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1.
Kavita R Hegde Svitlana Kovtun Shambhu D Varma 《Journal of ocular pharmacology and therapeutics》2007,23(5):492-502
Ultraviolet (UV) radiation is one of the important cataract risk factors. The present studies examined the hypothesis that this effect is due to the UV penetration through the cornea and subsequent induction of a photochemical generation of reactive species of oxygen (ROS) in the aqueous and lens. The hypothesis was ascertained by rat lens organ culture studies conducted under UV (365 nm), with media containing micromolar levels of riboflavin, with and without pyruvate, the latter acting as an ROS scavenger. The implication of ROS in the UV-induced damage was confirmed by measurements of peroxide generation. Damage to the lens was assessed physiologically by measuring the decrease in its active transport of rubidium ions. Biochemically, it was assessed by measuring the lowering of adenosine triphosphate and glutathione. The incorporation of pyruvate in the medium protected the lens against these deleterious effects. That the beneficial effect of pyruvate is attributable to its ROS-scavenging property was proven by the peroxide depletion in its presence, commensurate with its own utilization in parallel. A protective effect of this keto acid against UV-induced tissue damage has been shown for the first time, suggesting its clinical usefulness against UV irradiation-induced pathologies. Hence, further studies on the possible protective effects of such alpha-keto acids against UV damage are in progress. 相似文献
2.
William R. Reinus M.D. Franz J. Wippold II M.D. Kavita K. Erickson M.D. 《Emergency radiology》1994,1(2):81-84
We studied clinical predictors of cranial computed tomography (CT) abnormalities in patients with acute or acutely worsened
headache. Data were collected from chart review of 333 consecutive patients presenting to an emergency department and who
were clinically selected for cranial CT. Patients with a positive neurologic examination were at 10.7 times greater risk for
a positive CT than the rest of the sample (p<1.5 – 10−10). Using only neurologic examination to select patients for CT would have missed 30.3% of the positive scans. The amnesia,
depressed sensorium, and hypertension variables had CT yields approximating 10% or greater even in the presence of a negative
neurologic examination. Together with a positive neurologic examination, these variables detected 87.9% of the patients in
this sample with positive scans; their absence had a negative predictive value of 98.0%. Of the four patients with positive
scans who would have been missed using this strategy, one was discharged directly from the emergency department anyway and
the other three developed positive neurologic examinations within 24 hours. One died of causes unrelated to the intracranial
pathology. Positive neurologic examination, hypertension, history of amnesia, or a depressed sensorium provide reasonable
initial guidelines to select for CT patients with an acute headache. 相似文献
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Shalendra Kumar Faheem Ahmed Nagih M. Shaalan Rajesh Kumar Adil Alshoaibi Nishat Arshi Saurabh Dalela Fatima Sayeed Sourabh Dwivedi Kavita Kumari 《Materials》2022,15(22)
Magnetic nanostructures of CoFe2O4 were synthesized via a microwave-assisted hydrothermal route. The prepared nanostructures were investigated using X-ray diffraction (XRD), field emission electron microscopy (FE-SEM), energy dispersive X-ray (EDX) spectroscopy, high-resolution transmission electron microscopy (HR-TEM), selective area electron diffraction (SAED) pattern, DC magnetization, and dielectric spectroscopy measurements. The crystal structure studied using HR-TEM, SAED, and XRD patterns revealed that the synthesized nanostructures had a single-phase nature and ruled out the possibility of any secondary phase. The lattice parameters and unit cell volume determined from the XRD data were found to be 8.4821 Å and 583.88 Å3. The average crystallite size (~7.0 nm) was determined using Scherrer’s equation. The FE-SEM and TEM micrographs revealed that the prepared nanostructures had a spherical shape morphology. The EDX results showed that the major elements present in the samples were Co, Fe, and O. The magnetization (M) versus temperature (T) measurements specified that the CoFe2O4 nanostructures showed ferromagnetic ordering at room temperature. The blocking temperature (TB) determined using the M-T curve was found to be 315 K. The magnetic hysteresis (M-H) loop of the CoFe2O4 nanostructures recorded at different temperatures showed the ferromagnetic behavior of the CoFe2O4 nanostructures at temperatures of 200 K and 300 K, and a superparamagnetic behavior at 350 K. The dielectric spectroscopy studies revealed a dielectric constant (ε′) and loss tangent (tanδ) decrease with the increase in the frequency, as well as demonstrating a normal dispersion behavior, which is due to the Maxwell–Wagner type of interfacial polarization. The values of ε′ and tanδ were observed to increase with the increase in the temperature. 相似文献
6.
Shiying Silvia Zheng Zohra Ahmadi Halina Hoi Laam Leung Rose Wong Feng Yan Jos Sail Perdomo Beng Hock Chong 《Haematologica》2022,107(9):2195
Immune thrombocytopenia (ITP) is a bleeding disorder caused by dysregulated B- and T- cell functions, which lead to platelet destruction. A well-recognized mechanism of ITP pathogenesis involves anti-platelet and anti-megakaryocyte antibodies recognizing membrane glycoprotein (GP) complexes, mainly GPIb/IX and GPIIb/IIIa. In addition to the current view of phagocytosis of the opsonised platelets by splenic and hepatic macrophages via their Fc γ receptors, antibody-induced platelet desialylation and apoptosis have also been reported to contribute to ITP pathogenesis. Nevertheless, the relationship between the specific thrombocytopenic mechanisms and various types of anti-platelet antibodies has not been established. In order to ascertain such association, we used sera from 61 ITP patients and assessed the capacity of anti-platelet antibodies to induce neuraminidase 1 (NEU1) surface expression, RCA-1 lectin binding and loss of mitochondrial inner membrane potential on donors’ platelets. Sera from ITP patients with detectable antibodies caused significant platelet desialylation and apoptosis. Anti-GPIIb/IIIa antibodies appeared more capable of causing NEU1 surface translocation while anti-GPIb/IX complex antibodies resulted in a higher degree of platelet apoptosis. In ITP patients with anti-GPIIb/IIIa antibodies, both desialylation and apoptosis were dependent on FcγRIIa signaling rather than platelet activation. Finally, we confirmed in a murine model of ITP that destruction of human platelets induced by anti-GPIIb/IIIa antibodies can be prevented with the NEU1 inhibitor oseltamivir. A collaborative clinical trial is warranted to investigate the utility of oseltamivir in the treatment of ITP. 相似文献
7.
Kavita Sachdeva 《Indian journal of otolaryngology and head and neck surgery》2013,65(4):375-379
AIM of the study is to evaluate etiopathogenesis role played by predisposing conditions (Diabetes, Immunosupression), precipitating factors (trauma/surgery/ketoacidosis) and possible role of occupational hazard is discussed briefly. Clinical presentation and management of patients presenting with rhinoorbitocerebral mucormycosis is discussed. The prospective study of patient undergoing treatment of mucormycosis] without control Setting was done in ENT Deptt. NSCB Medical College, Jabalpur (tertiary referral centre of mid India). Subject were patients presenting with invasive fungal rhino sinusitis presenting with orbital involvement and cranial nerve palsies undergoing treatment. The detailed history, clinical examination including cranial nerve examination, blood test, CTscan and biopsy. Nasal endoscopy, CWL surgery and medical management with 6 month follow up. All six patients were diabetic when evaluated on presentation. Two patients had ketoacidosis. Four had history of surgery in recent past. Blood stained nasal discharge and dysaesthesia of face are early warning signs. They had necrotic lesion in nose and infraorbital area with 2, 3, 4, 5, 6 and 7 cranial nerve involvement. Skin necrosis/Mucosal necrosis, facial palsy and diplopia signify advanced disease. Altered sensorium, panopthalmitis & diabetes complicated with ketoacidosis signify bad prognosis. In present study two patients with advanced disease, altered sensorium and ketoacidosis succumbed within 72 hours in spite of anti fungal medicine. Of the four surviving patients, all responded well to treatment but had residual sixth and seventh nerve palsy. One patient defaulted in diabetes control & had recurrence after 6 months. Early diagnosis, aggressive surgical debridement and proper management of underlying metabolic abnormality along with amphotericin B can avert the bad prognosis of rhinoorbitocerebral mucormycosis. 相似文献
8.
Angela M. Beattie RGN PhD Rona Campbell PhD Kavita Vedhara PhD 《Health expectations》2014,17(3):429-439
Objective Individuals who have had one diabetic foot ulcer (DFU) are at high risk for developing further DFUs. This study was designed to examine the emotional and behavioural consequences of living with this heightened risk of re‐ulceration. Participants and setting Fifteen women and men living in south‐west England were interviewed at home or at the university by an academic psychologist. Design Interviews were audiotaped and transcribed verbatim. Thematic analysis using the constant comparative method was employed for data analysis. Results Participants reported having little perceived control in preventing further DFUs. This lack of control was associated with a range of negative emotions including fears and worries about developing further foot ulcers, amputation and guilt for the past neglect. Tensions were present between participants’ beliefs and reported behaviours, that is, what they felt they ought to be doing and what they were actually doing to care for their feet; most engaged in ‘strategic adherence’, that is, conducting a trade‐off between living a normal life and following foot‐care advice. Conclusion A lack of perceived control appears central to the emotional and behavioural responses of individuals living with the threat of re‐ulceration. We propose that these responses may serve to increase individuals’ risk of re‐ulceration and that these ‘risk factors’ should be considered part of the management of this patient group. 相似文献
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