Corneal thickness in congenital glaucoma

Central corneal thickness is very important measurement in glaucoma treatment because it influences the eye pressure measurements. A thinner cornea gives us artifactually lower intraocular pressure and a thicker cornea gives higher intraocular pressure reading, so it has to be corrected in both cases. The aim of this study is to compare central corneal thickness between congenital glaucoma patients and normal subjects. Prospective study included 27 patients with congenital glaucoma and 35 patients in control group. First group was subdivided in two subgroups: A--8 earlier operated patients, B--19 patients treated with topic therapy. Patients had no other corneal disorders, history of trauma, corneal surgery and they were not contact lens wearers. Measurements were performed by specular microscope Tomey EM 3000 on central corneas. This study showed that patients with congenital glaucoma have lower central corneal thickness than normal subjects. Also, the study showed that antiglaucomatous operation doesn't influence central corneal thickness. Central corneal thickness need to be a routine part of examination measurements because of need to correct intraocular pressure according to it, but also the thinner corneas values can suggest congenital glaucoma diagnosis beside the other parameters.     

Phenotypic rescue of a Drosophila model of mitochondrial ANT1 disease

A point mutation in the Drosophila gene that codes for the major adult isoform of adenine nuclear translocase (ANT) represents a model for human diseases that are associated with ANT insufficiency [stress-sensitive B¹ (sesB¹)]. We characterized the organismal, bioenergetic and molecular phenotype of sesB¹ flies then tested strategies to compensate the mutant phenotype. In addition to developmental delay and mechanical-stress-induced seizures, sesB¹ flies have an impaired response to sound, defective male courtship, female sterility and curtailed lifespan. These phenotypes, excluding the latter two, are shared with the mitoribosomal protein S12 mutant, tko^25t. Mitochondria from sesB¹ adults showed a decreased respiratory control ratio and downregulation of cytochrome oxidase. sesB¹ adults exhibited ATP depletion, lactate accumulation and changes in gene expression that were consistent with a metabolic shift towards glycolysis, characterized by activation of lactate dehydrogenase and anaplerotic pathways. Females also showed downregulation of many genes that are required for oogenesis, and their eggs, although fertilized, failed to develop to the larval stages. The sesB¹ phenotypes of developmental delay and mechanical-stress-induced seizures were alleviated by an altered mitochondrial DNA background. Female sterility was substantially rescued by somatic expression of alternative oxidase (AOX) from the sea squirt Ciona intestinalis, whereas AOX did not alleviate developmental delay. Our findings illustrate the potential of different therapeutic strategies for ANT-linked diseases, based on alleviating metabolic stress.KEY WORDS: Adenine nucleotide translocase, Mitochondrial disease, Mitochondrial biogenesis, Alternative oxidase     

Estrogen-androgen antagonism in the regulation of epidermal growth factor in mouse submandibular salivary gland and kidneys

To eludicate hormonal regulation of epidermal growth factor (EGF) concentration we studied the effects in adult female mice of ovariectomy and postovariectomy treatments with testosterone plus estradiol on the EGF concentrations in submandibular salivary gland (SMG), plasma, kidneys and urine. In the tissues, we also studied the location of EGF immunohistochemically and measured EGF mRNA. After ovariectomy, SMG EGF first decreased to one third of preovariectomy level. After postovariectomy day 10 it started to increase and reached by day 80 3.5-fold the preovariectomy level. Simultaneously, EGF mRNA increased. Testosterone treatment further strongly augmented the levels of both EGF mRNA and EGF. A small dose of estradiol counteracted slightly the mRNA effect of testosterone. After ovariectomy plasma EGF first increased 1.3-fold by day 10, then returned to the initial levels, and rose again 1.6-fold by day 80. Testosterone treatment induced a further 1.5-fold increase. Estradiol did not counteract this effect. Kidney EGF decreased 15% by postovariectomy day 20. This was preceded by a decrease in EGF mRNA from day 10 onwards. The EGF concentration recovered during the 80 days, but the EGF mRNA level stayed low. Testosterone treatment further reduced the levels of both EGF mRNA and EGF. This effect was counteracted by estradiol. Urine EGF increased after ovariectomy to a peak (1.7-fold) by day 40. It then returned to the preovariectomy levels by day 80. Testosterone treatment increased urinary EGF 1.9-fold; concomitant estradiol had no effect.     

Restoration of natural vegetation in degraded Imperata cylindrica grassland: understorey development in forest plantations

Abstract. Reclamation of former, degraded forest lands occupied by Imperata cylindrica is one of the crucial environmental and forestry issues in the humid tropics, notably Southeast Asia. We suggest that it is possible to gradually restore the original natural forest cover with the help of a sacrifice fallow crop of fast-growing exotic tree species. Recently, a set of suitable fast-growing plantation tree species has been identified and stand establishment methods developed for this purpose. We assessed the regeneration of natural vegetation in stands of different plantation tree species and evaluated the ecological impact of species composition in the plantation understorey. PCA ordination, regression analysis and analysis of covariance were applied at different stages of the study. We found a marked vegetational resemblance between stands dominated by Acacia mangium: they had the highest number of indigenous trees in their understorey, whereas stands of other plantation trees supported more diverse grass and herb vegetation. A high proportion of evergreen woody vegetation reduces the risk of fire and grass competition and enhances secondary succession towards natural forest.     

Satellite chlorophyll fluorescence measurements reveal large‐scale decoupling of photosynthesis and greenness dynamics in boreal evergreen forests

Mid‐to‐high latitude forests play an important role in the terrestrial carbon cycle, but the representation of photosynthesis in boreal forests by current modelling and observational methods is still challenging. In particular, the applicability of existing satellite‐based proxies of greenness to indicate photosynthetic activity is hindered by small annual changes in green biomass of the often evergreen tree population and by the confounding effects of background materials such as snow. As an alternative, satellite measurements of sun‐induced chlorophyll fluorescence (SIF) can be used as a direct proxy of photosynthetic activity. In this study, the start and end of the photosynthetically active season of the main boreal forests are analysed using spaceborne SIF measurements retrieved from the GOME‐2 instrument and compared to that of green biomass, proxied by vegetation indices including the Enhanced Vegetation Index (EVI) derived from MODIS data. We find that photosynthesis and greenness show a similar seasonality in deciduous forests. In high‐latitude evergreen needleleaf forests, however, the length of the photosynthetically active period indicated by SIF is up to 6 weeks longer than the green biomass changing period proxied by EVI, with SIF showing a start‐of‐season of approximately 1 month earlier than EVI. On average, the photosynthetic spring recovery as signalled by SIF occurs as soon as air temperatures exceed the freezing point (2–3 °C) and when the snow on the ground has not yet completely melted. These findings are supported by model data of gross primary production and a number of other studies which evaluated in situ observations of CO₂ fluxes, meteorology and the physiological state of the needles. Our results demonstrate the sensitivity of space‐based SIF measurements to light‐use efficiency of boreal forests and their potential for an unbiased detection of photosynthetic activity even under the challenging conditions interposed by evergreen boreal ecosystems.     

Chemotaxonomy of theSymphytum officinale agg. (Boraginaceae)

In a chemotaxonomic study of the genusSymphytum pyrrolizidine alkaloids and triterpenes were used as chemotaxonomical markers. A micro-extraction methods was developed for screening compounds of very small pieces of herbarium material. The occurrence of the pyrrolizidine alkaloids symphytine and (acetyl-)lycopsamine is very general forSymphytum taxa. Echimidine is present in someS. officinale L. plants and inS. tanaicense Steven. The triterpene isobauerenol is present inS. officinale, S. bohemicum Schmidt,S. tanaicense and inS. officinale var.lanceolatum Weinm. The chemotaxonomic hypothesis, proposed byGadella and collaborators, based on the presence of the triterpene isobauerenol inS. officinale and its absence inS. asperum Lepech. and the presence of the pyrrolizidine alkaloid echimidine inS. asperum and its absence inS. officinale, can no longer be applied absolutely to theS. officinale species complex. The pyrrolizidine alkaloid and triterpene pattern ofS. officinale (2n = 24) andS. bohemicum (2n = 24) is identical.S. bohemicum is morphologically, cytologically and phytochemically very similar toS. officinale. Furthermore, it readily crosses with the white flowered W. European diploids ofS. officinale. Therefore it seems likely that these two taxa are conspecific.S. tanaicense shows a pyrrolizidine alkaloid and triterpene pattern similar toS. officinale (2n = 40). Also on morphological and cytological grounds they are very similar. It seems highly probable thatS. tanaicense is conspecific withS. officinale (2n = 40) and represents an intraspecific variant only.S. officinale var.lanceolatum contained no pyrrolizidine alkaloids but did contain isobauerenol. This feature points to an origin fromS. officinale.     

The cellular basis of wing size modification in Drosophila: The effects of the miniature gene,crowding, and temperature

To elucidate the mechanisms whereby genes and environment influence wing size, we investigated the effects of various rearing temperatures and larval crowding conditions on the wings of the mutant miniature and wild-type fruit flies. In adults we monitored wing size, cell number, wing thickness, cell density; in larval imaginal discs we looked for cell death. Cell density was inversely proportional to wing size. Of particular interest was the finding that smaller wings tend to be thicker. Electron microscope studies showed that the miniature wing layers are grossly abnormal. We hypothesize that these abnormalities are due to abnormal cell flattening of the wing epithelial cells, and we conclude that gene and environmental effects on cell flattening may be an important component in determining cell density and hence organ size.