Machine learning ensembles, neural network, hybrid and sparse regression approaches for weather based rainfed cotton yield forecast

Cotton is a major economic crop predominantly cultivated under rainfed situations. The accurate prediction of cotton yield invariably helps farmers, industries, and policy makers. The final cotton yield is mostly determined by the weather patterns that prevail during the crop growing phase. Crop yield prediction with greater accuracy is possible due to the development of innovative technologies which analyses the bigdata with its high-performance computing abilities. Machine learning technologies can make yield prediction reasonable and faster and with greater flexibility than process based complex crop simulation models. The present study demonstrates the usability of ML algorithms for yield forecasting and facilitates the comparison of different models. The cotton yield was simulated by employing the weekly weather indices as inputs and the model performance was assessed by nRMSE, MAPE and EF values. Results show that stacked generalised ensemble model and artificial neural networks predicted the cotton yield with lower nRMSE, MAPE and higher efficiency compared to other models. Variable importance studies in LASSO and ENET model found minimum temperature and relative humidity as the main determinates of cotton yield in all districts. The models were ranked based these performance metrics in the order of Stacked generalised ensemble > ANN > PCA ANN > SMLR ANN > LASSO> ENET > SVM > PCA SMLR > SMLR SVM > SMLR. This study shows that stacked generalised ensembling and ANN method can be used for reliable yield forecasting at district or county level and helps stakeholders in timely decision-making.

Systems biology of chromium-plant interaction: insights from omics approaches

Plants are frequently subjected to heavy metal (HM) stress that impedes their growth and productivity. One of the most common harmful trace metals and HM discovered is chromium (Cr). Its contamination continues to increase in the environment due to industrial or anthropogenic activities. Chromium is severely toxic to plant growth and development and acts as a human carcinogen that enters the body by inhaling or taking Cr-contaminated food items. Plants uptake Cr via various transporters, such as sulfate and phosphate transporters. In nature, Cr is found in various valence states, commonly Cr (III) and Cr (VI). Cr (VI) is soil's most hazardous and pervasive form. Cr elevates reactive oxygen species (ROS) activity, impeding various physiological and metabolic pathways. Plants have evolved various complex defense mechanisms to prevent or tolerate the toxic effects of Cr. These defense mechanisms include absorbing and accumulating Cr in cell organelles such as vacuoles, immobilizing them by forming complexes with organic chelates, and extracting them by using a variety of transporters and ion channels regulated by various signaling cascades and transcription factors. Several defense-related proteins including, metallothioneins, phytochelatins, and glutathione-S-transferases aid in the sequestration of Cr. Moreover, several genes and transcriptional factors, such as WRKY and AP2/ERF TF genes, play a crucial role in defense against Cr stress. To counter HM-mediated stress stimuli, OMICS approaches, including genomics, proteomics, transcriptomics, and metallomics, have facilitated our understanding to improve Cr stress tolerance in plants. This review discusses the Cr uptake, translocation, and accumulation in plants. Furthermore, it provides a model to unravel the complexities of the Cr-plant interaction utilizing system biology and integrated OMICS approach.

Climate change impacts on insect pests for high value specialty crops in California

California is a global leader in production and supply of walnuts and almonds, and the state is the largest producer of peaches in the U.S. These crops have an important contribution to the California's agricultural economy. Damages to these crops from lepidopteran pests, mainly from Codling moth (Cydia pomonella) (family: Tortricidae), Peach twig borer (Anarsia lineatella) (family: Gelechiidae) and Oriental fruit moth (Grapholita molesta) (family: Tortricidae), are still high, despite the improvement in pest management activities. Given that temperature increase can directly impact the rate of growth and development of these pests, it is important to understand to what extent dynamics of these pests will change in future in California. The objective of this study was to quantify changes in the biofix, lifecycle length, and number of generations for these pests for the entire Central Valley of California. Using a well-established growing-degree days (GDD) model calibrated and validated using observations from orchards of California, and climate change projections from the Coupled Model Intercomparison Project phases 5 and 6 (CMIP5 and CMIP6) General Circulation Models, we found that biofix dates of these pests are expected to shift earlier by up to 28 days, and length of generations is expected to be shortened by up to 19 days, and up to 1.4 extra generations of these pests can be added by the end of the century depending on the scenario. Results from this work would enable industries to prioritize development of practices that are more effective in the long run, such as developing better cultural and biological pest solutions and insect tolerant varieties. Growers and researchers can take proactive actions to minimize future risks associated with these damaging pests. This work can be scalable to other pests and regions to understand regional dynamics of damaging agricultural pests under climate change.

Drought and salinity stresses induced physio-biochemical changes in sugarcane: an overview of tolerance mechanism and mitigating approaches

Sugarcane productivity is being hampered globally under changing environmental scenarios like drought and salinity. The highly complex nature of the plant responses against these stresses is determined by a variety of factors such as genotype, developmental phase of the plant, progression rate and stress, intensity, and duration. These factors influence plant responses and can determine whether mitigation approaches associated with acclimation are implemented. In this review, we attempt to summarize the effects of drought and salinity on sugarcane growth, specifically on the plant's responses at various levels, viz., physiological, biochemical, and metabolic responses, to these stresses. Furthermore, mitigation strategies for dealing with these stresses have been discussed. Despite sugarcane's complex genomes, conventional breeding approaches can be utilized in conjunction with molecular breeding and omics technologies to develop drought- and salinity-tolerant cultivars. The significant role of plant growth-promoting bacteria in sustaining sugarcane productivity under drought and salinity cannot be overlooked.

Balancing water and radiation productivity suggests a clue for improving yields in wheat under combined water deficit and terminal heat stress

Sustaining crop yield under abiotic stresses with optimized resource use is a prerequisite for sustainable agriculture, especially in arid and semi-arid areas. Water and heat stress are major abiotic stresses impacting crop growth and yield by influencing complex physiological and biochemical processes during the life cycle of crops. In a 2-year (2015-2017) research, spring wheat cv. HD-2967 was grown under deficit irrigation and delayed sowing conditions to impose water and terminal heat stresses, respectively. The data were analyzed for seasonal crop water use, radiation interception, water productivity (WP), and radiation productivity (RP) under combined water deficit and terminal heat stresses. Seasonal crop water use was significantly affected by stresses in the order of water + terminal heat > water > terminal heat. Water stress showed minimal effect on the light extinction coefficient and consequently on seasonal intercepted photosynthetically active radiation (IPAR). However, seasonal IPAR was primarily affected by combined water + terminal heat and terminal heat stress alone. The slope of crop water use and IPAR, i.e., canopy conductance, an indicator of canopy stomatal conductance, was more influenced by water stress than by terminal heat stress. Results showed that linear proportionality between WP and RP is no longer valid under stress conditions, as it follows a curvilinear relation. This is further supported by the fact that independent productivity (either water or radiation) lacked the ability to explain variability in the final economic yield or biomass of wheat. However, the ratio of RP to WP explained the variability in wheat yield/biomass under individual or combined stresses. This suggests a clue for improving higher wheat yield under stress by managing WP and RP. The highest biomass or yield is realized when the ratio of RP to WP approaches unity. Screening of genotypes for traits leading to a higher ratio of RP to WP provides an opportunity for improving wheat productivity under stressed environments.

Targeting Apoptotic Pathway of Cancer Cells with Phytochemicals and Plant-Based Nanomaterials

Apoptosis is the elimination of functionally non-essential, neoplastic, and infected cells via the mitochondrial pathway or death receptor pathway. The process of apoptosis is highly regulated through membrane channels and apoptogenic proteins. Apoptosis maintains cellular balance within the human body through cell cycle progression. Loss of apoptosis control prolongs cancer cell survival and allows the accumulation of mutations that can promote angiogenesis, promote cell proliferation, disrupt differentiation, and increase invasiveness during tumor progression. The apoptotic pathway has been extensively studied as a potential drug target in cancer treatment. However, the off-target activities of drugs and negative implications have been a matter of concern over the years. Phytochemicals (PCs) have been studied for their efficacy in various cancer cell lines individually and synergistically. The development of nanoparticles (NPs) through green synthesis has added a new dimension to the advancement of plant-based nanomaterials for effective cancer treatment. This review provides a detailed insight into the fundamental molecular pathways of programmed cell death and highlights the role of PCs along with the existing drugs and plant-based NPs in treating cancer by targeting its programmed cell death (PCD) network.

Heat stress tolerance in peas (Pisum sativum L.): Current status and way forward

In the era of climate change, the overall productivity of pea (Pisum sativum L.) is being threatened by several abiotic stresses including heat stress (HS). HS causes severe yield losses by adversely affecting several traits in peas. A reduction in pod yield has been reported from 11.1% to 17.5% when mean daily temperature increase from 1.4 to 2.2°C. High-temperature stress (30.5-33°C) especially during reproductive phase is known to drastically reduce both seed yield and germination. HS during germination and early vegetative stage resulted in poor emergence and stunted plant growth along with detrimental effects on physiological functions of the pea plant. To combat HS and continue its life cycle, plants use various defense strategies including heat escape, avoidance or tolerance mechanisms. Ironically, the threshold temperatures for pea plant and its responses are inconsistent and not yet clearly identified. Trait discovery through traditional breeding such as semi leaflessness (afila), upright growing habit, lodging tolerance, lower canopy temperature and small seeded nature has highlighted their utility for greater adaptation under HS in pea. Screening of crop gene pool and landraces for HS tolerance in a targeted environment is a simple approach to identify HS tolerant genotypes. Thus, precise phenotyping using modern phenomics tools could lead to increased breeding efficiency. The NGS (next generation sequencing) data can be associated to find the candidate genes responsible for the HS tolerance in pea. In addition, genomic selection, genome wide association studies (GWAS) and marker assisted selection (MAS) can be used for the development of HS tolerant pea genotypes. Additionally, development of transgenics could be an alternative strategy for the development of HS tolerant pea genotypes. This review comprehensively covers the various aspects of HS tolerance mechanisms in the pea plant, screening protocols, omic advances, and future challenges for the development of HS tolerant genotypes.

Multigene phylogeny and haplotype analysis reveals predominance of oomycetous fungus, Phytophthora meadii (McRae) associated with fruit rot disease of arecanut in India

An oomycetous fungus Phytophthora causing fruit rot is the most devastating disease of arecanut in different agro-climatic zones of Karnataka with varied climatic profiles. The main aim of this investigation was to characterize the geo-distant Phytophthora populations infecting arecanut using robust morphological, multi-gene phylogeny and haplotype analysis. A total of 48 geo-distant fruit rot infected samples were collected during the South-West monsoon of 2017–19. Pure culture of the suspected pathogen was isolated from the infected nuts and pathogenic ability was confirmed and characterized. Colony morphology revealed typical whitish mycelium with stellate or petalloid pattern and appearance with torulose hyphae. Sporangia were caducous, semipapillate or papillate, globose, ellipsoid or ovoid-obpyriform in shape and sporangiophores were irregularly branched or simple sympodial in nature. Subsequent multi-gene phylogeny (ITS, β-tub, TEF-1α and Cox-II) and sequence analysis confirmed the identity of oomycete as Phytophthora meadii which is predominant across the regions studied. We identified 49 haplotypes representing the higher haplotype diversity with varying relative haplotype frequency. Comprehensive study confirmed the existence of substantial variability among geo-distant populations (n = 48) of P. meadii. The knowledge on population dynamics of the pathogen causing fruit rot of arecanut generated from this investigation would aid in developing appropriate disease management strategies to curtail its further occurrence and spread in arecanut ecosystem.

Exciton-Tryptophan Coupling Pulse Behavior Along with Corona Formation, Binding Analysis and Interaction Study of ZnO Nanorod-Serum Albumin Protein Bioconjugate

The bioconjugate of bovine serum albumin (BSA) and zinc oxide nanorods (ZnO NRs) is investigated to explore the behavior of the tryptophan (Trp)-exciton coupling and corona formation. The pulse like nature of the coupled system between Trp of BSA and exciton of ZnO NRs has been observed after analysis of the optical parameters like refractive index, susceptibility, and optical dielectric constant. The time constant for tryptophan, exciton surface binding (t₁ ) and reorganization (t₂ ) are found to be (t₁ ) 8min, 7min and (t₂ ) 150 min, 114.5 min, respectively. The close proximity binding of BSA with ZnO NRs via tryptophan as well as exciton is responsible for bioconjugate formation. The aggregated structure of BSA is observed from small-angle X-ray scattering study in interaction with ZnO NRs. The change in secondary structure and tertiary deformation of the serum protein have been studied from FTIR and emission quenching analysis. The number of binding sites (n) signified to the enhancement of the cooperative binding. The binding has been found to be endothermic and favored by unfavorable positive enthalpy with a favorable entropy change from the result of the isothermal titration calorimetry (ITC).

Impacts, Tolerance, Adaptation, and Mitigation of Heat Stress on Wheat under Changing Climates

Heat stress (HS) is one of the major abiotic stresses affecting the production and quality of wheat. Rising temperatures are particularly threatening to wheat production. A detailed overview of morpho-physio-biochemical responses of wheat to HS is critical to identify various tolerance mechanisms and their use in identifying strategies to safeguard wheat production under changing climates. The development of thermotolerant wheat cultivars using conventional or molecular breeding and transgenic approaches is promising. Over the last decade, different omics approaches have revolutionized the way plant breeders and biotechnologists investigate underlying stress tolerance mechanisms and cellular homeostasis. Therefore, developing genomics, transcriptomics, proteomics, and metabolomics data sets and a deeper understanding of HS tolerance mechanisms of different wheat cultivars are needed. The most reliable method to improve plant resilience to HS must include agronomic management strategies, such as the adoption of climate-smart cultivation practices and use of osmoprotectants and cultured soil microbes. However, looking at the complex nature of HS, the adoption of a holistic approach integrating outcomes of breeding, physiological, agronomical, and biotechnological options is required. Our review aims to provide insights concerning morpho-physiological and molecular impacts, tolerance mechanisms, and adaptation strategies of HS in wheat. This review will help scientific communities in the identification, development, and promotion of thermotolerant wheat cultivars and management strategies to minimize negative impacts of HS.

Projecting potential impact of COVID-19 on major cereal crops in Senegal and Burkina Faso using crop simulation models

CONTEXT

The rapid emergence of COVID-19 could have direct and indirect impacts on food production systems and livelihoods of farmers. From the farming perspective, disruption of critical input availability, supply chains and labor, influence crop management. Disruptions to food systems can affect (a) planting area; and (b) crop yields.

OBJECTIVES

To quantify the impacts of COVID-19 on major cereal crop's production and their cascading impact on national economy and related policies.

METHODS

We used the calibrated crop simulation model (DSSAT suite) to project the impact of potential changes in planting area and grain yield of four major cereal crops (i.e., rice, maize, sorghum, and millet) in Senegal and Burkina Faso in terms of yield, total production, crop value and contribution to agricultural gross domestic product (GDP). Appropriate data (i.e., weather, soil, crop, and management practices) for the specific agroecological zones were used as an input in the model.

RESULTS AND CONCLUSIONS

The simulated yields for 2020 were then used to estimate crop production at country scale for the matrix of different scenarios of planting area and yield change (-15, -10, -5, 0, +5, +10%). Depending on the scenario, changes in total production of four cereals combined at country levels varied from 1.47 M tons to 2.47 M tons in Senegal and 4.51 M tons to 7.52 M tons in Burkina Faso. The economic value of all four cereals under different scenarios ranged from $771 Million (M) to $1292 M in Senegal and from $1251 M to $2098 M in Burkina Faso. These estimated total crop values under different scenarios were compared with total agricultural GDP of the country (in 2019 terms which was $3995 M in Senegal and $3957 M in Burkina Faso) to assess the economic impact of the pandemic on major cereal grain production. Based on the scenarios, the impact on total agricultural GDP can change -7% to +6% in Senegal and - 8% to +9% in Burkina Faso.

SIGNIFICANCE

Results obtained from this modeling exercise will be valuable to policymakers and end-to-end value chain practitioners to prepare and develop appropriate policies to cope or manage the impact of COVID-19 on food systems.

Effect of Foliar Micronutrients (B, Mn, Fe, Zn) on Maize Grain Yield, Micronutrient Recovery, Uptake, and Partitioning

Timing of micronutrient demand and acquisition by maize (Zea mays L.) is nutrient specific and associated with key vegetative and reproductive growth stages. The objective of this study was to determine the fate of foliar-applied B, Fe, Mn, Zn, and Fe/Zn together, evaluate the effect of foliar micronutrients applied at multiple rates and growth stages on maize grain yield, and determine their apparent nutrient recovery efficiency (ANR). Five Randomized Complete Block Design (RCBD) experiments were conducted in 2014 and 2015 at five locations across Nebraska. Total dry matter was collected at 5-6 stages, and separated into leaves, stalk, and reproductive tissue as appropriate to determine micronutrient uptake, partitioning, and translocation. Foliar B, Mn, Zn, and Fe/Zn had no effect on grain yield for most application time by rate levels, though, at the foliar Mn site, there was a 19% yield increase due to a V18 application of 0.73 kg Mn ha^-1 which corresponded with reduced Mn uptake in maize grown in control plots. At the foliar Zn site, there was 4.5% decrease in yield due to a split foliar application of 0.84 kg Zn ha^-1 total, applied at V11 and V15 stage, which increased leaf Zn concentrations greater than the established toxic level. Only the Fe site had consistent grain yield response and was the only experiment that had visual signs of micronutrient deficiency. Regardless of application time from V6 to R2, there was a 13.5-14.6% increase in grain yield due to 0.22 kg Fe ha^-1 foliar application. Most micronutrients had limited or no translocation, however, early season applications of B, prior to V10, had significant mobilization to reproductive tissues at or after VT. Foliar Mn, Zn, and B application had ANR LSmeans of 9.5, 16.9, and 2.5%, respectively, whereas the Fe/Zn mix had negative ANR LSmeans of -9.1% Fe and -1.3% Zn which indicate suppression. These data highlight the importance of confirming a micronutrient deficiency prior to foliar application, guide specific growth stages to target with specific micronutrients, track the fate of foliar-applied micronutrients, and describe the variable effect of foliar-applied micronutrients on grain yield.

Iodine adsorption characteristics of activated carbon obtained from Spinacia Oleracea (spinach) leaves

Spinach leaves powder was modified by activation with conc. H2SO4 and was characterized by using FTIR, optical microscopy, XRD analysis and methylene blue adsorption method. The maximum specific surface area measured by the Methylene blue adsorption method was 499 m2/g. The adsorption of iodine was investigated by varying parameters as pH, adsorbent dose, contact time and I2 concentration. The adsorption process was fitted to the Langmuir model controlled by pseudo - second –  order kinetics with a constant rate value of 0.00305 g/(mg·min). The maximum adsorption was at pH 10. The maximum adsorption capacity was 909.091 mg/g. The ∆G value was -25 kJ/mole, which confirmed the physico - chemcal adsorption process.

Differential white blood cell count in the COVID-19: A cross-sectional study of 148 patients

BACKGROUND

SARS-CoV-2 infection alters various blood parameters, which may indicate disease severity and thus help in better clinical management.

AIM

To study the association between various hematological parameters and disease severity of COVID-19. To analyze the effects of hypertension and diabetes on neutrophil-lymphocyte ratio and neutrophil-monocyte ratio in patients suffering from COVID-19.

MATERIALS AND METHODS

The study was a cross-sectional study involving 148 laboratory-confirmed cases of SARS-CoV-2 infection. The patients were divided into three groups on the basis of disease severity. Various hematological parameters were analyzed. The effects of hypertension and diabetes on NLR and NMR in COVID-19 patients were evaluated.

RESULTS

Of the 148 patients, 78.4%, 8.1% and 13.5% cases were in the mild, moderate and severe groups, respectively. Mean age was 42.63 ± 16.04 years (IQR: 29, 54.75; Range: 7-74). 58.8% patients were male while the rest (42.2%) were female. Mean TLC (cells/mm³), neutrophil (%), lymphocyte (%), monocyte (%), eosinophil (%), neutrophil-lymphocyte ratio (NLR) and neutrophil-monocyte ratio (NMR) among mild, moderate and severe COVID-19 was statistically significant (p < 0.05). Basophil (%) and lymphocyte-monocyte ratio (LMR) was statistically insignificant among the three groups. Lymphocyte (%), monocyte (%) and eosinophil (%) were negatively correlated to disease severity. Among diabetics, both NLR and NMR were statistically significant (p < 0.05). However, among hypertensive cases, only the NLR was statistically significant.

CONCLUSION

Older age, higher TLC, neutrophilia, lymphopenia, eosinopenia, high NLR and high NMR are associated with severe COVID-19. High NLR and high NMR are indicative of severe disease among diabetic patients. High NLR also indicates severe disease among hypertensive patients.

Performance of lemongrass (Cymbopogon citrates) oil as growth promoter in broiler

An attempt was taken to study the growth performance of lemongrass oil (Cymbopogon citraturs) as a growth promoter on the broiler production. A total of 180day-old broiler chicks were procured from private hatchery (Shivam Hatchery Birgung, Parsa, Nepal) and were allocated following Completely Randomized Design (CRD) into four treatment groups (each treatment with 3 replications and each replication with 15 birds); T1= control, T2= containing lemongrass oil 200 ml/100 kg feed, T3= containing lemongrass oil 400 ml/100 kg feed and, T4= containing lemongrass oil 600 ml/100 kg feed. The study was carried out for 36 days at Avian Research Unit, Regional Agriculture Research Station, Parwanipur, Bara, Nepal. Concentrate mixture and lemongrass oil were procured from Shakti Feed Industry, Birgung; Herbs Processing Plant of Ministry of Forest and Soil Conservation, Jadibuti, Kathmandu, respectively. Experimental birds were provided ad libitum amount of starter feed from 0 to 21 days and finisher feed from 22 to 36 days. Feed intake was recorded daily and body weight gain was measured in 7 days interval. The study revealed that the cumulative feed intake per bird was found higher in T3 (3443.17g) followed by T4 (3377.33g) and T2 (3354.04g), respectively, and were statistically non-significant among the diet groups. The FCR was highest in T3 (1:1.44 kg) and lowest in T4 (1:1.51 kg), and differed insignificantly among the diet groups. Similarly, the total weight gain of the experimental bird was found to be higher in T3 (2385.13g) followed by T1 (2279.46g) and T2 (2271.86g), respectively.  The average daily gain of experimental birds noted higher in T3 (66.25g) followed by T1 and T2 (63.31g) and (63.1g), respectively. The experiment suggested that inclusion of lemongrass oil could be considered as an alternative to antibiotic growth promoter in broiler diet to enhance the production performance. Bang. J. Anim. Sci. 2018. 47 (2): 85-91

Renal Artery Thrombosis with Renal Infarction: A Rare Cause of Acute Abdomen

Renal artery thrombosis with renal infarction is a rare entity. Due to the nonspecific clinical presentation, the diagnosis is usually delayed. We describe such a case in a middle-aged man with membranous nephropathy who was in remission and presented with severe abdominal pain. He was managed with selective intra-arterial thrombolysis with a good outcome.

ABO-incompatible renal transplantation in developing world - crossing the immunological (and mental) barrier

ABO incompatibility has been considered as an important immunological barrier for renal transplantation. With the advent of effective preconditioning protocols, it is now possible to do renal transplants across ABO barrier. We hereby present a single center retrospective analysis of all consecutive ABOi renal transplants performed from November 2011 to August 2014. Preconditioning protocol consisted of rituximab, plasmapheresis and intravenous immunoglobulin (IVIG) and maintenance immunosuppression consisted of tacrolimus, mycophenolate sodium, and prednisolone. The outcome of these ABOi transplants was compared with all other consecutive ABO-compatible (ABOc) renal transplants performed during same time. Twenty ABOi renal transplants were performed during the study period. Anti-blood group antibody titer varied from 1:2 to 1:512. Patient and graft survival was comparable between ABOi and ABOc groups. Biopsy proven acute rejection rate was 15% in ABOi group, which was similar to ABOc group (16.29%). There were no antibody-mediated rejections in ABOi group. The infection rate was also comparable. We conclude that the short-term outcome of ABOi and ABOc transplants is comparable. ABOi transplants should be promoted in developing countries to expand the donor pool.

Invasive gastric mucormycosis and cytomegalovirus infection in an ABO incompatible renal transplant recipient

Opportunistic infections are common in immunocompromised patients, such as solid organ transplant recipients. Both fungal and viral infections in posttransplant period increase morbidity and mortality. Cytomegalovirus (CMV) remains one of the most important pathogens. CMV disease may manifest as a nonspecific febrile syndrome or tissue-invasive infections. Zygomycosis is a rare infection, usually presents in rhino-cerebral, pulmonary and disseminated forms; gastrointestinal (GI) tract being a rare site of involvement. Newer techniques for early diagnosis and efficient therapies are essential for a better outcome of the disease; however, mortality rate remains high despite aggressive therapy. We report a renal transplant recipient, who developed gastric mucormycosis along with tissue invasive CMV disease, within 4 weeks of renal transplant and was diagnosed on the basis of upper GI endoscopy and gastric biopsy. The patient succumbed to the infection in spite of gastrectomy, antifungal and antiviral therapy.

Paired kidney exchange transplantation: Maximizing the donor pool

In the last decade, paired kidney exchange (PKE) transplantation has gained popularity worldwide as a viable alternative for end stage renal disease (ESRD) patients who have incompatible or sensitized donors. This study presents our experience with PKE transplantation and compares outcome between PKE and non-PKE renal transplant recipients. Between February 2010 and November 2013, 742 transplants were performed, of which 26 (3.5%) were PKE transplantations. All were two-way exchanges. PKE recipients were significantly older than non-PKE (46.73 ± 9.71 vs. 40.08 ± 13.36 years; P = 0.012) while donor ages were comparable. PKE patients had significantly higher number of HLA mismatches (5.03 ± 1.14 vs. 3.49 ± 1.57; P < 0.0001). After a median follow-up of 20 months (range: 3–47 months), there was no significant difference in patient survival (PKE 96.16% vs. non-PKE 96.65%; P = 0.596) and death censored graft survival (PKE 96.16% vs. non-PKE 96.37%; P = 1). Mean serum creatinine at 1 month and at last follow-up was lower in PKE versus non-PKE group (0.98 ± 0.33 vs. 1.3 ± 0.61 mg/dl; P = 0.008 and 0.96 ± 0.30 vs. 1.27 ± 0.57 mg/dl, P = 0.006, respectively). Biopsy proven acute rejection rate was 11.5% in PKE group and 16.89% in non-PKE patients (P = 0.6). To conclude, paired kidney donation is an excellent way of increasing the donor pool and needs to be promoted to overcome the shortage of suitable kidney in our country.

Pyoderma gangrenosum in a renal transplant recipient: A case report and review of literature

Pyoderma gangrenosum (PG) is a rare disorder of unknown etiology characterized by multiple cutaneous ulcers with mucopurulent or hemorrhagic exudate. This sterile neutrophilic dermatosis is known to occur in association with malignancy, infection, autoimmune disorders and drugs. Occurrence of PG in a renal transplant recipient, who is already on immunosuppressants, is rare. We hereby report a renal transplant recipient who developed PG 1-month after transplant and responded well to treatment with escalated dose of oral steroid.

Peritonitis in a continuous ambulatory peritoneal dialysis patient by two different species of enterococci: A rare finding

Peritonitis in a continuous ambulatory peritoneal dialysis patient by two different species of enterococci is a rare condition. We report a case of peritonitis from which vancomycin sensitive Enterococcus faecalis and vancomycin resistant Enterococcusc faecium were isolated. It also emphasizes the effectiveness of linezolid for the treatment of vancomycin resistant enterococcal infection.

Sunitinib induced nephrotic syndrome and thrombotic microangiopathy

Sunitinib is an oral, multitargeted receptor tyrosine kinase inhibitor of targets such as vascular endothelial growth factor and platelet derived growth factor receptor. It is used for the treatment of metastatic renal cell carcinoma (RCC). Use of sunitinib has been associated with renal dysfunction and nephrotic syndrome. However, simultaneous occurrence of nephrotic syndrome and renal dysfunction in a patient treated with sunitinib is rare. We report a case of metastatic RCC treated with sunitinib for 22 months who presented with nephrotic syndrome and renal dysfunction. Renal biopsy was diagnostic of thrombotic microangiopathy with diffuse effacement of podocytic foot process.

Worm infestation among the school children of Dhankuta District

Intestinal parasitic infections (IPI) cause serious public health problem in Nepal. They are more prevalent in the poor segments of the population with low household income, poor handling of personal and environmental sanitation, overcrowding and limited access to clean water. The objective of the study is to assess knowledge and practice about worm infestation and to find out the relation of knowledge and practice with the selected variables. A cross-sectional study was conducted in 200 students of Grade 9 and 10 in Government and private schools of Dhankuta. The chi-square test was used to measure the association of knowledge and practice about worm infestation. The knowledge regarding risk factors of worm infestation due to unhygienic pig farming practices is significantly higher in female (66.4%) than male (44.8%). All the risk factors were found to be significantly higher in knowledge among the private school as compared to Government school. Regarding Fathers occupation, unemployed (100.0%) believe it is due to poor personal hygiene and very less of labor (50%) which is significantly associated. Regarding Mother Group, students never eat raw meat and vender food whose mothers have skilled worker. The school going students of Dhankuta were aware of the knowledge regarding the worm infestation but had less knowledge among the school children of Government as compared to private.

Postrenal transplant laryngeal and visceral leishmaniasis - A case report and review of the literature

Visceral leishmaniasis (kala-azar) is a disease caused by protozoa of genus Leishmania. It is currently regarded as the second most dreaded parasitic disease, next to malaria. There have been very few case reports of visceral leishmaniasis among the renal transplant recipients. We present a renal allograft recipient with symptoms of fever, sore throat, hoarseness of voice, lymphadenopathy, splenomegaly, and pancytopenia after 7 years post-transplant period. On investigating, he was diagnosed to have extensive visceral leishmaniasis with laryngeal involvement. Despite extensive PubMed literature search, we could not find any case report of postrenal transplant visceral and laryngeal leishmaniasis and to the best of our knowledge this is the first case report of this kind.

Diffuse mesangial sclerosis - Report of two cases

Diffuse mesangial sclerosis (DMS) is a rare cause of nephrotic syndrome in the infantile and childhood period. DMS is a phenotypic expression of syndromic entities such as WAGR syndrome (Wilms’ tumor, aniridia, genitourinary anomalies and mental retardation), Denys Drash syndrome, Pierson syndrome, Frasier syndrome, or Galloway–Mowat syndrome. We report two cases of DMS, one presenting in first year of life and another in second decade of life. Both of them had fatal outcome. Recognition of the disease is very important in modifying the management of patient and active surveillance of family members.

Tuberculin reactivity in bacille calmette-guerin vaccinated individuals with sputum positive pulmonary tuberculosis

The study was carried out to assess the value of tuberculin skin test for the diagnosis of Tuberculosis (TB) in BCG vaccinated individuals and to find out the sensitivity rate of tuberculin skin test (TST) in comparison to acid fast bacilli positive pulmonary TB. Similar population with high BCG vaccination coverage having both pulmonary TB patients (n=150) and apparently healthy individuals (n=150) in eastern Nepal were enrolled in this comparative study. Sputum from all the subjects was subjected to Z-N microscopy. TST was performed on these subjects by standard Mantoux method. Among the patients (mean age 36.18±14.15 yrs) and controls (mean age 35.61±13.44 yrs), 55.33 % and 47.33 % respectively have been found to be positive PPD reactors (>10mm) which is statistically not significant (P>0.05). About 23% of the patients & 27% of controls failed to react (anergic) to 5 TU PPD. PPD reactivity rate was high in the patients whose sputum smears were graded as 1+ in Z-N microscopy. The sensitivity of TST was highest for the induration of >5mm (77.3%). Specificity increased with increasing size of induration and was highest (73.3%) with induration of >15 mm. Tuberculin skin test is an all or none phenomenon. In Nepal, tuberculin test has a limited value in the diagnosis of pulmonary TB as both the apparently healthy individuals and patients with sputum smear positive pulmonary TB who had been immunized with BCG, showed almost similar rate of tuberculin reactivity. DOI: http://dx.doi.org/10.3126/jcmsn.v7i1.5970 JCMSN 2011; 7(1): 28-35

High-level gentamicin resistance and vancomycin resistance in clinical isolates of enterococci in a tertiary care hospital in eastern Nepal

High-level gentamicin resistance and vancomycin resistance in enterococci, a family of important opportunistic pathogens, have emerged as a significant clinical problem over recent years. The present study was conducted to determine the high-level gentamicin and vancomycin resistance among the clinical isolates of enterococci. A total of 110 phenotypically identified enterococcal isolates were subjected to determination of high-level gentamicin resistance (by disk diffusion and agar dilution methods) and vancomycin resistance (by agar screening and agar dilution methods). About 36% of the isolates were found to have high-level gentamicin resistance, which indicates that gentamicin no longer remains an appropriate choice for inclusion in combination therapy with cell wall-active agents. Ten percent isolates exhibited resisance to vancomycin during screening. However, agar dilution confirmed that the isolates did not have resistance to vancomycin but had reduced susceptibility to it, which indicates their impending emergence of resistance to vancomycin.

Antiviral activity of some plants used in Nepalese traditional medicine

Methanolic extracts of 41 plant species belonging to 27 families used in the traditional medicine in Nepal have been investigated for in vitro antiviral activity against Herpes simplex virus type 1 (HSV-1) and influenza virus A by dye uptake assay in the systems HSV-1/Vero cells and influenza virus A/MDCK cells. The extracts of Astilbe rivularis, Bergenia ciliata, Cassiope fastigiata and Thymus linearis showed potent anti-herpes viral activity. The extracts of Allium oreoprasum, Androsace strigilosa, Asparagus filicinus, Astilbe rivularis, Bergenia ciliata and Verbascum thapsus exhibited strong anti-influenza viral activity. Only the extracts of A. rivularis and B. ciliata demonstrated remarkable activity against both viruses.

De Garengeot hernia: an analysis of our experience

AIM

The presence of a vermiform appendix in a femoral hernia sac is termed De Garengeot hernia. It may present as a tender and/or erythematous groin swelling and is often misdiagnosed as an incarcerated or strangulated femoral hernia. The purpose of this study is to review the management of De Garengeot hernia at a single institution since 1991.

MATERIALS AND METHODS

A retrospective analysis of seven consecutive patients operated upon at our institution from 1991 to 2006 with De Garengeot hernia was undertaken. Patients' demographics, treatment performed and postoperative outcome were analysed.

RESULTS

There were three men and four women. The median age was 55 years. None of the patients were diagnosed preoperatively. The commonest presenting symptom was painful groin swelling. All patients therefore underwent emergency surgery with a presumptive diagnosis of either incarcerated or strangulated femoral hernia. Operative findings included four normal appendices, two inflamed appendices and one perforated appendix in the femoral hernial sac. Patients with normal appendix (n = 4) had mesh hernia repair without an appendicectomy. The rest of the patients (n = 3) with abnormal appendix underwent emergency open appendicectomy followed by sutured hernia repair. We had no deaths in this series and one minor wound infection. No recurrent hernia has been detected to date.

CONCLUSION

Inflammation of the appendix determines the type of hernia repair and surgical approach. Incidental appendicectomy in the case of a normal appendix is not preferred.

Patterns of leaf conductance and water potential of five Himalayan tree species

We studied variations in water relations and drought response in five Himalayan tree species (Schima wallichii (DC.) Korth. (chilaune) and Castanopsis indica (Roxb.) Miq. (dhale katus) at an elevation of 1400 m, Quercus lanata Smith (banjh) and Rhododendron arboreum Smith (lali gurans) at 2020 m, and Quercus semecarpifolia Smith (khasru) at 2130 m) at Phulchowki Hill, Kathmandu, Nepal. Soil water potential at 15 (Psi(s15)) and 30 cm (Psi(s30)) depths, tree water potential at predawn (Psi(pd)) and midday (Psi(md)), and leaf conductance during the morning (g(wAM)) and afternoon (g(wPM)) were observed from December 1998 to April 2001, except during the monsoon months. There was significant variation among sites, species and months in Psi(pd), Psi(md), g(wAM) and g(wPM), and among months for all species for Psi(s15). Mean Psi(pd) and Psi(md) were lowest in Q. semecarpifolia (-0.40 and -1.18 MPa, respectively) and highest in S. wallichii (-0.20 and -0.63 MPa, respectively). The minimum Psi value for all species (-0.70 to -1.79 MPa) was observed in March 1999, after 4 months of unusually low rainfall. Some patterns of Psi(pd) were related to phenology and leaf damage. During leafing, Psi(pd) often increased. Mean g(wAM) and g(wPM) were highest in Q. semecarpifolia (172 and 190 mmol m(-2) s(-1), respectively) and lowest in C. indica (78 and 74 mmol m(-2) s(-1), respectively). Soil water potential (Psi) at 15 cm depth correlated with plant Psi in all species, but rarely with g(wAM) and not with g(wPM). Plant Psi declined with increasing elevation, whereas g(w) increased. As Psi(pd) declined, so did maximal g(w), but overall, g(w) was correlated with Psi(pd) only for R. arboreum. Schima wallichii maintained high Psi, with low stomatal conductance, as did Castanopsis indica, except that C. indica had low Psi during dry months. Rhododendron arboreum maintained high Psi(pd) and g(w), despite low soil Psi. Quercus lanata had low g(w) and low Psi(pd) in some months, but showed no correlation between tree Psi and g(w). Quercus semecarpifolia, which grows at the highest elevation, had low soil and plant Psi and high g(w).

Health and social benefits from improving community hygiene and sanitation: an Indian experience

India is a country where Atomic Age and near Stone Age people co-exist. On one hand India has achieved development in many areas, but on the other hand there is still the practice of open defecation and manual cleaning of human excreta from bucket privies by scavengers. National sanitation coverage is only about 34% meaning that 66% of the population practises open defecation. Such unhygienic conditions lead to infections and high mortality and morbidity in the community. Low sanitation coverage could be due to lack of affordable sanitation technology and awareness or motivation. Although the sewerage system was introduced in India long ago, high operational and maintenance costs have prohibited it from being implemented in most towns and cities. Similarly, the cost of a septic tank is beyond most people, and disposal of undigested sludge from septic tanks remains a problem. In contrast, the pour-flush two-pit toilet (known as Sulabh Shauchalaya) is a low cost, socially acceptable and appropriate technology that does not require scavengers to clean the pits. Sulabh has converted and constructed over 1.2 million such toilets throughout India, making 240 towns scavenger-free. Liberated scavengers are thereby available to take up vocational training in various market-oriented trades enabling self-employment. The on-site/ decentralised systems of waste management has improved community health and hygiene, particularly in socially deprived groups, and reduced the financial burden of local government.

A recombinant monocysteine mutant (Ser to Cys-155) of fast skeletal troponin T: identification by cross-linking of a domain involved in a physiologically relevant interaction with troponins C and I

Troponin T (TnT), a subunit of the heterotrimeric troponin (Tn) complex, is essential for the Ca2+ regulation of vertebrate striated muscle contraction both in vivo and in vitro. With the exception of bovine cardiac TnT, all known vertebrate TnT isoforms lack a thiol group, a property which makes the wild-type proteins unsuitable as cross-linking substrate. We generated a mutant human fast skeletal TnT in which Ser155 was changed to Cys (TnT-Cys155). Mutation of this residue in TnT as well as in vitro expression in Escherichia coli and purification of the recombinant mutant protein did not affect its biological properties in terms of in vitro binding to troponin I (TnI), troponin C (TnC), actin-tropomyosin (actin-Tm), and actomyosin ATPase activity. TnT-Cys155 was labeled with 4-maleimidobenzophenone (BP-TnT155) and photo-cross-linked to TnI, TnC, Tm, and all of the thin filament proteins. BP-TnT155 did not cross-link to Tm and showed weak Ca2+/Mg2+-independent cross-linking with TnI in the binary complex and in the presence of all thin filament protein components. BP-TnT155 showed Ca2+/Mg2+-dependent cross-linking with TnC in the binary and ternary complexes and Ca2+-favored cross-linking with TnI in the ternary complex. Thus, residue 155 of TnT is within 10 A (the length of cross-linker) of TnC in the presence or absence of Ca2+ and comes within 10 A of both TnI and TnC in the presence of Ca2+. TnT residue 155 is in close proximity to or may even partly encompass the Tm binding site. These results suggest that TnT, in association with TnI, may participate in the "information transfer" mediated by the Ca2+ binding signal from TnC to Tm and the region around TnT residue 155 probably acts as a linker between troponin and actin-Tm in this signal transmission process. Our results also suggest that TnT contains at least one Ca2+/Mg2+-dependent TnC binding region located between its Tm and TnI binding regions. A recombinant truncated fragment of TnI, TnI96-181, containing amino acid residues 96-181 and labeled with BP at Cys-133, failed to cross-link with TnT, indicating that the region around Cys-133 of TnI is not involved in binary interaction with TnT.

Identification and mutagenesis of a highly conserved domain in troponin T responsible for troponin I binding: potential role for coiled coil interaction

Troponin T (TnT), a thin filament myofibrillar protein, is essential for the Ca2+ regulation of striated muscle contraction in vertebrates, both in vivo and in vitro. To understand the role of TnT in this process, its interaction with two other troponin components, troponin I (TnI) and troponin C (TnC) was examined by using the yeast two hybrid system, which is a genetic approach to detect protein-protein interactions. Computer assisted analysis of phylogenetically distant TnT amino acid sequences unveiled a highly conserved protein domain that is characterized by a heptad repeat (HR) motif with a potential for alpha-helical coiled coil formation. A similar, potentially coiled coil forming domain is also conserved in all known TnI sequences. These protein motifs appeared to be the regions where TnI-TnT interaction may take place. Deletions and point mutations in TnT, which disrupted its HR motif, severely reduced or abolished TnI binding, but binding to TnC was not affected, indicating that the TnT-TnI and TnT-TnC binary interactions can be uncoupled. Remarkably, the truncated fragments of TnT and TnI in which the HR motifs were retained showed binary interaction in the yeast two hybrid system. It was also observed that the formation of the TnT-TnI heterodimers is favored over the homodimers TnT-TnT and TnI-TnI. These results indicate that the evolutionarily conserved HR motifs may play a role in TnT-TnI dimerization, presumably through the formation of alpha-helical coiled coils.

DNA sequencing and comparative sequence analysis reveal that the Escherichia coli genomic DNA may replace the target DNA during molecular cloning: evidence for the erroneous assembly of E. coli DNA into database sequences

DNA sequencing and similarity search of databases provide experimental evidence that portions of the host Escherichia coli genome may get ligated into the cloning vector, resulting in clones containing nontargeted inserts. Several lines of evidence suggest that this non-targeted ligation, as observed by us while subcloning troponin I cDNA, is presumably due to a recombination-mediated mechanism by which host DNA replaces the target DNA in the cloning vector. The E. coli genome mapping to 64-65 min and 92.8-00.1 min, the latter containing insertion sequences, appears to be the hotspot regions involved in this process. We examined the possibility that some sequences reported in the databases may also contain genomic sequences of E. coli. A search of current databases revealed that a rat hepatic glutathione transporter cDNA contains a 2.2-kb-long portion of the E. coli genome that has been wrongly assembled into its 5' untranslated and coding regions. In addition, about 30 sequences in databases, including a Yersinia pestis toxin gene, showed relatively high sequence identity with those portions of the E. coli genome that were present in the nonauthentic clones.

Interaction of deletion mutants of troponins I and T: COOH-terminal truncation of troponin T abolishes troponin I binding and reduces Ca2+ sensitivity of the reconstituted regulatory system

The interaction between troponin I (TnI) and troponin T (TnT) remains the least understood binary interaction among the regulatory proteins of vertebrate striated muscle. To identify the specific binding domains of TnI and TnT and to evaluate the interactions of TnT with troponin C and tropomyosin (Tm), we generated an NH2-terminal fragment of human fast skeletal beta TnT (TnT1-201; residues 1-201) using site-directed mutagenesis. The mutant protein failed to bind to rabbit skeletal muscle TnI as judged by HPLC, showed reduced TnC binding and reduced ternary troponin (Tn) complex formation, and exhibited a much reduced Ca2+ sensitivity in the reconstituted regulatory system. It is shown that the amount of Tn complex formed by TnT1-201 rather than the activity of the mutant Tn complex affected this Ca2+ sensitivity. Binding of the mutant to Tm was similar to that of intact TnT. These results support the view that the COOH-terminal segment of TnT is necessary for binding to TnI and TnC and Ca2+ sensitivity in the thin filament, whereas its NH2-terminus strongly binds to Tm. To identify the regions of TnI which bind to muscle TnT, we used four recombinant fragments of fast skeletal muscle TnI containing amino acid residues 1-94 (TnI1-94), 1-120 (TnI1-120), 96-181 (TnI96-181), and 122-181 (TnI122-181) and a synthetic peptide, TnI98-114, containing residues 98-114 corresponding to the inhibitory region. Only TnI1-120 showed weak binding to TnT but not to TnT1-201. These results suggest that (i) a region within the NH2-terminal 120 residues of TnI interacts with TnT and (ii) the COOH-terminal residues 202-258 of TnT contain the interaction site of TnI. Overall, our results also imply that residues 159-201 constitute the smallest region of TnT which contributes to the Ca2+ sensitivity of actoS1 ATPase in a reconstituted regulatory system.

Photo-cross-linking of rabbit skeletal troponin I deletion mutants with troponin C and its thiol mutants: the inhibitory region enhances binding of troponin I fragments to troponin C

Contraction of vertebrate striated muscle is regulated by the strong Ca(2+)-dependent interaction between troponin I (TnI) and troponin C (TnC). To critically evaluate this interaction, we generated four recombinant deletion fragments of rabbit fast skeletal TnI: the NH2-terminal fragment (TnI1-94), the NH2 terminus and the inhibitory region (TnI1-120), the inhibitory region and the COOH terminus (TnI96-181), and the COOH-terminal fragment (TnI122-181) containing amino acid residues 1-94, 1-120, 96-181, and 122-181, respectively. Native TnC and seven thiol mutants, containing single cysteine residues in the two globular domains and in the central helix of TnC, e.g., Cys-12, Cys-21, Cys-57, Cys-89, Cys-122, Cys-133, and Cys-158, were labeled with 4-maleimidobenzophenone, and their interaction with the recombinant TnI fragments and the synthetic inhibitory peptide (TnI98-114, residues 98-114) was studied by photo-cross-linking. Extensive cross-linking occurred between various domains of TnC and TnI. The cross-linking patterns (a) showed that both NH2- and COOH-terminal fragments of TnI are accessible to both of the globular domains of TnC, (b) indicated that linkage of the NH2- and COOH-terminal sequences to the inhibitory region of TnI (TnIir) caused marked enhancement of cross-linking with native TnC and all seven thiol mutants, and (c) identified the region in TnC where TnIir binds as that containing residues 98, 133, 158, and 57. Thus, the results suggest that TnI and TnC may adopt flexible and dynamic conformations in which multiple interactions involving various domains of the two polypeptides occur and TnIir acting as a linker facilitates these interactions. The interaction of TnI and its fragments with actin, TnC, and TnT, considered together with the biological activity indicates that residues 96-120 represent a key structural and functional region of TnI. Whereas the NH2-terminal region of TnI stabilizes binding to TnC and TnT, the COOH-terminal region stabilizes TnC and actin binding.

Assignment of the human fast skeletal troponin T gene (TNNT3) to chromosome 11p15.5: evidence for the presence of 11pter in a monochromosome 9 somatic cell hybrid in NIGMS mapping panel 2

Human fast skeletal troponin T (TnTf), the tropomyosin binding component of the multisubunit troponin complex, plays an important role in the Ca2+ regulation of striated muscle contraction. Specific primers designed from the 3' end of human TnTf cDNA were used to amplify an intronic region by polymerase chain reaction (PCR). This TnTf-specific PCR product was detected from two somatic cell hybrids containing human chromosomes 9 and 11, respectively, in NIGMS mapping panel 2. However, further studies with other somatic hybrid cell lines (Bios Laboratory) localized the TnTf gene (HGMW-approved symbol TNNT3) only to chromosome 11. This observation was further confirmed by fluorescence in situ hybridization with a 12-kb TnTf genomic probe generated by extended PCR, showing the sublocalization of the gene to band p15.5 on chromosome 11. This locus is of specific interest, as Beckwith-Wiedemann syndrome and various childhood and adult tumor-related abnormalities have been mapped to this region. The study also indicates the presence of an 11pter region in the NIGMS cell hybrid GM10611, which has previously been reported to contain only human chromosome 9.

Overproduction and rapid purification of human fast skeletal beta troponin T using Escherichia coli expression vectors: functional differences between the alpha and beta isoforms

Troponin T (TpnT), an essential component of the Ca(2+)-regulatory troponin complex, is involved in protein-protein interactions with other thin-filament proteins during muscle contraction in vertebrate striated muscle (VSM). The isoforms of TpnT are encoded by members of a multigene family which, by alternate splicing, produces a complex pattern of isoproteins in VSM. The functional domains of TpnT are only tentatively identified and structure-function analysis on this protein is limited due to the heterogeneity of the multiple isoforms. We reasoned that the overproduction and purification of a single TpnT species in Escherichia coli would provide an insight into these studies, besides being useful in crystallizing the protein. We cloned the human fast skeletal beta TpnT-encoding cDNA (beta TpnTf) in three expression vectors. Overexpression was achieved in an E. coli BL21 (DE3) lysogen using a T7 RNA polymerase promoter-based vector, pET17b. The unfused recombinant protein was purified by a simple and rapid procedure in a biologically active and immunoreactive form. This is the first successful synthesis of a complete beta TpnTf polypeptide from any species using an in vitro expression system. Purified human beta TpnTf, a predominant fetal form, was less Ca(2+)-sensitive and exhibited considerably reduced affinity for troponin C and tropomyosin, as compared to the rabbit fast skeletal alpha TpnT, a predominant adult isoform. These results provide a biochemical correlate to the age-related differences in Ca2+ sensitivity of tension development in vertebrate fast skeletal muscles.

Overexpression and rapid purification of rabbit fast skeletal troponin I from Escherichia coli: effect of different promoters, host strains, and culture conditions

Rabbit fast skeletal troponin I (TnIf) cDNA was expressed using two Escherichia coli expression vectors, pRE1 containing the bacteriophage lambda pL promoter and pAED4, a T7 RNA polymerase-based vector. Although both vectors expressed TnIf, overexpression of the target protein was achieved with pAED4. The effect of several parameters such as culture condition, compatible host strain, and inhibition of protein synthesis by rifampicin on the expression of TnIf was investigated. The overexpressed target protein synthesized during a brief induction period of only 2 h was conveniently purified from inclusion bodies by a simple and rapid procedure involving extraction with urea, ultracentrifugation, DE-52 column chromatography, and gel filtration. About 50-75 mg of highly purified TnIf was obtained per liter E. coli culture by this method, which does not involve time-consuming multistep procedures such as affinity and ion exchange chromatography as previously reported in the literature. The isolated unfused protein is stable and is indistinguishable from native protein in all biological parameters examined. The parameters optimized in this report for overexpression of TnIf may also be applicable for other eukaryotic proteins.

Evaluation of psoralen with solar ultraviolet light (puvasol) and adjunctive topical tar therapy in psoriasis

Fifty patients having psoriasis were studied with a view to assess the efficacy of 'puvasol' (Oral psoralen with sun-rays exposure) alone and in combination with topical tar therapy and were placed in 2 groups, each group being consisted of 25 patients. At the end of 8 weeks, out of 25 patients (Group 1) receiving 'Puvasol' in combination with topital tar therapy 15 patients (60%) showed complete clearance, marked improvement of lesions were seen in 4 cases (16%) and deterioration in one case (4%). Out of 25 patients (Group I) receiving 'Puvasol' alone 8 cases (32%) showed complete clearance of lesions and 11 patients (44%) showed marked im-provement of lesions. It is found that topical tar therapy when used as an adjunct to 'Puvasol' was more effective than 'Puvasol' alone.

Isolation and characterization of human fast skeletal beta troponin T cDNA: comparative sequence analysis of isoforms and insight into the evolution of members of a multigene family

A cDNA encoding human fast skeletal beta troponin T (beta TnTf) has been isolated and characterized from a fetal skeletal muscle library. The cDNA insert is 1,000 bp in length and contains the entire coding region of 777 bp and 5' and 3' untranslated (UT) segments of 12 and 211 bp, respectively. The 3' UT segment shows the predicted stem-loop structure typical of eukaryotic mRNAs. The cDNA-derived amino acid sequence is the first available sequence for human beta TnTf protein. It is encoded by a single-copy gene that is expressed in a tissue-specific manner in fetal and adult fast skeletal muscles. Although the human beta TnTf represents the major fetal isoform, the sequence information indicates that this cDNA and the coded protein are quite distinct from the fetal and neonatal TnTf isoforms reported in other mammalian fetal muscles. The hydropathy plot indicates that human beta TnTf is highly hydrophilic along its entire length. The protein has an extremely high degree of predicted alpha-helical content involving the entire molecule except the carboxy-terminal 30 residues. Comparative sequence analysis reveals that the human beta TnTf shares a high level of sequence similarity in the coding region with other vertebrate TnTf and considerably reduced similarity with slow skeletal and cardiac TnT cDNAs. The TnT isoforms have a large central region consisting of amino acid residues 46-204 which shows a high sequence conservation both at the nucleotide and amino acid levels. This conserved region is flanked by the variable carboxy-terminal and an extremely variable amino-terminal segment. The tropomyosin-binding peptide of TnT, which is represented by amino acid residues 47-151 and also includes a part of troponin I binding region, is an important domain of this central segment. It is suggested that this conserved segment is encoded by an ancestral gene. The variable regions of vertebrate striated TnT isoforms reflect the subsequent addition and modification of genomic sequences to give rise to members of the TnT multigene family.

Beta-subunit of human chorionic gonadotropin hormone and firefly luciferase simultaneously synthesized in insect cells using a recombinant baculovirus are differentially expressed and transported

A recombinant baculovirus vAc beta hCG-luc was constructed that carried the cDNAs encoding firefly luciferase (luc) and beta-subunit of human chorionic gonadotropin (beta hCG) placed under the transcriptional control of individual copies of the baculovirus polyhedrin gene promoter. The simple, rapid, and sensitive detection of LUC expression was used for selecting recombinant viruses that simultaneously expressed beta hCG, which was identical in all respects to that synthesized using a recombinant baculovirus carrying the beta hCG gene alone. Immunofluorescence staining of virus-infected cells using anti-LUC antibodies revealed that LUC, a nonglycosylated, intracellular protein was retained within the cells whereas beta hCG, an extensively glycosylated, secretory protein, was processed and secreted into the culture medium. LUC and beta hCG were both immunoreactive on Western blot. beta hCG was bioactive, as evident from its ability to associate with alpha hCG and bind with the receptor and produce testosterone in an in vitro mouse Leydig cell assay system. Comparison of recombinant LUC and beta hCG synthesized by the virus-infected insect cells surprisingly revealed that the level of the former was quantitatively higher by at least 10-fold than the latter. A blot of total RNA isolated from vAc beta hCG-luc-infected insect cells, when probed with probes corresponding to the 3' region of the beta hCG or luc genes, indicated differential transcription of the two genes. Computer-aided sequence analysis indicated extensive secondary structure and stem-loop complex-forming potential of the beta hCG gene, which could be responsible for the transcriptional difference observed.

Antibodies to human papillomavirus and to other genital infectious agents and invasive cervical cancer risk

Human papillomaviruses (HPVs) play an important part in the development of cervical cancer, but the role of other infectious agents, such as herpes simplex virus (HSV), is not clear. We assayed serum samples collected from 219 women with cervical cancer and from 387 controls for antibody to infectious agents. HPV 16-E7 and/or HPV 18-E7 antibodies were significantly related to cervical cancer risk (RR 1.9, 95% CI 1.2-3.2). Antibodies to HSV types 1 and 2, Chlamydia trachomatis, and to multiple infectious agents were associated with cervical cancer when seroprevalence rates in all cases and controls were compared, but when HPV-seropositive cases and controls were compared these associations were weaker and non-significant. This finding suggests that past infections with sexually transmitted infections other than HPV may be surrogate markers of exposure to HPV, and of no separate aetiological significance.

Characterization of a rabbit fast skeletal troponin I cDNA: a comparative sequence analysis of vertebrate isoforms and tissue-specific expression of a single copy gene

A cDNA encoding skeletal fast troponin I (TnIf) has been isolated and characterized from an adult rabbit fast skeletal muscle cDNA library. This cDNA contains the entire coding region of 549 base pairs (bp), the 3' untranslated (UT) segment of 78 bp and the 5' UT segment of 74 bp. The 3' UT segment shows the predicted stem-loop structure characteristic of eukaryotic mRNAs. The cDNA-derived amino acid sequence is not identical to the chemically-derived and the recently reported cDNA-derived amino acid sequences for rabbit TnIf, and thus enables to make the necessary corrections in the sequence information. The rabbit TnIf is encoded by a single copy gene which is expressed in adult fast skeletal muscle in a tissue-specific manner. Comparative sequence analysis of the vertebrate TnI isoforms and their cDNAs shows a high level of sequence conservation in the coding region among the TnIf interspecies isoforms. The sequence similarity is markedly decreased among the fast, slow and cardiac intra- and inter-species isoforms. The C-terminal halves of TnI isoforms including a segment believed to be involved in critical interactions with actin and troponin C (TnC) show high sequence conservation whereas the N-terminal halves show considerable difference in sequence and size. The significance of these results in relation to the biological function and evolution of members of the vertebrate TnI multigene family is discussed.

Simultaneous synthesis of enzymatically active luciferase and biologically active beta subunit of human chorionic gonadotropin in caterpillars infected with a recombinant baculovirus

The beta subunit of human chorionic gonadotropin (beta hCG), a secretory and extensively glycosylated hormone, and firefly luciferase, a non-secretory enzyme, were simultaneously synthesized in Spodoptera larvae upon infection with a dual expression recombinant baculovirus, vAc beta hCG-luc. Luciferase was retained predominantly in the body tissue while beta hCG was secreted into the hemolymph of infected larvae. Both the proteins were similar to their authentic counterparts in terms of immunoreactivity and bioactivity. The caterpillar-derived recombinant hCG exhibited reduced electrophoretic mobility on SDS-PAGE and increased biological activity as compared to the hCG expressed in insect cells in culture. The implications of using the larval system for expressing an extensively glycosylated protein are discussed.