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Abstract
Although rare, reports of carcinoma cervix recurring in abdominal incision, episiotomy scars, laparoscopic port sites, and drain sites are available. However, recurrence in the scar of a previous cesarean section (CS) is unreported. A 49-year-old female with a diagnosis of keratinizing squamous cell carcinoma (SCC) of cervix, stage IIB, was treated by radical radiotherapy. She had undergone CS, through midline abdominal incision, for three previous deliveries. Twenty months later, she presented with a nodule of size 2.5 x 2 cm(2) on the 26-year-old abdominal CS scar. Infiltration of the skin and extension into the deeper structures of the abdominal wall was present in an area of 5 x 4 cm(2). There was no evidence of disease on the cervix. A fine-needle aspiration cytologic examination from the nodule revealed keratinizing SCC. Ultrasonography and computerized tomography scan revealed a mass lesion along the abdominal CS scar with subcutaneous nodule and peritoneal extension. Multiple metastatic lesions were present in the liver. She was treated with chemotherapy and radiotherapy. The patient has lived for more than 12.5 months. The first report of recurrence of carcinoma cervix in a CS scar is presented. Literature on surgical scar recurrence in carcinoma cervix is reviewed.
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Abstract
Small DNA tumour viruses have evolved a number of mechanisms to drive nondividing cells into S phase. Virally encoded oncoproteins such as adenovirus E1A and human papillomavirus (HPV) E7 can bind an array of cellular proteins to override proliferation arrest. The DNA methyltransferase Dnmt1 is the major mammalian enzyme responsible for maintaining CpG methylation patterns in the cell following replication. One of the hallmarks of tumour cells is disrupted DNA methylation patterns, highlighting the importance of the proper regulation of DNA methyltransferases in normal cell proliferation. Here, we show that adenovirus 5 E1A and HPV-16 E7 associate in vitro and in vivo with the DNA methyltransferase Dnmt1. Consistent with this interaction, we find that E1A and E7 can purify DNA methyltransferase activity from nuclear extracts. These associations are direct and mediated by the extreme N-terminus of E1A and the CR3 zinc-finger domain of E7. Furthermore, we find that a point mutant at leucine 20 of E1A, a residue known to be critical for its transformation functions, is unable to bind Dnmt1 and DNA methyltransferase activity. Finally, both E1A and E7 can stimulate the methyltransferase activity of Dnmt1 in vitro. Our results provide the first indication that viral oncoproteins bind and regulate Dnmt1 enzymatic activity. These observations open up the possibility that this association may be used to control cellular proliferation pathways and suggest a new mechanism by which small DNA tumour viruses can steer cells through the cell cycle.
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Effect of Prevailing Local Treatment Options of Breast Cancer on Survival Outside Controlled Clinical Trials: Experience of a Specialist Breast Unit in North India. World J Surg 2006; 30:1794-801. [PMID: 16983461 DOI: 10.1007/s00268-006-0037-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND This study aimed at analyzing different treatments of breast cancer (BC) prevalent in the region, their effect on patients' survival, and discusses the most suitable method within available resources. METHODS The study was set up at a tertiary care hospital in north India. We retrospectively reviewed data of 473 female BC patients who attended the departments of Surgical Oncology and Radiotherapy from January 1997 to December 1999. Patients with cTNM stage IV and inoperable stage III were included; those who defaulted or were lost to follow-up were excluded. Out of 473 patients, 372 were selected. The selected patients were divided into groups on the basis of place and type of local treatment they received: (1) local excision only, (2) standard breast conservation therapy (BCT), (3) total mastectomy (TM) + axillary lymph node dissection + radiotherapy (RT), and (4) modified radical mastectomy (MRM) + RT. Data regarding recurrence and survival were analyzed in December 2005. Minimum follow-up was 6 years. RESULTS Overall recurrence rates were significantly higher in patients operated elsewhere (P <0.0001). Of 194 operated at our Breast Unit, 25 (14.6%) of 171 MRM patients and none of 23 BCT had recurrence. Of 178 patients operated elsewhere, 44 (100%), 6 (42.9%), 41 (41%), and 8 (40%) developed recurrence in groups 1, 2, 3, and 4 respectively. Overall survival was significantly better in patients with MRM at our unit versus TM outside (93.6% vs. 80%). CONCLUSIONS Several types of treatment from improper local excision alone, BCT, TM, to a carefully done MRM are prevalent here. Properly done, MRM yields significant local control with survival benefit and appears to remain the gold standard in management of our BC patients.
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Pre-operative assessment of K-nail length in fracture shaft of femur. Kathmandu Univ Med J (KUMJ) 2006; 4:316-318. [PMID: 18603925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
INTRODUCTION Internal fixation of diaphyseal fracture of shaft of femur in an adult by Kuntscher nail is the most common operative method of treatment in Nepal where operative facilities for the same exist. Since the complete range of K-nail sizes and length are not available in most operation theatres in Nepal, most orthopaedic surgeons assess the size and length of the K-nail pre-operatively by various methods and keep one size above and below the assessed length for the planned surgery. MATERIALS AND METHODS The following measurements were taken in five hundred people involved in the study: Measurement No. 1: Tip of the greater trochanter to lateral knee joint line minus 2 cm. Measurement No. 2: Tip of the olecranon process to the tip of little finger, and Measurement No. 3: Tip of the greater trochanter to the upper pole of patella. An average of all three lengths were analysed to see if there were any differences in their mean lengths. RESULTS Analysis showed that there were significant differences between the mean lengths measured by the three different methods. The average length of measurement no: 2 was 3 cm longer than the average length of measurement no: 1, which is the reference pre-operative length of K.nail. CONCLUSION However, in practice since measurement no:2 is more convenient to perform and can also be used when the patient has sustained bilateral fractures of femur, an accurate pre-operative K-nail length assessment can be done by subtracting 3 cm from measurement no:2, i.e. the tip of the olecranon process to the tip of the little finger.
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Abstract
Platelet factor-3 (PF(3)) availability and platelet aggregation to ADP (4 micromol/l) and adrenaline (1.2 micromol/l) were evaluated in patients being treated with 5-fluorouracil (5-FU) for gastrointestinal malignancy. It produced a significant reduction in platelet aggregation and platelet factor-3 (PF(3)) availability ( P < 0.001) without being associated with thrombocytopenia. The changes in platelet aggregation occurred during the first week of chemotherapy and continued with subsequent courses. This acquired abnormality may be responsible for a haemorrhagic diathesis even without obvious thrombocytopenia. Study of platelet function is important and may be considered to assess the haematological toxicity in patients being treated with systemic 5-FU therapy.
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Catheters, coils, cathlab crashes—New vistas for cardiac surgery. Indian J Thorac Cardiovasc Surg 2006. [DOI: 10.1007/s12055-006-0684-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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157
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Verruciform xanthoma of the oral mucosa. JNMA J Nepal Med Assoc 2006; 45:207-11. [PMID: 17160099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023] Open
Abstract
Verruciform xanthoma is a rather rare lesion that is mostly confined to the oral mucosa. The clinical picture may vary considerably. The diagnosis is based on the presence of numerous xanthoma cells in the connective tissue papillae. A case of verruciform xanthoma on the gingiva in relation to lower right posterior region in a 43-year-old man is presented. The findings reported in the literature are also discussed.
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Surveillance of bacteriological quality of natural water resources in rural areas around Kasauli Town, Distt. Solan, Himachal Pradesh. THE JOURNAL OF COMMUNICABLE DISEASES 2005; 37:289-95. [PMID: 17278659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A study was conducted to find out the bacteriological quality of water during the monsoon season in local areas around Kasauli Town, and to evaluate the management of water resources in rural areas. The water samples were collected from bowries and hand pumps. As there is no municipal water supply in majority of these areas, the local residents depends mainly on these natural resources without any treatment of water. All the 14 surface water samples collected from bowries were found bacteriologically polluted with total coliform count ranging from 35-1800+. The main contaminants isolated were atypical thermotolerant E. coli, Pseudomonas fluorescence, Enterobacter cloacae, Aeromonas liquifaciens, Citrobacter freundii and Pseudomonas pseudomaleii. Among seven hand pump samples, two were found to have Coliform count 80 and 250 respectively. These two water samples were found contaminated with Citrobacter freundii and E. coli &Aeromonas liquefaciens respectively. These bacteriological contaminations appear to be both from vegetative & human or animal excreta sources. The study therefore suggested that the water from these natural resources requires treatment either by boiling or chlorination before human consumption to avoid any outbreak.
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Quench detection and data acquisition system for SST-1 superconducting magnets. FUSION ENGINEERING AND DESIGN 2005. [DOI: 10.1016/j.fusengdes.2005.06.288] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Interaction between the Water Soluble Poly{1,4-phenylene-[9,9-bis(4-phenoxy butylsulfonate)]fluorene-2,7-diyl} Copolymer and Ionic Surfactants Followed by Spectroscopic and Conductivity Measurements. J Phys Chem B 2005; 109:19108-15. [PMID: 16853464 DOI: 10.1021/jp052233o] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The interaction has been studied in aqueous solutions between a negatively charged conjugated polyelectrolyte poly{1,4-phenylene-[9,9-bis(4-phenoxybutylsulfonate)]fluorene-2,7-diyl} copolymer (PBS-PFP) and several cationic tetraalkylammonium surfactants with different structures (alkyl chain length, counterion, or double alkyl chain), with tetramethylammonium cations and with the anionic surfactant sodium dodecyl sulfate (SDS) by electronic absorption and emission spectroscopy and by conductivity measurements. The results are compared with those previously obtained on the interaction of the same polymer with the nonionic surfactant C12E5. The nature of the electrostatic or hydrophobic polymer-surfactant interactions leads to very different behavior. The polymer induces the aggregation with the cationic surfactants at concentrations well below the critical micelle concentration, while this is inhibited with the anionic SDS, as demonstrated from conductivity measurements. The interaction with cationic surfactants only shows a small dependence on alkyl chain length or counterion and is suggested to be dominated by electrostatic interactions. In contrast to previous studies with the nonionic C12E5, both the cationic and the anionic surfactants quench the PBS-PFP emission intensity, leading also to a decrease in the polymer emission lifetime. However, the interaction with these cationic surfactants leads to the appearance of a new emission band (approximately 525 nm), which may be due to energy hopping to defect sites due to the increase of PBS-PFP interchain interaction favored by charge neutralization of the anionic polymer by cationic surfactant and by hydrophobic interactions involving the surfactant alkyl chains, since the same green band is not observed by adding either tetramethylammonium hydroxide or chloride. This effect suggests that the cationic surfactants are changing the nature of PBS-PFP aggregates. The nature of the polymer and surfactant interactions can, thus, be used to control the spectroscopic and conductivity properties of the polymer, which may have implications in its applications.
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Accuracy of ultrasonography in evaluation of level and cause of biliary obstruction: a prospective study. Kathmandu Univ Med J (KUMJ) 2005; 3:17-21. [PMID: 16401938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
AIM To find out the accuracy of ultrasound in evaluation of level and cause of biliary obstruction. MATERIALS AND METHODS Forty-five patients (26 to 86 years of age) with suspected biliary obstruction underwent Ultrasonography followed by Direct Cholangiograms (Percutaneous Transhepatic Cholangiography / Endoscopic Retrograde Cholangiography). The levels of biliary obstructions were grouped as hilar, suprapancreatic and intrapancreatic. Similarly the causes were grouped as malignant and benign. Diagnosis was confirmed either at surgery or histopathologically (USG-guided FNAC or ERC-biopsy). RESULTS Ultrasonography accurately identified the level of obstruction in 89 %( hilar), 91% (suprapancreatic) and 87% ( intrapancreatic) cases. Malignancy was found in 33 patients and remaining 12 had benign diseases. USG accurately identified malignant and benign causes in 91% and 84% cases respectively. Findings were found to be statistically significant (p-value =< 0.05 at 95%confidence interval). CONCLUSION This study showed that USG has high accuracy in identifying the level and cause of biliary obstruction. Considering cost, availability and patient friendly nature, Ultrasound should be the first imaging modality of choice in evaluation of biliary obstruction.
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Abstract
There are clinical, laboratory and imaging criteria to distinguish multiple sclerosis (MS) from neuromyelitis optica (NMO) and acute disseminated encephalomyelitis (ADEM). While MS has unknown aetiology, NMO is commonly associated with vasculitis and ADEM is supposed to be parainfectious in origin. In the present study, six patients are described from a group of 67 with a central demyelinating disorder whose clinical presentation did not conform to existing diagnostic criteria for ADEM, NMO or MS. Their clinical, laboratory and imaging characteristics were studied and analysed. Some features suggested a particular diagnosis but some other features favoured another diagnosis. The features included spinal cord involvement in a large vertical segment with cord swelling, optic neuritis, no lesions in the cerebral cortex, paraplegia with urinary retention during the acute phase, no oligoclonal band in cerebrospinal fluid, absence of any evidence of vasculitis, wide time-gap between spinal cord and optic nerve involvement, good recovery from acute phase of disease and a relatively benign course. We conclude that there exists a subpopulation of patients with central demyelinating disease in this region with mixed clinical features. Overall features suggested either a widened clinical spectrum of MS, NMO or ADEM or a possible overlap between them.
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Fluorescence Enhancement of the Water- Soluble Poly{1,4-phenylene-[9,9-bis- (4-phenoxybutylsulfonate)]fluorene-2,7-diyl} Copolymer inn-Dodecylpentaoxyethylene Glycol Ether Micelles. Macromolecules 2004. [DOI: 10.1021/ma048780+] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
The study was performed with the aim of prospectively characterizing infectious meningitis of different aetiology using magnetization transfer (MT) MRI. Spin-echo (SE) T(1), T(2) and pre- and post-contrast T(1) weighted MT images in 100 patients with aetiologically proven meningitis were evaluated for the visibility and enhancement of the meninges on pre- and post-contrast T(1) weighted MT images, respectively. The MT ratio (MTR) was calculated from the thickened meninges in tuberculous meningitis. In addition, the percentage difference in the mean signal intensity (SI) of the meninges and adjacent brain parenchyma was calculated and compared between different groups using 2-tailed student's t-test. T(1) weighted MT images were highly sensitive (96%) in the detection of abnormal meningeal enhancement. Meninges were visible on pre-contrast T(1) weighted MT images only in patients with tuberculous meningitis. The MTR from meninges in tuberculous infection was 19.10+/-1.02, and the percentage difference in the mean SI of the meninges and the adjacent T(2) normal brain parenchyma was significantly higher (p<0.05) in the tuberculous group compared with that in the non-tuberculous group. MT MRI is an important technique for the detection and characterization of infectious meningitis of different aetiology. Visibility of the meninges on pre-contrast T(1) weighted MT images may be considered highly suggestive of tuberculous meningitis.
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Abstract
BACKGROUND Since publication of the UK Prospective Diabetes Study (UKPDS) in 1998, there has been a clear evidence base for tight glycaemic (HBA(1c) < 7.0%) and blood pressure (BP < 140/85 mmHg) control. AIM To determine the effect of UKPDS-based intensified glycaemic and BP targets on the care of type 2 diabetic patients attending a routine diabetes clinic. DESIGN Two surveys, each of 500 consecutively attending type 2 diabetic patients. METHODS The first survey was in a 3-month period in 1999, shortly after publication of the UKPDS study. The second was identical, but 2 years later. Glycaemic control (by DCCT-aligned HBA(1c)), BP and treatment details were recorded in both. RESULTS BP control was significantly improved in the second survey (mean +/- SD systolic BP from 151 +/- 25 to 146 +/- 26 mmHg, p = 0.001; diastolic from 77 +/- 13 to 72 +/- 12 mmHg, p < 0.0001) and the proportion of patients on anti-hypertensive treatment increased from 33% to 60% (p < 0.0001). Mean HbA(1c) however remained unchanged (8.7 +/- 1.8% in 1999 vs. 8.5 +/- 1.8% in 2001), although there was evidence of more intensive treatment patterns, with declining numbers on diet alone and more on oral agents and/or insulin. DISCUSSION Intensified BP control may be achievable within the confines of routine diabetes care, but achievement of optimal glycaemic targets remains problematic.
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GYNECOLOGICAL MALIGNANCY IN BPKMCH, BHARATPUR: A RETROSPECTIVE ANALYSIS OF 321 CASES. JNMA J Nepal Med Assoc 2003. [DOI: 10.31729/jnma.825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Gynecological Malignancy is the leading cancer in female not only in Nepal butworldwide. A retrospective study of histopathological specimens was conducted inBPKMCH Bharatpur from July 1999 to January 2001, duration of 19 months. Total321 cases of Gynecological Malignancy were diagnosed in Department of Pathologyof BPKMCH. Out of which 272(84.73%) cases of cancer of cervix; 17 cases (5.29%)of cancer of vulva; 14 cases (4.36%) of ovarian cancer, 12 cases (3.73%) of cancer ofvagina and 6 cases (1.86%) of endometrial cancer were detected. Cancer of cervixwas most common in 40-49 years age group followed by 50-59 years age group. Meanage of the patients with cancer of cervix was 50 years and 10 months; minimum of 29years and maximum of 76 years. Out of 272 cases of cancer of cervix, 266 (97.79%)were squamous cell carcinoma and rest 6 (2.20%) were adenocarcinoma. Commonesthistology in vulva and vagina was squamous cell carcinoma, whereas adenocarcinomawas commonest in endometrium and ovary. The higher incidence of gynecologicalmalignancies particularly carcinoma of cervix was observed in BPKMCH.Key Words: Cancer, Cervix, Vagina, Vulva, Ovary.
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NICOTINE ENHANCES ENDOTHELIAL CELL (EC) ADHESION MOLECULE EXPRESSION VIA P38 MITOGEN-ACTIVATED PROTEIN KINASE (MAPK). Shock 2003. [DOI: 10.1097/00024382-200306001-00088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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168
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Abstract
OBJECTIVES Some patients with neurocysticercosis (NCC) develop perilesional gliosis during the course of healing and carry poor prognosis for the seizure control. We evaluated the clinical status of these patients during complete control of their original seizures on anti-epileptic drugs (AED). MATERIAL AND METHODS We studied 172 patients with solitary NCC, 45 with perilesional gliosis as visible on magnetization transfer spin echo (MTSE) magnetic resonance imaging and 127 without gliosis, for any abnormal symptom during the course of their "seizure-free" period. All of them received optimum doses of AED to control the original seizures. RESULTS Patients with gliosis had high incidence of abnormal symptoms with or without corresponding abnormalities on surface electroencephalogram (EEG). These symptoms disappeared on increasing the dose or adding a new AED. The symptoms, which were transient episodic in nature, included heaviness, dystonic posturing, weightlessness, numbness and alien limb phenomenon on the side of the body contralateral to cerebral lesion, and headache. CONCLUSION Patients with NCC who develop perilesional gliosis during the process of healing tend to suffer from disturbing intermittent symptoms during their apparent control of seizures. The symptoms are controllable with increased dosage of previously prescribed or addition of another AED. As these symptoms could possibly be epileptic in nature, their identification and treatment may have a bearing on long-term seizure control after stopping AED therapy.
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Predictive value of ultrasonography in the diagnosis of palpable breast lump. Kathmandu Univ Med J (KUMJ) 2003; 1:78-84. [PMID: 16388202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
A lump is the first symptom in over 80 percent of all patients with cancer of the breast. Consequently, the finding of any lump in the breast is a highly significant sign and warrants a thorough investigation. The present study was undertaken to study the predictive value of ultrasonography in the diagnosis of palpable breast lumps. Fifty-two female patients with palpable breast lumps that were unilateral underwent ultrasonography of the breast. Thirty-six of these patients who had solitary, unilateral, solid lumps were followed up with FNAC/biopsy/mammography and the findings were compared. The mean age group was seen to be 41 years. The youngest patient was 17 years old and the oldest was 80 years. The validity of USG in the diagnosis of palpable breast lumps was calculated. A sensitivity value of 95%, specificity of 94.10%, positive and negative predictive values of 95.50% and 93.75% were noted and were comparable to other similar studies. The sensitivity, specificity, positive and negative predictive values were statistically significant (p=0.0000006) and were comparable to the values obtained by different studies conducted elsewhere. Among the multiple USG parameters, shape, margins, vascularity, surrounding tissue character, sound transmission through the lump were more significant in the diagnosis of benign vs. malignant lumps. Echogenicity and echotexture were of less significance.
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2P-0488 Nicotine enhances endothelial cell (EC) adhesion molecule expression — Involvement of protein kinase C (PKC), P38 mitogen-activated protein kinase (MAPK) and NFkB. ATHEROSCLEROSIS SUPP 2003. [DOI: 10.1016/s1567-5688(03)90629-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Hypogammaglobulinemia in pediatric lung transplant recipients is associated with increase mortality. J Heart Lung Transplant 2003. [DOI: 10.1016/s1053-2498(02)00876-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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3P-0655 STAT-3 activation in smooth muscle cells (SMC) subjected to cyclic strain. ATHEROSCLEROSIS SUPP 2003. [DOI: 10.1016/s1567-5688(03)90875-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Sonographic and colour doppler morphology in carcinoma gallbladder. Indian J Cancer 2002; 39:143-8. [PMID: 12928573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Conventional radiography has limitations in accurate diagnosis of gallbladder cancer (GBC). Ultrasonography (USG) allows correct diagnosis in 70-80% advanced and 23% early GBC. Present study was initiated to identify morphology and flow characteristics in GBC using conventional USG and Colour Doppler USG (CD-USG). In 100 patients, USG assessed morphology of mass lesion/wall thickening together with associated features. Of these, 60 cases were studied using CD-USG for intralesional/perilesional vascularity, peak systolic flow velocity (V max), resistive index (RI) and pulsatility index (PI). USG identified GB with mass lesion in 44% cases (Group-I) and only mass in GB fossa in 56% cases (Group-II). Findings identified calculi (73%), liver infiltration (74%), intrahepatic ductal dilatation (IHDD) (52%), lymphadenopathy (19%) and ascites (5%). CD-USG revealed vascularity, mainly pulsatile flow, in 78.3% cases (in 91.3% Group-I cases). Mean Vmax was 0.3037 m/sec (0.109 - 0.646 m/sec.), mean RI was 0.6621 (0.526 - 1.000) and PI was 1.282 (0.772 -2.140), Mean Vmax and PI were higher in Group-I compared to Group-II. Presence of calculus in 73% cases suggests a high association between calculus and malignancy. As flow signals were seen in 78% of all cases and 91.3% Group-I cases undergoing CD-USG, USG and CD-USG together can improve pickup rate of GBC.
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MRI features of toxoplasma encephalitis in the immunocompetent host: a report of two cases. Neuroradiology 2002; 44:834-8. [PMID: 12389133 DOI: 10.1007/s00234-002-0852-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2001] [Accepted: 07/06/2002] [Indexed: 10/27/2022]
Abstract
Central nervous system involvement due to toxoplasmosis in an immunocompetent host is rare. We describe MRI features in two immunocompetent patients with cerebral toxoplasmosis and compare these with those for the immunocompromised host.
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Demonstration of Scolex in Calcified Cysticercus Lesion using Gradient Echo with or without Corrected Phase Imaging and its Clinical Implications. Clin Radiol 2002. [DOI: 10.1053/crad.2002.0979] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Demonstration of scolex in calcified cysticercus lesion using gradient echo with or without corrected phase imaging and its clinical implications. Clin Radiol 2002; 57:826-34. [PMID: 12384109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
AIM This study was performed to determine the magnetic resonance imaging (MRI) sequence that was best suited to demonstrate the scolex in a calcified lesion and to seek the explanation for the appearance of a negative phase in a calcified scolex on corrected gradient refocused echo (GRE) phase imaging. MATERIALS AND METHODS Forty-nine patients with single/multiple computed tomography (CT) documented homogeneous calcified lesions and/or calcified scolices in cysts were studied with conventional spin echo and corrected GRE phase imaging. Calcium and different paramagnetic substances from cysticerci scolices of a sample of infected swine muscle were quantified. RESULTS The scolex could be demonstrated in 29/39 patients with single calcified lesion. GRE imaging with an echo time of 35ms was the only sequence that demonstrated scolex in all these 29 cases. 15/29 patients with a single calcified lesion, in all 10 patients with multiple calcified lesions and infected swine muscle with multiple cysts and calcified scolex, corrected GRE phase imaging showed negative phase in all these scolices. Estimation of minerals from the calcified scolices from the swine muscle showed by spectroscopic techniques 41.2% of the total mineral contents as paramagnetic substances. CONCLUSION We conclude that GRE imaging is the imaging method of choice for demonstration of the scolex in a CT calcified lesion. The negative phase on corrected GRE phase imaging is due to the presence of large amount of paramagnetic substances.
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Dynamic critical behavior of failure and plastic deformation in the random fiber bundle model. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2002; 66:016116. [PMID: 12241435 DOI: 10.1103/physreve.66.016116] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2002] [Revised: 04/03/2002] [Indexed: 05/23/2023]
Abstract
The random fiber bundle (RFB) model, with the strength of the fibers distributed uniformly within a finite interval, is studied under the assumption of global load sharing among all unbroken fibers of the bundle. At any fixed value of the applied stress sigma (load per fiber initially present in the bundle), the fraction U(t)(sigma) of fibers that remain unbroken at successive time steps t is shown to follow simple recurrence relations. The model is found to have stable fixed point U*, filled (sigma) for applied stress in the range 0 < or = sigma < or = sigma(c), beyond which total failure of the bundle takes place discontinuously [abruptly from U*, filled (sigma(c)) to 0]. The dynamic critical behavior near this sigma(c) has been studied for this model analyzing the recurrence relations. We also investigated the finite size scaling behavior near sigma(c). At the critical point sigma = sigma(c), one finds strict power law decay (with time t) of the fraction of unbroken fibers U(t)(sigma(c)) (as t--> infinity). The avalanche size distribution for this mean-field dynamics of failure at sigma < sigma(c) has been studied. The elastic response of the RFB model has also been studied analytically for a specific probability distribution of fiber strengths, where the bundle shows plastic behavior before complete failure, following an initial linear response.
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Utility of databases and information technology in pediatric neurology. Neurol India 2002; 50:123-7. [PMID: 12134172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Significant number of neurological patients in the pediatric age group have genetic and/or metabolic basis. It is difficult to remember details of each of them as their number is very large and the disorders are encountered infrequently. This impracticality necessitates the use of various websites and data base search. The internet has become a tool by which one can obtain and disseminate information. It has enhanced the medical person's ability to know at the earliest the developments in different medical specialities. Furthermore, these rare disorders are being recognized on the basis of specialized tests available only at selected centres which deal with few of these disorders. Our objective is to provide pediatric neurologists easy access to the expanding body of medical information and also to make them aware of the advancements in information technology, which is likely to facilitate telemedicine as a future consultancy service. Information about these diseases can also be facilitated by e-consultations.
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Needle aspiration as a diagnostic tool and therapeutic modality in suppurative lymphadenitis following Bacillus Calmette Guerin vaccination. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2002; 50:788-91. [PMID: 12240843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
OBJECTIVES Outbreaks are known to occur after Bacillus Calmette Guerin (BCG) vaccination. An outbreak of suppurative lymphadenitis in 18 infants, following BCG vaccination is reported from Sikkim, with incidence of 8.6%. The outbreak occurred after a change of vaccine. METHODS In a prospective study the cases of suppurative lymphadenitis were diagnosed by needle aspiration cytology and culture of the material aspirated and managed only with repeated needle aspiration and no antitubercular treatment was given. RESULTS Cytomorphology revealed necrosis alone in 66.6% and necrotizing granulomas in 22.2%. Acid and alcohol fast bacilli were detected in 77.7% cases. Mycobacterium bovis was isolated in eight cases. One case of staphylococcal suppurative lymphadenitis was detected. Sixteen cases were managed with weekly aspiration with mean period of resolution in eight weeks. CONCLUSIONS Needle aspiration is useful in the diagnosis and effective in the management of these cases. No antitubercular treatment is desired and required in the cases of suppurative lymphadenitis following BCG vaccination.
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181
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Valley sign in duchenne muscular dystrophy: importance in patients with inconspicuous calves. Neurol India 2002; 50:184-6. [PMID: 12134184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Several patients of Duchenne muscular dystrophy (DMD) do not demonstrate clinically remarkable calf hypertrophy. A new clinical sign visible behind the shoulders, which may be called 'valley sign', was tested for its utility in such cases as clinical diagnosis becomes difficult in these patients. Out of 142 DMD patients seen in the last 7 years, 12 were found to have inconspicuous calves. All the 12 patients had clinical, biochemical and/or genetic evidence of DMD. The new sign was examined by 3 independent observers in these 12 DMD patients and in 10 patients with other neuromuscular diseases. Eight DMD patients and none of the others showed positive sign. This signifies importance of this sign in the clinical diagnosis of DMD in those children in whom the calf muscle bulk is apparently normal.
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Multiparametric quantitation of the perilesional region in patients with healed or healing solitary cysticercus granuloma. Neuroimage 2002; 15:1015-20. [PMID: 11906241 DOI: 10.1006/nimg.2001.1036] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of this study was to compute T2 values and magnetization transfer (MT) ratios in the perilesional region of healing and healed cysticercus granulomas to determine if there are T2 abnormalities not apparent on conventional T2-weighted imaging and to determine the relationship between seizure control and the quantitative measures. Sixty-three patients were studied. T2 values and MT ratios were computed for the perilesional region and were compared with measurements from the contralateral normal-appearing region. A significantly increased T2 value was found for the perilesional region compared to the corresponding contralateral region despite the absence of qualitative abnormality on conventional T2-weighted magnetic resonance imaging. For patients showing normal-appearing perilesional regions on MT imaging, there was no significant difference in T2 and MT ratios between the perilesional and the normal contralateral regions. There was a statistically significant inverse correlation between perilesional T2 values and MT ratios, suggesting each was associated with perilesional gliosis. The study illustrates that quantitative evaluation of MT ratios and T2 augments the qualitative visual assessment of the perilesional region in healing or healed cysticercus granulomas.
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MRI demonstration of unsuspected intraventricular rupture of pyogenic cerebral abscesses in patients being treated for meningitis. Neuroradiology 2002; 44:114-7. [PMID: 11942361 DOI: 10.1007/s002340100696] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report three patients with pyogenic meningitis who showed a partial response to medical treatment. MRI demonstrated an unsuspected brain abscess with intraventricular rupture, a possible cause of the partial response to treatment.
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184
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Guillain-Barre syndrome and Campylobacter infection. THE SOUTHEAST ASIAN JOURNAL OF TROPICAL MEDICINE AND PUBLIC HEALTH 2001; 32:527-30. [PMID: 11944711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Campylobacter infection of the gastrointestinal tract has been observed as an antecedent illness in some patients with Guillain-Barre syndrome (GBS); these patients have been reported to have poor prognosis. We investigated 29 patients with GBS, admitted to our hospital from January 1996 to December 1999 for recent Campylobacter enteritis by culture of their stool specimens. Campylobacter upsaliensis and C. jejuni were isolated from stools of one patient each with acute motor axonal neuropathy (AMAN) and acute inflammatory demyelinating polyradiculoneuropathy (AIDP) respectively. The patient with C. upsaliensis infection was a 7 year-old male child who developed features of AMAN, 7 days after onset of diarrhea. He recovered gradually within 24 days with residual deficit in the form of foot drop. This deficit has persisted for last three and half years. The other patient with C. jejuni infection was a 9 year-old boy, who developed AIDP after 9 days of acute diarrhea. This patient recovered completely within 28 days of illness without any deficit. None of the patients had relapse of GBS. The present findings indicate the need of planned systematic studies to explore the role of C. upsaliensis and other campylobacters as agents of antecedent diarrhea in patients of GBS with different clinical presentations and prognosis.
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SMN2-deletion in childhood-onset spinal muscular atrophy. AMERICAN JOURNAL OF MEDICAL GENETICS 2001; 101:198-202. [PMID: 11424133 DOI: 10.1002/ajmg.1386] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The human genome has two homologous survival motor neuron genes, SMN1 and SMN2. Although deletions of SMN1 are frequently reported in childhood-onset spinal muscular atrophy (SMA), SMN2 have been found to be intact in patients with the disorder. We report on a 5-year-old boy with childhood-onset SMA who has a homozygous deletion of SMN2. He had wasting, weakness, and hyporeflexia, predominantly in the distal muscles. The muscles involved showed chronic neurogenic changes on electromyogram. There was no sensory involvement. A nerve conduction study showed near normal conduction velocity with reduction in the amplitude of the compound muscle action potential. Analysis of polymerase chain reaction-restriction fragment length polymorphism as well as single-strand conformation polymorphism on exons 7 and 8 of the SMN genes revealed the SMN2-deletion. Base sequencing and densitometric analysis of the critical region (exon 7) did not show any microdeletion or duplication of SMN1, but confirmed the deletion of SMN2. We conclude that a deletion of SMN2 may also result in the SMA phenotype.
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Pulmonary thromboendarterectomy combined with other cardiac operations: indications, surgical approach, and outcome. Ann Thorac Surg 2001; 72:13-7; discussion 17-9. [PMID: 11465167 DOI: 10.1016/s0003-4975(01)02686-8] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Patients with pulmonary hypertension due to chronic thromboembolic disease benefit from pulmonary thromboendarterectomy. A subset of these patients present with concomitant coronary or valvular disease. METHODS From July 1990 to July 2000, 90 patients (68 males, 22 females, mean age 68 years) with pulmonary vascular resistance (PVR) ranging from 297 to 2261 dynes x sec x cm(-5) underwent pulmonary thromboendarterectomy in conjunction with coronary bypass grafting (59 patients), coronary artery bypass grafting/foramen ovale closure (24 patients), tricuspid annuloplasty (3 patients), mitral valve repair (2 patients), and aortic valve replacement (2 patients). The perioperative and hemodynamic outcomes of these patients were compared with the cohort of 1,100 isolated pulmonary thromboendarterectomies performed at our institution during this time. RESULTS Overall perioperative survival (93.3%; 84 of 90 patients) and mean diminution in PVR (521 dynes x sec x cm(-5)) for patients undergoing combined operations were similar to those undergoing pulmonary thromboendarterectomy alone (94.2% survival; 1034 of 1100 patients; 547 dynes x sec x cm(-5) mean PVR reduction). Although patients undergoing combined operations were older (mean age 68 vs 50 years, p < 0.0001), had longer hospital stays (median 14 vs 9 days), and had worse left ventricular function (mean preoperative cardiac output 3.1 vs 4.4, p < 0.0001), there was no difference in cross-clamp time, resolution of tricuspid regurgitation, or postoperative systolic function between these two groups. CONCLUSIONS Pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension may be performed safely in conjunction with other cardiac operations. Older patients evaluated for pulmonary thromboendarterectomy should be screened for concomitant coronary and valvular disease.
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Human angiopoietin gene expression is a marker for severity of pulmonary hypertension in patients undergoing pulmonary thromboendarterectomy. J Thorac Cardiovasc Surg 2001; 122:65-73. [PMID: 11436038 DOI: 10.1067/mtc.2001.113753] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE A consistent pathologic feature seen in lungs of patients with pulmonary hypertension from thromboembolic disease is hyperplasia of the media of pulmonary arterioles. The molecular factors responsible for these vessel wall changes are unknown. Angiopoietin-1 is a gene responsible for the formation of the media of blood vessels in utero. We hypothesized that aberrant expression of the angiopoietin-1 gene in the adult lung would be a major contributing factor in the development of pulmonary hypertension. METHODS From April 1999 to March 2000, a total of 35 patients (18 men, 17 women, mean age 52 years) with pulmonary hypertension and pulmonary vascular resistance ranging from 407 to 2006 dynes x sec x cm(-5) underwent pulmonary endarterectomy at our institution. Before cardiopulmonary bypass, lung biopsy specimens were taken from each patient. Biopsy specimens were also obtained from 10 patients (5 women, 5 men, mean age 55 years) undergoing lung resection for causes other than pulmonary hypertension. All specimens were blindly scored by a pathologist for degree of medial hyperplasia. Quantitative reverse transcriptase-polymerase chain reaction, Western blot, and immunohistochemistry were used to quantitate angiopoietin-1 messenger RNA and protein in each sample. RESULTS Lung specimens from all patients with pulmonary hypertension demonstrated up-regulation of angiopoietin-1 at the messenger RNA level. The degree of angiopoietin-1 transcription was directly proportional to the preoperative pulmonary vascular resistance and medial wall hyperplasia/hypertrophy in each patient. By immunohistochemistry, angiopoietin-1 protein was confined to the media of pulmonary arterioles. Lung biopsy specimens from patients without pulmonary hypertension had no detectable expression of angiopoietin-1 at the messenger RNA or protein level. CONCLUSION Angiopoietin-1, a gene responsible for vessel development in the embryonic lung, is up-regulated in the lung parenchyma of patients with pulmonary hypertension. The level of expression of angiopoietin-1 at messenger RNA and protein levels correlates to the severity of pulmonary hypertension in patients with thromboembolic disease and serves as a target for strategies to treat this disease.
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Biotechnological potential of Microcystis sp. in Cu, Zn and Cd biosorption from single and multimetallic systems. Biometals 2001; 14:67-74. [PMID: 11368277 DOI: 10.1023/a:1016607729691] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This paper provides information on biosorption of Cu, Zn and Cd by Microcystis sp. in single, bi and trimetallic combination. Highest biosorption of Cu followed by Zn and Cd in single as well as in mixtures containing two or three metals was noticed. The order of inhibition of Cu, Zn and Cd biosorption in bi and trimetallic combinations was suggestive of screening or competition for the binding sites on the cell surface. This observation was reconfirmed by Freundlich adsorption isotherm. Kf values were maximum for Cu (Kf = 45.18), followed by Zn (Kf = 16.71), and Cd (Kf = 15.63) in single metallic system. The Kf values for each test metal was reduced in solution containing more than one metal. Further, the reduction in biosorption of each metal ion due to presence of other metal ion was of greater magnitude at relatively higher concentrations of interfering metal ion. The biosorption of Cu at saturation was less affected when secondary metal (Cd or Zn) was added in the medium. Above results suggest that Microcystis holds great potential for metal biosorption from mixture.
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The activity of the murine DNA methyltransferase Dnmt1 is controlled by interaction of the catalytic domain with the N-terminal part of the enzyme leading to an allosteric activation of the enzyme after binding to methylated DNA. J Mol Biol 2001; 309:1189-99. [PMID: 11399088 DOI: 10.1006/jmbi.2001.4709] [Citation(s) in RCA: 195] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The mammalian DNA methyltransferase Dnmt1 is responsible for the maintenance of the pattern of DNA methylation in vivo. It is a large multidomain enzyme comprising 1620 amino acid residues. We have purified and characterized individual domains of Dnmt1 (NLS-containing domain, NlsD, amino acid residues: 1-343; replication foci-directing domain, 350-609; Zn-binding domain (ZnD), 613-748; polybromo domain, 746-1110; and the catalytic domain (CatD), 1124-1620). CatD, ZnD and NlsD bind to DNA, demonstrating the existence of three independent DNA-binding sites in Dnmt1. CatD shows a preference for binding to hemimethylated CpG-sites; ZnD prefers methylated CpGs; and NlsD specifically binds to CpG-sites, but does not discriminate between unmethylated and methylated DNA. These results are not compatible with the suggestion that the target recognition domain of Dnmt1 resides in the N terminus of the enzyme. We show by protein-protein interaction assays that ZnD and CatD interact with each other. The isolated catalytic domain does not methylate DNA, neither alone nor in combination with other domains. Full-length Dnmt1 was purified from baculovirus-infected insect cells. Under the experimental conditions, Dnmt1 has a strong (50-fold) preference for hemimethylated DNA. Dnmt1 is stimulated to methylate unmodified CpG sites by the addition of fully methylated DNA. This effect is dependent on Zn, suggesting that binding of methylated DNA to ZnD triggers the allosteric activation of the catalytic center of Dnmt1. The allosteric activation model can explain kinetic data obtained by others. It suggests that Dnmt1 might be responsible for spreading of methylation, a process that is observed during aging and carcenogenesis but may be important for de novo methylation of DNA.
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Recombinant human DNA (cytosine-5) methyltransferase. III. Allosteric control, reaction order, and influence of plasmid topology and triplet repeat length on methylation of the fragile X CGG.CCG sequence. J Biol Chem 2001; 276:18605-13. [PMID: 11359795 DOI: 10.1074/jbc.m100404200] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Steady-state kinetic analyses revealed that the methylation reaction of the human DNA (cytosine-5) methyltransferase 1 (DNMT1) is repressed by the N-terminal domain comprising the first 501 amino acids, and that repression is relieved when methylated DNA binds to this region. DNMT1 lacking the first 501 amino acids retains its preference for hemimethylated DNA. The methylation reaction proceeds by a sequential mechanism, and either substrate (S-adenosyl-l-methionine and unmethylated DNA) may be the first to bind to the active site. However, initial binding of S-adenosyl-l-methionine is preferred. The binding affinities of DNA for both the regulatory and the catalytic sites increase in the presence of methylated CpG dinucleotides and vary considerably (more than one hundred times) according to DNA sequence. DNA topology strongly influences the reaction rates, which increased with increasing negative superhelical tension. These kinetic data are consistent with the role of DNMT1 in maintaining the methylation patterns throughout development and suggest that the enzyme may be involved in the etiology of fragile X, a syndrome characterized by de novo methylation of a greatly expanded CGG.CCG triplet repeat sequence.
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Cervical dural sac and spinal cord in juvenile muscular atrophy of distal upper extremity. Neurology 2001; 56:575. [PMID: 11222817 DOI: 10.1212/wnl.56.4.575] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Herbicide resistance from a divided EPSPS protein: the split Synechocystis DnaE intein as an in vivo affinity domain. Gene 2001; 263:39-48. [PMID: 11223241 DOI: 10.1016/s0378-1119(00)00568-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We report that the N- and C-terminal splicing domains of the intein found in the dnaE gene of Synechocystis sp. PCC6803 (Ssp DnaE intein) are capable of association in vivo and in vitro, even with key splicing residues changed to alanine (Cys(1), Asn(159), and Cys(+1) to Ala). These studies utilized the herbicide resistant form of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) from Salmonella typhimurium and an Escherichia coli strain with the EPSPS gene deleted from its genome (E. coli strain ER2799). EPSPS was mapped to identify potential split sites using a facile Tn7 linker scanning procedure. Forty positions were found to tolerate a five amino acid insertion while 21 sites did not, as assayed by the rescue of growth of E. coli strain ER2799. Further characterization of these sites by inserting a full length Ssp DnaE intein identified residue 235 of EPSPS as the optimal position. The EPSPS gene was then divided into amino acids 1-235 and 236-427 which were fused to residues 1-123 and 124-159 of a splicing defective Ssp DnaE intein, respectively. Expression of the EPSPS-intein fusions from separate DNA molecules conferred resistance to the herbicide glyphosate, indicating that the intein splicing domains were bringing the EPSPS fragments together to generate activity. As a control the split EPSPS without the intein-affinity domain did not allow cell growth. The use of an intein as an in vivo affinity domain was termed intein-mediated protein complementation (IPC). Intein fragment assembly was verified in vitro by immobilizing the C-terminal splicing domain of the Ssp DnaE intein on a resin and demonstrating that the N-terminal 235 amino acids of EPSPS only bound to the resin when fused to the N-terminal splicing domain of the Ssp DnaE intein. As chloroplast DNA is not transmitted by pollen in plants such as corn and soybean, transgene spread via pollen may be controlled in the future by expressing inactive gene fragments from separate DNA locations, such as the nuclear and chloroplast genome, and using the split intein to generate protein activity.
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Abstract
Japanese-B virus encephalitis (JE) is considered a uniphasic illness with a variable outcome. Biphasic illness patterns have never been reported previously. From an endemic zone in India we observed six patients of JE (from 62 patients treated in 7 years) who had an early relapse resulting in the biphasic clinical course. Five had poor socio-economic status and three had laboratory evidence of nutritional deficiency. Two patients were adults and the other four were children. Fever, rigors, headaches, body aches, altered consciousness, rigidity and tremors predominated the first phase of illness. During the second phase, behavioural changes, dystonia, pen-oral dyskinesia, drooling, mutism and muscle wasting due to anterior horn cell involvement were the important features. Though the serial antibody titres against the JE virus showed a four-fold rise in the initial or late convalescent phases, there was no increase during the second phase of the illness as compared to the first phase. On MRI, fresh lesions appeared during the second phase at the sites known for their involvement in JE, suggesting recrudescence of the virus. One patient survived with major sequelae, two with minor sequelae and the other three had complete recovery. We conclude that some patients with JE may have an early relapse after partial recovery, giving rise to the biphasic illness pattern. A locally prevalent genetic variant of the virus or host factors may be responsible for the altered clinical course of the disease. Biphasic illness does not necessarily mean a bad prognosis.
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Carrier detection in non-deletional Duchenne/Becker muscular dystrophy families using polymorphic dinucleotide (CA) repeat loci of dystrophin gene. Indian J Med Res 2001; 113:19-25. [PMID: 11280167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
BACKGROUND & OBJECTIVES Carrier detection and prenatal diagnosis is of great importance for families with one or more sons affected with Duchenne/Becker muscular dystrophy (D/BMD). In about 35-40 per cent of these patients, the causative mutation does not involve gross rearrangement in the structure of dystrophin gene. In these non-deletional families, genetic counselling can be provided only by linkage analysis. The aim of the present study was to determine the carrier status of female relatives in north Indian families with non-deletional D/BMD using highly polymorphic intragenic dinucleotide (CA) repeat markers. METHODS Six short tandem repeats (STRs) spanning 5' (1), central (4) and 3' regions of the dystrophin gene were used to analyse 14 unrelated families comprising 68 individuals with 12 female siblings at risk of being carriers. RESULTS Five female siblings inherited at risk STR haplotype, six inherited normal haplotype and one had meiotic recombination. The intragenic recombinations were observed in three families at the central region STR loci and in one family between the proximal and central regions of the gene. INTERPRETATION & CONCLUSIONS Our study suggested that at least 6 STR markers spanning 5', central and 3' regions of the dystrophin gene are essential to ascertain one or more informative loci and to rule out recombinations in non-deletional D/BMD families for carrier analysis.
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195
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Vascularization of developing human olfactory neuroepithelium - a morphometric study. Cells Tissues Organs 2000; 166:349-53. [PMID: 10867436 DOI: 10.1159/000016750] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The present study reveals intraepithelial capillaries in the olfactory neuroepithelium of human fetuses aged between 12 and 24 weeks of gestation, which disappear at birth. The area occupied by the intraepithelial capillaries increases significantly with fetal age (0.047 +/- 0.014 microm(2)/microm(2) at 12 weeks and 0.101 +/- 0. 025 microm(2)/microm(2) at 24 weeks) and with the thickness of the epithelium (45.00 +/- 6.74 microm at 8 weeks and 64.10 +/- 8.51 microm at 24 weeks). The vascularization of the developing neuroepithelium may suggest increased metabolic demand during development and maturation of the olfactory neuroepithelium, and postnatal retreat of capillaries to the underlying lamina propria may suggest diffusion of nutrients and gases from blood vessels into the lamina propria and direct gaseous exchange from the atmosphere.
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196
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Parkinsonism due to predominant involvement of substantia nigra in Japanese encephalitis. Neurology 2000; 55:602. [PMID: 10953209 DOI: 10.1212/wnl.55.4.602] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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197
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Perilesional gliosis and seizure outcome: a study based on magnetization transfer magnetic resonance imaging in patients with neurocysticercosis. Ann Neurol 2000; 48:181-7. [PMID: 10939568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
We studied the effect of perilesional gliosis on seizure recurrence after stopping antiepileptic drug (AED) therapy in 108 patients with a solitary cysticercal brain cyst. All patients received albendazole therapy in the beginning, and magnetic resonance imaging (MRI) done after 2 seizure-free years showed complete disappearance of the lesion in 67, partial degeneration in 12, and healing by calcification in 29. The gliosis, which was not visible on initial MRI, was observed near the lesion in 22 (20%) patients on T1-weighted magnetization transfer spin-echo (MTSE) MRI. Initial seizure control was difficult with single AED therapy in 16 of 22 patients with gliosis but only in 8 of 86 patients without gliosis. On stopping AED therapy, patients with perilesional gliosis had a higher incidence of seizure recurrence (19 of 22 patients) compared with those who did not demonstrate gliosis (9 of 86 patients). The presumption that gliosis visible on MTSE MRI correlates with seizure recurrence had a high specificity (96%) but only moderate sensitivity (68%). Our findings suggest that there is a group of patients with neurocysticercosis in whom the risk of seizure recurrence is actually high. Several such patients have perilesional gliosis that can be identified on T1-weighted MTSE MRI. These patients probably need long-term AED administration.
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Hybrid mouse-prokaryotic DNA (cytosine-5) methyltransferases retain the specificity of the parental C-terminal domain. EMBO J 2000; 19:2103-14. [PMID: 10790376 PMCID: PMC305692 DOI: 10.1093/emboj/19.9.2103] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2000] [Revised: 03/10/2000] [Accepted: 03/10/2000] [Indexed: 11/14/2022] Open
Abstract
The mouse (cytosine-5) DNA methyltransferase (Dnmt1) consists of a regulatory N-terminal and a catalytic C-terminal domain, which are fused by a stretch of Gly-Lys dipeptide repeats. The C-terminal region contains all of the conserved motifs found in other cytosine-5 DNA methyltransferases including the relative position of the catalytic Pro-Cys dipeptide. In prokaryotes, the methyltransferases are simpler and lack the regulatory N-terminal domain. We constructed three hybrid methyltransferases, containing the intact N-terminus of the murine Dnmt1 and most of the coding sequences from M.HhaI (GCGC), M.HpaII (CCGG) or M.SssI (CG). These hybrids are biologically active when expressed in a baculovirus system and show the specificity of the parental C-terminal domain. Expression of these recombinant constructs leads to de novo methylation of both host and viral genomes in a sequence-specific manner. Steady-state kinetic analyses were performed on the murine Dnmt1-HhaI hybrid using poly(dG-dC).poly (dG-dC), unmethylated and hemimethylated oligonucleotides as substrates. The enzyme has a slow catalytic turnover number of 4.38 h(-1) for poly(dG-dC). poly(dG-dC), and exhibits 3-fold higher catalytic efficiency for hemimethylated substrates.
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Inhibition of early DNA-damage and chromosomal aberrations by Trianthema portulacastruml. In carbon tetrachloride-induced mouse liver damage. Cell Biol Int 2000; 23:703-8. [PMID: 10736194 DOI: 10.1006/cbir.1999.0439] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The underlying molecular mechanisms of the antihepatotoxic activity of Trianthema portulacastrum by monitoring its effect on mouse liver DNA-chain break, sugar-base damage and chromosomal aberrations, during chronic or acute treatment with carbon tetrachloride (CCl(4)) have been studied. Daily oral feeding with the ethanolic extract (150 mg/kg basal diet, per os) was given 2 weeks before CCl(4)treatment and continued until the end of the experiment (13 weeks). T. portulacastrum extract offer unique protection (P< 0.05-0. 001) against the induction of liver-specific structural-type chromosomal anomalies 15, 30 or 45 days after the last CCl(4)insult, compared to control mice. This was further evidenced by extract-mediated protection (15 days prior feeding following a single necrogenic dose of CCl(4)) of the generation of DNA chain-break and Fe-sugar-base damage assays. The observed hepatoprotective mechanism could be due to its ability to counteract oxidative injury to DNA in the liver of mouse.
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Structure and function of the mouse DNA methyltransferase gene: Dnmt1 shows a tripartite structure. J Mol Biol 2000; 297:293-300. [PMID: 10715201 DOI: 10.1006/jmbi.2000.3588] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dnmt1 is the predominant DNA methyltransferase (MTase) in mammals. The C-terminal domain of Dnmt1 clearly shares sequence similarity with many prokaryotic 5mC methyltransferases, and had been proposed to be sufficient for catalytic activity. We show here by deletion analysis that the C-terminal domain alone is not sufficient for methylating activity, but that a large part of the N-terminal domain is required in addition. Since this complex structure of Dnmt1 raises issues about its evolutionary origin, we have compared several eukaryotic MTases and have determined the genomic organization of the mouse Dnmt1 gene. The 5' most part of the N-terminal domain is dispensible for enzyme activity, includes the major nuclear import signal and comprises tissue-specific exons. Interestingly, the functional subdivision of Dnmt1 correlates well with the structure of the Dnmt1 gene in terms of intron/exon size distribution as well as sequence conservation. Our results, based on functional, structural and sequence comparison data, suggest that the gene has evolved from the fusion of at least three genes.
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