Etiological study of generalized lymphadenopathy in a tertiary care hospital

Background: This study was done to know about the clinical biochemical as well as radiological profile of patients presented as generalized lymphadenopathy in a tertiary care centre and to know the different causes of generalized lymphadenopathy.Methods: 116 patients of generalized lymphadenopathy were included this study based on the inclusion and exclusion criteria. Detailed history, physical examination and relevant systemic examination including detailed examination of lympho-reticular system were done as per a structured proforma and necessary lab investigations were done for confirming diagnosis.Results: Among 116 patients of generalized lymphadenopathy 59.5% were non-malignant causes where 40.5% diagnosed as malignant causes. Among them tuberculosis consist of 39 (33.6%), NHL 18 (15.5%), reactive lymphadenopathy 16 (13.8%), CLL and HD 8 (6.9%) each, ALL 7 (6%), SLE 5(4.3%), Kikuchi’s disease 4 (3.4%), AML and RA 3 (2.6%) each and castleman’s disease, phenytoin lymphadenopathy, metastatic lung and breast carcinoma 1 (0.9%) each. Cervical groups of lymph nodes were most commonly involved 86 patients (74.1%) followed by axillary groups 73 patients (62.9%). Lymph nodes size 1.5cm were due to malignant and non-malignant granulomatous cases. FNAC give definite diagnosis 80.9% malignant cases where 76.8% in non-malignant cases. HPE shown definite diagnosis in 100% cases both malignant and non-malignant diseases.Conclusions: Tuberculosis is most common cause of generalized lymphadenopathy followed by lymphoma. And reactive lymphadenitis is also an important consideration.

A case of complicated bullous systemic lupus erythematosus managed with Rituximab

Skin Involvement is seen nearly 76 per cent of Systemic lupus erythematosus (SLE) patients, but bullous lesion however accounting for less than one per cent of cutaneous manifestation of lupus erythematosus. A 21-year-old female presented with fever, polyarthalgia and vesicobullous skin lesion and acute renal failure. Clinico-pathological evaluation imparted she was having bullous systemic lupus erythematosus (BSLE) with lupus nephritis. She was put on rituximab after initial resuscitation. She had responded dramatically with resolution of skin lesion and recovery from acute renal failure. She was followed up for one year without complication with stable disease course

A Low - Cost Effective Therapy Of Pastular Dermatitis Atrophicans(PDA)

The clinical entity PDA mainly affects lower socio- economic group in tropical countries. Its cure/control poses a challenge to dermatologists. To evaluate a low â€" cost drug therapy, dapsone was tried among patients of chronic folliculitis of legs along with tropical providone â€" iodine application. Forty- two patients who came for regular follow â€" up revealed satisfactory result with marked improvement in about 70% cases with minimal side- effects. The antibacterial and immunomodulatory action of dapsone may be beneficial in these cases. The possible role of androgen triggering effect remains an open question in its pathogenesis and chronicity

Maximizing Mismatch Discrimination by Surface-Tethered Locked Nucleic Acid Probes via Ionic Tuning

Several investigations on DNA-based nucleic acid sensors performed in the past few years point toward the requirement of an alternative nucleic acid that can detect target DNA strands more efficiently, i.e., with higher sensitivity and selectivity, and can be more robust compared to the DNA sensor probes. Locked nucleic acid (LNA), a conformationally restricted DNA analogue, is potentially a better alternative than DNA, since it is nuclease-resistant, it can form a more stable duplex with DNA in a sequence-specific manner, and it interacts less with substrate surface due to presence of a rigid backbone. In this work, we probed solid-phase dehybridization of ssDNA targets from densely packed fully modified ssLNA probes immobilized onto a gold(111) surface by fluorescence-based measurement of the “on-surface” melting temperatures. We find that mismatch discrimination can be clearly improved by applying the surface-tethered LNA probes, in comparison to the corresponding DNA probes. We show that concentration as well as type of cation (monovalent and polyvalent) can significantly influence thermal stability of the surface-confined LNA–DNA duplexes, the nature of concentration dependence contradicting the solution phase behavior. Since the ionic setting influenced the fully matched duplexes more strongly than the singly mismatched duplexes, the mismatch discrimination ability of the surface-confined LNA probes could be controlled by ionic modulations. To our knowledge, this is the first report on ionic regulation of melting behavior of surface-confined LNA–DNA duplexes

Regulating the On-Surface LNA Probe Density for the Highest Target Recognition Efficiency

The recent emergence of on-surface LNA-based assays as potentially better alternatives over DNA-based approaches, due to enhanced sensitivity and target specificity, raises the need for the precise identification of the factors that control the performance of these assays. In this work, we investigated whether the probe density of fully modified ssLNA probes on the gold(111) surface could influence the target recognition capacity of the LNA sensing layer and illustrated simple means to control it, primarily by adjusting the salt concentration, nature of the cation, and pH of the immobilization buffer. It was observed that monovalent Na⁺ could more effectively control the sensor probe density compared to bivalent Mg²⁺, leading to better target recognition. Interestingly, unlike in the case of ssDNA sensor probes, the target recognition efficiency of the LNA layer at the optimum probe density was found to be almost spacer-independent, probably due to the rigidity of the LNA backbone. The optimized LNA sensor layer could discriminate single base mismatches, detect a minimum target DNA concentration of 5 nM, and sense a significant level of hybridization within a time scale of a few minutes. To our knowledge, for the first time, we identify the factors that control the on-surface LNA probe density for maximizing the performance of the LNA sensing layer

Ordered Self-Assembled Locked Nucleic Acid (LNA) Structures on Gold(111) Surface with Enhanced Single Base Mismatch Recognition Capability

Locked nucleic acid (LNA) is a conformationally restricted nucleic acid analogue, which is potentially a better alternative than DNA for application in the nucleic acid based biosensor technologies, due to its efficient and sequence-specific DNA/RNA detection capability and lack of molecule–surface interaction on solid surfaces, compared to DNA. We report, for the first time, a straightforward way (based on simple immersion method) of generating an ordered self-assembled LNA monolayer, which is bioactive, onto a gold(111) surface. This layer is capable of giving rise to a stronger DNA recognition signal (4–4.5 times) than its DNA counterpart, and importantly, it can differentiate between a fully complementary DNA target and that having a single base mismatch, where the mismatch discrimination ratio is almost two times compared to the ratio relevant in case of DNA-based detection. We have presented high-resolution atomic force microscopy (AFM) topographs of the well-defined one-dimensional LNA molecular ordering (few hundred nanometers long) and of the two-dimensional ordered assembly formed over a large area (7 μm × 7 μm) due to parallel positioning of the one-dimensional ordered arrangements. The effects of different parameters such as LNA concentration and incubation time on LNA self-assembly have been investigated. Further, reflection absorption infrared (RAIR) spectroscopy has been applied to obtain information about the orientation of the surface-immobilized LNA molecules for the first time. It has been found that the LNA molecules undergo an orientational transition from the “lying down” to the “upright” configuration in a time scale of few hours

Enhancing On-Surface Mismatch Discrimination Capability of PNA Probes by AuNP Modification of Gold(111) Surface

Unambiguous identification of single base mismatches in nucleic acid sequences is of great importance in nucleic acid detection assays. However, ambiguities are often encountered with, and therefore, a strategy for attaining substantially large enhancement of mismatch discrimination has been worked upon in this study. Short single-stranded peptide nucleic acid (PNA) and deoxyribonucleic acid (DNA) sensor probes that are immobilized onto gold nanoparticle (AuNP) modified Au(111) surface have been applied for target DNA detection. It will be shown that while both PNA and the analogous DNA probes exhibit generally better target detection abilities on the AuNP-modified Au(111) surface (elicited from fluorescence-based measurement of on-surface <i>T</i>_m values), compared to the bare Au(111) surface, PNA supersedes DNA, for all sizes of AuNPs (10, 50, and 90 nm) applied, with the difference being quite drastic in the case of the smallest 10 nm AuNP. It is found that while the AuNP curvature plays a pivotal role in target detection abilities of the PNA probes, the changes in the surface roughness caused by AuNP treatment do not exert any significant influence. This study also presents a means for preparing PNA–AuNP hybrids without altering PNA functionality and without AuNP aggregation by working with the surface-affixed AuNPs

Facilitating Mismatch Discrimination by Surface-Affixed PNA Probes via Ionic Regulation

There has been a search for alternative nucleic acids that can be more effectively used in nucleic acid detection technologies compared to the DNA probes. Peptide nucleic acid (PNA), which contains a non-ionic peptidic backbone, offers such possibilities since it is nuclease-resistant, it binds to DNA with high affinity, and it can be readily self-assembled onto solid substrates, e.g., gold(111), with a molecular backbone orientation away from the substrate. Although application of PNA as a sensor probe has been exemplified, so far there is little or no account of the ionic modulation of single base mismatch discrimination capacity of surface-tethered PNA probes. Herein, we report “on-surface” melting temperatures of PNA-DNA duplexes formed on gold(111) surface, as obtained from fluorescence measurements. We show that surface-tethered PNA forms a stabler duplex than DNA, and is more effective in single base mismatch discrimination than DNA. Importantly, although PNA backbone is non-ionic, variation in the ionic components in hybridization buffer, i.e., varying concentration of monovalent sodium ion, and the nature of anion and the cation, exhibits clear effects on the mismatch discrimination capacity of PNA probes. In general, with decreasing cation concentration, PNA-DNA duplexes are stabilized and mismatch discrimination capacity of the PNA probes is enhanced. The stabilizing/destabilizing effects of anions are found to follow the Hofmeister series, emphasizing the importance of hydrophobic interaction between nucleobases for stability of the PNA-DNA duplexes. Interestingly, the nature of ionic dependence of “on-surface” mismatch detection ability of PNA probes differs significantly from the “solution” behavior of these probes