Browsing by Author "Sandhyamani, S"

Now showing 1 - 20 of 30
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    Atypical meningioma: A clinicopathological analysis
    (NEUROLOGY INDIA, 2000) Joseph, E; Sandhyamani, S; Rao, MB; Nair, S; Radhakrishnan, VV
    In this retrospective study, 382 operated cases of meningiomas were reviewed, 32 cases (8.3%) were histopathologically classified as atypical meningioma, The anatomical locations and histological features in all the thirty-two cases were correlated with their recurrence rates and biological behaviour. The overall recurrence rate for atypical meningioma within two years was 28% as compared to 9.3% in benign meningiomas. It is being emphasized that an accurate histopathological interpretation of atypical meningioma is essential for predicting the recurrence, biological behavior as well as postoperative management modalities.
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    Bonnet monkey model for pancreatic changes in induced malnutrition
    (PANCREAS, 1999)
    Pancreatic degenerative lesions of identical nature could be induced in bonnet monkeys (Macaca radiata) fed protein-deficient tapioca or cassava starch-based and corn-starch-based diets for 3 or 5 months. Marked to severe lobular and acinar cell atrophy in animals fed low-protein diets resembled human pancreatic atrophy resulting from protein deficiency. Animals fed low-protein, high-carbohydrate diets showed lesions akin to tropical chronic calculus pancreatopathy with diabetes mellitus. The pancreatic lesions comprised moderate to marked acinar cell atrophy, marked islet hyperplasia or nesidioblastosis with hypertrophy and mucoid metaplasia of the duct epithelium. Mucoid vasculopathy of the pancreatic artery and arterioles was observed in all animals given protein-deficient diets. It was enhanced in those given additional carbohydrate. Identical lesions were observed after using either source of carbohydrate. This excluded the role of toxic factors such as cyanoglycosides or heavy metals from a tapioca source in initiating the lesions. The study establishes monkey models for the spectrum of human pancreatic changes associated with malnutrition owing to protein deficiency and nutritional imbalance with low-protein high-starch diets. The experiments demonstrate the dual effects of similar diets on the parenchyma and vasculature of the pancreas.
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    Case 1-1994. Mistaken diagnosis of coarction of the aorta with aortoesophageal fistula.
    (Journal of cardiothoracic and vascular anesthesia, 1994)
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    Cerebral aneurysms in atrial myxoma: a delayed, rare manifestation.
    (Neurology India, 2005)
    Atrial myxomas are the most common primary tumors of the heart. Neurologic involvement usually occurs as a stroke with ischemic episodes. Following excision of cardiac myxomas, delayed neurologic events owing to aneurysms are rare and have not been reported from India. We report an operated case of left atrial myxoma. The patient initially presented with a stroke and 6 months after the surgery, developed multiple intracerebral hemorrhages due to the rupture of fusiform cerebral aneurysms, without recurrence of the cardiac tumor.
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    Cerebral hyperperfusion syndrome following aortocarotid bypass surgery.
    (Journal of cardiothoracic and vascular anesthesia, 1993)
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    Clinico-pathological study of cerebral aneurysms
    (NEUROLOGY INDIA, 2004)
    Aims and Objectives: A clinico-pathological study of cerebral aneurysms was undertaken to understand the histopathogical nature of the lesions and to ascertain possible etiological risk factors. Material and Methods: Of the 255 cases of cerebral aneurysms operated upon at our Institute during the two-year period between Jan 1999 to Dec 2000, a detailed study was conducted on 57 cases where the aneurysm sac could be excised and subjected to histopathological examination. Aneurysm sacs were fixed in 10% buffered formaldehyde and processed through graded alcohol. Paraffin-embedded sections were examined, using hematoxylin and eosin, Verhoeff van Gieson's and toluidine blue staining techniques. Histopathological observations were analyzed and correlated with clinical features. Results: The ages of the patients ranged from 17-65 years and there were 33 males and 24 females. Twenty-six patients were chronic smokers and 19 patients had hypertension. There were 54 saccular and 3 fusiform aneurysms, predominantly involving the anterior circulation (52 cases) than posterior circulation (5 cases). In 35 cases, histopathological studies demonstrated mucoid deposits between hyperplastic cellular elements in the true and false aneurysm wall and/or parent artery or vasavasora. The changes were associated with dystrophic changes in the internal elastic lamina. Conclusion: Besides significant risk factors like smoking and hypertension, such mucoid vasculopathic changes may have predisposed vessels to structural weakness and aneurysm formation in our patients.
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    Disposable polyethylene wiremesh capsules for histopathological tissue processing.
    (Indian journal of pathology & microbiology, 1994)
    An attempt was made to find a suitable alternative material for tissue carriers other than gauze and stainless steel capsules. Since polyethylene (high density) wire mesh is resistant to all acids, alkalis and inorganic chemicals and has no known solvent at room temperature, it is a suitable alternative disposable material for histopathological tissue processing purposes.
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    Dysplastic gangliocytoma of the cerebellum (Lhermitte-Duclos disease)--a case report with review of the literature.
    (Indian journal of cancer, 1992)
    Dysplastic gangliocytoma of the cerebellum is an uncommon malformative lesion and clinically manifest as a slow growing space occupying lesion. In this report, the characteristic clinical and histopathological features of a case of dysplastic gangliocytoma of the cerebellum are described.
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    Experiences with carotid endarterectomy at Sree Chitra Tirunal Institute
    (ANNALS OF INDIAN ACADEMY OF NEUROLOGY, 2008) Unnikrishnan, M; Siddappa, S; Anto, R; Babu, V; Paul, B; Kapilamoorthy, TR; Sivasankaran, S; Sandhyamani, S; Sreedhar, R; Radhakrishanan, K
    Background: Atherosclerotic carotid artery disease poses a grave threat to cerebral circulation, leading to a stroke with its devastating sequelae, if left untreated. Carotid endarterectomy has a proven track record with compelling evidence in stroke prevention. Objectives: a)To confirm that carotid endarterectomy (CEA) is safe and effective in preventing stroke at both short and long term. b) to demonstrate long term patency of internal carotid artery when arteriotomy repair is performed using autologous saphenous vein patch. Materials and Methods: During ten years, from September 1997 to February 2008, thirty nine patients who underwent consecutive carotid endarterectomy at our institute, form the basis of this report. Their age ranged from thirty to seventy eight years, with a mean age of 56. There were four women in this cohort. Thirty seven patients were symptomatic with >70% stenosis and two were asymptomatic with >80% stenosis, incidentally detected. Imaging included Duplex scan and MRA for carotid territory and brain, and non-invasive cardiac assessment. Co-morbidities included smoking, hypertension, diabetes, and coronary artery disease. Carotid Endarterectomy was performed under general anaesthesia, using carotid shunt and vein patch arteriotomy repair. Results: All the patients made satisfactory recovery, without major adverse cerebral events in this series. Morbidities included Transient Ischemic Attack (TIA) in two, needing only medications in one, and carotid stenting in the other. Minor morbidities included neck hematoma in two and transient hypoglossal paresis in three patients. Yearly follow-up included duplex scan assessment for all the patients. Two patients died of contralateral stroke, two of myocardial events and two were lost to follow up. Thirty three patients are well and free of the disease during the follow up of three to 120 months. Conclusion: Carotid endarterectomy provided near total freedom from adverse cerebral events and its catastrophic sequelae, leading to excellent outcome, both short as well as long term.
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    Focal occlusive disease of the common femoral artery: a report of 20 cases.
    (Cardiovascular surgery (London, England), 1994)
    Occlusive disease localized to the common femoral artery without contiguous involvement of the external iliac and superficial femoral arteries is distinctly uncommon in vascular surgical practice. Twenty patients with focal occlusive disease in 21 common femoral arteries are featured in this report. All except one had severe disabling symptoms: Fontaine classification was stage I in one patient, stage IIb in 13, and stage III in six patients. The probable aetiology, based on clinical features and angiographic observations, was identified as atherosclerosis (nine cases), thromboangiitis obliterans (three) and Takayasu's arteritis (two). Histological features of mucoid vasculopathy, a novel disorder, was seen in one patient while no specific aetiology was evident in five patients. Associated lesions were seen in fourteen patients: aortoiliac in one, femoropopliteal in seven (without any continuity to the common femoral lesion), internal iliac in three and tibial in three. Balloon angioplasty of the common femoral artery lesions was attempted in 14 patients with successful outcome in nine. Three patients (including two with failed balloon angioplasty), underwent thromboendarterectomy and two bypass procedures (iliofemoral, one; femoropopliteal, one). Late reocclusion occurred in one patient each in the angioplasty and surgical groups. There were no procedure-related complications in either group.
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    Influence of Tissue Fluorescence Measurement and Imaging by Auto-Fluorescence of Substrata
    (JOURNAL OF APPLIED SPECTROSCOPY, 2015) Kumar, BS; Sandhyamani, S; Nazeer, SS; Jayasree, RS
    Polymers, glass and fiber reinforced materials are increasingly being used in photophysical devices. The inherent fluorescence of devices made of these materials may itself become important during fluorescence detection. It may interfere with or even negate the low fluorescence signals emitted from fluorophores molecules of interest especially when the fluorophores exist in microvolume samples. Such effects are significant when tissue micro-sections placed on substrata of high background fluorescence. Using different excitation wavelengths, fluorescence spectral and imaging studies were carried out to examine the effect of background fluorescence of microslides made of various substrata such as glass, polycarbonate and aluminium on autofluorescence of tissue sections. With decreasing wavelength of excitation, all substrata showed increased autofluorescence. Glass showed least inherent fluorescence and aluminium showed more reflectance than autofluorescence. After continuous exposure to blue and UV light, all substrata showed irreversible decreased autofluorescence. During spectrofluorimetric studies, a definite blue shift was observed in the autofluorescence of tissue sections placed on microslides made of each of the materials. This suggests an interference of tissue autofluorescence by background fluorescence emitted by the substratum. This may lead to false positive or negative reporting of the fluorophores, particularly important while analyzing micro-sections of biological samples. Microscopic imaging did not show any background fluorescence for glass substratum with blue light. However, with UV light, glass also showed background fluorescence during imaging. Other substrata showed strong background fluorescence or reflectance with both blue and UV light. This study has the potential for accurate quantification of fluorescence spectral and decay and improved fluorescence imaging using the photobleaching effect.
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    Influence of tissue fluorescence measurement and imaging by autofluorescence of substrata
    (Journal of Applied Spectroscopy, 2015-08) Santhosh Kumar, B; Sandhyamani, S; Nazeer, SS; Jayasree, RS
    Polymers, glass and fi ber reinforced materials are increasingly being used in photophysical devices. The inherent fl uorescence of devices made of these materials may itself become important during fl uorescence detection. It may interfere with or even negate the low fl uorescence signals emitted from fl uorophores molecules of interest especially when the fl uorophores exist in microvolume samples. Such effects are signifi cant when tissue micro-sections placed on substrata of high background fl uorescence. Using different excitation wavelengths, fl uorescence spectral and imaging studies were carried out to examine the effect of background fl uorescence of microslides made of various substrata such as glass, polycarbonate and aluminium on autofl uorescence of tissue sections. With decreasing wavelength of excitation, all substrata showed increased autofl uorescence. Glass showed least inherent fl uorescence and aluminium showed more refl ectance than autofl uorescence. After continuous exposure to blue and UV light, all substrata showed irreversible decreased autofl uorescence. During spectrofl uorimetric studies, a defi nite blue shift was observed in the autofl uorescence of tissue sections placed on microslides made of each of the materials. This suggests an interference of tissue autofl uorescence by background fl uorescence emitted by the substratum. This may lead to false positive or negative reporting of the fl uorophores, particularly important while analyzing micro-sections of biological samples. Microscopic imaging did not show any background fl uorescence for glass substratum with blue light. However, with UV light, glass also showed background fl uorescence during imaging. Other substrata showed strong background fl uorescence or refl ectance with both blue and UV light. This study has the potential for accurate quantifi cation of fl uorescence spectral and decay and improved fl uorescence imaging using the photobleaching effect.
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    Intracalvarial schwannoma: A case report with review of literature
    (NEUROLOGY INDIA, 2014) Amita, R; Sandhyamani, S; Abraham, M; Nair, S; Praveen, A; Kapilamoorthy, TR
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    Intracranial Ewings Sarcoma/peripheral primitive neuroectodermal tumor
    (NEUROLOGY INDIA, 2014) Amita, R; Sandhyamani, S; Nair, S; Kapilamoorthy, TR
    Central nervous system primitive neuroectodermal tumours (CNS PNET) are aggressive embryonal tumours composed of undifferentiated or poorly differentiated neuroepithelial cells seen in the pediatric age group. This is rare and only a handful of cases of ES/pPNET in CNS are reported. We report such a case in a 3 year old child. Reporting of more such cases is needed to better define these rare tumours of the dura.
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    Intraventricular neurocytoma: a report of two cases.
    (Indian journal of cancer, 1994)
    Central neurocytomas are uncommon intracranial neoplasms. More than one hundred cases are documentated in the literature. In this report we describe the clinical and histopathological features in two patients with intraventricular neurocytoma. As the light microscopic features of neurocytoma resemble with that of an oligodendroglioma, it is essential to differentiate these two tumours, using either ultrastructural or immunohistochemical techniques.
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    Low-protein corn-starch based diets exclude role of toxic factors from tapioca in induction of mucoid vasculopathy and associated disorders
    (TROPICAL TUBER CROPS: PROBLEMS, PROSPECTS AND FUTURE STRATEGIES, 1996) Sandhyamani, S
    Using low-protein tapioca-starch-based diets, degenerative cardiovascular changes similar to those in the human disorder, mucoid vasculopathy, were induced in a monkey model. The experiments were repeated using low-protein corn-starch-substituted diets and identical changes were obtained. The experiments demonstrated the etiologic role of protein deficiency in mucoid vasculopathy and lesion enhancement by either tapioca-starch or corn-starch in protein-deficient state. The experiments excluded the possibility of any toxic factors from tapioca starch in inducing the changes. The role of high carbohydrate (irrespective of the source) with low-protein intake in the development of degenerative diseases could also be established.
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    Metachronous malignant fibrous histiocytoma of skull - A case report
    (RIVISTA DI NEURORADIOLOGIA, 2005) Pendharkar, HS; Bodhey, NK; Gupta, AK; Purkayastha, S; Sandhyamani, S; Burathoki, SK
    Primary Malignant Fibrous Histiocytoma (MFH) of skull is a rare tumour with malignant features similar to MFH located elsewhere. Primary MFH of bone may metastasize to soft tissues or other bones. We report a case of a metachronous MFH involving the skull.
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    Mucoid arteriosclerotic and nerve degenerative lesions in esophageal carcinoma
    (HUMAN PATHOLOGY, 1999) Sandhyamani, S; Cooper, K
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    Optical diagnosis of the progression and reversal of CCl(4)-induced liver injury in rodent model using minimally invasive autofluorescence spectroscopy
    (Analyst., 2015-03) Nazeer, SS; Sandhyamani, S; Jayasree, RS
    Worldwide, liver cancer is the fifth most common cancer in men and seventh most common cancer in women. Intoxicant-induced liver injury is one of the major causes for severe structural damage with fibrosis and functional derangement of the liver leading to cancer in its later stages. This report focuses on the minimally invasive autofluorescence spectroscopic (AFS) studies on intoxicant, carbon tetrachloride (CCl4)-induced liver damage in a rodent model. Different stages of liver damage, including the reversed stage, on stoppage of the intoxicant are examined. Emission from prominent fluorophores, such as collagen, nicotinamide adenine dinucleotide (NADH), and flavin adenine dinucleotide (FAD), and variations in redox ratio have been studied. A direct correlation between the severity of the disease and the levels of collagen and redox ratio was observed. On withdrawal of the intoxicant, a gradual reversal of the disease to normal conditions was observed as indicated by the decrease in collagen levels and redox ratio. Multivariate statistical techniques and principal component analysis followed by linear discriminant analysis (PC-LDA) were used to develop diagnostic algorithms for distinguishing different stages of the liver disease based on spectral features. The PC-LDA modeling on a minimally invasive AFS dataset yielded diagnostic sensitivities of 93%, 87% and 87% and specificities of 90%, 98% and 98% for pairwise classification among normal, fibrosis, cirrhosis and reversal conditions. We conclude that AFS along with PC-LDA algorithm has the potential for rapid and accurate minimally invasive diagnosis and detection of structural changes due to liver injury resulting from various intoxicants.