Yeast thioredoxin reductase Trr1p controls TORC1-regulated processes

The thioredoxin system plays a predominant role in the control of cellular redox status. Thioredoxin reductase fuels the system with reducing power in the form of NADPH. The TORC1 complex promotes growth and protein synthesis when nutrients, particularly amino acids, are abundant. It also represses catabolic processes, like autophagy, which are activated during starvation. We analyzed the impact of yeast cytosolic thioredoxin reductase TRR1 deletion under different environmental conditions. It shortens chronological life span and reduces growth in grape juice fermentation. TRR1 deletion has a global impact on metabolism during fermentation. As expected, it reduces oxidative stress tolerance, but a compensatory response is triggered, with catalase and glutathione increasing. Unexpectedly, TRR1 deletion causes sensitivity to the inhibitors of the TORC1 pathway, such as rapamycin. This correlates with low Tor2p kinase levels and indicates a direct role of Trr1p in its stability. Markers of TORC1 activity, however, suggest increased TORC1 activity. The autophagy caused by nitrogen starvation is reduced in the trr1Δ mutant. Ribosomal protein Rsp6p is dephosphorylated in the presence of rapamycin. This dephosphorylation diminishes in the TRR1 deletion strain. These results show a complex network of interactions between thioredoxin reductase Trr1p and the processes controlled by TOR

MÅ‘ssbauer and Magnetic investigations on OPC blended with Silicafume

          The Mössbauer spectra of optimum amount of (20%) silica fume blended cement paste using CO(Rh) Source have been interpreted for its hydration kinetics using two waters namely DW and EW.  The obtained results were correlated with the setting time, compressive strength and magnetic data measurement using Kappa bridge.  This is preferred as its offers some resistance to sulphate attack observed from their studies

Survival analysis and visual outcome in a large series of corneal transplants in India

AIM/BACKGROUND—The public health significance of corneal transplantation in dealing with corneal blindness in the developing world would depend upon the survival rate of transplants. This study was done to analyse the survival rate of corneal transplants in a large series in India, and to evaluate the influence of various risk factors on transplant survival.
METHODS—The records of a series of 1725 cases of corneal transplants carried out during 1987-95 at a tertiary eye care institution in India were reviewed. The Kaplan-Meier method was used to determine 5 year survival rates of corneal transplants performed for the various categories of preoperative diagnosis. Multivariate Cox proportional hazards regression was used to assess how preoperative diagnosis, socioeconomic status, age, sex, vascularisation of host cornea, quality of donor cornea, and training status of surgeon influenced transplant survival. The effect of these variables on visual outcome was assessed using multiple logistic regression.
RESULTS—The survival rates at 1, 2, and 5 years for all corneal transplants performed for the first time in 1389 cases were 79.6% (95% confidence interval = 77.3-81.9%), 68.7% (65.7-71.7%) and 46.5% (41.7-51.3%). The 5 year survival rate was highest if the corneal transplant was done for keratoconus (95.1% (84.8-100%)) and lowest if carried out for previous transplant failure (21.2% (13.8-28.6%)). The relative risk of transplant failure was higher if the preoperative diagnosis was previous transplant failure (2.04 (1.62-2.55)), aphakic bullous keratopathy (1.78 (1.38-2.28)), corneal clouding due to miscellaneous causes including congenital conditions and glaucoma (1.63 (1.21-2.19)), or adherent leucoma (1.11 (0.81-1.51)) than for the other preoperative diagnoses. Patients with lower socioeconomic status had higher relative risk of transplant failure (1.28 (1.16-1.42)), as did patients <10 years of age (1.42 (1.23-1.64)). Higher relative risk of transplant failure was associated with vascularisation of the host cornea before transplantation (1.15 (1.04-1.27)), and with the use of fair quality donor cornea for transplantation compared with excellent, very good, or good quality donor cornea (1.26 (1.06-1.52)). Before corneal transplant 80.2% of the eyes were blind (visual acuity <3/60), whereas at last follow up 41.8% eyes were blind. The odds of having visual acuity >6/18 were higher if the transplant was done for keratoconus (9.99 (6.10-16.36)) or corneal dystrophies (1.77 (1.21-2.58)) than for the other preoperative diagnoses.
CONCLUSION—Reasonable success with corneal transplantation is possible in the developing world if data from this part of the world regarding the different survival rates for the various preoperative diagnoses and the influence of risk factors on transplant survival and visual outcome are taken into account while determining priority for transplant cases in the present situation of limited availability of donor corneas.


Accuracy of Surgeon's Estimation of Sella Margins during Endoscopic Surgery for Pituitary Adenomas: Verification Using Neuronavigation

We assessed the accuracy of a surgeon's localization of sella margins during endoscopic transsphenoidal surgery for pituitary adenomas, as verified using a neuronavigational system, and we identify types of pathology in which neuronavigation is of most benefit. We performed a prospective cohort study of 32 consecutive patients undergoing image-guided endoscopic transsphenoidal surgery for pituitary adenomas. We assessed the margin of error in the surgeon's localization of the superior and inferior margins of the sella and the lateral margins as determined by the medial border of left and right carotid arteries, using a magnetic resonance–based neuronavigational system. The overall mean error of localization of sella margins by the surgeon was 4.5 ± 3 mm. Localization of the inferior sella margin was more accurate (3.1 ± 2 mm mean error) compared with localization of the left (4.8 ± 3 mm) or right carotid arteries (4.6 ± 3 mm). Giant adenomas (> 2.5 cm), more invasive adenomas (Hardy grade IV), and those with parasellar extension (Hardy grades D and E) were associated with larger errors in localization of the carotid arteries. There was no significant difference when stratifying for recurrent surgery, nostril of approach, and sella morphology. During endoscopic transsphenoidal surgery, the margin of error in the surgeon's estimation of the sella margins for adenomas less than 2.5 cm located predominantly within the sella is relatively small. The margin of error increases for giant adenomas, with greater invasiveness and parasellar spread, and the use of neuronavigation can be especially useful in such cases

Indications for penetrating keratoplasty in India

Indications for penetrating keratoplasty (PK) in the developing world from a large series are not well documented. This study was done to evaluate the indications for PK in a major eye care institution in India. The records for a consecutive series of 1,964 PKs were analysed and multiple logistic regression was used to study the effect of age, socioeconomic status and sex on the indications for PK. The indications for PK were corneal scarring in 551 (28.1%) including adherent leukoma in 147 (7.5%), regrafts in 336 (17.1%), active infectious keratitis in 239 (12.2%), aphakic bullous keratopathy in 231 (11.8%), pseudophakic bullous keratopathy in 209 (10.6%), corneal dystrophies in 165 (8.4%) including Fuchs' dystrophy in 23 (1.2%), keratoconus in 118 (6%), and miscellaneous in 115 (5.9%). The odds that the patient belonged to lower socioeconomic status were significantly higher if the PK was done for active infectious keratitis (odds ratio 2.73, p&lt;0.0001), corneal scarring (odds ratio 1.72, p=0.0009) or regraft (odds ratio 1.44, p=0.047). Corneal scarring, including adherent leukoma, and active infectious keratitis are relatively more common indications whereas keratoconus, pseudophakic bullous keratopathy and Fuchs' dystrophy are less common indications for PK in India than reported from the developed world. Indications for PK which carry a poorer prognosis for graft survival are relatively more common in India than in the developed world