High light-induced changes in whole-cell proteomic profile and its correlation with the organization of thylakoid super-complex in cyclic electron transport mutants of Chlamydomonas reinhardtii

Light and nutrients are essential components of photosynthesis. Activating the signaling cascades is critical in starting adaptive processes in response to high light. In this study, we have used wild-type (WT), cyclic electron transport (CET) mutants like Proton Gradient Regulation (PGR) (PGRL1), and PGR5 to elucidate the actual role in regulation and assembly of photosynthetic pigment-protein complexes under high light. Here, we have correlated the biophysical, biochemical, and proteomic approaches to understand the targeted proteins and the organization of thylakoid pigment-protein complexes in the photoacclimation. The proteomic analysis showed that 320 proteins were significantly affected under high light compared to the control and are mainly involved in the photosynthetic electron transport chain, protein synthesis, metabolic process, glycolysis, and proteins involved in cytoskeleton assembly. Additionally, we observed that the cytochrome (Cyt) b₆ expression is increased in the pgr5 mutant to regulate proton motive force and ATPase across the thylakoid membrane. The increased Cyt b₆ function in pgr5 could be due to the compromised function of chloroplast (cp) ATP synthase subunits for energy generation and photoprotection under high light. Moreover, our proteome data show that the photosystem subunit II (PSBS) protein isoforms (PSBS1 and PSBS2) expressed more than the Light-Harvesting Complex Stress-Related (LHCSR) protein in pgr5 compared to WT and pgrl1 under high light. The immunoblot data shows the photosystem II proteins D1 and D2 accumulated more in pgrl1 and pgr5 than WT under high light. In high light, CP43 and CP47 showed a reduced amount in pgr5 under high light due to changes in chlorophyll and carotenoid content around the PSII protein, which coordinates as a cofactor for efficient energy transfer from the light-harvesting antenna to the photosystem core. BN-PAGE and circular dichroism studies indicate changes in macromolecular assembly and thylakoid super-complexes destacking in pgrl1 and pgr5 due to changes in the pigment-protein complexes under high light. Based on this study, we emphasize that this is an excellent aid in understanding the role of CET mutants in thylakoid protein abundances and super-complex organization under high light.

Reversible changes in structure and function of photosynthetic apparatus of pea (Pisum sativum) leaves under drought stress

The effects of drought on photosynthesis have been extensively studied, whereas those on thylakoid organization are limited. We observed a significant decline in gas exchange parameters of pea (Pisum sativum) leaves under progressive drought stress. Chl a fluorescence kinetics revealed the reduction of photochemical efficiency of photosystem (PS)II and PSI. The non-photochemical quenching (NPQ) and the levels of PSII subunit PSBS increased. Furthermore, the light-harvesting complexes (LHCs) and some of the PSI and PSII core proteins were disassembled in drought conditions, whereas these complexes were reassociated during recovery. By contrast, the abundance of supercomplexes of PSII-LHCII and PSII dimer were reduced, whereas LHCII monomers increased following the change in the macro-organization of thylakoids. The stacks of thylakoids were loosely arranged in drought-affected plants, which could be attributed to changes in the supercomplexes of thylakoids. Severe drought stress caused a reduction of both LHCI and LHCII and a few reaction center proteins of PSI and PSII, indicating significant disorganization of the photosynthetic machinery. After 7 days of rewatering, plants recovered well, with restored chloroplast thylakoid structure and photosynthetic efficiency. The correlation of structural changes with leaf reactive oxygen species levels indicated that these changes were associated with the production of reactive oxygen species.

High light-induced changes in thylakoid supercomplexes organization from cyclic electron transport mutants of Chlamydomonas reinhardtii

The localization of carotenoids and macromolecular organization of thylakoid supercomplexes have not been reported yet in Chlamydomonas reinhardtii WT and cyclic electron transport mutants (pgrl1 and pgr5) under high light. Here, the various pigments, protein composition, and pigment-protein interactions were analyzed from the cells, thylakoids, and sucrose density gradient (SDG) fractions. Also, the supercomplexes of thylakoids were separated from BN-PAGE and SDG. The abundance of light-harvesting complex (LHC) II trimer complexes and pigment-pigment interaction were changed slightly under high light, shown by circular dichroism. However, a drastic change was seen in photosystem (PS)I-LHCI complexes than PSII complexes, especially in pgrl1 and pgr5. The lutein and β-carotene increased under high light in LHCII trimers compared to other supercomplexes, indicating that these pigments protected the LHCII trimers against high light. However, the presence of xanthophylls, lutein, and β-carotene was less in PSI-LHCI, indicating that pigment-protein complexes altered in high light. Even the real-time PCR data shows that the pgr5 mutant does not accumulate zeaxanthin dependent genes under high light, which shows that violaxanthin is not converting into zeaxanthin under high light. Also, the protein data confirms that the LHCSR3 expression is absent in pgr5, however it is presented in LHCII trimer in WT and pgrl1. Interestingly, some of the core proteins were aggregated in pgr5, which led to change in photosynthesis efficiency in high light.

Prevalence and Associated Factors of Cesarean Section in Dhulikhel Hospital, Kathmandu University Hospital

Background The Cesarean Section (CS) is a major obstetric life-saving procedure used to avoid pregnancy and childbirth complications. Cesarean sections are becoming more popular across the world, as well as in Nepal. Objective To assess the prevalence of cesarean section and its associated factors among women in Dhulikhel, Nepal. Method A cross-sectional study was conducted where 1246 pregnant women of age 15-45 years, admitted and delivered in hospital, were selected through purposive sampling technique and interviewed using structured questionnaires in Dhulikhel Hospital, Kathmandu University Hospital, Kavre, Nepal. Result The prevalence of cesarean section among women was 39.7% where the most common indication was previous cesarean section with scar tenderness, 27.9%. Half of the participants, i.e. 50.6%, were primigravida. Majority of women, 97.5% had done their antenatal checkup and among them 74.8% had their checkup in Dhulikhel Hospital, Kathmandu University Hospital. Most of them, i.e.76.2% had emergency cesarean section and 69.5% had primary cesarean section. Women of the age group 30-45 years (AOR=2.23) and women with higher secondary education level (AOR=2.03) were two times more likely to perform cesarean section. Women involved in service (AOR=1.37) and business (AOR=1.23) had greater odds of performing cesarean section than homemakers. Women giving birth to infants weighing 3.51- 5.00 kg were more likely to perform cesarean section (AOR=1.33). Conclusion The prevalence of cesarean section is noticeably high where the educated, employed and higher aged women are more inclined to cesarean section. More obstetric factors could be explored to determine the rise in cesarean section in Nepal which can help in decision making for clinicians.

Temperature-induced reversible changes in photosynthesis efficiency and organization of thylakoid membranes from pea (Pisum sativum)

High temperature can induce a substantial adverse effect on plant photosynthesis. This study addressed the impact of moderately high temperature (35 °C) on photosynthetic efficiency and thylakoid membrane organization in Pisum sativum. The Chl a fluorescence curves showed a significant change, indicating a reduction in photosynthetic efficiency when pea plants were exposed to moderate high-temperature stress. The pulse-amplitude modulation measurements showed decreased non-photochemical quenching while the non-regulated energy dissipation increased in treated compared to control and recovery plants. Both parameters indicated that the photosystem (PS)II was prone to temperature stress. The PSI donor side limitation increased in treated and recovery plants compared to control, suggesting the donor side of PSI is hampered in moderate-high temperature. Further, the PSI acceptor side increased in recovery plants compared to control, suggesting that the cyclic electron transport is repressed after temperature treatment but revert back to normal in recovery conditions. Also, the content of photoprotective carotenoid pigments like lutein and xanthophylls increased in temperature-treated leaves. These results indicate the alteration of macro-organization of thylakoid membranes under moderately elevated temperature, whereas supercomplexes restored to the control levels under recovery conditions. Further, the light harvesting complex (LHC)II trimers, and monomers were significantly decreased in temperature-treated plants. Furthermore, the amount of PSII reaction center proteins D1, D2, PsbO, and Cyt b6 was reduced under moderate temperature, whereas the content of LHC proteins of PSI was stable. These observations suggest that moderately high temperature can alter supercomplexes, which leads to change in the pigment-protein organization.

Infants later diagnosed with autism have lower canonical babbling ratios in the first year of life

BACKGROUND

Canonical babbling-producing syllables with a mature consonant, full vowel, and smooth transition-is an important developmental milestone that typically occurs in the first year of life. Some studies indicate delayed or reduced canonical babbling in infants at high familial likelihood for autism spectrum disorder (ASD) or who later receive an ASD diagnosis, but evidence is mixed. More refined characterization of babbling in the first year of life in infants with high likelihood for ASD is needed.

METHODS

Vocalizations produced at 6 and 12 months by infants (n = 267) taking part in a longitudinal study were coded for canonical and non-canonical syllables. Infants were categorized as low familial likelihood (LL), high familial likelihood diagnosed with ASD at 24 months (HL-ASD) or not diagnosed (HL-Neg). Language delay was assessed based on 24-month expressive and receptive language scores. Canonical babble ratio (CBR) was calculated by dividing the number of canonical syllables by the number of total syllables. Generalized linear (mixed) models were used to assess the relationship between group membership and CBR, controlling for site, sex, and maternal education. Logistic regression was used to assess whether canonical babbling ratios at 6 and 12 months predict 24-month diagnostic outcome.

RESULTS

No diagnostic group differences in CBR were detected at 6 months, but HL-ASD infants produced significantly lower CBR than both the HL-Neg and LL groups at 12 months. HL-Neg infants with language delay also showed reduced CBR at 12 months. Neither 6- nor 12-month CBR was significant predictors of 24-month diagnostic outcome (ASD versus no ASD) in logistic regression.

LIMITATIONS

Small numbers of vocalizations produced by infants at 6 months may limit the reliability of CBR estimates. It is not known if results generalize to infants who are not at high familial likelihood, or infants from more diverse racial and socioeconomic backgrounds.

CONCLUSIONS

Lower canonical babbling ratios are apparent by the end of the first year of life in ASD regardless of later language delay, but are also observed for infants with later language delay without ASD. Canonical babbling may lack specificity as an early marker when used on its own.

Change in the photochemical and structural organization of thylakoids from pea (Pisum sativum) under salt stress

Salt can induce adverse effects, primarily on the photosynthetic process, ultimately influencing plant productivity. Still, the impact of salt on the photosynthesis process in terms of supercomplexes organization of thylakoid structure and function is not understood in Pea (Pisum sativum). To understand the structure and function in the leaves and thylakoids under salt (NaCl) treatment, we used various biophysical and biochemical techniques like infrared gas analyzer, chlorophyll a fluorescence, circular dichroism, electron microscopy, blue native gels, and western blots. The net photosynthetic rate, transpiration rate, and stomatal conductance were reduced significantly, whereas the water use efficiency was enhanced remarkably under high salt conditions (200 mM NaCl). The photochemical efficiency of both photosystem (PS) I and II was reduced in high salt by inhibiting their donor and acceptor sides. Interestingly the non-photochemical quenching (NPQ) is reduced in high salt; however, the non-regulated energy dissipation (NO) of PSII increased, leading to inactivation of PSII. The obtained results exhibit inhibition of NAD(P)H dehydrogenase (NDH) mediated pathway-dependent cyclic electron transport under salinity caused a decrease in proton motive force of ΔpH and Δψ. Further, the electron micrographs show the disorganization of grana thylakoids under salt stress. Furthermore, the macro-organization and supercomplexes of thylakoids were significantly affected by high salt. Specifically, the mega complexes, PSII-LHCII, PSI-LHCI, and NDH complexes were notably reduced, ultimately altering the electron transport. The reaction center proteins of oxygen-evolving complexes, D1 and D2 proteins were affected to high salt indicating changes in photochemical activities.

Selection of ACC deaminase positive, thermohalotolerant and drought tolerance enhancing plant growth-promoting bacteria from rhizospheres of Cyamopsis tetragonoloba grown in arid regions

Plant growth-promoting bacteria (PGPB) expressing 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity are widely acknowledged to have a role in mitigation of abiotic stress caused by extreme environmental conditions. Consequently, several studies have focused on the isolation of ACC deaminase positive PGPBs. However, the application of such strains in drought-prone arid regions has remained grossly under-exploited. In order to be used in arid agroecosystems, PGPBs need to have the dual capability: to express ACC deaminase and to have the ability to tolerate increased temperature and salt concentration. Conspicuously, to date, very few studies have reported about isolation and characterization of PGPBs with this kind of dual capability. Here we report the isolation of bacterial strains from rhizosphere(s) of Cyamopsis tetragonoloba, a commercial crop from arid regions of Rajasthan, India, and their characterization for ACC deaminase activity and thermohalotolerance. Isolates found positive for desired traits were subsequently assessed for plant growth promotion under simulated drought conditions. Our finding showed that although the bacterial diversity within the rhizosphere of C. tetragonoloba grown in the arid region is quite poor, multiple isolates are ACC deaminase positive. Four isolates were found to be ACC deaminase positive, thermohalotolerant, and successfully enhanced drought tolerance. These isolates were identified as strains belonging to genera Pseudomonas, Enterobacter, and Stenotrophomonas based on 16S rRNA sequence homology.

Restoration of photosynthetic activity and supercomplexes from severe iron starvation in Chlamydomonas reinhardtii

The eukaryotic alga Chlamydomonas (C.) reinhardtii is used as a model organism to study photosynthetic efficiency. We studied the organization and protein profile of thylakoid membranes under severe iron (Fe²⁺) deficiency condition and iron supplement for their restoration. Chlorophyll (Chl) a fluorescence fast OJIP transients were decreased in the severe Fe²⁺ deficient cells resulting in the reduction of the photochemical efficiency. The circular dichroism (CD) results from Fe²⁺ deficient thylakoid membranes show a significant change in pigment-pigment and pigment-protein excitonic interactions. The organization of super-complexes was also affected significantly. Furthermore, super-complexes of photosystem (PS) II and PSI, along with its dimers, were severely reduced. The complexes separated using sucrose gradient centrifugation shows that loss of super-complexes and excitonic pigment-pigment interactions were restored in the severely Fe²⁺ deficient cells upon Fe supplementation for three generations. Additionally, the immunoblots demonstrated that both PSII, PSI core, and their light-harvesting complex antenna proteins were differentially decreased. However, reduced core proteins were aggregated, which in turn proteins were unfold and destabilized the supercomplexes and its function. Interestingly, the aggregated proteins were insoluble after n-Dodecyl β-D-maltoside solubilization. Further, they were identified in the pellet form. When Fe²⁺ was added to the severely deficient cells, the photosynthetic activity, pigment-proteins complexes, and proteins were restored to the level of control after 3^rd generation.

Excitation Density Dependent Photoluminescence Studies on Homo-Epitaxial GaN Nanowall Networks Grown by Laser Assisted Molecular Beam Epitaxy

The optical properties of laser-assisted molecular beam epitaxy grown homo-epitaxialGaN nanowall networks (NWNs) were investigated using power dependent photoluminescence (PL) spectroscopy and compared with homo-epitaxial GaN thin film. The pore size and tip width of GaN NWN sample is ˜120-180 nm and 10-15 nm, respectively. The ultraviolet-visible spectroscopy study shows that the GaN NWNs have low optical light reflection and minimum Fabry-Perot cavity effect than GaN film. The room temperature PL spectroscopy reveals that the GaN NWNs possesses enhanced band gap of 3.51 eV with blue shift of 90 meV than the GaN film (3.42 eV). The excitation density dependent PL spectroscopy measurements reveal that the GaN NWNs nanowall and near band emission (NBE) peak position and its linewidth invariant. The intensity of NBE peak for GaN film and nanowalls varies linearly whereas NBE to defect related yellow luminescence peak intensity ratio shows a non-linear variation on the excitation density. The excitation density in PL measurements plays a key role when the sample quality compared on the basis of PL data.

Fructose-induced ROS generation impairs glucose utilization in L6 skeletal muscle cells

High fructose consumption has implicated in insulin resistance and metabolic syndrome. Fructose is a highly lipogenic sugar that has intense metabolic effects in liver. Recent evidences suggest that fructose exposure to other tissues has substantial and profound metabolic consequences predisposing toward chronic conditions such as type 2 diabetes. Since skeletal muscle is the major site for glucose utilization, in the present study we define the effects of fructose exposure on glucose utilization in skeletal muscle cells. Upon fructose exposure, the L6 skeletal muscle cells displayed diminished glucose uptake, glucose transporter type 4 (GLUT4) translocation, and impaired insulin signaling. The exposure to fructose elevated reactive oxygen species (ROS) production in L6 myotubes, accompanied by activation of the stress/inflammation markers c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase 1/2 (ERK1/2), and degradation of inhibitor of NF-κB (IκBα). We found that fructose caused impairment of glucose utilization and insulin signaling through ROS-mediated activation of JNK and ERK1/2 pathways, which was prevented in the presence of antioxidants. In conclusion, our data demonstrate that exposure to fructose induces cell-autonomous oxidative response through ROS production leading to impaired insulin signaling and attenuated glucose utilization in skeletal muscle cells.

Fluoride contamination and fluorosis in rural community in the vicinity of a phosphate fertilizer factory in India

We studied chronic fluoride intoxication in 10 villages of Udaipur receiving F emissions from phosphate fertilizer factories. Although fluoride remained below permissible limit in most of the drinking water samples, the incidence of fluorosis in adults as well as in children was surprisingly high. Khemli appeared to be the most affected village (with >48% cases) where, about 93% of 2 h air samples contained fluoride above 2.0 μg m(-3) and crops and vegetable F ranged from 27.5 to 143.4 μg g(-1). Concentrations of fluoride and inorganic P in urine showed asynchrony and were well linked with prevalence of fluorosis. The study indicated that air-borne fluoride was the major factor for higher prevalence of fluorosis in these rural areas.

A Fully Integrated RF-Powered Contact Lens With a Single Element Display

We present progress toward a wirelessly-powered active contact lens comprised of a transparent polymer substrate, loop antenna, power harvesting IC, and micro-LED. The fully integrated radio power harvesting and power management system was fabricated in a 0.13 μm CMOS process with a total die area of 0.2 mm(2). It utilizes a small on-chip capacitor for energy storage to light up a micro-LED pixel. We have demonstrated wireless power transfer at 10 cm distance using the custom IC and on-lens antenna.

Circuit techniques for wireless brain interfaces

Efficient, miniaturized wireless recording is critical for both existing and emerging health-monitoring applications. One important example of this is in the brain interface community, where new technologies allow improved observation and understanding of brain functions. This, in turn, drives the need for ever smaller, lower power, and higher performance circuitry for chronic recording. This paper describes circuit and system techniques for low power wireless brain interfaces. Active and passive architectures are described and compared, and measured in-vivo data from both are presented.

Air-borne heavy metal contamination to dietary vegetables: a case study from India

Contamination of edible parts of three dietary vegetables, Spinach (Spinacia oleracea L.), Radish (Raphanus sativus L.), and Tomato (Lycopersicon esculentum Mill.) by air-borne cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and lead (Pb) was determined using pot culture experiments at three sites in the city of Varanasi, India. The data revealed that although Cr and Cu in vegetables remained below their safe limits, about 68% of the total samples contained Cd, Ni, and Pb above their respective safe limits of 1.5, 1.5, and 2.5 μg g(-1). Site wise synchrony and air accumulation factor (AAF) indicated that atmospheric deposition was the main contributor of metal contamination to vegetables. The study suggests that if the present trends of atmospheric deposition are continued, air-borne heavy metals will contaminate the agricultural produce with long-term health implications.

Metal contamination of Ganga River (India) as influenced by atmospheric deposition

Metal contamination of Ganga river in relation to atmospheric deposition was investigated. The data revealed that, although Cr and Cu remained below their maximum admissible concentrations, levels of Cd and Pb in mid-stream waters at five out of six stations were higher than their respective maximum admissible concentration. About 62% of water samples contained Ni above its maximum admissible concentration of 20 microg L(-1). Metal concentrations in water showed significant correlation and seasonal synchrony with atmospheric deposition. The study forms the first report on air-driven metal contamination of Ganga and has relevance from human health perspectives.

Accumulation of heavy metals in dietary vegetables and cultivated soil horizon in organic farming system in relation to atmospheric deposition in a seasonally dry tropical region of India

Increasing consciousness about future sustainable agriculture and hazard free food production has lead organic farming to be a globally emerging alternative farm practice. We investigated the accumulation of air-borne heavy metals in edible parts of vegetables and in cultivated soil horizon in organic farming system in a low rain fall tropical region of India. The factorial design of whole experiment consisted of six vegetable crops (tomato, egg plant, spinach, amaranthus, carrot and radish) x two treatments (organic farming in open field and organic farming in glasshouse (OFG)) x seven independent harvest of each crop. The results indicated that except for Pb, atmospheric deposition of heavy metals increased consistently on time scale. Concentrations of heavy metals in cultivated soil horizon and in edible parts of open field grown vegetables increased over time and were significantly higher than those recorded in OFG plots. Increased contents of heavy metals in open field altered soil porosity, bulk density, water holding capacity, microbial biomass carbon, substrate-induced respiration, alkaline phosphatase and fluorescein diacetate hydrolytic activities. Vegetable concentrations of heavy metal appeared in the order Zn > Pb > Cu > Ni > Cd and were maximum in leaves (spinach and amaranths) followed by fruits (tomato and egg plant) and minimum in roots (carrot and radish). Multiple regression analysis indicated that the major contribution of most heavy metals to vegetable leaves was from atmosphere. For roots however, soil appeared to be equally important. The study suggests that if the present trend of atmospheric deposition is continued, it will lead to a destabilizing effect on this sustainable agricultural practice and will increase the dietary intake of toxic metals.

Enhanced production of biomass, pigments and antioxidant capacity of a nutritionally important cyanobacterium Nostochopsis lobatus

A diazotrophic cyanobacterium Nostochopsis lobatus was evaluated for enhanced production of biomass, pigments and antioxidant capacity. N. lobatus showed potentially high antioxidant capacity (46.12 microM AEAC) with significant improvement under immobilized cell cultures (87.05 microM AEAC). When a mixture of P and Fe was supplemented, biomass, pigments, nutritive value and antioxidant capacity increased substantially at pH 7.8. When considered separately, P appeared to be a better supplement than Fe for the production of biomass, chlorophyll and carotenoids. However, for phycocyanin, phycoerythrin, nutritive value and antioxidant capacity, Fe appeared more effective than P. Our study indicates N. lobatus to be a promising bioresource for enhanced production of nutritionally rich biomass, pigments and antioxidants. The study also suggests that P and Fe are potentially effective supplements for scale-up production for commercial application.

Microbial biomass at land water interface and its role in regulating ecosystem properties of a fresh water dry tropical woodland lake

This study was aimed at determining microbial biomass at land water interface and the role it plays in regulating ecosystem properties of a fresh water dry tropical woodland lake. Four microbial variables namely biomass-C (Cmic), fumigated CO2-C, substrate induced respiration (SIR) and basal respiration (BR) were measured in humus samples collected from land water interface over a period of one year Microbial biomass (Cmic) was maximum during February (718 micorg CO2-C g(-1)). Similar was the case of fumigated CO2-C (560 microg CO2-C g(-1) 10 d(-1)), SIR (2900 microg CO2-C g(-1)) and BR (480 microg CO2-C g(-1)). Humus-N appeared maximum (1.60%) during November and phenolics (204 microg g(-1)) during December Gross primary productivity (GPP) was found maximum (3.30 g Cm(-2)d(-1)) during March. Almost similar trend appeared for chlorophyll and phytoplankton density. Variation in microbial biomass at land water interface can be explained by seasonality and the quality of substrate material. Asynchrony in the peaks of microbial variables with phytoplankton pulsation and GPP suggested that the microbial biomass through nutrient mineralization regulates ecosystem functioning of a fresh water woodland lake. This has relevance for evaluating the nature of anthropogenic perturbations and for maintenance of fresh water lakes void of human disturbances.

Evaluation of air pollution phytotoxicity downwind of a phosphate fertilizer factory in India

The effects of air pollution on plants downwind of a fertilizer factory at Udaipur, India, were studied using three woody perennials. Seedlings of these species including a shrub (Carissa carandas L.), a leguminous avenue tree (Cassia fistula L.) and a fruit tree (Psidium guajava L.) were grown in earthen pots at different study sites receiving varying levels of air pollution input. Changes in plant growth, morphological characteristics, photosynthetic pigment, ascorbic acid, N and S contents and in dry matter allocation were considered in relation to the status of ambient air quality. Observations with these parameters have indicated that the ambient air around the factory contained pollutants at phytotoxic levels. Plant height, basal diameter, conopy area, leaf area and chlorophyll, ascorbic acid and foliar-N concentrations decreased with increasing pollution load. However, foliar-S increased slightly at polluted sites. Air pollution load around the factory have also altered the biomass allocation. Root:shoot ratios increased in C. fistula and P. guajava at polluted sites. In contrast, for C. carandas the above ground parts, where foliage assumed predominance showed precedence over the root growth. This species responded characteristically to air pollution stress by allocating more of its photosynthate towards leaf production and shoot growth.

The influence of catchment on chemical and biological characteristics of two freshwater tropical lakes of southern Rajasthan

The effects of catchment characteristics on chemical and biological properties of two freshwater tropical lakes of Udaipur, Rajasthan were investigated. The study indicated that the catchment characteristics influence, in a major way, the water chemistry and dredging, could be an effective measure for the restoration of dryland lakes.

Cyanobacterial flora and the physico-chemical environment of six tropical fresh water lakes of Udaipur, India

The cyanobacteria and physico-chemical environments of six tropical fresh water lakes of Udaipur, India were investigated. These lakes receive varying nutrient inputs from different sources. Altogether 51 species of cyanobacteria were recorded. Species composition varied between lakes and between seasons. Lake VI (Baghdara), which receives nutrients from natural sources only, differed considerably from the others in water chemistry and composition of dominant species. Lake II (Swaroop Sagar), eutrophied due to sewage inputs, was species poor. Non-diazotrophs, represented by 27 species, dominated during summer. With few exceptions, N2-fixing species, both heterocystous and unicellular diazotrophs (represented by 24 species), were dominant during winter. Microcystis aeruginosa, Phormidium sp. and Anabaena flos-aque were the dominant taxa of lakes characterized by sewage eutrophication. The study shows that both species diversity and community composition were affected by water chemistry.

Hyperimmunoglobulinemia E in the absence of atopy and filarial infection: the Huaorani of Ecuador

Hyperimmunoglobulinemia E (HIGE) is associated with various conditions such as atopy, dermatitis, hypersensitivity reactions, and certain parasitic infections. In the course of vaccination initiatives in the province of Napo, eastern Ecuador, blood samples were collected from one of the two remaining rural subgroups of Huaorani Indians who in 1979 were reported to have the world's highest concentrations of IgE. One subgroup of Huaorani, the Dicaron, lives in a protected Amazonian region which has reportedly suffered from extensive pollution after petroleum industry exploration. Plasma was collected from 31 members of the Dicaron (age range 15-75 years), eight non-Dicaron Huaorani, and 16 Quichua Indians from the same province, and tested for IgE, IgG, IgM, IgA, and immunoglobulin allotypes. Subjects were examined for evidence of filariasis, a group of parasitic diseases associated with HIGE. Mean IgE concentration in the Dicaron was measured by CAP ELISA at 11,850 IU/mL (range 5000-33,000) while IgA and IgM concentrations were within normal limits compared to North American controls. IgG levels were slightly elevated and there was no evidence of filariasis. Compared to the Quichua and non-Dicaron Huaorani, two other Amerindian tribes in the Ecuadorian Amazon, the highest concentrations of IgE were recorded from the Dicaron who live within the allegedly polluted section of the Amazon. We conclude that an unexplained HIGE syndrome exists among only one subgroup of Huaorani, the Dicaron. Other eastern Ecuadorian Amerindians, such as the Quichua and resettled Huaorani, have IgE concentrations expected in a population with intestinal helminthiasis. Environmental factors cannot be excluded as the cause of HIGE in the Dicaron.

Resolution, molecular structure and biological activities of the D- and L-enantiomers of potent anti-implantation agent, DL-2-[4-(2-piperidinoethoxy)phenyl]-3-phenyl-2H-1-benzopyran

Compound 1 (DL-2-[4-(2-piperidinoethoxy)phenyl]-3-phenyl-2H-1-benzopyran, CDRI 85/287) a potent anti-estrogen and anti-implantation agent has been successfully resolved into its pure D- and L-enantiomers. Biological studies showed L-enantiomer to be the active form, exhibiting a fivefold higher receptor affinity for the rat uterine cytosolic estrogen receptor, 100% contraceptive efficacy at 1.3 mg/kg dose in single day schedule and 89% inhibition of estradiol induced increase of uterine weight at its contraceptive dose. The absolute stereochemistry determined by X-ray crystallographic analysis showed that the L-enantiomer has 2R configuration at its asymmetric centre.

Chronic lymphocytic leukemia presenting as jaundice

Hematological and lymphoid malignancies rarely present with manifestations outside these tissues. We report a patient with chronic lymphocytic leukemia (CLL) presenting with jaundice and generalized lymphadenopathy. The liver profile was suggestive of hepatitis; biopsy showed mild cholestasis. The findings suggest paraneoplastic jaundice with CLL.

Morphogenesis of the human external male genitalia

The morphogenesis of the external genitalia of human fetuses (16-250 mm crown-rump [CR] length, 6-26 weeks of gestation) obtained after medical termination of pregnancy were studied. Differential development (male/female) started after 50 mm CR length (9 weeks). At that time the external genitalia consisted of a cylindrical genital tubercle 2 mm in length with a visible coronary sulcus and glans and genital swellings on either side. A groove on the ventral aspect of the genital tubercle extended to the coronary sulcus; the lateral boundaries of this groove separated to form the urethral folds. In male fetuses the free edges of the urethral folds fused, starting from the proximal end, to form a tunnel over the ventral aspect of the phallus. The pelvic urethra opened into this tunnel, slightly distal to its origin. The mesodermal tissue forming the genital swellings migrated ventrally and then medially. As medial migration started, the skin in the midline between the genital swellings was raised up as a skin fold, which subsequently, as the genital swellings migrated further, became elevated. The proximal part of the tunnel formed by fusion of the urethral folds (proximal to the point of entry of the pelvic urethra) also was compressed and pushed out as the genital swellings fused in the midline over the root of the phallus. These changes took place at between 80 and 110 mm CR length (12-13 weeks' gestation); at this stage the phallus appeared short and was bent ventrally. With further growth and caudal migration of the scrotum, the phallus lost its ventral curvature. The appearance of the external genitalia at different gestational ages bore a close resemblance to that in children with hypospadias. We therefore conclude that hypospadias can be explained on the basis of an embryological arrest due to the absence of the required stimulus for male phenotypic development at the appropriate time.

Adaptational strategy of a tropical shrub Carissa Carandas L. to urban air pollution

This paper reports the adaptational response of a tropical shrub Carissa Carandas L. to urban air pollution stress in Varanasi, India. Saplings of C. carandas were grown at a density of one per pot and kept for two years at 25 selected sites in the urban environment. Different sites received different levels of air pollution input. Changes in vegetative growth pattern (leafing and branching), in morphological features and in the distribution of biomass to above and below ground structures were considered in relation to the ambient air quality.Different levels of air pollution input produced different sets of harmful effects. Although the air pollution level at Varanasi reduced the plant height, basal diameter, canopy area, leaf area and total plant biomass of C. carandas, this species retained a major fraction of its photosynthate to above-ground plant parts where foliage assumes predominance. Since carbon gain is dependent not only on the rate of carbon acquisition per unit leaf tissue but also on the amount of photosynthetic tissue present, a shift in relative contribution of photosynthate to leaf production and shoot growth appears to be a pollution-induced adaptive response in C. carandas.

Congenital sulfhemoglobin and transient methemoglobinemia secondary to diarrhoea

Sulfhemoglobinemia and Methemoglobinemia are common causes of cyanosis arising due to accumulation of abnormal heme pigment. We present an unusual case of congenital sulfhemoglobinemia along with diarrhoea induced methemo-globinemia in a neonate. A high index of suspicion and a proper diagnostic approach is needed to determine the true frequency of their occurrence together.

Pregnancy associated anemia and iron: a pilot study

Iron deficiency occurs when the rate of loss of utilization exceeds its assimilation. Treatment is based on iron supplementation but due to side effects compliance to iron therapy is poor. A double blind comparative study was done using a novel time release preparation of ferrous sulphate (Code A) v.s. sustained release ferrous sulphate preparation (Code B) on 60 pregnant women in mid or late pregnancy with anaemia. The amount of ferrous sulphate in Code A was less than half of Code B. The patients were sequentially randomised as Code A or Code B recipient. The non compliance rate was 33%, and for both Code A & Code B. The mean improvement in hemoglobin after 4 weeks of therapy was 2.01 gm% for Code A and 2.3 gm% for Code B. Iron absorption as evidenced by improvement in S. Iron, TIBC and ferritin levels was better with Code A. The improvement in subjective symptoms of anaemia was better than average in Code B preparation. Code A group had comparatively more side effects both major and minor, this may have been the reason for a slightly higher drop out rate in this group. In conclusion the timed release preparation has a comparable haematological response and better absorption with significantly lower doses as compared to the sustained release preparation.

Pregnancy induced hypertension and antithrombin-III

This study was undertaken to determine the coagulation profile of women with pregnancy induced hypertension and to evaluate the changes in the level of AT-III in pre-eclampsia and eclampsia and its correlation with severity of disease in order to evaluate if it can be used as a marker for severity of PIH. 119 women with PIH in the third trimester of pregnancy constituted the study group. Age and parity matched 25 normal pregnant and 25 non-pregnant women were taken as control group. No significant difference between the coagulation profile of non-pregnant and normal pregnant women was seen. There is evidence of consumption coagulopathy in PIH patients and AT-III activity shows a gradual and almost linear reduction in various groups ranging from normal pregnant women to eclampsia. Reduction in AT-III activity has positive correlation with PIH and it can be a useful marker for severity of PIH.

Screening for HIV seropositive blood - a critical evaluation

HIV screening of all donated blood is mandatory in India. The program instituted has many inherent lacunac like arbitrary identification of centres, absence of a guardian quality control program, criterion for test kit selection and absence of standard guidelines. This study was undertaken to evaluate the effects of frequent change of testing laboratory, change of testing staff, change of reagent kits and time of blood donation. All the donations at blood bank Safdarjang Hospital, during the year 1993, were taken for study. HBsAg and VDRL positivity were used as control/check value for similarity of donor population. Tests done during this period in three different laboratories show that the change of laboratory, change of reagent kit and the experience and training of the testing laboratory staff affect the test results, causing an increase in the number of false positive tests. This leads to destruction of donated blood which would have been otherwise fit for transfusion. It is suggested that a proper policy plan may be made and implemented in order to make the blood screening more effective.

Evaluation of air pollution phytotoxicity in a seasonally dry tropical urban environment

This study was conducted in the urban environment of Varanasi, India, to evaluate the plant responses to urban air pollution. Twenty sites were selected in four different zones of the city. At each site, seven woody perennials of same age classes were selected. Out of the four zones (I, II, III and IV), zone IV was used as a reference (control) zone as it received the minimum pollution input. Plant species growing in polluted and control areas were compared with respect to foliar dust load, per cent leaf area injury, leaf area, specific leaf weight and chlorophyll, ascorbic acid, SO 4 (2-) S and total N concentration in the leaves. Results indicated that the air pollution level in Varanasi causes leaf damage, reduces leaf area, specific leaf weight and chlorophyll, ascorbic acid and total N concentrations in the leaves. Sulphur concentration in leaves increased with increasing level of SO2 in the ambient air. The magnitude of such changes was maximum at the zone receiving maximum pollution load. Carissa carandas was found to be the most sensitive species and Bougainvillea spectabilis, the least. The study shows that the urban air pollution level in Varanasi is detrimental for the growth of plants involved in this study.

Evaluation of two techniques (RPHA and latex agglutination) for use as a screening tool for HBsAg

RPHA and latex agglutination are two cost effective techniques available for HBsAg screening in our country. Most of the blood banks and other clinical laboratories use RPHA technique or latex agglutination test for screening of donors or patients positive for Hepatitis B surface Ag (HBsAg). All the reagent kits available in the Indian market do not give the ranges of specificity, sensitivity and predictive values for the particular test. Also no data is available if they were tested on Asian sera. Therefore it was decided to evaluated the two most often used techniques RPHA and latex agglutination for their sensitivities and efficacy as a screening test. Our results indicate that though RPHA may be used in a diagnostic set up, it is a poor screening tool as it gives a fairly large number of false negatives and has a low sensitivity. Latex agglutination on the other hand, does not give any false negative results and is recommended for preliminary screening, wherever cost is a constraint. The sera with positive results should be subsequently tested by EIA to rule out the false positive results.

Human female phenotypic development: role of fetal ovaries

Morphogenesis of external genitalia was studied in human fetuses obtained from cases of medical termination of pregnancies and cases of spontaneous abortions. Eighty-two fetuses, 16 mm crown rump (CR) length (6 weeks gestation) to 240 mm CR length (26 weeks gestation), were studied. Fetal sex was determined with the help of chorionic villus of fetal skin biopsies in cases of fetuses less than 70 mm CR length. Growth and differentiation up to 50 mm CR length (9 weeks gestation) was identical for both sexes. After this there was rapid growth and differentiation in males. But in females subsequent growth until 180-200 mm CR-length stage (20 weeks gestation), was restricted to growth of labia majora. After this there was rapid ventral outgrowth of the region of perineum between the clitoris and anus, which brought the urethral and vaginal orifices to the surface. There was also further growth of labia. This process of feminization of external genitalia was completed by the 26th week of gestation. Histology revealed that ovary and testes could be clearly identified at 60 mm CR length stage. Maturation of fetal testes progressed rapidly, but there was little change in the histological appearance of ovaries until 160-180 mm CR-length stage (18-20 weeks of gestation). Follicular growth started after this. Feminization of urogenital sinus started after follicular growth started in the fetal ovaries. So from the temporal profile of events, it appears that it may be initiated by fetal ovarian steroids.