Risk Assessment Tool for Pressure Ulcer Development in Indian Surgical Wards.

The aims of this paper were to compare the predictive validity of three pressure ulcer (PU) risk scales-the Norton scale, the Braden scale, and the Waterlow scale-and to choose the most appropriate calculator for predicting PU risk in surgical wards of India. This is an observational prospective cohort study in a tertiary educational hospital in New Delhi among 100 surgical ward patients from April to July 2011. The main outcomes measured included sensitivity, specificity, positive predictive value (PVP) and negative predictive value (PVN), and the area under the curve of the receiver operating characteristic (ROC) curve of the three PU risk assessment scales. Based on the cutoff points found most appropriate in this study, the sensitivity, specificity, PVP, and PVN were as follows: the Norton scale (cutoff, 16) had the values of 95.6, 93.5, 44.8, and 98.6, respectively; the Braden scale (cutoff, 17) had values of 100, 89.6, 42.5, and 100, respectively; and the Waterlow scale (cutoff, 11) had 91.3, 84.4, 38.8, and 97, respectively. According to the ROC curve, the Norton scale is the most appropriate tool. Factors such as physical condition, activity, mobility, body mass index (BMI), nutrition, friction, and shear are extremely significant in determining risk of PU development (p < 0.0001). The Norton scale is most effective in predicting PU risk in Indian surgical wards. BMI, mobility, activity, nutrition, friction, and shear are the most significant factors in Indian surgical ward settings with necessity for future comparison with established scales.

Sclerosing lymphocytic lobulitis in a male patient with asthma.

Sclerosing lymphocytic lobulitis is commonly but not exclusively associated with type I diabetes mellitus. Association with other autoimmune diseases is known and also disease is infrequently seen in males. We herein report a rare case of sclerosing lymphocytic lobulitis in a male patient with asthma. Recognition of this entity in the absence of diabetes and awareness of its existence in males is important to avoid unwarranted surgical procedures because it may mimic carcinoma both clinically and radiologically.

UV-B exposure enhances senescence of wheat leaves: Modulation by photosynthetically active radiation.

The alterations in structure and function of photosystem II (PS II) during the senescence of primary leaves of wheat seedlings have been compared with the changes induced by ultraviolet-B (UV-B) radiation in the presence or absence of photosynthetically active radiation (PAR). The results indicated that the senescence-induced loss in pigment content, thylakoid membrane integrity and carotenoid-to-chlorophyll (Car-to-Chl) energy transfer efficiency was intensified by exposure to UV-B radiation. Different parameters for the measurement of PS II activity, such as Chl a fluorescence, O2-evolution and thermoluminescence intensity, were altered during senescence and these alterations were furthered by UV-B irradiation. The damage of photosynthetic apparatus by UV-B exposure in the presence of PAR was less than the damage in absence of PAR. The activation of molecular defense mechanisms could be a factor in the alleviation of UV-B damage in the presence of PAR.

The mystery of oxygen evolution: analysis of structure and function of photosystem II, the water-plastoquinone oxido-reductase.

Photosystem II (PS II) of thylakoid membrane of photosynthetic organisms has drawn attention of researchers over the years because it is the only system on Earth that provides us with oxygen that we breathe. In the recent past, structure of PS II has been the focus of research in plant science. The report of X-ray crystallographic structure of PS II complex by the research groups of James Barber and So Iwata in UK is a milestone in the area of research in photosynthesis. It follows the pioneering and elegant work from the laboratories of Horst Witt and W. Saenger in Germany, and J. Shen in Japan. It is time to analyze the historic events during the long journey made by the researchers to arrive at this point. This review makes an attempt to critically review the growth of the advancement of concepts and knowledge on the photosystem in the background of technological development. We conclude the review with perspectives on research and technology that should reveal the complete story of PS II of thylakoid in the future.

Ultraviolet-A induced changes in photosystem II of thylakoids: effects of senescence and high growth temperature.

Ultraviolet-A (UV-A) radiation induced changes in photosystem II (PS II) of senescing leaves of wheat seedlings were investigated. UV-A radiation did not show any significant effect on the level of photosynthetic pigments. However, the decline in F(v)/F(m) and oxygen evolution rate indicated the damaging effect of the radiation on primary photochemistry of PS II. Modification at the Q(B)-binding site was inferred from the observed downshift of peak temperature of thermoluminescence (TL) B-bands. The UV-A induced changes in PS II of chloroplasts from senescing leaves were found to be synergistically accelerated by high growth temperature.

Prediction of structure and organisation of chlorophyll a/b binding polypeptides in PS I and II.

Secondary structures, functionally important residues, antigenic sites, membrane spanning segments and hydropathicity of light harvesting chlorophyll a/b binding polypeptides (LHC) are predicted by theoretical methods from the amino acid sequence of the polypeptides. The reported structural features of the Pea LHC (Lhcb 1 gene product) from electron crystallographic studies have been compared by alignment with other types of chlorophyll a/b binding polypeptides for structural prediction. Fifteen conserved residues D85, D89, E113, H116, E/Q133, E/Q181, E189, D/N233, E252, N/H255, Q/E269, E/D/Q280, N281, H285, D288 (number indicates position in the aligned sequence), are identified which are potential ligands to Mg2+ of chlorophylls. Three amino acid residues D89, E/Q131 and D/N 233 are proposed as ligands to chlorophylls b2, a7 and b2 respectively, for which ligands are not identified in electron crystallographic study.

Response of senescing wheat leaves to ultraviolet A light: changes in energy transfer efficiency and PS II photochemistry.

Response of senescing leaves of wheat seedlings to ultraviolet A (UVA) radiation (365 nm) has been examined. The results indicate that senescence-induced disorganization of thylakoid membrane, decline in carotenoid-to-chlorophyll energy transfer, and enhancement of lipid peroxidation are furthered by radiation. The senescence-induced decline in photochemical activity of photosystem II further declines on irradiation. UVA does not specifically alter any site other than those damaged by senescence.

Effect of magnesium and calcium ions on photoinduced lipid peroxidation and thylakoid breakdown of cell-free chloroplasts.

Aging of cell-free chloroplasts at pH 7.0 and 9.0 causes a decline in the level of photosynthetic pigments, quenching of chlorophyll a fluorescence and enhancement in fluorescence polarization. These changes are correlated with photoinduced enhancement of thylakoid lipid peroxidation. The alkaline earth metal cations, namely magnesium and calcium, show opposite actions on lipid peroxidation and modulate thylakoid disorganisation differently. Magnesium ion may stabilise thylakoid membrane by retarding lipid peroxidation. It lowers aging-induced quenching of fluorescence intensity and enhancement of fluorescence polarization. Calcium ion, on the other hand, stimulates disorganisation of thylakoid membranes. It enhances membrane lipid peroxidation, quenching of chlorophyll a fluorescence intensity and fluorescence polarization.

Phytochrome-mediated delay of plastid senescence in mustard cotyledons: changes in pigment contents and ultrastructure.

Changes in pigment contents and ultrastructure have followed in cotyledons of mustard (Sinapis alba L.) seedlings during dark-mediated senescence. The seedlings were kept in white light for 7 d, treated with 5 min long wavelength far-red light and then kept in darkness up to 14 d after sowing. Under these conditions the chloroplasts remain stable for 2 d before a sequential plastidal disintegration commences. The data indicate a selective breakdown of the light-harvesting chlorophyll a/b protein. Phytochrome retards the differential loss of chlorophyll a, b and carotenoids and preserves the fine structure of chloroplasts.

Ageing of chloroplasts in vitro - III. Comparison of the effects of ageing in vitro and senescence on the red absorption band and primary photochemical reactions of sunflower chloroplasts.

A comparison of changes in absorption properties and electron transport activities of chloroplasts ageing in vivo and in vitro is made. Chloroplasts from sunflower leaves senescing in vivo during 7 days in dark do not show a blue shift of the red absorption band; in contrast, the shift becomes apparent within 24 h of in vitro ageing of isolated organelles. Photosynthetic activity by chloroplasts is lost much faster during in vitro than in vivo ageing. During in vitro ageing, the rate of degradation of thylakoid membranes as characterised by the shift in the red absorption band and loss in Hill reaction is further accelerated in chloroplasts isolated from dark-induced senescing leaves, suggesting the influence of the in vivo status of the chloroplasts on their in vitro stability.

Ageing of chloroplasts in vitro - III. Comparison of the effects of ageing in vitro and senescence on the red absorption band and primary photochemical reactions of sunflower chloroplasts.

A comparison of changes in absorption properties and electron transport activities of chloroplasts ageing in vivo and in vitro is made. Chloroplasts from sunflower leaves senescing in vivo during 7 days in dark do not show a blue shift of the red absorption band; in contrast, the shift becomes apparent within 24 h of in vitro ageing of isolated organelles. Photosynthetic activity by chloroplasts is lost much faster during in vitro than in vivo ageing. During in vitro ageing, the rate of degradation of thylakoid membranes as characterised by the shift in the red absorption band and loss in Hill reaction is further accelerated in chloroplasts isolated from dark-induced senescing leaves, suggesting the influence of the in vivo status of the chloroplasts on their in vitro stability.

Changes in photoelectron transport of chloroplasts isolated from dark stressed leaves of maize seedlings.

Transfer of light-grown maize seedlings to dark causes a loss in the the contents of chlorophyll, protein and RNA of leaves, and a decline in DCPIP photoreduction by isolated chloroplasts. The loss in DCPIP-Hill reaction is attributed to the dark stress-induced damage of O2 evolving system of thylakoid membranes.