Nature-inspired polymer photocatalysts for green NADH regeneration and nitroarene transformation

Photocatalysis has emerged as a promising approach for generating solar chemical and organic transformations under the solar light spectrum, employing polymer photocatalysts. In this study, our aim is to achieve the regeneration of NADH and fixation of nitroarene compounds, which hold significant importance in various fields such as pharmaceuticals, biology, and chemistry. The development of an in-situ nature-inspired artificial photosynthetic pathway represents a challenging task, as it involves harnessing solar energy for efficient solar chemical production and organic transformation. In this work, we have successfully synthesized a novel artificial photosynthetic polymer, named TFc photocatalyst, through the Friedel-Crafts alkylation reaction between triptycene (T) and a ferrocene motif (Fc). The TFC photocatalyst is a promising material with excellent optical properties, an appropriate band gap, and the ability to facilitate the regeneration of NADH and the fixation of nitroarene compounds through photocatalysis. These characteristics are necessary for several applications, including organic synthesis and environmental remediation. Our research provides a significant step forward in establishing a reliable pathway for the regeneration and fixation of solar chemicals and organic compounds under the solar light spectrum.

Comparison of different rainfall products with gauge-based measurements over Narmada River Basin, India

The present study evaluates and compares the performance of different rainfall products, namely, Climate Hazards Group InfraRed Precipitation with Station (CHIRPS), India Meteorological Department (IMD) gridded, Prediction of Worldwide Energy Resource (POWER), and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Network-Climate Data Record (PERSIANN-CDR) with gauge-based measurements over Narmada River basin, India. The ground-based daily rainfall data (1981-2020) of 11 gauging stations have been collected from the Water Resources Department, Madhya Pradesh and the evaluation of rainfall product has been accomplished on a point-to-grid basis (nearest neighbor method) at annual and seasonal scales with the help of continuous and categorical statistical metrics. The results reveal a strong positive correlation (> 0.75) between rainfall estimates of different products and gauge-based measurements at annual scale demonstrating higher similarity in rainfall estimates and observed data, whereas seasonal estimates have exhibited comparatively weaker relationship. Likewise, percent bias (PBIAS) demonstrates least bias in annual and monsoon rainfall estimates and high in other seasons. These findings reveal that rainfall estimates tend to improve with increasing time scale (season to annual). However, majority of the rainfall products have overestimated the low rainfall (western region) and underestimated the high rainfall (eastern and southeastern regions). Further, the values of critical success index (CSI) indicate IMD gridded product outperforms in detecting rainfall events accurately followed by POWER, PERSIANN-CDR, and CHIRPS. These results suggest that IMD gridded estimates provide the best alternate to ground-based rain measurements. However, rainfall estimates from POWER, PERSIANN-CDR and CHIRPS can also be used in various hydrometeorological investigations over Narmada River basin.

Changes in agricultural land use and its consequences on crop productivity, diversity, and food availability in an agriculturally developed state of India

The present study, covering a period of 52 years (1966-2017), explores changes in agricultural land use and its consequences on crop productivity, diversity, and food availability in Haryana, an agriculturally developed state of India. The time series data on different parameters (area, production, yield, etc.) were collected from the secondary sources and analyzed with the help of compound annual growth rate, trend tests (simple linear regression and Mann-Kendall), and change point detection tests such as Pettitt, standard normal homogeneity, Buishand range, and Neumann ratio. Apart from above, the relative share of area and yield to total change in output was determined using decomposition analysis. The results revealed that agricultural land use became intensive and underwent significant alteration with multifold shifting in area from coarse cereals (maize, jowar, and bajra) to fine food grains (wheat and rice). The yield of all crops, especially wheat and rice witnessed a significant increase which subsequently led to an upsurge in their production. However, the production of maize, jowar, and pulses recorded negative growth despite of an increase in their yield. The results also revealed manifold increase in use of modern key inputs during the first two periods (1966-1985), but afterwards input use rate slowed down. Additionally, the decomposition analysis revealed that yield effect remained positive in changing the production of all crops, but area contributed positively only in wheat, rice, cotton, and oilseeds. The major findings of this study imply that the production of crops can be enhanced only through improvement in yield because there is no further scope left for horizontal expansion in cultivable area of the state.

Comparative analysis of discharge and sediment flux from two contiguous glacierized basins of Central Himalaya, India

In the present study, suspended sediment load (SSL), sediment yield and erosion rates in Pindari Glacier basin (PGB) and Kafni Glacier basin (KGB) have been estimated using daily discharge and suspended sediment concentration (SSC) data for three ablation seasons (2017-2019). For this, one meteorological observatory and two gauging sites have been established at Dwali (confluence point), and water samples have been collected twice in a day for high flow period (July to September) and daily for lean period (May, June and October). An area-velocity method and stage-discharge relationship has been established to convert water level into discharge (m³ s^-1). For estimating SSC (mg/l), collected water samples have been filtered, dried, analysed and confirmed with an automatic suspended solid indicator. Further, SSL, sediment yield and erosion rates have been computed using SSC data. The results reveal that mean annual discharge in PGB (35.06 m³ s^-1) has been found approximately 1.7 times higher than KGB (20.47 m³ s^-1). The average SSC and SSL in PGB have been observed about 396.07 mg/l and 1928.34 tonnes, and in KGB, it is about 359.67 mg/l and 1040.26 tonnes, respectively. The SSC and SSL have followed the pattern of discharge. A significant correlation of SSC and SSL has been found with discharge in both the glacierized basins (p < 0.01). Interestingly, average annual sediment yield in PGB (3196.53 t/km²/yr) and KGB (3087.23 t/km²/yr) have been found almost identical. Likewise, the erosion rates in PGB and KGB have been witnessed about 1.18 and 1.14 mm/yr, respectively. Sediment yield and erosion rates in PGB and KGB have been found in correspondence with other basins of Central Himalaya. These findings will be beneficial for engineers and water resource managers in the management of water resources and hydropower projects in high-altitude areas and in the planning and designing of water structures (dams, reservoirs etc.) in downstream areas.

EPIDEMIOLOGY AND SEASONAL VARIATION OF APPENDICITIS – A SINGLE CENTER RETROSPECTIVE STUDY FROM NORTH-EAST INDIA

Background. Acute appendicitis is the most common surgical emergency presenting in emergency department, and appendectomy is one of the most common surgeries. There is a wide variation in the incidence of acute appendicitis reported for different countries, different regions, race, sex, age and also seasons. Objective. The aim of this study was to understand the epidemiological trend and the seasonal variation of appendicitis in the northeast region of India. Methods. It was a retrospective hospital-based study conducted in Jan 2016 – Dec 2020 at a Tertiary Care Teaching Hospital in the northeast region of India. The patient data were obtained from the Medical Record Department of the hospital and the data regarding the weather was obtained from the Indian Meteorological Department (IMD) and the website www.worldweather.com. The statistical analysis was done using SPSS software version 24.0, and the seasonal variation was studied using Kruskal Wallis test. Results. Acute appendicitis affected both the sexes equally with a marginal higher incidence in males. It also had higher peak during the second and third decade of life in both the sexes. The incidence of acute appendicitis was high in the pre-monsoon and monsoon season with peak in the monsoon season. Conclusions. Acute appendicitis is more common during the pre-monsoon and monsoon season, a period known for humidity, high incidence of bacterial and viral infections.

Correction: Synthesis of sub-nanometric Cu2O catalysts for Pd-free C–C coupling reactions

Correction for ‘Synthesis of sub-nanometric Cu2O catalysts for Pd-free C–C coupling reactions’ by Ankit Agrawal et al., React. Chem. Eng., 2021, 6, 929–936, https://doi.org/10.1039/D1RE00054C.

Exploring spatial and temporal drought over the semi-arid Sahibi river basin in Rajasthan, India

Rajasthan state of India is prone to recurrent droughts; hence, exploring drought severities over the semi-arid Sahibi river basin is crucial for drought management. To investigate drought severity, the Rainfall Anomaly Index (RAI) was applied at two time spans, such as annual (January to December) and the monsoon season (June to September), using long-term daily rainfall data (1961-2017) for nine rain gauge stations. Similarly, for the examination of various drought characteristics like magnitude, duration and intensity, run theory analysis was used. Trends in rainfall, drought severity, magnitude, duration and intensity were computed by employing both parametric (simple linear regression) and non-parametric (Mann-Kendall and Sen's slope) tests, while spatial pattern maps of rainfall and drought characteristics were prepared using geographical information system. The analysis of rainfall records revealed a declining trend in eastern and central parts, whereas remaining areas of the basin witnessed an increasing trend during two time spans. During the study period, drought occurrence varied both geographically and temporally. The extreme, severe and moderate drought events were more common during monsoon season. Amongst the stations, Tapukara, Bairath and Mundawar rain gauge stations experienced the largest number of drought events compared to other stations. At both time scales, the most extreme droughts in the Sahibi basin occurred in 1979, 1986, 1987, 1989 and 2002. At the annual time span, the basin had the longest drought duration of 300 days, with a drought magnitude of - 758.3 mm. Likewise, the Tapukara rain gauge station had the longest dry spell of 310 days, followed by Behrod and Kotkasim (306 days each), Kotputli and Tijara (305 days each) and Mundawar (303 days). Finally, the findings of this study are expected to be useful to agricultural scientists, policymakers and water resource managers.

Synthesis of sub-nanometric Cu2O catalysts for Pd-free C–C coupling reactions

The current template route provides Cu₂O nanocrystals with various shapes and depends on the homologues of glucose. These morphology-controlled Cu₂O nanocrystals show high activity for the external base-free Ullmann homocoupling of aryl halides.

MODERN APPROACHES IN MANAGEMENT OF CHILDREN WITH CHRONIC HEPATITIS B IN REMISSION OF ACUTE LYMPHOBLASTIC LEUKEMIA

The aim of the study is to assess the effectivity of the drug «Betargin» in complex management of patients with chronic hepatitis B (CHB) in remission of acute lymphoblastic leukemia (ALL). The research had shown the results of treatment of 41 children with CHB in remission of ALL aged from 3 to 17 years old, who were on dispensary observation in Vinnytsia Regional Children's Clinical Infectious Diseases Hospital during 2013-2017 years. Patients were devided into the following groups: the comparison group (group A), which included 18 children with CHB in remission of ALL, who received basis therapy; the main group (group B) which consisted of 23 patients with CHB in remission of ALL, who got betaine arginine complex («Betargin») in addition to basis therapy. The control group was formed out of 30 healthy children. Determination of effectivity of the proposed treatment regimen was performed by studying the indicators of cholestasis, cytolysis, hepatocellular insufficiency, and lipid metabolism. To assess the liver's fibrosis level and necroinflammatory activity we used the determination of the level of plasma osteopontin in the serum using the enzyme-linked immunosorbent assay (ELISA) method: Human Osteopontin Quantikine (RDD systems, Dos Too, Minneapolis, MS, USA). The verification of the diagnosis of CHB was based on the detection of specific markers of HBV-infection in blood using ELISA and PCR analysis. During our scientific research we established that using betaine arginine complex in management of CHB in remission of ALL led to considerable improvement of children's general condition, namely due to reducing (p<0,05) the incidence of asthenovegetative (8.6% against 33.3% in the comparison group), dyspeptic (13.1% against 38.8%) as well as pain syndromes (4.3% against 11%) and hepatomegaly (13.1% against 38.8%). The activity of ALT in the main group was in 1.6 times less (p<0,05) than in comparison group at the end of the course of treatment. «Betargin» has an antifibrotic effect which is confirmed by a decrease in the level of plasma osteopontin up to 104,92 ng/ml against 178,15 ng/ml in the comparison group (p<0,05).

Association between climatic variables and COVID-19 pandemic in National Capital Territory of Delhi, India

Globally, since the end of December 2019, coronavirus disease (COVID-19) has been recognized as a severe infectious disease. Therefore, this study has been attempted to examine the linkage between climatic variables and COVID-19 particularly in National Capital Territory of Delhi (NCT of Delhi), India. For this, daily data of COVID-19 has been used for the period March 14 to June 11, 2020, (90 days). Eight climatic variables such as maximum, minimum and mean temperature (°C), relative humidity (%), bright sunshine hours, wind speed (km/h), evaporation (mm), and rainfall (mm) have been analyzed in relation to COVID-19. To study the relationship among different climatic variables and COVID-19 spread, Karl Pearson's correlation analysis has been performed. The Mann-Kendall method and Sen's slope estimator have been used to detect the direction and magnitude of COVID-19 trends, respectively. The results have shown that out of eight selected climatic variables, six variables, viz. maximum temperature, minimum temperature, mean temperature, relative humidity, evaporation, and wind speed are positively associated with coronavirus disease cases (statistically significant at 95 and 99% confidence levels). No association of coronavirus disease has been found with bright sunshine hours and rainfall. Besides, COVID-19 cases and deaths have shown increasing trends, significant at 99% confidence level. The results of this study suggest that climatic conditions in NCT of Delhi are favorable for COVID-19 and the disease may spread further with the increasing temperature, relative humidity, evaporation and wind speed. This is the only study which has presented the analysis of COVID-19 spread in relation to several climatic variables for the most densely populated and rapidly growing city of India. Thus, considering the results obtained, effective policies and actions are necessary especially by identifying the areas where the spread rate is increasing rapidly in this megacity. The prevention and protection measures should be adopted aiming at to reduce the further transmission of disease in the city.

Renewable Aromatics from Tree-Borne Oils over Zeolite Catalysts Promoted by Transition Metals

Despite the ever-growing demand for benzene-toluene-xylene (BTX), the alternative route of production from tree-borne oils is rarely investigated and poorly understood. Here, we have synthesized a Zn-loaded Y-zeolite catalyst for the continuous production of bio-BTX from tree-borne oils (nonedible seed oil), e.g., neem oil. Our approach involves low-temperature selective cracking-dehydrogenation-aromatization of neem oil over metal-supported catalysts to xylene-rich aromatics. The physicochemical properties of the prepared catalyst were characterized using powder XRD, N₂ physisorption, TEM, NH₃-TPD, XPS, Py-FTIR, solid-NMR, and TG analyses. Mesoporous Y-zeolites with a pore diameter of 7.4 Å showed better selectivity toward aromatics and were found to be the most effective catalyst for the aromatization process, especially for BTX. The aromatic yield was found to increase with the addition of Zn, and the highest conversion of 90-94% with an ∼75% BTX yield was achieved with the ZnY catalyst. During aromatization, a sizable number of short alkanes and olefins were also obtained on acidic Y-zeolites. The off-gas composition shows the presence of ∼45% C₂-C₄ olefins with 8.9% H₂. The incorporation of Zn species can promote the dehydrogenation activity, and the subsequent aromatization required a suitable pore network. The optimized ZnY catalyst inspires the formation of toluene and xylenes, inhibiting the formation of benzene and gaseous alkanes.

Comparison of two multifraction radiotherapy schedules in management of painful bone metastases: A single institution prospective study

Background

Metastatic disease of bone is a common complication of most of the advanced malignancies. The majority of patients with bone metastases (BM) experience pain during their disease course and pain control can significantly improve their quality of life. Radiotherapy (RT) is an important modality in the management of BM and different schedules are followed worldwide.

Aim

The aim of this study was to compare two multi-fractionated RT regimens (30Gy in 10 fractions and 20Gy in 5 fractions) with respect to the patient's performance, response and pain score in palliative management of painful BM.

Methods

This prospective observational study was undertaken between October 2015 and September 2017 at a government medical college in central India. Two fractionation regimens (30 Gy/10 fractions and 20 Gy/5 fractions) were used to treat 50 patients with painful BM (n = 25 in each arm). Patients were treated on telecobalt machine and response assessment done in terms of complete/partial/intermediate response and pain progression. Assessment was performed at one, two and three months post treatment. Statistical analysis was done using Fisher's exact test, student t-test and Chi-square test. A value of P < 0.05 was considered significant.

Results

There were 9 males (36%) and 16 females (64%) in arm A, and 15 males (60%) and 10 females (40%) in arm B. The median age was 47.50 years (range 28-81 years) in arm A and 54 years (range 34-85 years) in arm B. There was no statistically significant difference between the two groups in terms of pain palliation at a 1 month (p = 0.73), 2 month (p = 0.75) or 3 month (p = 0.71) follow up. In addition, the mean performance scores at the end of 3^rd month in the 2 arms did not show any statistically significant difference (p = 0.51).

Conclusion

A shorter treatment schedule (5 fractions) was equally efficacious as the standard schedule (10 fractions) in our setting. With the advantage of shorter overall treatment time and avoidance of re-irradiation, this schedule may be favourable for high volume centres.

Role of Isotocin in the Regulation of the Hypophysiotropic Dopamine Neurones in the Preoptic Area of the Catfish, Clarias batrachus

Dopamine (DA) has emerged as a potent inhibitory neuromodulator of luteinsing hormone (LH) secretion and reproduction in teleosts. The DA neurones located in the anterior subdivision of nucleus preopticus periventricularis (NPPa) in the preoptic area (POA) innervate the pituitary gland and regulate LH cells. Although a reduction in the inhibitory DAergic tone is crucial for stimulatory action of gonadotrophin-releasing hormone (GnRH) on LH cells, the role of other hypothalamic factors is suggested but not fully understood. Nonapeptide, isotocin (IST) has emerged as a likely candidate that may also influence the LH cell function. IST neurones reside in the nucleus preopticus and innervate LH cells. While IST treatment dramatically elevated LH secretion, the IST levels in brain peaked during spawning. In a pilot study on the catfish, Clarias batrachus, we observed a dense network of IST-immunoreactive (IST-IR) fibres in the NPPa, the region known to harbour hypophysiotropic DA neurones. Application of the double immunofluorescence method showed a dense IST-IR fibre network around the tyrosine hydroxylase-immunoreactive (TH-IR) neurones in the NPPa region. A great majority of the TH-IR neurones in the NPPa were contacted by IST-IR fibres during the spawning phase. The NPPa therefore appears to be a site for the intense interaction of DA and IST. IST-IR fibre innervation in NPPa showed reproduction phase-dependent changes. The percent fluorescent area of IST-IR fibres showed a gradual increase from the resting through prespawning phases (resting: 7.5 ± 1.04; preparatory: 8.6 ± 0.8; prespawning: 15.5 ± 1.4), reaching a peak in the spawning phase (28 ± 2.3; P < 0.001). Compared to the spawning phase, a drastic reduction in IST-IR fibres in the NPPa was observed during the postspawning phase (8.4 ± 0.9; P < 0.001). Superfused slices of the POA of C. batrachus treated with IST peptide resulted in a significant reduction in TH immunoreactivity in the NPPa (Control: 45.3 ± 4.2; IST peptide, 5 μm: 29.4 ± 4.7; P < 0.05). We suggest that the intense interaction between IST and DA in the NPPa, most probably of an inhibitory nature, may be critical for the regulation of LH cells and reproduction in teleosts.

Phytochemistry, pharmacology and traditional uses of Leptadenia pyrotechnica- An important medicinal plant

Traditional Systems of medicines always played important role in the global health. In the traditional health medicinal plants providing a new areas of drug research. The demand for plant based medicines, food supplement, health products, pharmaceuticals and cosmetics are increasing in both developing and developed countries due to the growing recognition that the natural products are non toxic, have less side effects and easily available. Leptadenia pyrotechnica (Forsk.) commonly known as Kheep belonging to family Asclepiadaceae. Leptadenia pyrotechnica leafless much branched shrub. All parts of Leptadenia pyrotechnica are used in traditional medicines. The present article gives an account of updated information on its phytochemistry pharmacological properties. Ethnomedical uses say to possess significant antioxidant, anti-inflammatory, antibacterial, anthelmentic, antilipoxygenase, cytotoxic, antitumour, hypolipidemic and anti atherosclerotic activity. The present review contains wide number of isolated chemical constituents and various ethnomedical and traditional uses of Leptadenia pyrotechnica. It include information about historical background, conceptual basis, different disciplines studied in the systems, research and development aspects, drug manufacturing aspects and impact of globalization.

Drought yield index to select high yielding rice lines under different drought stress severities

BACKGROUND

Drought is the most severe abiotic stress reducing rice yield in rainfed drought prone ecosystems. Variation in intensity and severity of drought from season to season and place to place requires cultivation of rice varieties with different level of drought tolerance in different areas. Multi environment evaluation of breeding lines helps breeder to identify appropriate genotypes for areas prone to similar level of drought stress. From a set of 129 advanced rice (Oryza sativa L.) breeding lines evaluated under rainfed drought-prone situations at three locations in eastern India from 2005 to 2007, a subset of 39 genotypes that were tested for two or more years was selected to develop a drought yield index (DYI) and mean yield index (MYI) based on yield under irrigated, moderate and severe reproductive-stage drought stress to help breeders select appropriate genotypes for different environments.

RESULTS

ARB 8 and IR55419-04 recorded the highest drought yield index (DYI) and are identified as the best drought-tolerant lines. The proposed DYI provides a more effective assessment as it is calculated after accounting for a significant genotype x stress-level interaction across environments. For rainfed areas with variable frequency of drought occurrence, Mean yield index (MYI) along with deviation in performance of genotypes from currently cultivated popular varieties in all situations helps to select genotypes with a superior performance across irrigated, moderate and severe reproductive-stage drought situations. IR74371-70-1-1 and DGI 75 are the two genotypes identified to have shown a superior performance over IR64 and MTU1010 under all situations.

CONCLUSION

For highly drought-prone areas, a combination of DYI with deviation in performance of genotypes under irrigated situations can enable breeders to select genotypes with no reduction in yield under favorable environments compared with currently cultivated varieties. For rainfed areas with variable frequency of drought stress, use of MYI together with deviation in performance of genotypes under different situations as compared to presently cultivated varieties will help breeders to select genotypes with superior performance under all situations.

Tube sigmoidostomy: a valuable alternative to sigmoidopexy for sigmoid volvulus

OBJECTIVE

To compare the effectiveness of tube sigmoidostomy and sigmoidopexy as effective treatment options for patients with acute uncomplicated sigmoid volvulus.

METHODS

The records of 72 patients with acute uncomplicated sigmoid volvulus with obstruction who were treated by tube sigmoidostomy (Group I: n=32) and sigmoidopexy (Group II: n=40) were reviewed retrospectively. Follow-up period was 22 months (range: 6-51 months).

RESULTS

Results show significant improvement in postoperative tachycardia, respiratory distress and urine output in Group I patients as compared to those in Group II. Most of the clinical parameters of Group I patients normalized by day 3, while it took up to 7 days in Group II patients. Intraabdominal hypertension caused by persistent colonic dilatation after sigmoidopexy was found to be an important determinant of postoperative morbidity. As compared to tube sigmoidostomy, the sigmoidopexy group had delayed recovery, more chances of abdominal fascial dehiscence, and longer hospital stay, as well as more prolonged abdominal discomfort, constipation, and recurrent volvulus rates during follow-up.

CONCLUSION

Tube sigmoidostomy provides both fixation and decompression of the redundant sigmoid colon in the postoperative period while allowing time to recover from massive dilatation and edema caused by prolonged volvulus. Compared with sigmoidopexy for the treatment of uncomplicated sigmoid volvulus, tube sigmoidostomy leads to lesser rates of morbidity and recurrence. Thus, it can be considered as a definitive alternative treatment option for uncomplicated sigmoid volvulus.

Vitamin D Status of term exclusively breastfed infants and their mothers from India

OBJECTIVES

(i) To measure 25-OH vitamin D levels in term infants at 10 weeks and 6 months and to correlate with maternal vitamin D levels at 10-week postpartum (ii) To evaluate infants at 6 months for rickets.

PATIENTS AND METHODS

A total of 179 exclusively breastfed infant-mother pairs 96 appropriate-for-gestational age (Group 1) and 83 small- for- gestational age infants (Group 2) recruited at 10 weeks. At 6 months, 52 in group 1 and 45 in group 2 were evaluated. Venous blood sample were collected at 10 weeks and 6 months in infants and at 10 weeks in mothers for calcium, phosphorus, alkaline phosphatase and 25-OH vitamin D estimation.

RESULTS

Mean 25-OH vitamin D levels of infants (n = 97) were 11.55 ± 7.17 ng/mL at 10 weeks and 16.96 ± 13.33 ng/mL at 6 months (p < 0.001). Mean vitamin D levels of infants in group 1 and group 2 did not differ at recruitment and 6 months (p > 0.05)). Maternal vitamin D levels in group 1 and group 2 were 8.89 ± 5.97 and 9.87 ± 6.44 ng/mL, respectively (p = 0.44). Significant correlation was observed between 25-OH vitamin D of infants and mothers (p < 0.05). At 10 weeks, 55.67% infants, 70% mothers and at 6 months, 44.33% infants had vitamin D < 11 ng/mL. At 6 months, 16.49% infants developed rickets.

CONCLUSIONS

Exclusively breastfed infants and their mothers are Vitamin D deficient, hence the need to improve vitamin D status.

Ofloxacin-associated retinopathy in rabbits: role of oxidative stress

Ofloxacin, a quinolone, is an extensively used, well-tolerated antibacterial agent but has been reported to induce photosensitivity at low incidences. In the present investigation, the possible role of oxidative stress in ofloxacin-induced retinopathy in rabbits was evaluated. It was observed that ofloxacin at a dose rate of 10 and 20 mg/rabbit, twice daily for 21 consecutive days, resulted in significant elevation in the extent of lipid peroxidation and depletion of the blood glutathione levels. Marked alterations were also observed in various parameters of the glutathione-redox cycle. There was significant increase in the enzymic activity of glutathione peroxidase and glutathione reductase, whereas a significant decrease was observed in the activities of superoxide dismutase, catalase, and glutathione-S-transferase enzymes. Histopathological studies revealed retinal damage especially in the pigmented cell layer. Degenerative changes in liver and kidneys were also observed. Liver showed focal areas of necrosis, dilation of sinusoids, and cellular infiltration, whereas in kidneys, there was glomerular and tubular degeneration, suggesting impaired renal functioning.

New compounds from Commiphora myrrha (Nees) Engl

Phytochemical investigation of Commiphora myrrha (Nees) Engl. has afforded six new compounds identified as cadina-3-en-15-ol (myrracadinol A) (1), 7, 8-seco-2, 5-dihydroxy-12-acetoxycalam-8-ene (myrracalamene A) (2), 7, 8-seco-2, 3, 5-hydroxy-12-acetoxycalame-8-ene (myrracalamene B) (3), 7, 8-seco-cadin-3, 8-dien-2beta, 12-diol (myrracadinol B) (4), 7, 8-seco-12-hydroxycalam-8-ene (myrracalamene C) (6), 7, 8-seco-cadin-3,7(12)-dien-5alpha,10alpha-diol (myrracadinol C) (7) along with a known compound tria-cont-1-ene (5). Their structures were elucidated on the basis of spectral and chemical analyses.

Mother's iron status, breastmilk iron and lactoferrin--are they related?

OBJECTIVE

Exclusive breastfeeding is recommended till 6 months age. Factors regulating the breastmilk iron and lactoferrin levels are incompletely known. Considering high prevalence of nutritional anemia in lactating mothers, we studied the iron status of lactating mothers, their breastmilk iron and lactoferrin levels to determine any relationship between them.

DESIGN

Prospective study with 6 months follow-up.

SETTING

Tertiary care referral hospital.

SUBJECTS

Hundred nonanemic and 100 anemic mothers with their babies recruited at birth. Fifty-two nonanemic and 50 anemic mothers and their babies completed the 6-month follow-up.

INTERVENTIONS

Hemoglobin (Hb), total iron binding capacity (TIBC), percent transferrin saturation (%TS), serum iron (SI) and serum ferritin measured on day 1 and 6 months postpartum. Breastmilk iron and lactoferrin measured on day 1, 14 weeks and 6 months after delivery.

RESULTS

Breastmilk iron decreased progressively from day 1 to 14 weeks and at 6 months in both groups, but no significant difference was noted between nonanemic and anemic mothers (P>0.05). Significant decline in breastmilk lactoferrin concentration from day 1 to 14 weeks in nonanemic and anemic mothers (P<0.001) noted. Hemoglobin, TIBC, %TS, SI and serum ferritin of both groups had no correlation with breastmilk iron and lactoferrin concentration on day 1, 14 weeks and 6 months after delivery.

CONCLUSIONS

Breastmilk iron and lactoferrin concentration had no relationship with the mother's Hb and iron status.

Absence of corpus luteum rescue by chorionic gonadotropin in women immunized with a contraceptive vaccine

OBJECTIVE

To determine whether antibodies induced by a betahCG vaccine in women are competent to neutralize the luteotropic action of hCG.

DESIGN

Prospective clinical study.

SETTING

Hospitals and a laboratory at an academic center.

PATIENT(S)

Six immunized and three control women of reproductive age, participating in a clinical testing of betahCG contraceptive vaccine.

INTERVENTION(S)

Increasing doses of hCG simulating early pregnancy.

MAIN OUTCOME MEASURE(S)

Anti-hCG antibody titers, serum progesterone and urinary hCG levels, and onset of menses.

RESULT(S)

Administration of hCG to mimic early pregnancy sustained serum progesterone concentrations and extended the luteal phase in control women. In contrast, serum progesterone levels declined and the luteal phase was not extended if prevailing antibody titers were > or =40 ng/mL in women who had been immunized with a betahCG based vaccine. No booster effect was seen in anti-hCG titers after hCG challenge.

CONCLUSION(S)

Antibodies elicited by a betahCG vaccine inactivate hCG and prevent the hormone from rescuing corpus luteum, resulting in progesterone fall and normal menses. Lack of booster in the antibody response confirms the reversibility of the approach.

High expression of human chorionic gonadotrophin beta-subunit using a synthetic vaccinia virus promoter

We have constructed a recombinant vaccinia virus to express the beta-subunit of human chorionic gonadotrophin (betahCG), a secretory glycoprotein that is used as an antigen for a contraceptive vaccine. The cDNA encoding the subunit was cloned under the control of a synthetic promoter that could be recognised by a vaccinia virus RNA polymerase to direct transcription. The peak expression level of betahCG directed by a late synthetic promoter (Psyn) was 11.5 microg/ml, a level that was at least sixfold higher than that directed by the p7.5 early/late promoter. The expressed protein was correctly processed post-translationally such that it attained a conformation with correctly folded discontinuous epitope(s) similar to that seen in native betahCG.

Enhanced immunogenicity of a contraceptive vaccine using diverse synthetic carriers with permissible adjuvant

A vaccine directed against human chorionic gonadotropin (hCG) has previously undergone clinical testing demonstrating the feasibility of the approach in preventing pregnancy in women. Some individuals, however, did not respond adequately despite employing highly immunogenic bacterial toxoids as carriers. We investigated the potential of three promiscuous pathogen-derived Th peptides as carriers, employing alum as the adjuvant. While conjugation with each peptide improved the antibody response against hCG in mice of different haplotypes, immunisation with a combination of these peptide-conjugates generated anti-hCG responses higher than those achieved with the individual peptides or tetanus toxoid (TT). Antibodies were of high affinity and capable of neutralising the bioactivity of hCG but were devoid of anti-peptide reactivity. These results have implication for the design of hCG vaccine with improved immunogenicity for diverse population.

Formulation and characterization of immunoreactive tetanus toxoid biodegradable polymer particles

Poly lactide-co-glycolide and polylactide polymer particles entrapping immunoreactive tetanus toxoid (TT) were prepared with a view to developing a single shot controlled release vaccine formulation. Denaturation of TT by dichloromethane (DCM) during primary emulsification stage of particle formulation was minimized by incorporation of an optimal amount of rat serum albumin (RSA) in the internal aqueous phase. Incorporation of RSA as a stabilizer during the primary emulsification stage of polymer particle formulation protected the immunoreactivity of TT, enhanced its encapsulation efficiency and also led to uniform polymer particle formation. Use of sonication, both during primary and secondary emulsification processes, resulted in formation of nanoparticles whereas microparticles were formed when the secondary emulsion was carried out by homogenization. Immunoreactive TT particles made from different polymers incorporating stabilizers released antigen continuously for more than four months in vitro. Single injection of both type of particles encapsulating stabilized TT elicited anti-TT antibody titers in rats for more than five months, which was higher than that obtained with TT injected in saline. Anti-TT antibody titers in vivo were in accordance with the in vitro release characteristics of immunoreactive TT from the particles. Immune responses with hydrophobic polymer particles were better than those made using hydrophilic polymers. These results indicate the importance of protecting the immunoreactivity of TT during formation of polymer particles for sustained and improved antibody response.

Humoral hyporesponsiveness to a conjugate contraceptive vaccine and its bypass by diverse carriers using permissible adjuvant

A contraceptive vaccine directed against human chorionic gonadotropin (hCG) has previously undergone clinical testing that demonstrated the feasibility of the approach in preventing pregnancy in women. Some immunized volunteers however, did not respond with an adequate anti-hCG antibody response despite employing highly immunogenic bacterial toxoids as carriers. Since there is some evidence that T cell responses to a complex protein typically focus on a few immunodominant epitopes, we investigated the responsiveness to hCG in mice of different haplotypes using the protein carrier diphtheria toxoid (DT). Our data showed a differential carrier effect of DT. With the aim of making a more potent immunogen employing promiscuous pathogen-derived Th peptides as carriers, peptide:antigen stoichiometric ratios were optimized. When tested individually using alum as the adjuvant, three such peptide conjugates improved the anti-hCG response, though not consistently to levels higher than the DT conjugate. Immunization with a combination of these synthetic epitopes generated anti-hCG responses higher than those achieved with DT or with the individual peptides. Antibodies were of high affinity and capable of neutralizing the bioactivity of hCG, but were devoid of anti-peptide reactivity. These results support our view that differential hyporesponsiveness in a diverse population may arise from inadequate carrier effect and that it can be overcome by use of pathogen-derived broadly reactive non-B Th epitopes employing only alum, a permissible adjuvant.

Prior immunity to a carrier enhances antibody responses to hCG in recipients of an hCG-carrier conjugate vaccine

Pre-sensitization with carrier often leads to epitopic suppression of subsequent anti-hapten antibody responses. To ascertain whether epitopic suppression occurs in humans, we examined the effect of pre-existing anti-carrier immunity on antibody responses to hCG in volunteers of a clinical trial of an hCG-based conjugate birth-control vaccine. When we studied the correlation between pre-vaccination anti-carrier immunity and post-vaccination anti-hCG responses, we found that prior immunity to the carriers did not lead to epitopic suppression of anti-hCG responses. On the contrary, it was found that prior immunity to TT, one of the two carriers used in this vaccine, led to enhancement of anti-hCG responses. Our data indicates that prior immunity to the carriers may not be detrimental to the performance of conjugate vaccines, and may actually be beneficial in some cases.

Regain of fertility and normality of progeny born during below protective threshold antibody titers in women immunized with the HSD-hCG vaccine

PROBLEM

Phase II clinical trials with the heterospecies dimer of beta hCG and alpha-subunit of ovine luteinizing hormone (HSD)-human chorionic gonadotrophin (hCG) vaccine showed that pregnancy was prevented at and above 50 ng/ml titers, whereas conceptions occurred below 35 ng/ml of hCG bioneutralization capacity. The effect of below-protective threshold anti-hCG antibodies on the progression of pregnancy and the normality of progeny was studied.

METHOD OF STUDY

Four women enrolled by informed consent in the Phase II trials. The women studied were immunized with the HCG vaccine and did not receive booster injections in consideration of their desire to have another child. They were examined clinically at least once every month until delivery. The babies were followed up from 2 to 3.5 years, and their anthropometric indices were compared with elder siblings.

RESULTS

The pregnancies progressed to 35 to 38 weeks with the usual obstetric problems, and the children developed normally.

CONCLUSIONS

The anti-fertility effect of the HSD-hCG vaccine is reversible and low titers of antibodies below the protective threshold have no apparent side effects on the progression of pregnancy and on the early development of the progeny.

Stabilization of dichloromethane-induced protein denaturation during microencapsulation

This paper describes the denaturation of protein drugs by dichloromethane (DCM) during the primary emulsification step of the microencapsulation process using biodegradable polymer matrix for controlled-release application. It was found that interaction of proteins such as tetanus toxoid (TT), diphtheria toxoid (DT), ovine growth hormone (oGH), and human chorionic gonadotropin-based antifertility vaccine (beta-hCG-TT) with DCM during primary emulsification stages of particle formulation led to the precipitation of the proteins at the aqueous organic interface with concomitant reduction in their immunoreactivity. On the other hand, the B subunit of E. coli enterotoxin (LTB) was found to be comparatively stable toward the denaturing action of DCM. Attempts were made to overcome the DCM-induced denaturation by incorporation of stabilizers during the primary emulsification step of the particle formulation. Of the many additives tested to overcome the DCM-induced denaturation of proteins, serum albumins and polyvinyl alcohol (PVA) showed promising results in terms of retention of the immunoreactivity of the protein. TT stabilized by the incorporation of serum albumin during the primary emulsification step not only showed immunoreactivity in vitro, but also invoked antibody titers in rats comparable to those obtained for the native protein molecules. Incorporation of 2.5% of serum albumins in the internal aqueous phase not only protected the protein from the degradative action of DCM but also led to stabilized primary emulsion, which is necessary for uniform entrapment of protein drugs in the polymer matrix.

Dihydropyrancarboxamides related to zanamivir: a new series of inhibitors of influenza virus sialidases. 2. Crystallographic and molecular modeling study of complexes of 4-amino-4H-pyran-6-carboxamides and sialidase from influenza virus types A and B

The first paper in this series (see previous article) described structure-activity studies of carboxamide analogues of zanamivir binding to influenza virus sialidase types A and B and showed that inhibitory activity of these compounds was much greater against influenza A enzyme. To understand the large differences in affinities, a number of protein-ligand complexes have been investigated using crystallography and molecular dynamics. The crystallographic studies show that the binding of ligands containing tertiary amide groups is accompanied by the formation of an intramolecular planar salt bridge between two amino acid residues in the active site of the enzyme. It is proposed that the unexpected strong binding of these inhibitors is a result of the burial of hydrophobic surface area and salt-bridge formation in an environment of low dielectric. In sialidase from type A virus, binding of the carboxamide moeity and salt-bridge formation have only a minor effect on the positions of the surrounding residues, whereas in type B enzyme, significant distortion of the protein is observed. The results suggest that the decreased affinity in enzyme from influenza B is directly correlated with the small changes that occur in the amino acid residue interactions accompanying ligand binding. Molecular dynamics calculations have shown that the tendency for salt-bridge formation is greater in influenza A sialidase than influenza B sialidase and that this tendency is a useful descriptor for the prediction of inhibitor potency.