Biomedical subjects
Publications and source records attributed to V Gupta.
A rare case of Ewing's sarcoma of os calcis is described here. Its atypical clinical and radiological features often delay the diagnosis. These features and review of literature are discussed.
This study evaluates the use of artificial neural networks to estimate stroke volume from pre-processed, thoracic impedance plethysmograph signals from 20 healthy subjects. Standard back-propagation was used to train the networks, with Doppler stroke volume estimates as the desired output. The trained networks were then compared to two classical biophysical approaches. The coefficient of determination (R2 x 100%) between the biophysical approaches and the Doppler was 8.20% and 9.90%, while it was 77.38% between the best neural network and the Doppler. Among these methods, only the neural network residuals had a significant zero mean Gaussian distribution (alpha=0.05). Our results indicate that an invertible relationship may exist between thoracic bioimpedance and stroke volume, and that artificial neural networks may offer a potentially advantageous approach for estimating stroke volume from thoracic electrical impedance, both because of their ease of use and their lack of confounding assumptions.
PURPOSE: To evaluate changes at the anterior chamber angle during Valsalva maneuver in eyes suspected to have a primary adult glaucoma. METHODS: Seventy-six consecutive patients underwent recording of applanation tonometry, measurement of the anterior chamber angle recess, angle opening distance, angle recess area, scleral spur-iris root distance, iris thickness, iridociliary angle, ciliary body thickness, anterior chamber depth, and pupil size on ultrasound biomicroscopy before and during the Valsalva maneuver. The Valsalva maneuver was standardized to a pressure of 40 mmHg for 15 seconds, using a manometer. RESULTS: The mean baseline intraocular pressure changed from 19.5+/-4.1 mmHg to 29.5+/-4.8 mmHg during Valsalva (p<0.0001). The anterior chamber angle recess narrowed from 17.9+/-9.5 to 7.8+/-9.2 degrees (p=0.0001). The angle recess area diminished from 0.15+/-0.14 mm2 to 0.14+/-0.12 mm2 (p=0.03) and the scleral spur to iris distance decreased from 0.19+/-0.2 mm to 0.16+/-0.18 mm (p=0.0001). The iridociliary angle narrowed from 72.6+/-33.5 degrees to 62.5+/-32.8 degrees (p=0.04). There was a significant increase in the thickness of the ciliary body, from 0.99+/-0.19 mm to 1.12+/-0.16 mm (p=0.001) and in iris thickness from 0.47+/-0.07 mm to 0.55+/-0.09 mm (p=0.0001). There was no significant change in the angle opening distance, anterior chamber depth, or pupillary diameter. A significant narrowing of the angle to less than 5 degrees was seen in 37 eyes, with iridocorneal apposition present in 28 eyes. After multivariate regression analysis it was found that the baseline ciliary body thickness and angle recess were significant predictors of narrowing of the angle (R2=96.1%). CONCLUSIONS: Significant elevation of the intraocular pressure, narrowing of the anterior chamber angle recess, thickening of the ciliary body, and increase in the iris thickness is seen during the Valsalva maneuver. The Valsalva maneuver may lead to angle closure in eyes anatomically predisposed to primary angle closure glaucoma.
The effect of p-phenylene diamine on the peroxidation of liposomized samples of lecithin and peanut oil was studied under optimal conditions. The p-phenylene diamine was found to affect the formation of thiobarbituric acid reactive products of lipid peroxidation and the efficacy of various free radical scavengers.
PURPOSE: To report a case of polymicrobial infectious keratitis in one eye of a patient who had undergone bilateral simultaneous laser in situ keratomileusis (LASIK). METHODS: A 21-year-old healthy female developed infectious keratitis in her right eye after bilateral LASIK surgery. Material obtained from the infective foci was sent for bacterial and fungal cultures and herpes simplex virus antigen detection, and broad spectrum antimicrobial therapy was instituted. RESULTS: Staphylococcus epidermidis and Fusarium solani were detected on culture and herpes simplex virus antigen was found to be positive. The patient did not respond to medical therapy and subsequently the ulcer perforated. A therapeutic keratoplasty was performed and the final best-corrected visual acuity was 20/40, 1 month after keratoplasty. CONCLUSION: Polymicrobial infectious keratitis, although rare, is a potential sight-threatening complication of LASIK.
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Dysphagia, a swallowing disorder, is a problem encountered frequently in the rehabilitation of stroke and head injury patients. In normal individuals, safe passage of a food bolus into the esophagus is ensured by laryngeal elevation and closure of the airway. Inadequate laryngeal elevation can lead to aspiration, choking, and even death. The course of recovery in the current clinical practice is rather tedious. Recently, investigators have developed and evaluated the accelerometry technique for noninvasive assessment of laryngeal elevation. The purpose of the present paper is to present case reports of patients with poor laryngeal elevation treated with computerized biofeedback therapy using dynamic acceleration measurements. Acceleration was measured from the dysphagic patient during swallowing, and was dynamically displayed on the computer screen along with an acceleration signal from a typical, normal subject. The patient was asked to elicit a swallow response such that his/her acceleration display matched the display of the normal subject. Each patient had nine therapy sessions, lasting about half an hour each. All five patients improved significantly in acceleration magnitude and in swallowing function as confirmed by the videofluorography evaluation.
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A 10-year-old boy was admitted with cardiac tamponade. Initial pericardiocentasis yielded pus. A subxiphoid tube-pericardiostomy was done and thick, purulent material was drained out. Subsequently, pericardiectomy was undertaken as features of pericardial constriction persisted. At surgery, however, an intrapericardial mass was discovered. Successful excision was performed and the patient made an uneventful recovery. Histopathology of the mass revealed features of an intrapericardial teratoma. Rarity of the lesion, and a hitherto unreported mode of presentation make this case worthy of documentation.
BACKGROUND AND OBJECTIVE: To compare various laser wavelengths: argon green (514 nm), vs krypton red (647 nm), vs frequency doubled Nd:YAG (532 nm), and vs diode (810 nm), for laser photocoagulation treatment in clinically significant macular edema (CSME) in diabetics. PATIENTS AND METHODS: Four different wavelengths were used to sequentially treat 271 eyes of 164 diabetic patients with CSME. Follow up was conducted for a minimum of 6 months (9.8 +/- 1.3 months). Retreatment was performed if residual edema involving the foveal avascular zone persisted at 3 months. RESULTS: Reduction/elimination of CSME was observed in 93.3% of argon-treated eyes, 88.5% in krypton red group, 92.9% with frequency doubled Nd:YAG, and 84.8% with diode laser with no statistically significant difference between the groups (P > 0.05 for all groups). The number of eyes requiring retreatment was highest with the diode laser having 44.3% of eyes requiring retreatment and least with frequency doubled Nd:YAG having only 15.5% of eyes requiring retreatment (P = 0.0002). CONCLUSIONS: All lasers are equally effective in reducing/eliminating CSME. However, Nd:YAG may have an advantage because of requiring fewer retreatments.
Fungal scleritis is a rare entity. A 50-year-old patient with culture proven Aureobasidium pullulans corneal ulcer underwent therapeutic keratoplasty. He developed scleritis 5 days following surgery. Although the patient had symptomatic improvement after antifungal therapy, surgical debridement, and cryotherapy, visual improvement was only marginal. Aureobasidium pullulans should be looked for as a cause for keratomycosis and scleromycosis, especially in tropical countries.
Evaluation of mandibular mass lesions is a perplexing clinical problem. Some of these lesions have very similar clinical presentation and even similar or overlapping imaging features. Plain radiographs and orthopantomograms are frequently requisitioned for the diagnosis and are helpful in localization and characterization of these lesions. However, the specificity of diagnosis remains low. A study was undertaken to further characterize these lesions using Computed Tomography (CT) and analysis of cross sectional images of various mandibular mass lesions. Of these, imaging features of ameloblastoma and central giant cell granuloma (CGCG) were studied and compared, which is reported in this paper.
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Mammary sarcomas are uncommon tumors. Of these pure chondrosarcoma without any other area of epithelial or mesenchymal differentiation feature as even rarer. This excludes tumors like malignant cystosarcoma phyllodes and metaplastic carcinoma where malignant cartilaginous areas may be present. Further primary chondrosarcoma arises from breast stroma and not from underlying bone or cartilage. Only five cases of pure and primary chondrosarcoma have been reported so far. The sixth case is reported here.
Endoscopic brush cytology is a valuable technique for the evaluation of biliary strictures. The sensitivity of this technique varies from 30% to 83%, however, it can have specificity of 100%. We retrospectively evaluated the usefulness of wire-guided biliary brush cytology in biliary strictures in our hospital over a 3 years period from 1997 to 2000. Brushings from 58 biliary strictures were obtained during endoscopic retrograde cholangiography. They were compared with histological proof obtained by surgical biopsy or percutaneous fine-needle aspiration cytology and/or clinical findings. These were reported as benign or malignant. Eleven patients were excluded due to incomplete data. Eighteen patients had benign brushings. Fourteen of the 29 patients in whom histological confirmation of malignancy brushings was obtained were also reported as malignant. The sensitivity of endoscopic brushings was 48.2%, specificity 100% and diagnostic accuracy 55.2%. No major complications were seen in our study group.
Primary systemic or AL amyloidosis is a multisystem disorder characterized by diffuse extracellular infiltration of a fibrillar protein of monoclonal light chain origin (AL). Majority of the patients have monoclonal immunoglobulin in serum and/or urine and some have clonal proliferation of plasma cells in their bone marrow. This disease has the widest spectrum of organ involvement, most commonly affecting the kidneys, heart and liver. Involvement of peripheral nervous system is not infrequent and may be the presenting feature of the disease process. Thus, recognition of peripheral neuropathy and affecting the kidney as an early symptom of AL amyloidosis may widen the scope for therapeutic intervention. We describe here a rare case of primary amyloidosis (AL) kappa-light chain presenting with clinical features of peripheral neuropathy and affecting the kidney and heart at an early age of 18 years, hitherto unreported in literature. The case was further interesting as it was not associated with increased serum/urine immunoglobulins or plasma cells in bone marrow. Diagnosis was confirmed using immuno-electron microscopy on sural nerve biopsy.
Protooncogenes have the ability to induce and/or maintain the transformed state when they are overly expressed or altered by mutation or gene rearrangement. To study the possible involvement of these cellular oncogenes in the neoplastic transformation, we have analyzed their expression in 44 fresh samples obtained from primary, recurrent, or metastatic tumors from patients with a variety of sarcomas and a melanoma. Our analysis was carried out by the northern blot technique using poly (A)+ RNA hybridized with human cellular DNA probes. A normal 2.3-kb c-myc transcript was observed almost universally at various levels. A normal c-k-ras transcript of 5.2-kb was detected at a low level in most of the samples. In three samples we detected aberrant c-k-ras transcripts of 7.0 and 8.5-kb, while in two other samples we found an aberrant lower-molecular-weight transcript of 1.4-kb. N-myc was expressed in only three samples, and in all instances, the transcripts were aberrant (more than 10-kb). A normal 3.7-kb c-sis transcript was expressed at a low level in most of the sarcomas and the melanoma but was uniquely overexpressed in giant cell tumors of bone. C-fos (2.2-kb) was expressed at a low level in almost half of the samples; c-myb was never expressed. We conclude that c-k-ras, n-myc, c-sis, and c-myc are aberrantly or overexpressed in sarcoma/melanoma, and their activation may play a role in the transforming events leading to development and/or progression of these tumors.