Phylogenetic status and diet of red fox (Vulpes vulpes griffithii) inhabiting Ayubia National Park, Pakistan

Abstract The red fox (Vulpes vulpes) is a medium-sized carnivore that occurs in different regions of Pakistan, however, still lacks scientific data on its ecology and distribution. The current study investigated the phylogenetic status and diet of the red fox (V.v. griffithii) occurring in Ayubia National Park, Pakistan. Through camera trapping and molecular analysis, we confirmed the occurrence of red fox in the study area. Based on mitochondrial cytochrome B (304 bp) and limited sampling, nearly all red foxes of Ayubia National Park and surrounding Himalayan ranges fall within Holarctic maternal lineage, whereas red foxes found in plains of Pakistan are part of the basal Palearctic maternal lineage. Using 32 scats, we found that red fox diet comprises of 80% animal-based prey species (both wild and domestic) and 19% plant matter. The wild animal prey species included Cape hare (Lepus capensis) and flying squirrel (Pteromyini sp.), which constituted 17% and 15% of diet, respectively. Red foxes infrequently consumed House mouse (Mus musculus), Himalayan Palm civet (Paguma larvata) and sheep (Ovis aries), each comprising around 6% to 9% of red fox diet. The fox species also scavenged on domestic donkey opportunistically. Based on our sampling, our study suggests that the red fox (V.v. griffithii) that occurs in Ayubia National Park and across the lesser Himalayan ranges belongs to Holarctic maternal lineage. The study also highlights consumption of plant seeds by red foxes, indicating it may play an important ecological role in seed dispersal in Ayubia National Park.

Functional studies for the TRAF6 mutation associated with hypohidrotic ectodermal dysplasia

BACKGROUND

Hypohidrotic ectodermal dysplasia (HED) is a rare condition characterized by hypotrichosis, hypohidrosis and hypodontia. A de novo heterozygous mutation in the tumour necrosis factor receptor-associated factor 6 gene (TRAF6) was recently identified in a patient with HED, while functional consequences resulting from the mutation remained unknown.

OBJECTIVES

To determine the mechanism by which the TRAF6 mutation results in HED.

METHODS

We performed coimmunoprecipitation (co-IP) studies to determine whether the mutation would affect the interaction of TRAF6 with transforming growth factor β-activated kinase 1 (TAK1), TAK1-binding protein 2 (TAB 2) and ectodysplasin-A receptor-associated death domain protein (EDARADD). We then performed co-IP and glutathione S-transferase-pulldown assays to determine the TRAF6 binding sequences in EDARADD. In addition, we analysed the effect of the mutant TRAF6 protein on the affinity between wild-type TRAF6 and EDARADD, as well as on EDARADD-mediated nuclear factor (NF)-κB activation.

RESULTS

The mutant TRAF6 protein was capable of forming a complex with TAK1 and TAB 2 in a similar way to wild-type TRAF6. However, the mutant TRAF6 protein completely lost the affinity to EDARADD, while the wild-type TRAF6 bound to the N-terminal domain of EDARADD. Furthermore, the mutant TRAF6 inhibited the interaction between the wild-type TRAF6 and EDARADD, and also potentially reduced the EDARADD-mediated NF-κB activity.

CONCLUSIONS

We conclude that the mutant TRAF6 protein shows a dominant negative effect against the wild-type TRAF6 protein, which is predicted to affect the EDARADD-mediated activation of NF-κB during the development of ectoderm-derived organs, and to lead to the HED phenotype.

Accessory gallbladder: a new anatomical variation arising from both left and right hepatic ducts

We present a case of accessory gallbladder demonstrating an anatomical variation not previously reported. While rare, accessory gallbladders are an important consideration if a cholecystectomy is to be performed. We also present a brief literature review of accessory gallbladders.

Tuberculosis simulating brain tumour

The purpose of the study is to highlight the varied presentation of tuberculosis (TB) simulating a brain tumour. Headache and seizures are becoming frequent presenting complaints without any history of tuberculosis. The study comprises 1200 patients of both sexes with ages ranging from ten to sixty years. CT scan and MRI brain control with and without contrast medium were the investigations performed in these cases. In some patients Electroencephalography (EEG), cerebral angiography (DSA) and spectroscopy were also performed. The final diagnosis of tuberculosis was made on the basis of craniotomy, stereotactic and burr hole biopsies with histopathology in most of the cases. Forty per cent of the patients were followed up for eight months. They were put on anti-tuberculosis treatment with symptomatic and anti-epileptic drugs. The incidence was 544 and 757 per 100,000 in Africa and Indo Pakistan respectively. The male to female ratio was 1:1. Tuberculosis, especially with CNS involvement, is not only common in immunosuppressed patients in our setting, but TB has been and remains an important public health problem. TB may involve the CNS either as meningitis or as parenchymal granulomas or abscesses. Patients with brain TB usually present with fever, multiple cranial nerve involvement and occasional behavioural changes. CSF findings remain non specific in most cases. The most common sites are the cerebral hemisphere and basal ganglion in adults and the cerebellum in children. Tuberculosis has unique findings on brain CT and MRI. Cortical and subcortical locations are typical whereas the brain stem is a less common site. Tuberculosis lesions are usually solitary but multiple in 10% to 35% of cases. In spite of all these facts some cases of brain TB still need aggressive neurointervention to reach the final diagnosis of brain TB. Tuberculosis in the CNS may manifest in many different ways. So one should always include tuberculosis in the differential diagnosis in the etiology of delayed onset epilepsy and acute on chronic headache. In case of a discrepancy between clinical manifestations and CT/MRI findings, one can always anticipate tuberculous lesion in the brain.

Expression and inducibility of endosulfan metabolizing gene in Rhodococcus strain isolated from earthworm gut microflora for its application in bioremediation

The metabolizing potential of a bacterial strain Rhodococcus MTCC 6716, isolated from the gut of an Indian earthworm (Metaphire posthuma) was studied for endosulfan bioremediation. In the present work, the optimum conditions for the maximum growth, kinetic of endosulfan degradation, regression equation, half life and correlation coefficient were studied. Endosulfan induced alterations in the expression of mRNA and protein of specific endosulfan metabolizing marker gene (Esd) was studied. Maximum growth of bacteria was observed at pH 7.0, 30°C and 0.085 M sodium chloride concentration in a liquid culture medium. Endosulfan was degraded by Rhodococcus strain up to 97.23% within 15 days without producing toxic metabolite and with strong correlation coefficient (-0.728) and half life 5.99 days. Endosulfan degradation was mediated through gene(s) present in genomic DNA. Expression of marker gene was found endosulfan concentration dependent. The results suggest that this novel strain (Rhodococcus) may be utilized for bioremediation of endosulfan.

Broader leaves result in better performance of indica rice under drought stress

Leaf growth is one of the first physiological processes affected by changes in plant water status under drought. A decrease in leaf expansion rate usually precedes any reduction in stomatal conductance or photosynthesis. Changes in leaf size and stomatal opening are potential adaptive mechanisms, which may help avoid drought by reducing transpiration rate, and can be used to improve rice genotypes in water-saving cultivation. The indica rice cultivar IR64 and four of its near-isogenic lines (NILs; BC(3)-derived lines) unique for leaf size traits, YTK 124 (long leaves), YTK 127 (broad leaves), YTK 205 (short leaves) and YTK 214 (narrow leaves), were compared in this study for changes in leaf growth and its water status. The plants were subjected to two soil water regimes, well-watered and progressive soil drying measured by the fraction of transpirable soil water (FTSW). Applied drought reduced leaf number, total leaf area, specific leaf area, plant biomass, tiller number, plant height, stomatal conductance, amount of water transpired, leaf relative water content, and leaf water potential more in IR64 and the NILs than in the respective controls; nonetheless, transpiration efficiency (TE) was slightly higher under drought than in the well-watered controls. NILs with broader leaves had higher biomass (and its individual components), less stomatal conductance, and higher TE under drought than NILs with narrow and shorter leaves. Under drought, leaf number was positively correlated with tiller number and plant height; nonetheless, root weight and total biomass, water transpired and TE, and plant height and TE were positively correlated with each other. However, a negative correlation was observed between stomatal conductance and the FTSW threshold at which normalized transpiration started to decline during soil drying. Overall, the IR64-derived lines with broader leaves performed better than NILs with narrow and short leaves under drought.

Relationship of awards in multiple choice questions and structured answer questions in the undergraduate years and their effectiveness in evaluation

BACKGROUND

A number of evaluation tools for assessing the cognitive and affective domains in accordance with Bloom's taxonomy are available for summative assessment. At the University of Health Sciences, Lahore, Multiple Choice Questions (MCQs) and Structured Answer Questions (SAQs) are used for the evaluation of the cognitive domain at all six hierarch levels of taxonomy using the tables of specifications to ensure content validity. The rationale of having two evaluation tools seemingly similar in their evaluative competency yet differing in feasibility of construction, administration and marking is being challenged in this study.

METHODS

The MCQ and SAQ awards of the ten percent sample population amounting to 985 students in fifteen Medical and Dental Colleges across Punjab were entered into SPSS-15 and correlated according to the cognitive and affective level of assessment in relation to the Bloom's taxonomy and their grouping in the Tables of Specifications, using parametric tests. 3494 anonymously administered questionnaires were analyzed using ethnograph.

RESULTS

No statistically significant difference was found in the mean marks obtained by the students when MCQs and SAQs were compared according to their groupings in the Tables of Specifications at all levels of cognitive hierarchical testing. End-of-yearcognitive level testing targets set were not met and more questions were set at the lower cognitive testing levels. Expenses incurred in setting MCQs and SAQs were comparable but conduct and assessment costs for MCQs and SAQs were 6% and 94% of the total respectively. In both MCQs and SAQs students performed better at higher cognitive testing levels whereas the SAQs and MCQs were able to marginally test the lower levels of affective domain only. Student's feedback showed that attempting MCQs required critical thinking, experience and practice.

CONCLUSION

MCQs are more cost effective means at levels of cognitive domain assessment.

Samplers for evaluation and quantification of ultra-low volume space sprays

A field study was conducted to explore the suitability of 5 pesticide deposition samplers for airborne spray and ground deposits from ultra-low-volume (ULV) space sprays. Samplers included horizontally stretched stationary cotton ribbons at 2 heights, rotating ribbon, rotating Teflon slides, and filter paper. Slides were also used for droplet-size analysis. A set of 7 samplers of each type was placed at 1, 7, 15, 25, 40, 65, and 90 m from the spray line along the spray swath. Water and BVA13 oil with fluorescent dyes as tracers were sprayed with the use of a truck-mounted ULV sprayer at dusk and dawn. Results suggest that the horizontal and rotating cotton ribbons are best for quantification of airborne spray and filter paper is best for ground deposition collection. The rotating slide samplers only detected the BVA13 oil-based sprays.

Canopy penetration and deposition of barrier sprays from electrostatic and conventional sprayers

An experimental study was conducted to investigate the usefulness of electrostatic and conventional sprayers for barrier applications. Two conventional and three electrostatic sprayers were used in the study. Usefulness of the sprayers was rated based on penetration of spray into and deposition onto 2 sides of leaves on natural vegetation. Bifenthrin (Talstar adulticide) was applied at labeled rate, fluorescent dye was added to the tank mix as tracer, and all sprayers applied the dye and insecticide at the same rate. The results indicated that sprayers producing larger droplets produced significantly higher deposition on vegetation in barrier applications than the sprayers producing smaller droplets. Sprayers with higher air velocity at the nozzle discharge proved significantly better for barrier sprays than the sprayers with lower air velocity. Electrostatic sprayers did not show any improvement in deposition on vegetation or in penetration into vegetation over the conventional sprayers. There was no difference in deposition between truck-mounted and backpack sprayers.

Radiation-Inducedin VitroPhototoxic Potential of Some Fluoroquinolones

Photosensitizing drugs that can damage cellular biomolecules is a matter of concern. Lomefloxacin, norfloxacin, ofloxacin, and enoxacin (broad-spectrum antibiotics of fluoroquinolone group) are used for the treatment of Gram-positive and Gram-negative bacterial infections. Phototoxicity and possible mechanism of their action was assessed under the exposure of ambient levels of UV-A, UV-B, and sunlight at a concentration generally used in the treatment of various diseases. Singlet oxygen (1O2), superoxide anion radical (O2.-) generation, DNA damage, and lipid peroxidation in human blood were studied. All the fluoroquinolones tested in this study produced 1O2 and O2.- under exposure to UV-A, UV-B, and sunlight depending on the concentrations (0 to 60 microg/mL) of the drugs. Enoxacin showed a higher yield of 1O2 and O2.- than other drugs. These materials also degraded deoxyguanosine and induced lipid peroxidation in vitro under exposure to UV-A, UV-B, and sunlight (depending on the dose of radiation). The formation of the reactive oxygen species (ROS) by the photoexcited drugs may be considered as a possible mechanism of their action.

Osteosynthesis for a T-shaped fracture of the femoral neck and trochanter: a case report

Ipsilateral fractures of the femoral neck and trochanter are uncommon. We report a 30-year-old man with a T-shaped fracture separating the trochanter and neck from the head. He underwent osteosynthesis using a dynamic compression plate, screws, and pins. Bone union occurred 4 months postoperatively. At the one-year follow-up, the patient was free of pain and had no evidence of avascular necrosis. It is important to preserve the femoral head in young patients by preventing further compromise of the tenuous blood supply.

Measurements of natural radioactivity and radon exhalation rates from different brands of cement used in Pakistan

The measurement of activity due to the naturally occurring radionuclide has been carried out in different brands of cement available in Pakistan. The gamma spectra of the collected samples were obtained using high-purity germanium detector and analysed for the presence of 232Th, 238U and 40K. The assessment of radiological hazards due to these radionuclides has also been made. The studies concerning the determination of radon-exhalation rates from these samples of cement were also carried out using CR-39 based NRPB radon dosimeters. The range of activity concentrations were found for 226Ra (from 25.10 +/- 1.55 to 52.60 +/- 3.20 Bq kg(-1)), 232Th (from 10.30 +/- 0.65 to 30.40 +/- 1.70 Bq kg(-1)) and 40K (from 17.25 +/- 1.55 to 292.95 +/- 23.05 Bq kg(-1)). The estimated value of radium equivalent concentration was from 11.16 +/- 2.60 to 114.98 +/- 7.11 Bq kg(-1). The calculated absorbed dose rate in air and the annual effective dose were in the range from 18.54 +/- 1.17 to 52.90 +/- 3.31 nGy h(-1) and 0.09 +/- 0.01 to 0.26 +/- 0.02 mSv, respectively. The external and internal hazard indices were in the range from 0.11 +/- 0.01 to 0.31 +/- 0.02 and 0.18 +/- 0.01 to 0.45 +/- 0.03, respectively. The radon exhalation rates from different brands of cement were found in the range from 3.3 +/- 0.7 to 8.1 +/- 1.7 mBq kg(-1) h(-1).

Prevention of beta-thalassemia in a large Pakistani family through cascade testing

BACKGROUND

We report cascade testing of a large Pakistani family for beta-thalassemia alleles. The family was still practicing consanguineous marriages and was at risk of having more affected births.

OBJECTIVE

The objective of this study was to show that identification of disease carriers in families with index cases in order to create awareness about disease and provide genetic counseling would result in reduction of the frequency of beta-thalassemia in Pakistan.

METHODS

In this large family with an index case, 27 available living members were tested for beta-thalassemia. Carriers of the disease were detected by measuring hemoglobin indices, and amplification refractory mutation system polymerase chain reaction was used for mutation analysis. Genetic counseling was provided to members of this family.

RESULTS

There were already 3 marriages between the carrier members and 1 between a carrier and noncarrier in this large family; 12 (44.4%) members were found to carry the mutant gene, representing a very high carrier rate compared to the 5.4% carrier frequency of beta-thalassemia in the general population of Pakistan. The family was counseled for prevention of affected births. The initially reluctant family gradually became cooperative and seriously attended the genetic counseling sessions.

CONCLUSION

Cascade testing is more practical than general population screening in a country with limited health facilities where consanguineous marriages are practiced. This report emphasizes the need of extensive testing within families with index cases to identify the carriers of beta-thalassemia in order to reduce disease occurrence through awareness and genetic counseling.

Phototoxicity assessment of drugs and cosmetic products using E. coli

A gram negative bacteria Escherichia coli (Dh5alpha strain) was developed as an alternate test system of phototoxicity. Eight drugs (antibiotics) and cosmetic products (eight face creams) were examined for their phototoxicity using this test system. Five known phototoxic compounds were used to validate the test system. UVA-radiation induced phototoxicity of these compounds was tested by agar gel diffusion assay. Decrease in colony forming units (CFU) was taken as an end point of phototoxicity. The phototoxic compounds and antibiotics produced significant reduction in CFU (p<0.001) at 80 microg/ml concentrations under exposure to UVA-radiation (5.4-10.8 J/cm(2)). One face cream was found phototoxic and produced significant decrease in CFU of E. coli at 1.0mg/ml concentration under UVA exposure (10.8 J/cm(2)). The minimum effective concentration of tetracycline and dose of UVA-radiation were also determined by observing growth inhibition of E. coli through disc diffusion assay. The observations suggested that E. coli can be used as an alternative test system for phototoxicity evaluation of chemicals. A battery of test systems is required to conclude the toxic/phototoxic potential of a chemical agent. In view of the speed, easiness, sensitivity and low cost, E. coli is introduced as one of the alternate test system for phototoxicity studies in safety evaluation of various chemical ingredients or formulations used in cosmetics and drugs.

Nutrient homeostasis, metabolism of reserves, and seedling vigor as affected by seed priming in coarse rice

The influence of seed priming on germination, seedling vigor, ion homeostasis, and starch metabolism in coarse rice was studied. Priming treatments included pregermination (a traditional soaking method being used for rice nursery preparation), hydropriming for 48 h, osmohardening with KCl or CaCl2 (ψs –1.25 MPa solution) for 24 h, ascorbate priming (10 mg·L–1) for 48 h, and hardening for 24 h. Compared with controls, all priming treatments (except pregermination) reduced the time to start germination, improved the rate of germination and synchronization, and the length of shoot and root, seedling fresh and dry mass, number of secondary roots, the concentration of reducing sugars, and α-amylase activity, although the extent of these changes was different in seeds subjected to different treatments. These seed treatments resulted in higher germination that might be due to overcoming dormancy. Osmohardening with KCl was more effective than CaCl2 for these parameters. Nitrogen concentration remained unaffected in seedlings; however, Ca2+ concentrations in both seeds and seedlings were greater in seeds osmohardenerd with CaCl2 than with all other treatments, including the control. Seed priming enhanced K+ concentration in both seeds and seedlings, leading to improved α-amylase activity. There were positive correlations between seed K+ concentration and amylase activity, and the concentration of reducing sugars with amylase activity, seedling dry mass, or number of secondary roots. Osmohardening with KCl performed better than all other treatments including control. Priming improved the K+ balance that activates α-amylase, a basis for seed invigoration.

Endosulfan degradation by a Rhodococcus strain isolated from earthworm gut

A Rhodococcus MTCC 6716 bacterial strain was isolated apparently for the first time from the gut microflora of an Indian earthworm (Metaphire posthuma). Endosulfan was used as a carbon source by the strain and degraded it up to 92.58% within 15 days. Furthermore, the isolated strain of the bacterium did not produce the persistent form of the toxic metabolite endosulfan sulfate. This strain exhibits luxury growth in minimal medium with high concentrations of endosulfan (80 microg mL(-1)). Degradation of the endosulfan occurred simultaneously with bacterial growth and an increase in chloride ion (87.1%) in the growth medium, suggesting nearly complete degradation of the insecticide. This strain is able to tolerate 45 degrees C and retain its degradation potential even under sunlight exposure. Since endosulfan is used worldwide for pest control and its residues have been retained for long periods in soil, water, and agricultural products, the strain isolated by us is valuable for bioremediation of endosulfan-contaminated soil and water.

Virtual cystoscopy: reality in imaging of bladder tuberculosis

We present a case of urinary tuberculosis investigated initially by ultrasound and multidetector computed tomography (MDCT). The MDCT-derived volumetric data were used to generate virtual cystoscopy (VC) images, which revealed a bladder ulcer. The presence of this ulcer was confirmed by conventional cystoscopy-guided biopsy and there was good agreement regarding various features of the ulcer, such as the site, size and shape, as detected by virtual and conventional cystoscopies. VC, a result of simple postprocessing of preacquired MDCT data, proved valuable in the characterization of the bladder lesion in conjunction with CT and ultrasound images. Although a larger study is warranted, in our case these en face VC representations of the ulcer served as useful precursors to conventional cystoscopic biopsy.

Effect of solar UV radiation on earthworm (Metaphire posthuma)

Human health risks like damage to the eyes, immune system, and skin are known to be associated with increasing ultraviolet radiation (UVR) in the environment. In this study, we evaluated the phototoxic effects of UVR in sunlight and its possible mechanism of action by using earthworm as an alternative model because earthworm skin contains several biomolecules (tetraene and triene sterol) similar to human beings. We studied the generation of reactive oxygen species (ROS), photooxidation of lipids, and histopathological changes in earthworm integument. It was observed that UVR-exposed earthworm skin homogenate produced a significant amount of singlet oxygen ((1)O(2)), superoxide anion (O(2)(*)(-)), hydroxyl radicals ((*)OH), and photooxidation of lipids. The production of ROS and lipid peroxidation product was found dependent on the dose of solar UVR in earthworm integument. Histological anomalies such as thickening, vacuolation, and hypertrophy of epidermal cells were observed when the animals were exposed for 1 to 2h, while a higher exposure period (3h) caused degeneration of circular and longitudinal muscles. Continuous sunlight exposure for more than 3h was found lethal to worms. These observations suggested that the current level of UVR in sunlight may produce significant phototoxic effects in the earthworms probably via the generation of ROS (photodynamic action). Possible increases in UVR in view of ozone depletion may be more detrimental to the biomolecules in the worm's skin. The earthworm thus turned out as a simple, sensitive, and cost-effective test organism for the assessment of the hazardous potential of solar radiation and also for planning safety measures for human beings.

Morphological and metabolic alterations in duckweed (Spirodela polyrhiza) on long-term low-level chronic UV-B exposure

Laboratory grown duckweed (Spirodela polyrhiza) plants were exposed to 0.72 and 1.44J of UV-B radiation daily for 7 days at 0.4mW/cm(2) intensity. Chlorosis and necrosis were observed along with depletion in protein, pigments (chlorophyll, pheophytin, carotenoids, phycoerythrin, phycocyanin, and flavoxanthin), biomass, root length, and frond size in UV-B-exposed plants. The study confirms morphological and metabolic alterations leading to reduction in the productivity of duckweed following long-term exposure to UV-B radiation.

Tibial shaft fractures treated with the AO unreamed tibial nail

BACKGROUND

The AO unreamed tibial nail (UTN) has been used for both open and closed tibial fractures. The reported results have been mixed. We evaluated its outcome in our unit.

AIM

To assess the outcome of tibial shaft fractures treated with the AO UTN.

METHODS

Forty-eight patients underwent intramedullary nailing between 1995 and 2000 using the AO UTN. Follow-up details were available for 45 patients.

RESULTS

Forty-four fractures united (97%). Complications included one non-union (2.2%), 15 delayed unions (33%), nine had either broken or bent interlocking screws (20%), six malunions (13%) and three patients underwent fasciotomy for compartment syndrome (7%). Twenty-one patients underwent at least one additional operation to obtain union (47%). Of these, five underwent exchange nailing (11%).

CONCLUSIONS

The AO UTN does have a high complication rate and, should it be used, we feel that early dynamisation or exchange nailing be considered to hasten union and prevent screw breakage.

Interwell tracing by environmental isotopes at Fimkassar Oilfield, Pakistan

Water flooding is an important operation to enhance oil recovery. Movement of injected water is traced to test the performance of the water flood and verify suspected geological barriers or flow channels, etc. This paper describes the application of environmental isotopes as interwell tracers at Fimkassar Oilfield in Chakwal District, Pakistan. Water flooding was started in March 1996 in the Sakessar formation (Eocene). When water appeared in the production well in June 1998, isotopes (18O, 2H and 3H) were used to determine the breakthrough/transit time of the water flood and the contribution of fresh injected water. Water samples were collected during June 1998-August 1999 from the injection well, the production well, and some other fields for reference indices of the Sakessar formation and analyzed for the 18O, 2H and 3H, and chloride contents. The isotopic results confirmed the breakthrough of injected water and indicated that the water in the production well was a mixture of the injected water and the formation water. The initial breakthrough time was 27 months. The contribution of injected water varied from 67% to 80%. This percentage did not change significantly from the time of breakthrough until the last sampling indicating good mixing in the reservoir and the absence of any high permeability channel. Chloride content did not give any information about the hydraulic connection between the injection well and the production well. The study proved the potential of environmental isotopes for interwell tracing.

Effect of UV-B radiation on some common antibiotics

Some of the commonly used antibiotics such as cephaloridine, cephalexin, cephradine, nystatin and nafcillin were tested for generation of singlet oxygen (1O(2)) under UV-B (290-320 nm) exposure and the order for 1O(2) generation was obtained: cephaloridine>cephalexin>nystatin>cephradine>nafcillin. In vitro study with deoxyguanosine (dGuo) showed that 1O(2) was responsible for drug-sensitized photodegradation of the guanine base of DNA and RNA. Sodium azide (NaN(3)) and 1,4-diazabicyclo [2.2.2] octane (DABCO) accorded significant inhibition (76-98%) in the production of (1)O(2) and photo-oxidation of dGuo. The combined effect of drug and UV-B irradiation is of paramount importance in view of cell-damaging reactions by 1O(2). Our findings are important because of increasing UV-B radiation on the earth's surface due to depletion of the stratospheric ozone layer. The selected drugs are used routinely for the treatment of various diseases and their combined action may cause undesirable phototoxic responses. Our study suggests that exposure to sunlight should be avoided after the intake of the photosensitive drugs.

Cloning of BNIP3h, a member of proapoptotic BNIP3 family genes

Apoptosis is regulated by interaction of antiapoptotic Bcl-2 family proteins with various proapoptotic proteins, several of which are also members of the Bcl-2 family. BNIP3 (formerly NIP3) is a proapoptotic mitochondrial protein classified in the Bcl-2 family based on limited sequence homology-3 (BH3) domain and COOH-terminal transmembrane domain. Sequence comparison of BNIP3 has indicated that there are several BNIP3 human homologs of this protein, like BNIP3L, Nix and BNIP3. We have cloned a new member of BNIP3 family from the cDNA library prepared from human dermal papilla cells and designated as BNIP3h. BNIP3h shows substantial homology with other BNIP3 family proteins. BNIP3h induced apoptosis from 24 hours after transfection in MCF7 cell lines and its apoptosis inducing activity is extended until 72 hours after transfection.

Sensitivity of duckweed (Lemna major) to ultraviolet-B radiation

The sensitivity of an important aquatic macrophyte, duckweed (Lemna major), to UV-B radiation was studied under experimental conditions at three different doses designated as no, mild, and severe injury dose by observing visible injury symptoms and estimating levels of chlorophyll, pheophytin, carotenoids, protein, starch, free sugar, and peroxidase activity. Laboratory-grown duckweed plants were exposed to UV-B radiation at 0.4 mW/cm(2) intensity for different time periods. Mild and severe injury were developed at 6.48 and 8.64 J, respectively. Peroxidase activity increased at all the exposure levels. Dose-dependent decrease in chlorophyll and starch with drastic depletion in protein and free sugar content were observed. Pheophytin and carotenoids content increased at no injury level, but decreased at higher exposure level. The results indicate that ambient UV-B radiation at the indicated level acts as a physiological stress in Lemna major.

Gelatin-sealed polyester resists Staphylococcus epidermidis biofilm infection

BACKGROUND

The purpose of this study was to show that gelatin-impregnated polyester grafts inhibit Staphylococcus epidermidis biofilm infection in a canine model of aortic graft interposition. A clinically native species and two engineered strains, which differed in slime and adhesin antigen components, were compared to determine differential gelatin and slime interactions.

METHODS

In vitro bacterial graft colonization was validated by immersion of graft segments in inoculating solutions (10(6) colony forming units/ml) of a clinically native species RP62A and two genetically engineered S. epidermidis species, M187sn3 (SN3: slime and adhesin negative) or M187sp11 (SP11: slime and adhesin positive), for 18 h at 23 degrees C. The grafts were washed, sonicated, and cultured to assess in vitro bacterial graft adherence. Grafts similarly inoculated were placed as aortic interposition grafts in dogs. Three sterile grafts were implanted as controls. Grafts were excised after 6 weeks and cultured for bacterial growth as in the in vitro study. Infection was defined by a positive culture in the excised grafts. Data were analyzed with nonparametric statistical methods.

RESULTS

In vitro bacterial graft adherence in colony forming units per milliliter was similar at 18 h postsonication for RP62A (8 x 10(4) +/- 1 x 10(4)), SN3 (7 x 10(4) +/- 2 x 10(4)), and SP11 (6 x 10(4) +/- 2 x 10(4)) (P = NS). Only one of five grafts inoculated with RP62A was culture positive after 6 weeks. No grafts inoculated with the engineered strains SN3 or SP11 were culture positive after explanation.

CONCLUSION

In vitro bacterial inoculation of gelatin-impregnated polyester was similar among the species and not dependent upon the presence of slime and adhesin components. Gelatin-impregnated polyester grafts demonstrated in vivo resistance to coagulase-negative staphylococcal biofilm infection.

Agricultural produce in the dry bed of the River Ganga in Kanpur, India--a new source of pesticide contamination in human diets

Vegetables grown in the dry bed field of the River Ganga in Kanpur, an important industrial city of North India, were analysed for the pesticides hexachlorocyclohexane (HCH), dichlorodiphenyl trichloroethane (DDT), their isomers and metabolites at three different sites. Residues of both the pesticides were found in all the samples. Mean levels of 109.35, 136.76 and 145.93 microg HCH/kg and 6.64, 49.3 and 46.70 microg DDT/kg were found in the rural upstream, city and downstream industrial areas, respectively. The mean total HCH and DDT levels were within safe limits as per the Indian Standard but some samples had HCH levels above the WHO/FAO limit. The pesticide residue level in vegetables was several fold higher than their surrounding sandy soil and could pose health problems since these popular vegetables are consumed regularly by the population.

The constitutive heat shock protein-70 is required for optimal expression of myelin basic protein during differentiation of oligodendrocytes

To further elucidate the role of the constitutive heat shock protein-70 (HSC70) as a chaperone for the synthesis of myelin basic protein (MBP), HSC70 content was decreased in oligodendrocyte precursor cells prior to MBP expression either by transfection with an antisense oligonucleotide specific for HSC70, or by exposure to low levels of quercetin, a bioflavonoid known to decrease synthesis of HSC70. As these cells underwent differentiation in vitro, antisense treatment decreased HSC70 levels to 66% of controls. At the same time, a sharp induction resulted in the stress-inducible heat shock protein-70 (HSP70). Levels of two other stress proteins increased as well, namely, the 25-kDa heat shock protein (HSP25) and the 78-kDa glucose regulated protein (GRP78). MBP synthesis proceeded over a normal time course, but at only 50% of control values. As HSC70 content returned to normal, MBP synthesis was also restored to normal levels. Quercetin reduced the expression of HSC70 to an even greater extent than transfection, and prevented the induction of HSP70. In contrast to antisense-treated cells, MBP synthesis was essentially blocked in quercetin-treated cells even though levels of HSP25 and GRP78 increased. Taken together, these observations (a) indicate that HSP70 partially compensates for decreased chaperoning of nascent MBP by HSC70 (HSC70 and HSP70 are closely related and perform similar functions); (b) preclude the involvement of HSP25 and GRP78 in MBP synthesis; and (c) emphasize the requirement of HSC70 for optimal synthesis of MBP.

Cells of the oligodendrocyte lineage proliferate following cortical stab wounds: an in vitro analysis

We have previously shown that a cortical stab wound induces the proliferation of microglia and astrocytes in situ, but no evidence was obtained for proliferation of cells of the oligodendrocyte lineage (Amat et al., 1996). To study further the properties of cells involved in repair following brain injury, groups of adult rats received either sham operations or bilateral stab wounds. Proliferating cells were labeled in vivo 3 days later with [3H]-thymidine (Thy) and sacrificed the same day. Oligodendrocyte-enriched preparations were isolated, cultured, and analyzed. The fate and antigenic phenotype of the proliferating cells was analyzed using three-color immunofluorescence combined with autoradiography at 1, 2, 3, 5, and 10 days in vitro (DIV). Cells were immunostained for ganglioside GD3 (glial stem cells), O4 antigen (cells of the oligodendrocyte lineage), galactosyl ceramide (GC, differentiated oligodendrocytes), and GFAP (astrocytes). Thymidine-labeled O4+/GC- cells were found only in cultures from wounded animals and most of them differentiated in vitro as mature oligodendrocytes, but no Thy+/O4+/GC+ oligodendrocytes were seen at 1, 2, or 3 DIV. There was also a marked increase in the number of Thy+/GD3+ cells in the experimental cultures. In both experimental and control groups the total number of Thy+ and Thy- GD3+ cells declined with time in culture concomitant with an increase in total number of both Thy+ and Thy- GFAP+ astrocytes, and without any significant change in the Thy+ cell fraction of O4+ oligodendrocytes in the experimental cultures. Therefore most of the GD3+/O4- cells apparently differentiated as GFAP+ astrocytes, not as oligodendrocytes. We conclude that O4+/GC- oligodendrocyte precursor cells, but not differentiated oligodendrocytes, proliferate in response to brain injury. These cells proliferate slowly or not at all in normal adult animals and constitute a phenotypically and kinetically distinct group from the GD3+ glial precursors. This result is consistent with the existence within the adult CNS of a quiescent premyelinating oligodendrocyte. We propose that these immature committed oligodendrocytes are induced to proliferate at the wound site and serve as a source of new oligodendrocytes.

Oligodendrocytes express gap junction proteins connexin32 and connexin45

Oligodendrocytes, the myelin-forming glia of brain, are connected by gap junctions in situ and in culture. Cultured oligodendrocytes from adult bovine and porcine brains were studied using immunocytochemical, molecular, and electrophysiological techniques in order to characterize the gap junction types. The expression of connexin32 was substantiated by the detection of low, but significant, signals using connexin-specific probes in Northern and Western blot analyses. Connexin43, which comprises gap junctions in astrocytes, was not detectable in pure oligodendrocytic cultures; mRNAs of connexin40 and connexin37 and connexin26 were also not detected. By means of two specific antibodies directed to the recently cloned connexin45 and by RT-PCR we were able to identify this connexin as a second oligodendrocytic gap junction protein. Whole cell voltage clamp recording provided evidence for electrical coupling between pairs of cultured oligodendrocytes (mean junctional conductance 3.9 nS, n = 38 pairs) and intracellular Lucifer Yellow injection indicated that oligodendrocytes were usually only weakly dye coupled, with spread generally being restricted to nearest neighbors. Unitary conductances ranged from > 20 to < 150 pS with modes of distribution at about 100 to 120pS and 40 to 20 pS, respectively. These unitary conductances are consistent with the channel events expected for connexin32 and connexin45. The low degree of functional coupling between oligodendrocytes in vitro corresponds with the low levels of connexin32 and connexin45 messenger RNAs and protein expression.

Glycosylation of polyclonal and paraprotein IgG in multiple myeloma

It has previously been shown that in multiple myeloma (MM) each IgG paraprotein exhibits a unique oligosaccharide profile. It has been assumed that this results from a clone specific glycosylation machinery. However, the abnormal physiological environment of the bone marrow in this disease may also affect normal plasma cells producing polyclonal IgG. We present data to show that this is so and that, in two cases, the oligosaccharide profile of the polyclonal IgG reflected that of the paraprotein from the same patient rather than that of normal polyclonal IgG.