brain for the analysis of serotonin (5-HT). Our results showed that 2-DG significantly and dose dependently attenuated the incidence and severity of IDPN-induced neurobehavioral toxicity. Administration of 2-DG also protected mice against IDPN-induced increase in striatal 5-HT levels. Further studies are warranted to investigate the neuroprotective mechanism of 2-DG against IDPN-induced neurotoxicity.

Tolerance to beta,beta'-iminodipropionitrile (IDPN)-induced neurobehavioural and vestibular toxicity in diabetic rats

The present investigation was undertaken to study the neurotoxic effects of beta,beta'-iminodipropionitrile (IDPN) in normal, diabetic and insulin-treated diabetic rats. Sprague-Dawley male rats were divided into five groups: control, IDPN, diabetes, diabetes plus IDPN and diabetes plus insulin plus IDPN. The diabetes was induced with a single i.p. injection of streptozotocin (50 mg kg(-1)). One month after the induction of diabetes, the rats were treated with IDPN (100 mg kg(-1), i.p.) daily for 11 days. One of the diabetic groups treated with IDPN also received daily injection of insulin (25 U kg(-1), s.c.), 1 h before IDPN. The rats were observed daily for abnormal head movements and circling. The grip strength of the forelimbs was also measured. In the IDPN group the dyskinetic symptoms appeared on the 8th day, whereas the onset of dyskinesia was on the 12th day in IDPN-treated diabetic rats. The incidence and severity of dyskinesia were significantly higher in IDPN-treated normal (non-diabetic) rats as compared to IDPN-treated diabetic rats. The treatment of diabetic rats with insulin normalized striatal dopamine (DA) turnover but partially reversed diabetes-induced protection against IDPN dyskinesia. There was severe degeneration of sensory hair cells in crista ampullaris of IDPN-treated normal rats, whereas the diabetic rats showed significant protection against IDPN-induced vestibular hair cell degeneration. In conclusion, our study clearly demonstrates that diabetic rats are resistant to IDPN-induced neurobehavioural and vestibular toxicity. The results also show that diabetes-induced protection against IDPN-induced dyskinesia can be partially reversed by insulin. The mechanism behind the decreased vulnerability of diabetic animals to IDPN remains to be resolved. Further studies are warranted to investigate this paradoxical phenomenon.

Proglumide, a cholecystokinin receptor antagonist, exacerbates beta, beta'-iminodipropionitrile-induced dyskinetic syndrome in rats

The present investigation was undertaken to study the effect of proglumide, a cholecystokinin (CCK) receptor antagonist, on iminodipropionitrile (IDPN)-induced excitation, chorea, and circling (ECC) syndrome in rats. The animals were exposed to IDPN in the dose of 100 mg/kg/day IP for 9 days. Proglumide (PG) was administered IP daily 1 h before IDPN in the doses of 250, 500, and 750 mg/kg body weight in three different groups of rats. The animals were observed daily for neurobehavioral abnormalities including dyskinetic head movements, circling, tail hanging, air righting reflex, locomotor activity, and contact inhibition of the righting reflex. After behavioral studies, blood and brain samples were collected for the analysis of malondialdehyde (MDA), conjugated dienes, vitamin E, and glutathione peroxidase (GSH-Px). The temporal bones were also collected for inner ear histopathology. Our results showed that proglumide significantly and dose-dependently exacerbated the incidence and the severity of IDPN-induced ECC syndrome during the treatment period as well as up to 3 weeks of postdosing. Administration of IDPN produced a significant increase in MDA and conjugated dienes and a decrease in vitamin E and GSH-Px, suggesting the role of oxygen-derived free radicals (ODFR) in IDPN-induced neurotoxicity. Concomitant treatment with proglumide potentiated IDPN-induced oxidative stress. The histopathology of the inner ear showed significantly high degeneration of sensory hair cells in the crista ampullaris of the rats treated with IDPN plus proglumide compared to IDPN-alone-treated animals. Further studies are warranted to determine the role of CCK in nitrile toxicity and drug-induced dyskinesia.

Effect of chronic administration of magnesium sulfate on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced neurotoxicity in mice

This investigation was aimed to study the effect of magnesium on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity in mice. Four groups of mice were given magnesium sulfate (MgSO4.7H2O) in drinking water at four different concentrations of 0.0 g/l (control), 2.5 g/l (low), 5.0 g/l (medium) and 10.0 g/l (high) respectively for a period of 16 weeks; these animals also received MPTP (30 mg/kg, intraperitoneally daily) during the last five days of Mg treatment. Other four groups of mice were given similar dose regimen of MgSO4 but received injections of saline instead of MPTP. Seventy-two hr after the last dose of MPTP, neurobehavioural studies including locomotor activity, pole climbing test and heart nociception test were performed and striata were collected for the analysis of dopamine. The results of this study show that treatment of mice with MgSO4 or MPTP individually has no effect on their behaviour. Concomitant administration of low dose of MgSO4 (2.5 g/l) along with MPTP produced increase in motor activity and latency to heat stimuli; whereas medium and high doses of MgSO4 in combination with MPTP produced opposite (as compared to low dose) effects resulting in a decrease in motor activity and latency to heat stimuli and increase in pole climbing time. However, MgSO4 dose-dependently exacerbated MPTP-induced depletion of striatal dopamine. The mortality was drastically increased (30-55%) in the animals receiving combined treatments of MPTP and MgSO4 as compared to the mice treated with MPTP alone (12%). This study clearly points towards the ability of MgSO4 to modify MPTP-induced neurotoxicity.

Relative performance of different types of passive dosimeters employing solid state nuclear track detectors

Radon and its progeny, known to be carcinogenic, are a matter of great concern in underground mines and energy conserved air-tight houses. Different shapes of dosimeters using solid state nuclear track detectors (SSNTDs) have been devised to measure radon concentrations in mines and dwellings. Sometimes intercomparison of results is required by various laboratories working with solid state nuclear track detector-based passive dosimeters. The present work includes the determination of various parameters for a set of dosimeters consisting of (1) box-type, (2) pen-type, (3) tube-type, (4) Karlsruhe Diffusion Chamber, and (5) bare-type dosimeters. In this research two types of plastics, allyl-diglycol-carbonate (C12H18O7) and cellulose nitrate (C6H8O8N2) known as CR-39 and CN-85, respectively, have been employed. The detection efficiency for alpha particles from radon and its progeny for CR-39 and CN-85 have been compared. All experiments have been carried out in a custom-designed exposure chamber connected to a radon source. The calibration factors, in terms of Bq m(-3) per unit track density (1.0 cm(-2)) with respect to box-type dosimeter, have been determined for intercomparison and standardization of measured radon concentrations by a set of passive radon dosimeters used in various laboratories of the world.

Gamma-ray activity and dose rate of brick samples from some areas of North West Frontier Province (NWFP), Pakistan

It is important to measure natural radioactivity due to gamma-rays from building materials and consequently to determine the dose rate from these materials. This helps to implement precautionary measures whenever the dose rate is found to be above the recommended limits. A knowledge of gamma radioactivity is required by the building construction association to adopt preventive measures to mitigate or minimize the harmful effects of ionizing radiation. The aim of this work was to measure the gamma activity due to 226Ra, 232Th and 40K in bricks from the Peshawar, Nowshera and Mardan districts of NWFP of Pakistan. The radiological doses to the occupants from the brick floor of a wooden house were calculated. The average gamma dose equivalent rate was calculated to be 0.14 mSv per year, which is well below the external gamma dose limit of 0.46 mSv per year as given in UNSCEAR [2].

Ulcerative colitis amongst the Saudis: six-year experience from Al-Madinah region

Ulcerative Colitis is now being recognized amongst the Arabs. After consideration of the clinical, endoscopic and histopathological data, 80 Saudi patients out of 1,182, were diagnosed as ulcerative colitis. There were 47 males and 33 females. The age ranged between two and 90 years (mean 36.5 years). Endoscopically, the disease was limited to the rectum in 22.5%, rectum and sigmoid in 30%, extended up to the splenic flexure in 27.5% and beyond the splenic flexure in 20% of the patients. Our data supports the recent observation that ulcerative colitis is not uncommon in this part of the world. There are differences in the extent of disease and the presence of local complications, between our patients and those in the high incidence areas.

Cephalobus litoralis: Biology and Tolerance to Desiccation

Cephalobus litoralis (Akhtar, 1962) Andrássy, 1984 reproduced parthenogenetically and completed its life cycle in 72-90 hours. Each female deposited 200-300 eggs. The nematodes showed synchronized movements in the rhythms of the anterior parts of the body. The nematodes were coiled when dried in culture medium or in slowly evaporating water droplets on the tops of culture plates, but in pellets they assumed irregular postures. Nematodes in pellets stored at high humidity could be reactivated after storage for 28 days.