Perforations and fistulae in gastrointestinal tuberculosis

Background: Perforation and fistulae, though uncommon, are serious complications of gastrointestinal tuberculosis. Patients with acute tuberculous perforation are subjected to surgery, whereas localized perforation and fistulae with subtle clinical signs are detected by barium contrast examination. There has been no report on radiological series regarding the incidence of perforation and fistulae, detected by barium contrast studies.

Material and Methods: A retrospective analysis of barium contrast studies of 684 proven cases of gastrointestinal tuberculosis seen over a period of 15 years was done to detect the incidence of perforation and fistulae.

Results: Fifty-two patients (7.6%) with localized perforation and fistulae were seen. Twenty-eight patients had evidence of perforation, and 24 patients showed fistulae formation. The most common site of perforation and fistulae was the small bowel followed by the colon. Associated abnormalities noted were ulcerations, strictures, nodular filling defects and extrinsic compression.

Conclusion: Perforation and fistulae along with other associated abnormalities of the gastrointestinal tract are suggestive of tuberculosis, particularly in a population predisposed to tuberculous infection.

Imaging of esophageal tuberculosis: A review of 23 cases

Purpose: To evaluate the various radiological abnormalities in patients with proven esophageal tuberculosis.

Material and Methods: The case records of 23 patients with proven esophageal tuberculosis were evaluated retrospectively for various radiological abnormalities. Twenty-two patients had secondary involvement of esophagus in the form of direct extension of mediastinal and pulmonary tuberculosis or spinal tuberculosis. Only 1 patient had primary involvement of the esophagus with no evidence of disease elsewhere. The diagnosis was confirmed by endoscopic and CT-guided biopsy/aspiration cytology in 7 and 6 cases, respectively. Diagnosis was made on the basis of surgical biopsy of lymph node and autopsy in 1 patient each. In the remaining 8 patients the diagnosis was based on radiological and endoscopic findings and the response to antituberculous treatment.

Results: Chest radiography (CXR) was abnormal in 65% patients. While the findings were non-conclusive for esophageal tuberculosis, characteristic lesions of tuberculosis in lungs or spine were suggestive of tuberculous etiology. In 15 patients, CT of the chest confirmed the corresponding CXR findings and also showed additional findings of mediastinal lymphadenopathy when CXR was normal. Fourteen patients showed mediastinal lymphadenopathy on CT of the chest. In all these patients, more than one group of lymph nodes was involved. The characteristic hypodense center of lymph nodes suggestive of tuberculosis was seen in 12 patients. Radiological abnormalities seen in barium swallow examination were extrinsic compression, traction diverticula, strictures, sinus/fistulous tracts, kinking and pseudotumor mass of esophagus in decreasing order of frequency. The middle third of the esophagus was found to be the most frequent site of involvement.

Iodixanol in Abdominal Digital Subtraction Angiography

The safety, tolerability and efficacy of iodixanol 270 mg I/ml were compared to those of iohexol 300 mg I/ml in a double-blind, randomized, parallel abdominal intra-arterial DSA phase III trial. Fifty-nine patients were included in the trial; 39 patients received iodixanol and 20 received iohexol. The mean volume of iodixanol administered was 235.8 ml (0.93 g I/kg b.w.) while the mean volume of iohexol was 254.7 ml (1.10 g I/kg b.w.). No differences in diagnostic information and radiographic density were apparent in spite of the difference in the concentration of iodine. No serious adverse events occurred. Four patients (10%) in the iodixanol group and 2 (10%) in the iohexol group experienced adverse events. Eight percent of the injections of iodixanol promoted discomfort, compared to 12%) of the injections of iohexol. An increase in S-urea and S-creatinine was seen with both agents the first day after injection, but appeared to be less pronounced with iodixanol than with iohexol. Other serum tests revealed no changes of clinical importance. Both iodixanol and iohexol were found to be effective, safe and well tolerated contrast media for abdominal intra-arterial DSA.

Astigmatism corrected common path probe for optical coherence tomography

BACKGROUND AND OBJECTIVES

Optical coherence tomography (OCT) catheters for intraluminal imaging are subject to various artifacts due to reference-sample arm dispersion imbalances and sample arm beam astigmatism. The goal of this work was to develop a probe that minimizes such artifacts.

MATERIALS AND METHODS

Our probe was fabricated using a single mode fiber at the tip of which a glass spacer and graded index objective lens were spliced to achieve the desired focal distance. The signal was reflected using a curved reflector to correct for astigmatism caused by the thin, protective, transparent sheath that surrounds the optics. The probe design was optimized using Zemax, a commercially available optical design software. Common path interferometric operation was achieved using Fresnel reflection from the tip of the focusing graded index objective lens. The performance of the probe was tested using a custom designed spectrometer-based OCT system.

RESULTS

The probe achieved an axial resolution of 15.6 μm in air, a lateral resolution 33 μm, and a sensitivity of 103 dB. A scattering tissue phantom was imaged to test the performance of the probe for astigmatism correction. Images of the phantom confirmed that this common-path, astigmatism-corrected OCT imaging probe had minimal artifacts in the axial, and lateral dimensions.

CONCLUSIONS

In this work, we developed an astigmatism-corrected, common path probe that minimizes artifacts associated with standard OCT probes. This design may be useful for OCT applications that require high axial and lateral resolutions. Lasers Surg. Med. 49:312-318, 2017. © 2016 Wiley Periodicals, Inc.

Multiple pterygium syndrome: Challenge for anesthesiologist

Multiple pterygium syndrome (MPS) is a very rare autosomal recessive disorder characterized by flexion of joint and digit contractures, skin webbing, cleft palate, deformity of the spine, and cervical spine fusion. Difficult airway is associated mainly due to micrognathia, retrognathia, webbing of the neck, and limitation of the mouth opening and neck extension. We are reporting a case of a 5-year-old female diagnosed with MPS and exhibiting a bilateral club foot and congenital vertical talus. The patient was posted for manipulation and above the knee casting under general anesthesia.

In vivo imaging of airway cilia and mucus clearance with micro-optical coherence tomography

We have designed and fabricated a 4 mm diameter rigid endoscopic probe to obtain high resolution micro-optical coherence tomography (µOCT) images from the tracheal epithelium of living swine. Our common-path fiber-optic probe used gradient-index focusing optics, a selectively coated prism reflector to implement a circular-obscuration apodization for depth-of-focus enhancement, and a common-path reference arm and an ultra-broadbrand supercontinuum laser to achieve high axial resolution. Benchtop characterization demonstrated lateral and axial resolutions of 3.4 μm and 1.7 μm, respectively (in tissue). Mechanical standoff rails flanking the imaging window allowed the epithelial surface to be maintained in focus without disrupting mucus flow. During in vivo imaging, relative motion was mitigated by inflating an airway balloon to hold the standoff rails on the epithelium. Software implemented image stabilization was also implemented during post-processing. The resulting image sequences yielded co-registered quantitative outputs of airway surface liquid and periciliary liquid layer thicknesses, ciliary beat frequency, and mucociliary transport rate, metrics that directly indicate airway epithelial function that have dominated in vitro research in diseases such as cystic fibrosis, but have not been available in vivo.

Granulomatous and Eosinophilic Rhinitis in a Cow Caused by Pseudallescheria boydii Species Complex (Anamorph Scedosporium apiospermum)

A 2-year-old Hereford cow was presented to the teaching hospital for increased respiratory noise and bilateral bloody nasal discharge. A nodular rhinitis was detected clinically, and the nasal biopsy revealed a granulomatous and eosinophilic rhinitis with intralesional fungi. The cow was euthanized due to financial constraints. Grossly multifocal-to-coalescing, raised, ulcerated firm nodules were present in both nares. Histologically, the lamina propria was expanded by intense infiltrates of eosinophils, epithelioid macrophages, multinucleate giant cells, lymphocytes, and plasma cells. Associated with the inflammatory cells were variably sized, septate hyphae, 5–8 μm in diameter, admixed with numerous, terminal conidia, 6–30 μm in diameter, with a discrete outer wall identified by culture as Pseudallescheria boydii species complex (anamorph Scedosporium apiospermum). The infection was localized to the nasal cavity with no gross or microscopic evidence of a systemic dissemination.

Pharmacological Actions of Glucagon-Like Peptide-1, Gastric Inhibitory Polypeptide, and Glucagon

Glucagon family of peptide hormones is a group of structurally related brain-gut peptides that exert their pleiotropic actions through interactions with unique members of class B1 G protein-coupled receptors (GPCRs). They are key regulators of hormonal homeostasis and are important drug targets for metabolic disorders such as type-2 diabetes mellitus (T2DM), obesity, and dysregulations of the nervous systems such as migraine, anxiety, depression, neurodegeneration, psychiatric disorders, and cardiovascular diseases. The current review aims to provide a detailed overview of the current understanding of the pharmacological actions and therapeutic advances of three members within this family including glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP), and glucagon.

The clinical development process for a novel preventive vaccine: An overview

Each novel vaccine candidate needs to be evaluated for safety, immunogenicity, and protective efficacy in humans before it is licensed for use. After initial safety evaluation in healthy adults, each vaccine candidate follows a unique development path. This article on clinical development gives an overview on the development path based on the expectations of various guidelines issued by the World Health Organization (WHO), the European Medicines Agency (EMA), and the United States Food and Drug Administration (USFDA). The manuscript describes the objectives, study populations, study designs, study site, and outcome(s) of each phase (Phase I-III) of a clinical trial. Examples from the clinical development of a malaria vaccine candidate, a rotavirus vaccine, and two vaccines approved for human papillomavirus (HPV) have also been discussed. The article also tabulates relevant guidelines, which can be referred to while drafting the development path of a novel vaccine candidate.

Ultrasonography to investigate the effect of supplementing whole milk with complex carbohydrates and specific amino acids on curd retention in the abomasum of dairy calves

AIM

To determine whether the retention time of curd in the abomasum of calves was influenced by supplementing milk with a plant-derived carbohydrate and amino acid supplement, evaluated non-invasively using ultrasonography.

METHODS

Female dairy calves aged between 2-6 days of age were sourced from a commercial farm in March 2013. All calves were fed whole milk until weaning (4 L per day); 21 calves were supplemented with a probiotic until 18 days of age, and thereafter with a plant-derived complex carbohydrate and amino acid supplement until weaning, and 22 calves were just fed whole milk. Treatment groups were balanced for age, weight and breed. At 9-14, 24-29 and 52-57 days of age, the abomasum of each calf was examined using ultrasonography immediately before and after feeding, 1 and 2 hours after feeding, and then at 30 minute intervals until curd was no longer visible in the abomasum. Abomasal volume and curd size were recorded to assess retention time of curd in the abomasum.

RESULTS

At 9-14 days of age, mean retention time of curd in the abomasum was similar (4.6 hours) in both groups. At 24-29 days of age, when the supplemented calves had been receiving the supplement for approximately 10 days, mean curd retention time was longer by 1.4 (SE 0.28) hours in supplemented compared with unsupplemented calves (p<0.001). At 52-57 days of age, mean retention time was longer by 0.7 (SE 0.34) hours compared to unsupplemented calves (p=0.05).

CONCLUSION

Using ultrasonography, changes in abomasal content could be followed non-invasively over time and it was demonstrated that the plant-derived complex carbohydrate supplement increased the curd retention time in the abomasum. We speculate that the increased retention time enables an increased availability of nutrients following a more complete digestion of milk, thereby improving animal performance.

Integrated immunohistochemical and DNA copy number profiling analysis provides insight into the molecular pathogenesis of canine follicular lymphoma

Follicular lymphomas (FLs) typically exhibit a chromosome translocation that induces constitutive expression of the anti-apoptotic bcl2 protein and accumulation of additional molecular defects. This rearrangement offers a promising therapeutic target, but its nature as a fundamental driver of FL pathogenesis remains unclear as 15% of cases lack the translocation. We performed an integrated immunohistochemical and genomic investigation of 10 naturally occurring FL cases from domestic dogs, showing that, as with human tumours, they exhibit marked heterogeneity in the frequency and intensity of bcl2 protein expression. Genomic copy number aberrations were infrequent and broadly consistent with those of other canine B-cell lymphoma subtypes. None of the canine FL specimens exhibited a rearrangement consistent with the hallmark translocation of human FL, despite their remarkable histomorphologic similarity. Parallel exploration of canine and human cases may reveal alternative tumour-initiating mechanisms other than BCL2 disruption, yielding a more complete definition of the molecular pathogenesis of FL.

Agricultural wastes as a resource of raw materials for developing low-dielectric glass-ceramics

Agricultural waste ashes are used as resource materials to synthesize new glass and glass-ceramics. The as-prepared materials are characterized using various techniques for their structural and dielectric properties to check their suitability in microelectronic applications. Sugarcane leaves ash exhibits higher content of alkali metal oxides than rice husk ash, which reduces the melting point of the components due to eutectic reactions. The addition of sugarcane leaves ash in rice husk ash promotes the glass formation. Additionally, it prevents the cristobalite phase formation. These materials are inherently porous, which is responsible for low dielectric permittivity i.e. 9 to 40. The presence of less ordered augite phase enhances the dielectric permittivity as compared to cristobalite and tridymite phases. The present glass-ceramics exhibit lower losses than similar materials synthesized using conventional minerals. The dielectric permittivity is independent to a wide range of temperature and frequency. The glass-ceramics developed with adequately devitrified phases can be used in microelectronic devices and other dielectric applications.

Efficacy of modified rapid economic acetic acid-based Papanicolaou stain

BACKGROUND

Papanicolaou (Pap) staining is used with various modifications for the staining of cervical smears. It gives a good contrast with sharp nuclear features which aid in accurate interpretation. However, it utilises ethyl alcohol, which is expensive and difficult to purchase. We have attempted to devise a rapid Pap technique which uses acetic acid instead of ethyl alcohol, and yet provides good staining for correct diagnosis.

METHODS

Liquid-based cytology samples were collected from 102 patients as a part of routine screening. Two smears were prepared from each sample, which were stained with conventional as well as rapid Pap. In the rapid Pap method, the smears were fixed in methanol and dehydration was performed before and after OG6 with 0.5% acetic acid. The final dehydration was performed with methanol. Smears from both techniques were compared by two independent observers for staining quality.

RESULTS

With the rapid Pap stain, nuclear staining was comparable with that of conventional Pap (P < 0.05). Cytoplasmic staining was optimal in 69.6% of cases; however, the suboptimal staining in the rest of the smears did not pose any diagnostic problem.

CONCLUSION

The rapid Pap technique is a cost-effective alternative to conventional Pap which also saves time and provides good staining quality without compromising the diagnostic interpretation.

Ultra-high dynamic range electro-optic sampling for detecting millimeter and sub-millimeter radiation

Time-domain spectroscopy using coherent millimeter and sub-millimeter radiation (also known as terahertz radiation) is rapidly expanding its application, owing greatly to the remarkable advances in generating and detecting such radiation. However, many current techniques for coherent terahertz detection have limited dynamic range, thus making it difficult to perform some basic experiments that need to directly compare strong and weak terahertz signals. Here, we propose and demonstrate a novel technique based on cross-polarized spectral-domain interferometry to achieve ultra-high dynamic range electro-optic sampling measurement of coherent millimeter and sub-millimeter radiation. In our scheme, we exploit the birefringence in a single-mode polarization maintaining fiber in order to measure the phase change induced by the electric field of terahertz radiation in the detection crystal. With our new technique, we have achieved a dynamic range of 7 × 10⁶, which is 4 orders of magnitude higher than conventional electro-optic sampling techniques, while maintaining comparable signal-to-noise ratio. The present technique is foreseen to have great impact on experiments such as linear terahertz spectroscopy of optically thick materials (such as aqueous samples) and nonlinear terahertz spectroscopy, where the higher dynamic range is crucial for proper interpretation of experimentally obtained results.

μOCT imaging using depth of focus extension by self-imaging wavefront division in a common-path fiber optic probe

Optical coherence tomography (OCT) is an attractive medical modality due to its ability to acquire high-resolution, cross-sectional images inside the body using flexible, small-diameter, scanning fiber optic probes. Conventional, cross-sectional OCT imaging technologies have approximately 10-μm axial resolution and 30-μm lateral resolution, specifications that enable the visualization of microscopic architectural morphology. While this resolution is useful for many clinical applications, it is insufficient for resolving individual cells that characterize many diseases. To address this gap, a supercontinuum-laser-based, μm-resolution OCT (μOCT) system and a 500 μm-diameter, extended depth of focus single fiber optic probe for endoscopic and intravascular imaging were designed and fabricated. At the distal tip of the fiber optic probe, a cylindrical waveguide was used to divide the wavefront to provide multiple circular propagation modes. Once transmitted through a relatively high NA lens (NA >0.1), these modes were projected as multiple coaxial foci (~3 μm full width at half maximum (FWHM)) over a greatly extended focal depth range. The distal tip of the probe also contained a common-path reference reflectance to minimize polarization and dispersion imbalances between sample and reference arm light. Measurements showed that the probe provides a 20-fold depth of focus extension, maintaining a 3-5 µm lateral resolution (FWHM of PSF) and a 2 μm axial resolution over a depth range of approximately 1 mm. These results suggest that this new optical configuration will be useful for achieving high-resolution, cross-sectional OCT imaging in catheter/endoscope-based medical imaging devices.

The effects of milking frequency on insulin-like growth factor I signaling within the mammary gland of dairy cows

In dairy cows, short-term changes in milking frequency (MF) in early lactation have been shown to produce both an immediate and a long-term effect on milk yield. The effect of MF on milk yield is controlled locally within mammary glands and could be a function of changes in either number or activity of secretory mammary epithelial cells (MEC). Insulin-like growth factor I (IGF-I) signaling is one candidate factor that could mediate these effects, as it can be controlled locally within mammary glands. Both MEC number and activity can be affected by IGF-I signaling by activating the phosphoinositide 3-kinase (PI3K)/Akt and extracellular-signal-regulated kinase (ERK)1/2 pathways. To investigate the relationship between MF and IGF-I signaling, udder halves of 17 dairy cows were milked either 4 times a day (4×) or once a day (1×) for 14 d in early lactation. On d 14, between 3 and 5 h following milking, mammary biopsies were obtained from 10 cows from both udder halves, and changes in the expression of genes associated with IGF-I signaling and the activation of the PI3K/Akt and ERK1/2 pathways were measured. The mRNA abundance of IGF type I receptor, IGF binding protein (IGFBP)-3, and IGFBP-5 were lower following 4× milking relative to 1× milking. However, the mRNA abundance of IGF-I was not affected by MF. Both IGFBP3 and IGFBP5 are thought to inhibit IGF-I; therefore, decreases in their mRNA abundance may serve to stimulate the IGF-I signal in the 4×-milked mammary gland. The activation of PI3K/Akt pathway was lower in response to 4× milking relative to 1×, and the activation of the ERK1/2 was unaffected by MF, suggesting that they do not mediate the effects of MF.

Histopathological correlation of splenic disease with radiological and surgical findings: should we incorporate splenectomy into standard procedures for disseminated Millerian adenocarcinoma?

PURPOSE OF INVESTIGATION

To determine the positive predictive value (PPV) of both preoperative radiological and intraoperative identification of splenic disease in cases of advanced and recurrent gynaecological malignancy.

MATERIALS AND METHODS

A retrospective study of all splenectomies performed during surgeries for disseminated gynaecological malignancy at the Pan Birmingham Gynaecological Cancer Centre between May 21st, 2008 and January 31st, 2015.

RESULTS

Forty-one women were identified, most of whom had Stage 3C, high grade, serous Milllerian adenocarcinomas. Thirty-seven (90.2%) spleens were removed because of intraoperative suspicion of disease and the remaining four (9.8%) were removed following inadvertent injury. No spleens were detected radiologically that did not have obvious macroscopic disease. The PPV for the preoperative and intraoperative detection of splenic disease were 88.9% and 91.9%, respectively. Half of the spleens removed following inadvertent injury had disease identified following histopathological examination.

CONCLUSION

Intraoperative identification of splenic disease correlates well with histopathological examination. However, in 50% of splenectomies performed following inadvertent trauma and where disease was not suspected, metastases were identified.

Combined and individual doxorubicin/vancomycin drug loading, release kinetics and apatite formation for the CaO–CuO–P2O5–SiO2–B2O3 mesoporous glasses

The novel mesoporous glass series based on (25 − x)CaO–xCuO–10P₂O₅–5B₂O₃–60SiO₂ (x = 2.5, 5, 7.5, 10) has been prepared using the sol–gel technique.

Acute Effect of Electromagnetic Waves Emitted from Mobile Phone on Visual Evoked Potential in Adult Male : A Preliminary Study

Electromagnetic waves (EMW) emitted from mobile phone (MP) may cause variety of ocular effects, e.g., cataract, corneal edema and lacrimation of eyes. Currently very little information is available on acute effects of EMW emitted from MP on human visual system. So, study was planned to see the effects of EMW emitted from MP on visual evoked potential (VEP). This study was conducted in 9 healthy male subjects in the age group of 20 40 years with history of exposure to MP for around 1 hour/day for the last 3-9 years. After explaining the whole procedure to the subject, written consent was taken. Recording was done on RMS EMG EP MK-2 machine, using 10/20 system of electrode placement. The electrodes were placed at Cz (active electrode), O1-O2 (reference electrodes) and Fz (ground electrode). In dark room, subject was made to sit 1 meter away from screen of TV (275/350 mm size). The black and white checks of 16/16 mm size (subtending an angle of 32 minutes of an arc) were generated on the monitor by an electronic pattern generator. The contrast between black and white checks was 67%. The checks were made to reverse at a rate of 1 Hz and 100 responses were recorded. The subject was instructed to fix on small dot at its center with one eye; and the other eye was closed with hand. Waves of VEP were recorded before and after exposure to MP kept near to right ear (as right ear was found to be dominant ear, used by subjects to hear the MP, so right eye was near to MP and had more exposure compare to left eye) for 10 min. Statistical analysis was done by student ‘t’ test. After exposure to MP in left eye, there was significant increase (P<0.001) in latency of P100 wave without affecting the latency of other waves. Although amplitude of P100– N 75 waves was reduced but not statistically significant. But in right eye, after exposure to MP, latency of N75 (P<0.001), P100 (P<0.05) and N145 (P<0.001) waves were increased without any alteration in amplitude of P100 – P75 waves. Effect on right eye was slightly different. This study suggests that EMW emitted from MP may affect the VEP.

Effect Of Electromagnetic Waves Emitted From Mobile Phone On Brain Stem Auditory Evoked Potential In Adult Males

Mobile phone (MP) is commonly used communication tool. Electromagnetic waves (EMWs) emitted from MP may have potential health hazards. So, it was planned to study the effect of electromagnetic waves (EMWs) emitted from the mobile phone on brainstem auditory evoked potential (BAEP) in male subjects in the age group of 20-40 years. BAEPs were recorded using standard method of 10-20 system of electrode placement and sound click stimuli of specified intensity, duration and frequency.Right ear was exposed to EMW emitted from MP for about 10 min. On comparison of before and after exposure to MP in right ear (found to be dominating ear), there was significant increase in latency of II, III (p < 0.05) and V (p < 0.001) wave, amplitude of I-Ia wave (p < 0.05) and decrease in IPL of III-V wave (P < 0.05) after exposure to MP. But no significant change was found in waves of BAEP in left ear before vs after MP. On comparison of right (having exposure routinely as found to be dominating ear) and left ears (not exposed to MP), before exposure to MP, IPL of IIl-V wave and amplitude of V-Va is more (< 0.001) in right ear compared to more latency of III and IV wave (< 0.001) in left ear. After exposure to MP, the amplitude of V-Va was (p < 0.05) more in right ear compared to left ear. In conclusion, EMWs emitted from MP affects the auditory potential.

Perception of Dentists about Caries-risk Assessment tools in Jaipur, India: A Cross-sectional Study

BACKGROUND

Caries risk assessment (CRA) is an essential element of contemporary clinical care for infants, children, and adolescents. CRA tools aid in the detection as well as documentation of caries risk predictors and let the health care professionals to be more active in identifying and referring high-risk patients for proper treatment and required prevention. The aim of the study was to assess the information-seeking behavior of dental practitioners of Jaipur regarding CRA tools.

MATERIALS AND METHODS

A cross-sectional questionnaire-based survey was conducted among the dental practitioners of Jaipur city. A 17-itemed questionnaire was personally administered to 373 dental practitioners of Jaipur and their knowledge was assessed based on the questions about CRA tools and Cariogram. The data were analyzed using Chi-square test.

RESULTS

Around 80.5% of the practitioners were aware of CRA tools among which only one-fourth were practicing CRA. Significant correlation of qualification, specialty, and years of practice was found with knowledge of CRA tools, practice of CRA and preventive treatment and attitude toward risk assessment.

CONCLUSIONS

A substantial percentage of dentists did not practice CRA, but were interested in receiving more education about CRA and its tools.

Expression analysis of genes associated with sucrose accumulation in sugarcane (Saccharum spp. hybrids) varieties differing in content and time of peak sucrose storage

Sucrose synthesis/accumulation in sugarcane is a complex process involving many genes and regulatory sequences that control biochemical events in source-sink tissues. Among these, sucrose synthase (SuSy), sucrose phosphate synthase (SPS), soluble acid (SAI) and cell wall (CWI) invertases are important. Expression of these enzymes was compared in an early (CoJ64) and late (BO91) maturing sugarcane variety using end-point and qRT-PCR. Quantitative RT-PCR at four crop stages revealed high CWI expression in upper internodes of CoJ64, which declined significantly in both top and bottom internodes with maturity. In BO91, CWI expression was high in top and bottom internodes and declined significantly only in top internodes as the crop matured. Overall, CWI expression was higher in CoJ64 than in BO91. During crop growth, there was no significant change in SPS expression in bottom internodes in CoJ64, whereas in BO91 it decreased significantly. Apart from a significant decrease in expression of SuSy in mature bottom internodes of BO91, there was no significant change. Similar SAI expression was observed with both end-point and RT-PCR, except for significantly increased expression in top internodes of CoJ64 with maturity. SAI, being a major sucrose hydrolysing enzyme, was also monitored with end-point PCR expression in internode tissues of CoJ64 and BO91, with higher expression of SAI in BO91 at early crop stages. Enzyme inhibitors, e.g. manganese chloride (Mn(++) ), significantly suppressed expression of SAI in both early- and late-maturing varieties. Present findings enhance understanding of critical sucrose metabolic gene expression in sugarcane varieties differing in content and time of peak sucrose storage. Thus, through employing these genes, improvement of sugarcane sucrose content is possible.

Estimation of salivary nitric oxide in oral precancer patients

The role of nitric oxide (NO) in the initiation, promotion and progression of cancer has been the subject of speculation and conflicting reports in the literature. The high incidence of oral cancer and precancer has been linked to tobacco chewing and smoking habits; NO is considered an indicator of tobacco-related diseases. We compared salivary NO levels in oral precancer and normal patients. Unstimulated whole saliva was collected from 15 patients with oral precancer (group 1) and 15 healthy age and sex matched subjects (group 2). Salivary nitrite levels were estimated using a colorimetric method and a spectrophotometer. The salivary nitrite concentration of group 2 (median = 4.21 μg/ml) was significantly less than for group 1 (median = 12.91 μg/ml). We have added evidence concerning involvement of NO in the pathogenesis of oral cancer, but whether it is a potentially carcinogenic agent at the concentration at which it is present in oral precancer patients requires further evaluation.

Characterization of tissue-engineered posterior corneas using second- and third-harmonic generation microscopy

Three-dimensional tissues, such as the cornea, are now being engineered as substitutes for the rehabilitation of vision in patients with blinding corneal diseases. Engineering of tissues for translational purposes requires a non-invasive monitoring to control the quality of the resulting biomaterial. Unfortunately, most current methods still imply invasive steps, such as fixation and staining, to clearly observe the tissue-engineered cornea, a transparent tissue with weak natural contrast. Second- and third-harmonic generation imaging are well known to provide high-contrast, high spatial resolution images of such tissues, by taking advantage of the endogenous contrast agents of the tissue itself. In this article, we imaged tissue-engineered corneal substitutes using both harmonic microscopy and classic histopathology techniques. We demonstrate that second- and third-harmonic imaging can non-invasively provide important information regarding the quality and the integrity of these partial-thickness posterior corneal substitutes (observation of collagen network, fibroblasts and endothelial cells). These two nonlinear imaging modalities offer the new opportunity of monitoring the engineered corneas during the entire process of production.

Physiological, anatomical and transcriptional alterations in a rice mutant leading to enhanced water stress tolerance

Water stress is one of the most severe constraints to crop productivity. Plants display a variety of physiological and biochemical responses both at the cellular and whole organism level upon sensing water stress. Leaf rolling, stomatal closure, deeper root penetration, higher relative water content (RWC) and better osmotic adjustment are some of the mechanisms that plants employ to overcome water stress. In the current study, we report a mutant, enhanced water stress tolerant1 (ewst1) with enhanced water stress tolerance, identified from the ethyl methanesulfonate-induced mutant population of rice variety Nagina22 by field screening followed by withdrawal of irrigation in pots and hydroponics (PEG 6000). Though ewst1 was morphologically similar to the wild type (WT) for 35 of the 38 morphological descriptors (except chalky endosperm/expression of white core, decorticated grain colour and grain weight), it showed enhanced germination in polyethylene glycol-infused medium. It exhibited increase in maximum root length without any significant changes in its root weight, root volume and total root number on crown when compared with the WT under stress in PVC tube experiment. It also showed better performance for various physiological parameters such as RWC, cell membrane stability and chlorophyll concentration upon water stress in a pot experiment. Root anatomy and stomatal microscopic studies revealed changes in the number of xylem and phloem cells, size of central meta-xylem and number of closed stomata in ewst1. Comparative genome-wide transcriptome analysis identified genes related to exocytosis, secondary metabolites, tryptophan biosynthesis, protein phosphorylation and other signalling pathways to be playing a role in enhanced response to water stress in ewst1. The possible involvement of a candidate gene with respect to the observed morpho-physiological and transcriptional changes and its role in stress tolerance are discussed. The mutant identified and characterized in this study will be useful for further dissection of water stress tolerance in rice.