Critical role for TRIM28 and HP1ß/γ in the epigenetic control of T cell metabolic reprograming and effector differentiation.

Naive CD4+ T lymphocytes differentiate into different effector types, including helper and regulatory cells (Th and Treg, respectively). Heritable gene expression programs that define these effector types are established during differentiation, but little is known about the epigenetic mechanisms that install and maintain these programs. Here, we use mice defective for different components of heterochromatin-dependent gene silencing to investigate the epigenetic control of CD4+ T cell plasticity. We show that, upon T cell receptor (TCR) engagement, naive and regulatory T cells defective for TRIM28 (an epigenetic adaptor for histone binding modules) or for heterochromatin protein 1 ß and γ isoforms (HP1ß/γ, 2 histone-binding factors involved in gene silencing) fail to effectively signal through the PI3K-AKT-mTOR axis and switch to glycolysis. While differentiation of naive TRIM28-/- T cells into cytokine-producing effector T cells is impaired, resulting in reduced induction of autoimmune colitis, TRIM28-/- regulatory T cells also fail to expand in vivo and to suppress autoimmunity effectively. Using a combination of transcriptome and chromatin immunoprecipitation-sequencing (ChIP-seq) analyses for H3K9me3, H3K9Ac, and RNA polymerase II, we show that reduced effector differentiation correlates with impaired transcriptional silencing at distal regulatory regions of a defined set of Treg-associated genes, including, for example, NRP1 or Snai3. We conclude that TRIM28 and HP1ß/γ control metabolic reprograming through epigenetic silencing of a defined set of Treg-characteristic genes, thus allowing effective T cell expansion and differentiation into helper and regulatory phenotypes.

Handshake Sense Multiple Access Control for Cognitive Radio-Based IoT Networks.

Internet-of-Things (IoT) enabling technologies such as ZigBee, WiFi, 6LowPAN, RFID, Machine-to-Machine, LTE-Advanced, etc. depend on the license-free Industrial Scientific and Medical (ISM) bands for the Internet. The proliferation of IoT devices is not only anticipated to create a huge amount of congestion in the near future, but even now the unlicensed spectrum is not enough in the ISM bands. Towards this end, Cognitive Radio (CR) technology can resolve the spectrum shortage issue since CR users can opportunistically exploit white spaces in licensed channels of the adjacent wireless systems. In CR networks, it is critical to coordinate spectrum access among Secondary Users (SUs) while protecting priority rights of Primary Users (PUs). Therein, SUs need to take good care of hidden PUs in order to avoid harmful interference. Further, a densely deployed CR network can compromise spectrum sensing quality and certainty of the results when a large number of SUs contends to access the same channel. Therefore, based on the vulnerable sensing results, SUs can cause interference to the PUs. In this paper, we first investigate the leading issues and then propose a novel Handshake Sense Multiple Access with Collision Avoidance (HSMA/CA) protocol for CR-based IoT networks. Our proposed HSMA/CA scheme resolves hidden primary terminal problem and maintains sufficient priority rights to PUs in a densely distributed network. In addition, we optimize the spectrum sensing period to maximize the system performance by maintaining peculiarities in the sensing operation like false alarm and misdetection. To evaluate the performance of HSMA/CA, we have analyzed the protocol through the Markov chain model in terms of throughput and verify its accuracy by simulations. Simulation results show that our scheme is suitable for non-collaborative densely deployed CR-based IoT networks.

Ranked Sense Multiple Access Control Protocol for Multichannel Cognitive Radio-Based IoT Networks.

The widespread growth of the Internet-of-Things (IoT) and its dependence on the license-exempt Industrial, Scientific, and Medical (ISM) bands have made spectrum resources scarce. IoT can nonetheless get advantage from the Cognitive Radio (CR) technology to resolve the spectrum shortage issue. Since in CR networks the unlicensed Secondary Users (SUs) can exploit the white spaces in licensed channels of Primary Users (PUs) opportunistically. CR ad hoc networks are more useful in IoT due to ease of installation, low cost, and less complexity. However, CR ad hoc networks are prone to the rendezvous issue and hidden primary terminal problem. Moreover, the available channels in the CR system are not identical, PUs' and SUs' activities can diversify them as well. In this connection, channel selection by SUs is a complex balancing act since the transmission opportunities are space, frequency and time bounded. In this paper, we hence proposed a new Ranked Sense Multiple Access with Collision Avoidance (RSMA/CA) protocol for multichannel CR-based IoT networks. Our proposed RSMA/CA protocol not only resolves the hidden primary terminal problem but also avoids hidden and exposed terminal problems at the same time by mutual spectrum sensing. We suggest a new channel ranking mechanism to rank the available channels based on the long term qualities of the channels, PUs' return rate, and SUs' activities and tailor-made the algorithms in an existing scheme to make the rendezvous process more efficient. We analyze the performance of our proposed RSMA/CA in terms of normalized throughput through the Markov chain model and compared with that of the existing scheme. Simulation results show that our RSMA/CA protocol outperforms the existing scheme due to efficient rendezvous and access mechanisms.

Clinico-hematological and oxidative stress status in Nili Ravi buffaloes infected with Trypanosoma evansi.

Hemoparasitic diseases like trypanosomiasis have an adverse influence on the health and working capability of infected animals. Monitoring and identification of blood born parasitic infections in dairy animals are of vital importance to get the optimum production. In this study blood samples were collected from Nili Ravi buffaloes (n = 390) kept at different villages of district Lodhran, Punjab province of Pakistan. Blood samples were evaluated for red blood cell counts, total and differential leukocyte counts, hematocrit, hemoglobin, total proteins and different serum parameters such as alanine aminotransferase, aspartate aminotransferase, malondialdehyde, alkaline phosphatase, lactate dehydrogenase, phosphorous, copper, calcium and magnesium. Overall prevalence of Trypanosoma evansi was 4.61% based on microscopic smear examination, 11.02% with Formol Gel Test and 16.15% with PCR. Infected buffaloes showed different clinical signs, including high fever (105 ±â€¯1.0 °F), edema of face and legs, hyperemic mucosa of eyes, lachrymation, bulging eyes, pale mucus membranes and frequent urination. Microscopic examination of blood films showed morphologically different parasites. Statistical analysis did not indicate an association of infection based on age and sex of buffaloes. Results revealed significantly (p < 0.05) lower values of red blood cell counts, hemoglobin, hematocrit, mean corpuscular hemoglobin concentration and total proteins, while increased values of mean corpuscular volume, total white blood cells, monocyte, neutrophils, basophils and eosinophils in infected animals. Infected buffaloes were suffering from macrocytic hypochromic anemia. A significant (p < 0.05) increase in serum lipid per oxidation product (malondialdehyde) level and serum enzymes while a decrease in macrominerals and trace mineral (copper) in trypanosomiasis positive buffaloes were recorded. It was concluded that Trypanosoma evansi is prevalent in Pakistan under tropical and subtropical climatic conditions. It causes clinical disease with macrocytic hypochromic anemia and oxidative stress in infected buffaloes.

Adaptive and Economically-Robust Group Selling of Spectrum Slots for Cognitive Radio-Based Networks.

Auction theory has found vital application in cognitive radio to relieve spectrum scarcity by redistributing idle channels to those who value them most. However, countries have been slow to introduce spectrum auctions in the secondary market. This could be in part because a number of substantial conflicts could emerge for leasing the spectrum at the micro level. These representative conflicts include the lack of legislation, interference management, setting a reasonable price, etc. In addition, the heterogeneous nature of the spectrum precludes the true evaluation of non-identical channels. The information abstracted from the initial activity in terms of price paid for specific channels may not be a useful indicator for the valuation of another channel. Therefore, auction mechanisms to efficiently redistribute idle channels in the secondary market are of vital interest. In this paper, we first investigate such leading conflicts and then propose a novel Adaptive and Economically-Robust spectrum slot Group-selling scheme (AERG), for cognitive radio-based networks such as IoT, 5G and LTE-Advanced. This scheme enables group-selling behavior among the primary users to collectively sell their uplink slots that are individually not attractive to the buyers due to the auction overhead. AERG is based on two single-round sealed-bid reverse-auction mechanisms accomplished in three phases. In the first phase, participants adapt asks and bids to fairly evaluate uplink slots considering the dynamics of spectrum trading such as space and time. In the second phase, an inner-auction in each primary network is conducted to collect asks on group slots, and then, an outer-auction is held between primary and secondary networks. In the third phase, the winning primary network declares the winners of the inner-auction that can evenly share the revenue of the slots. Simulation results and logical proofs verify that AERG satisfies economic properties such as budget balance, truthfulness and individual rationality and improves the utilities of the participants.

Multiple Access Control for Cognitive Radio-Based IEEE 802.11ah Networks.

The proliferation of Internet-of-Things (IoT) technology and its reliance on the license-free Industrial, Scientific, and Medical (ISM) bands have rendered radio spectrum scarce. The IoT can nevertheless obtain great advantage from Cognitive Radio (CR) technology for efficient use of a spectrum, to be implemented in IEEE 802.11af-based primary networks. However, such networks require a geolocation database and a centralized architecture to communicate white space information on channels. On the other hand, in spectrum sensing, CR presents various challenges such as the Hidden Primary Terminal (HPT) problem. To this end, we focus on the most recently released standard, i.e., IEEE 802.11ah, in which IoT stations can first be classified into multiple groups to reduce collisions and then they can periodically access the channel. Therein, both services are similarly supported by a centralized server that requires signaling overhead to control the groups of stations. In addition, more regroupings are required over time due to the frequent variations in the number of participating stations, which leads to more overhead. In this paper, we propose a new Multiple Access Control (MAC) protocol for CR-based IEEE 802.11ah systems, called Restricted Access with Collision and Interference Resolution (RACIR). We introduce a decentralized group split algorithm that distributes the participating stations into multiple groups based on a probabilistic estimation in order to resolve collisions. Furthermore, we propose a decentralized channel access procedure that avoids the HPT problem and resolves interference with the incumbent receiver. We analyze the performance of our proposed MAC protocol in terms of normalized throughput, packet delay and energy consumption with the Markov model and analytic expressions. The results are quite promising, which makes the RACIR protocol a strong candidate for the CR-based IoT environment.

Prospective study of avian influenza H9 infection in commercial poultry farms of Punjab Province and Islamabad Capital Territory, Pakistan.

A prospective study was conducted from November 2013 to February 2014 to estimate the spatial clustering; cumulative incidence and risk factors associated with avian influenza (AI) subtype H9 infection on commercial poultry farms of Pakistan. A total of 400 farms were enrolled and followed during the study period. Among these, 109 farms submitted samples suspected for AI to the laboratory, and only 47 farms were confirmed positive by hemagglutinin inhibition (HI) test. Data was collected from these 109 farms about their demography, management, and biosecurity practices. The cumulative incidence of H9N2 was 11.75 % (95 % confidence interval (CI) 8.76-15.23). The highest number of cases (40.42 %) was reported in January. One most likely cluster (p = 0.009, radius = 4.61 km) occurred in the Kasur district. Multivariable logistic regression analyses showed that the presence of wild birds on the farms (odds ratio (OR) = 16.18; 95 % CI 3.94-66.45) was independently associated with H9N2 infection. Cleaning of cages before delivery on farm (OR = 0.16; 95 % CI = 0.06-0.47), presence of a footbath at the entrance of farm (OR = 0.24; 95 % CI 0.08-0.79), and changing of gloves (OR = 0.33; 95 % CI 0.11-0.99) were protective factors against H9N2 infection. Reducing the exposure to risk factors and adapting biosecurity measures may reduce the risk of AI H9N2 infection on commercial poultry farms in Pakistan.

Characterisation of the essential oil from Iphiona grantioides and investigation of its antibacterial and antioxidant properties.

Iphiona grantioides (Boiss) Anderb. is a medicinal plant featuring several traditional uses. Nevertheless, this plant has not been widely investigated by modern medicinal chemistry yet, as also the properties of its extracts.In this study, we report the extraction of the essential oil by hydrodistillation from the leaves of I. grantioides. This was characterised by GC-MS analysis and ten chemical constituents were identified.Our findings demonstrate that the essential oil is effective in inhibiting the growth of bacterial strains, and of Klebsiela pneumonia and Staphylococcus aureus in particular. Additionally, its antioxidant properties were evaluated, and it showed radical scavenging activity in vitro.

Synthesis of Isatin Derivatives Exhibiting Antibacterial, Antifungal and Cytotoxic Activities.

OBJECTIVE: The current objective was to synthesize biologically active Isatin derivatives. For this purpose, six (06) chemical entities of Isatin derivatives such as 3a-3c and 4a-4c were synthesized from Isatin substrate. METHODS: The pure compounds were characterized with the help of 1H-NMR, FT-IR, EIMS spectroscopic techniques. The synthesized amines 3a-3c and hydrazones 4a-4c were evaluated for their toxicity potential with the help of brine shrimp bioassay. RESULTS: The obtained results revealed that 3c exhibited promising toxicity (LD50 = 1.03 × 10-5 M) against Artemia salina. The pure chemical entities such as compounds 3a-3c and 4a-4c were evaluated against four Gram-negative (E. coli, P. aeruginosa, S. typhi, S. flexneri) and two Gram-positive (B. subtilis, S. aureus) bacteriae. The compound 3a displayed significant activity against two bacterial strains; i.e. P. aeruginosa, S. typhi, compound 3c demonstrated significant activity against P. aeruginosa. Compound 4b was the most active against S. typhi, displaying a greater diameter of the growth of inhibition zone (GIZ) than the standard drug. Compound 4c exhibited significant activity against P. aeruginosa and S. typhi. Compounds 3a-3c and 4a-4c exhibited moderate to significant antibacterial activity against three out of five strains. Only Compound 3c revealed promising toxicity (LD50 = 1.03 × 10-5 M) against Artemia salina. Antifungal studies of the compounds 3a-3c and 4a-4c against six fungal cultures; T. longifusus, C. albicans, A. flavus, M. canis, F. solani, and C. glabrata. All the compounds were active against one or more pathogens having inhibition (10- 90 %). Compound 3a exhibited significant inhibition i.e. 90 % against M. canis, 70 % against T. longifusus, compound 4b further displayed significant inhibition (90 %) against A. flavus and thus proved to be the most active member of the series. CONCLUSION: All compounds showed better antibacterial, antifungal and cytotoxic activities, which may provide a ground to prepare enhanced molecules with much higher antibacterial activities.

Assessment of odour problem in sewage-treated effluent in a closed loop irrigation system.

Uses of wastewater drives significant economic activity, supports countless livelihoods particularly those for developing countries. While using wastewater, the challenge is to identify practical, affordable safeguards that do not threaten the health of users. In Yanbu Al-Sinaiyah, treated sewage effluent (TSE) is used for landscape purposes. In the present study, the odour problem caused by TSE in community area has been addressed. Samples were collected and analysed for total coliform, odour, trihalomethanes (THMs), total organic carbon (TOC) and other physicochemical parameters. Results show that in distribution network, residual chlorine was below the detection limit, turbidity, THMs, TOC and total coliform concentration was much higher than point source, and concentration of these parameters was further increased in problematic areas. It was also observed that areas with odourous problem were at the tail of irrigation network. This indicates that odour problem was due to less residual chlorine high turbidity, high rate of coliform and TOC. In odourous water samples, carbon disulphide and dimethyl sulphide were also identified by GC/MS, while in other areas where there was no odour, both these compounds were not detected. Odour problem was successfully resolved by improving sand filtration system to minimise turbidity the main cause of odour, increasing the residual chlorine at the treatment plant and regularly flushing the distribution network.

1-Acetyl-3-[2-(2,3,5,6-tetra-fluoro-phen-yl)hydrazin-1-yl-idene]indolin-2-one.

In the title compound, C(16)H(9)F(4)N(3)O(2), the dihedral angle between the aromatic ring systems is 4.10 (14)° and a bifurcated intra-molecular N-H⋯(O,F) hydrogen bond generates an S(6) ring for the O-atom acceptor and an S(5) ring for the F-atom acceptor. A short C-H⋯O conact also occurs. In the crystal, mol-ecules are linked by C-H⋯O inter-actions.

N-{2-[N-(4-Methyl-phen-yl)oxamo-yl]phen-yl}propanamide.

The title compound, C(18)H(18)N(2)O(3), is the product of the heterocyclic ring cleavage at position 2 of 1-propionylisatin. Two centrosymmetric cyclic motifs, viz. R(2) (2)(14) and R(2) (2)(18), are formed by N-H⋯O hydrogen bonds with the propanamide and amino-phenyl units, respectively, as the N-H donors. These motifs combine into two C(2) (2)(8) chain motifs parallel to the b axis. The chain structure is stabilized by C-H⋯π inter-actions between the benzene rings, where C-H is from the phenyl ring of the cleaved part of 1-pro-pionylisatin.

Contrasting changes in snow cover and its sensitivity to aerosol optical properties in Hindukush-Karakoram-Himalaya region.

Snow cover plays a major role in the earth's climate system. The stability of the snow mass over Hindukush-Karakoram-Himalaya (HKH) in contrast to the worldwide retreat of mountainous glaciers and its relation to aerosol concentration remains poorly understood. The proposed study focused on the understanding of this relationship between various snow parameters and the optical properties of atmospheric aerosols over the HKH region of Northern Pakistan between March and June for a prolonged study period from 2005 to 2015. The aerosol's optical properties were retrieved from snow covered pixels in the study area to avoid the contamination of snow albedo (SA) by other features of land surfaces. The results revealed an increasing trend in the snow cover area (SCA) at the rate of 577.3, 1090.6 and 652.3 km2/year in March, May and June, respectively, with a decrease in April due to the uneven distribution of SCA during 2005-2015. The results revealed a strong positive correlation (R = 0.77) between SCA and SA, whereas SCA and SST were negatively correlated (R = -0.82) during the study period. The Cloud-Aerosol Lidar and Infrared Pathfinder (CALIPSO) indicated the presence of scattering and absorbing aerosols (e.g., dust, polluted dust, and smoke) both at high and low altitudes. However, the diminution of aerosol concentration was caused by their short time span in atmosphere and the occurrence of snowfall that washed them out from the snow at high altitudes. The findings indicated an increased SCA, with contrasting behavior in the ablation period. However, the presence of aerosols demands proper attention, to monitor any future threat to the high-altitude cryosphere.

Sodium arsenite toxicity on hematology indices and reproductive parameters in Teddy goat bucks and their amelioration with vitamin C.

Arsenic is a major environmental toxicant of concern, affecting both female and male reproductive systems. The present study was conducted to investigate the toxic effects of arsenic on semen quality and reproductive hormones of Teddy bucks, an important domestic species in regions of Pakistan. In addition to arsenic, vitamin C was fed to a subset of animals to determine if there were ameliorative effects on reproductive parameters. Sixteen adult Teddy bucks were randomly divided into four experimental groups: A (control), B (arsenic 5 mg/kg BW/day orally), and C (arsenic 5 mg/kg BW/day plus vitamin C of an oral dose of 200 mg/kg BW/day). The animals in experimental group D were given only vitamin C (oral dose of 200 mg/kg BW/day). Animals were fed treated food once a day for 12 weeks. Semen quality parameters (volume, motility, count, sperm morphology, live dead ratio, sperm membrane integrity, and sperm DNA integrity) of bucks from each experimental group were evaluated on a weekly basis. Hematology and the level of arsenic in the blood were assessed every 2 weeks. Serum was collected fortnightly to measure reproductive and stress hormones (testosterone, luteinizing hormone, follicle-stimulating hormones, and cortisol). At the end of the study, all the animals were slaughtered, and the testes of all the animals were collected and evaluated for histopathology. Semen parameters in arsenic-treated bucks were significantly reduced (p < 0.05) compared with controls. Moreover, the levels of male hormones (testosterone, luteinizing hormone, and follicle-stimulating hormone) were significantly decreased in arsenic-treated animals, while cortisol was significantly increased with arsenic exposure. The histopathological lesions in the testes were present in the form of the loss of germinal epithelium and atrophy of Leydig cells. Supplementation of vitamin C however ameliorated the adverse effects of arsenic on semen quality and hormones. The histopathological lesions were also ameliorated due to vitamin C treatment. This study demonstrates that arsenic can adversely affect reproductive endpoints in Teddy goat bucks and supports the hypothesis that vitamin C is an effective treatment in arsenic-induced toxicosis. This study has high significance for Pakistan, as water contaminated with arsenic is a top health concern and is a recurring issue for both domestic animals and humans.

Optimizing planting geometry for barley-Egyptian clover intercropping system in semi-arid sub-tropical climate.

Intercropping legumes with cereals has been a common cropping system in short-season rainfed environments due to its increased productivity and sustainability. Intercropping barley (Hordeum vulgare L.) with Egyptian clover (Trifolium alexandrinum L.) could increase the grain yield of barley and improve resource use efficiency of the intercropping system. However, non-optimum planting geometry has been a hurdle in the adaptation of barley-based cropping systems. This study was aimed at optimizing the planting geometry, and assess the productivity and profitability of barley-Egyptian clover intercropping system. Ten different planting geometries, differing in number of rows of barley, width and number of irrigation furrows and planting method were tested. Intercropping barley with Egyptian clover improved 56-68% grain yield of barley compared with mono-cropped barley. Barley remained dominant crop in terms of aggressiveness, relative crowding coefficient and competitive ratio. The amount of water used was linearly increased with increasing size of barley strip from 3 to 8 rows. The highest water use efficiency (4.83 kg/cf3) was recorded for 8-row barley strip system with 120 cm irrigation furrows compared to rest of the planting geometries. In conclusion, 8-rows of barley planted on beds with Egyptian clover in 120 cm irrigation furrows had the highest net income and cost benefit ratio. Therefore, it is recommended that this planting geometry can be used for better economic returns of barley-Egyptian clover intercropping system. However, barley strips with >8 rows were not included in this study, which is limitation of the current study. Therefore, future studies with >8 barley rows in strip should be conducted to infer the economic feasibility and profitability of wider barley strips.

Quality comparison of tap water vs. bottled water in the industrial city of Yanbu (Saudi Arabia).

This study was conducted to compare the quality of bottled water with potabilized desalinated tap water. Fourteen brands of local and imported bottled water samples were collected from the local market and analyzed for physicochemical parameters in the Royal Commission Environmental Laboratory. Results were compared with 5-year continuous monitoring data of tap water from different locations in Madinat Yanbu Al-Sinaiyah (MYAS) including storage tanks of desalination plant. Results show that there was no significant difference in the quality of tap water and bottled water. Bacteriological test was never found positive in the 5-year data in tap water. Similarly, physicochemical analysis shows the persistent quality of tap water. Based on hardness analysis, bottled and tap water are categorized as soft water. Trihalomethanes (THMs) study also indicates that traces of disinfection by products (DBPs) are present in both tap and bottled water and are much less than the World Health Organization and Environmental Protection Agency maximum permissible limits. It is also important to note that the tap water distribution network in MAYS is a high-pressure recirculation network and there is no chance to grow bacteria in stagnant water in pipe lines or houses. Recently, the Royal Commission has replaced the whole drinking water network, which was made of asbestos-cemented pipes with glass-reinforced plastic (GRP) pipes, to avoid any asbestos contaminations. Based on these results, it is concluded that drinking water distributed in the city is of very good and persistent quality, comparable with bottled water. Continuous monitoring also guarantees the safe drinking water to the community. Hence, it is the responsibility of the Royal Commission to encourage the peoples in the city to drink tap water as it is as good as bottled water even better than some of the brands and is monitored regularly. It is also much cheaper compared to bottled water and is available round the clock. Preference for tap water over bottled water will also reduce the production of bottled water that has flooded the market, the enormous strain on the environment, and the pollution due to used empty plastic bottles in the landfill area and will help to keep the city clean.

Antibiotic prophylaxis in clean general surgery.

OBJECTIVE: To find out the incidence of surgical site infection in clean general surgery cases operated without prophylactic antibiotics. DESIGN: A comparative study. PLACE AND DURATION OF STUDY: The study was carried out in Combined Military Hospital, Pano Aqil Cantonment, from July 2003 to December 2004. PATIENTS AND METHODS: One hundred and twenty-four clean surgical cases operated without antibiotic prophylaxis between July 2003 and December 2004, were studied and these were compared with similar number of cases who received antibiotics. The data was collected and analyzed using software SPSS (version 10.0). Chi-square and student "t" test were used to analyze the association between antibiotics and wound infection. RESULTS: The most frequent operation was repair of various hernias, 69.3% in group A and 75% in group B. More operations were carried out between 21-30 years, 38.7% in group A and 41.9% in group B. Surgical site infection occurred in one patient (0.8 %) in each group. Chi- square test (0.636) applied to group A and B showed no association of infection and administration/ no administration of antibiotics (p > 0.25). The "t" test applied on group A and B (t=0) also showed no significant difference between administration of antibiotics/ no antibiotics and infection (p > 0.25). CONCLUSION: The use of prophylactic antibiotic in clean, non implant and elective cases is unnecessary.

Leaching of styrene and other aromatic compounds in drinking water from PS bottles.

Bottled water may not be safer, or healthier, than tap water. The present studies have proved that styrene and some other aromatic compounds leach continuously from polystyrene (PS) bottles used locally for packaging. Water sapmles in contact with PS were extracted by a preconcentration technique called as "purge and trap" and analysed by gas chromatograph-mass spectrometer (GC/MS). Eleven aromatic compounds were identified in these studies. Maximum concentration of styrene in PS bottles was 29.5 microg/L. Apart from styrene, ethyl benzene, toluene and benzene were also quantified but their concentrations were much less than WHO guide line values. All other compounds were in traces. Quality of plastic and storage time were the major factor in leaching of styrene. Concentration of styrene was increased to 69.53 microg/L after one-year storage. In Styrofoam and PS cups studies, hot water was found to be contaminated with styrene and other aromatic compounds. It was observed that temperature played a major role in the leaching of styrene monomer from Styrofoam cups. Paper cups were found to be safe for hot drinks.

Is mechanical bowel preparation really necessary in colorectal surgery?

OBJECTIVE: To determine the outcome of colorectal surgery without mechanical bowel preparation. DESIGN: A descriptive, analytical and observational study. PLACE AND DURATION OF STUDY: Combined Military Hospital, Kharian and Pano Aqil, from September 1998 to April 2003. SUBJECTS AND METHODS: Forty-seven patients underwent debridement/resection and repair/primary anastomosis of colon and upper rectum without bowel preparation. Of these, 16 patients were operated in emergency. The anastomosis was carried out with polyglactin (vicryl) interrupted, full thickness single layer and no patient had defunctioning colostomy. Third generation cephalosporin, cefotaxime or ceftazidime and metronidazole were given perioperatively, repeated during surgery if lasted for more than 2 hours and continued for 3-5 days postoperatively. RESULTS: Anastomoses were ileocolic in 29.7%, colicocolic in 61.7% and colorectal in 14.8% cases. Anastomotic failure was seen in 4.2% and wound infection in 8.5% cases. There was one mortality (2.1%) due to unrelated cause. CONCLUSION: Mechanical bowel preparation is not necessary for safe colorectal surgery.