Biomedical subjects

Rakesh K Gupta

Publications and source records attributed to Rakesh K Gupta.

52 records · Page 3Linked to original sources

PubMed2003

Neuroendoscopic Transnasal Repair of Cerebrospinal Fluid Rhinorrhea.

Cerebrospinal fluid (CSF) rhinorrhea is a common condition managed by most otolaryngologists with the help of nasal endoscopy (sinoscopy). In the last 2 years, we have used a neuroendoscope with a working sheath to treat nine patients with CSF rhinorrhea. One patient developed a recurrence 1 month after treatment but then responded to conservative treatment. We conclude that the treatment of CSF rhinorrhea by a neuroendoscope with a working sheath is safe, effective, and easy and obviates the need for a separate sinoscope.

Journal Article↗

PubMed2003

Isolated abscess of extraocular muscle in two young boys: clinical and imaging features.

PURPOSE: To report two cases of a cystic isolated extraocular muscle abscess in a young boy. METHOD: Case report. RESULTS: Two cases of young boys with a cystic isolated extraocular muscle abscess are described. Each presented as an inflammatory lesion in the orbit that had been stable for approximately three weeks. Neurodiagnostic imaging of the two cases revealed a cystic lesion in close proximity to an extraocular muscle. An ultrasound-guided aspiration of each lesion revealed material that, when cultured, grew Staphylococcus aureus. Both patients recovered with appropriate antibiotic therapy. No other systemic illness could be identified in either case. CONCLUSION: These cases illustrate that an isolated abscess involving an extraocular muscle may present like an inflammatory cyst even without any evidence of systemic illness. When evaluating and managing such lesions, the authors recommend the use of ultrasound-guided aspiration to avoid complications arising from delay in diagnosis and inappropriate treatment.

Abscess↗

PubMed2003

Magnetization transfer MR imaging in patients with posttraumatic epilepsy.

BACKGROUND AND PURPOSE: Intractable epilepsy is a well-recognized complication following head trauma, and many factors have been implicated in its pathogenesis. This study was performed to determine the severity of tissue damage after severe head injury as assessed with magnetization transfer (MT) MR imaging and the relationship of this damage with seizure intractability. METHODS: Forty-four patients, 13 without seizures (disease controls) and 31 with seizures, underwent T1-weighted MT MR imaging 1-10 years after head trauma. Phase-corrected gradient-echo (GRE) imaging was also performed in all patients to look for the presence of hemosiderin. All patients were evaluated for the presence of an MT abnormality beyond an abnormality seen on T2-weighted images, an MT abnormality within a T2 abnormality, and hemosiderin deposition. RESULTS: Patients with an MT abnormality beyond a T2 abnormality had a significantly higher intractability of seizures compared with those with an MT abnormality within a T2 abnormality (P <.05). In addition, the mere presence of hemosiderin deposit was not associated with seizure intractability; however, gliosis around the hemosiderin as seen on T1-weighted MT images was associated with seizure intractability. CONCLUSIONS: T1-weighted MT imaging may be of value in predicting the intractability of the seizure in delayed posttraumatic epilepsy.

Adolescent↗

PubMed2002

Differentiation of hydatid cyst from cysticercus cyst by proton MR spectroscopy.

The metabolite patterns obtained by ex vivo proton MR spectroscopy of fluid from different locations of hydatid cysts of sheep and humans (n = 16) and cysticercus cysts of swine and humans (n = 25) were compared with an objective of differentiating the two parasites on the basis of their metabolite pattern. The spectra from hydatid fluid differed from cysticercus cyst by the absence of creatine in the former. When the hydatid cyst was fertile, malate and/or fumarate was also observed, which was absent in cysticercus cyst. The most likely explanation for the presence of creatine only in the cysticercus fluid is its active diffusion from the surrounding host tissue along with a contribution from the musculature present in the bladder wall of the cyst.

Animals↗

PubMed2002

Fertility assessment of hydatid cyst by proton MR spectroscopy.

BACKGROUND: Hydatid cysts, the larvae of the parasite Echinococcus granulosus, may lodge in any organ of intermediate hosts, namely, man and sheep. Complete cyst removal is the treatment of choice; however, spillage of fertile cysts during surgery leads to disease recurrence that may be prevented by preoperative detection of the fertility status of the cyst. With this perspective, ex vivo proton (1H) MR spectroscopy of hydatid fluid of human and sheep origin was performed to differentiate fertile from sterile cysts on the basis of their metabolite pattern. PATIENTS AND MATERIALS: Cysts of sheep and human origin were used as source of hydatid fluid. A fraction of this fluid was tested for cyst fertility and the rest was used for ex vivo1H spectroscopy. Histopathology of the cyst wall was done as a gold standard for this study. RESULTS: Of 10 sheep samples, 7 were fertile and 3 were sterile, while among 6 human samples, 5 were fertile and 1 was sterile. Spectroscopic and histopathological results corroborated each other. The fluid from microbiologically proven fertile cysts contained malate and fumarate along with other resonances and the histopathology of the fertile cyst wall demonstrated germinal lining and protoscoleces. CONCLUSIONS: The ex vivo spectroscopic differentiation of fertile and sterile cysts may be a stepping-stone for their in vivo separation in future and thus help in framing strategies for percutaneous/surgical management.

Animals↗

PubMed2002

Cerebellar hemangioblastoma simulating arachnoid cyst on imaging and surgery.

A case of posterior fossa hemangioblastoma simulating arachnoid cyst on imaging and peroperatively is presented. In vivo proton MR spectroscopy showed evidence of large lactate and resonance at 2.37 ppm not observed earlier in the cystic lesions, including arachnoid cyst. The demonstration of this resonance may help in characterization of these lesions that may be confused with arachnoid cysts on imaging and during surgery.

Adult↗

PubMed2002

Comparative evaluation of magnetization transfer MR imaging and in-vivo proton MR spectroscopy in brain tuberculomas.

We have compared and analyzed the value of in vivo proton MR spectroscopy (PMRS) and T1 weighted magnetization transfer (MT) MR imaging in tissue characterization of brain tuberculomas. We studied 33 cases of proven intracranial tuberculomas with in vivo PMRS and T1 weighted MT MR imaging. MT ratios from the rim and core of the tuberculomas were calculated and compared with metabolites seen on PMRS. Final diagnosis of tuberculoma was based on histopathology (n = 26) and/or associated tuberculous meningitis (n = 7) in all the cases. Out of the 33 patients who underwent both PMRS and T1 weighted MT MR imaging, spectroscopy showed only lipids at 0.9 ppm, 1.3 ppm, 2.0 ppm, and 2.80 ppm in 26 cases while lipids at 0.9 ppm, 1.3 ppm, 2.0 ppm and 2.80 ppm along with choline at 3.22 ppm was seen in remaining 7 patients. MT ratios from the core or solid necrosis varied from 21-29% while from the rim or cellular region varied from 16-24%. MT ratios from all the 33 lesions were consistent with tuberculomas while PMRS showed choline along with lipids in 7 predominantly cellular lesions simulating a neoplasm. We conclude that T1 weighted MT MR imaging appears to be more consistent in the tissue characterization of brain tuberculomas.

Adolescent↗

PubMed2002

Metallohistins: a new class of plant metal-binding proteins.

Two small multimeric histidine-rich proteins, AgNt84 and Ag164, encoded by two nodule-specific cDNAs isolated from nodule cDNA libraries of the actinorhizal host plant Alnus glutinosa, represent a new class of plant metal binding proteins. This paper reports the characterization of the purified in vitro-expressed proteins by size exclusion chromatography, circular dichroism, equilibrium dialysis, metal affinity chromatography coupled with mass spectrometry, and nuclear magnetic resonance spectroscopy. These analyses reveal that each polypeptide is capable of binding multiple atoms of Zn2+, Ni2-, Co2+, Cu2+, Cd2+ and Hg2+. A reversible shift in histidine Cepsilon1 and Cdelta2 protons in NMR analysis occurred during titration of this protein with ZnCl2 strongly suggesting that histidine residues are responsible for metal binding. AgNt84 and Ag164 are not related to metal binding metallothioneins and phytochelatins and represent a new class of plant metal binding proteins that we propose to call metallohistins. Possible biological roles in symbioses for AgNt84 and Ag164, and their potential for use in bioremediation are discussed.

Amino Acid Sequence↗

PubMed2002

Demonstration of scolex within calcified cysticercus cyst: its possible role in the pathogenesis of perilesional edema.

PURPOSE: This study was performed to understand the relation between the scolex as demonstrated on gradient echo (GRE) imaging in a calcified cysticercus cyst and the development of perilesional edema that may be of value in understanding the pathogenesis of this entity. METHODS: Twenty-one patients with solitary calcified lesion on computed tomography (CT), with seizures of recent onset (within 15 days), were selected for this study. All the patients were subjected to magnetic resonance imaging (MRI) including GRE imaging. The patients were grouped on the basis of presence or absence of perilesional edema around the calcified lesion on MRI. RESULTS: There were 14 patients with perilesional edema, and seven patients had no evidence of edema. Of these 14 patients with perilesional edema, rim enhancement was detected in 13 patients on postcontrast MRI, whereas no enhancement was observed in one patient. The scolex was seen in all these 14 patients on GRE images. Of the seven patients without evidence of edema, the scolex was not seen in any of these patients on GRE imaging. In addition, there was no evidence of any contrast enhancement on postcontrast study in any of the patients in this group. CONCLUSIONS: We conclude that the calcified cysts with scolex seen on GRE imaging are associated with perilesional edema. This is probably due to preservation of antigenic material in these calcified cysts, the release of which provokes an inflammatory response that may be responsible for the perilesional edema.

Adolescent↗

PubMed2002

L-asparaginase-induced reversible posterior leukoencephalopathy syndrome in a child with acute lymphoblastic leukemia.

Reversible posterior leukoencephalopathy syndrome (RPLS) is being increasingly described with various etiologies even in the absence of hypertension. We present an 11-year-old patient with acute lymphoblastic leukemia who presented with seizures while on treatment with L-asparaginase. MRI showed bilaterally symmetrical nonenhancing occipital lesions characteristic of RPLS. L-Asparaginase-induced RPLS is a rare cause of neurological symptoms in patients on induction chemotherapy.

Antineoplastic Agents↗

PubMed2002

Neuroendoscopic treatment of paediatric cerebrospinal fluid rhinorrhoea.

Endoscopic management of CSF rhinorrhoea in children is usually associated with a higher incidence of mucosal abrasion and post-operative synechiae formation due to surgical manoeuvres in narrower nasal passages. We have used the Gaab universal neuroendoscope for the treatment of CSF rhinorrhoea in children. Three patients were treated in the last 2 years with this technique. All patients became completely asymptomatic after the initial procedure without any significant complications. We conclude that the treatment of CSF rhinorrhoea in children by means of a neuroendoscope with a working sheath may be effective and less traumatic to the nasal passage.

Cerebrospinal Fluid Rhinorrhea↗

PubMed2001

Similarities and differences of MR findings between Japanese encephalitis and Wilson's disease.

Although Japanese Encephalitis (JE) and Wilson's disease (WD) are different entities, MR findings in both these conditions are quite similar. The purpose of this retrospective study was to find out the similarities and differences between JE and WD on MR imaging. The study group comprised 25 proven cases of JE and 10 cases of WD. Spin echo (SE) TI- and T2-weighted imaging was performed on a 1.5-T MR system. Fourteen of these 35 cases (10 JE, 4 WD) were also examined using T1-weighted magnetization transfer (MT) SE sequence before and after contrast administration. Although both JE and WD showed similar topographical distribution of lesions, predominant involvement of the basal ganglia and thalami, there were some differences. Brain stem lesion was more frequent for WD than for JE, and posteromedial part of the thalami was spared in WD. The lesion characteristics were also different between both; in WD mixed intensity in the basal ganglia and hyperintense linear rim at the peripheral putamen was observed frequently, whereas hyperintense basal ganglia on T2-weighted images, subacute hemorrhage in the thalami and meningeal enhancement were seen only in the patients with JE. These characteristic lesion criteria may help in differentiation of JE from WD on MR imaging.

Adult↗

PubMedDate not supplied

Human and porcine Taenia solium infection in rural north India.

72 members of a pig farming community and 50 slaughtered pigs in Uttar Pradesh, India, were examined between November 2000 and June 2001 for Taenia solium infection. 27 of the human subjects (38%) had intestinal taeniasis and 7 (9.7%) had reported seizures. All 3 of the latter who were examined had neurocysticercosis. 13 of the pigs (26%) had cysticercosis. Such high prevalences indicate the need for detailed assessment of the disease burden in this community.

Agricultural Workers' Diseases↗

PubMedDate not supplied

Role of diffusion-weighted imaging and in vivo proton magnetic resonance spectroscopy in the differential diagnosis of ring-enhancing intracranial cystic mass lesions.

OBJECTIVES: Proton magnetic resonance spectroscopy (PMRS) and diffusion-weighted imaging (DWI) were compared to determine which technique is more effective in the differential diagnosis of cystic intraparenchymal ring-enhancing lesions with variable perifocal edema. METHODS: Fifty-two patients (abscesses [n = 29], tumor cysts [n = 20], and benign cysts [n = 3]) formed the basis for comparative evaluation in this study. The criteria for abscess diagnosis were apparent diffusion coefficient (ADC) values less than 0.9 +/- 1.3 x 10 mm/s and presence of lactate cytosolic amino acids (AAs) with/without succinate, acetate, alanine, and glycine on PMRS. Criteria for nonabscess cyst identification were ADC values of 1.7-3.8 x 10 mm/s and presence of lactate and choline on PMRS. On the basis of these criteria, patients were categorized into abscess (n = 29) and nonabscess (n = 23) groups. Sensitivity and specificity of PMRS and DWI with respect to the final diagnosis were calculated based on the efficacy of these techniques. RESULTS: : Apparent diffusion coefficient values in 21 patients with abscesses were observed within the range of defined criteria, whereas in 8 patients, ADC values were beyond the range of defined criteria. Lactate and AAs with or without other metabolites were observed in 25 of 29 cases of abscesses on PMRS. In the nonabscess group, ADC values of cystic lesions in all patients were consistent with respect to the defined criteria. Only lactate was seen in 14 of 23 patients, whereas both lactate and choline were visible in 6 patients. In 3 patients with neurocysticercosis, AAs (n = 2), lactate (n = 3), acetate (n = 1), succinate (n = 3), choline (n = 2), and alanine (n = 3) were seen. The sensitivity of DWI and PMRS for differentiation of brain abscess from nonbrain abscess was 0.72 and 0.96, respectively, whereas the specificity was 1 for both techniques. CONCLUSION: Demonstration of restricted diffusion on DWI with reduced ADC is highly suggestive of brain abscess; however, in the absence of restriction, PMRS is mandatory to distinguish brain abscesses from cystic tumors.

Acetates↗

PubMedDate not supplied

Diffusion-weighted MR imaging in Japanese encephalitis.

OBJECTIVE: This study was performed to evaluate the role of diffusion-weighted imaging (DWI) in the diagnosis of Japanese encephalitis (JE) and to look for any relationship of the apparent diffusion coefficient (ADC) values with duration of the illness. METHODS: We performed DWI in fourteen patients of JE. T2 weighted (T2W) and DWI were compared for number and location of lesions in all patients. Based on imaging patients were divided in three groups: group 1 (n=9) showing more lesions on DWI compared with T2W images, group 2 (n=3) with equal number of lesions on T2W and DWI and group 3 (n=2) with lesions more pronounced on T2W than DWI. ADC values were computed for all the lesions. The time interval between onset of neurologic signs/symptoms and MRI were charted and correlated with ADC values. RESULTS: DWI was helpful in making early diagnosis of JE by showing characteristic involvement of bilateral thalami in four patients. Nine out of fourteen patients showed additional lesions on DWI. ADC from lesions in groups I, II and III measured 0.648 +/- 0.099 x 10 mm/s, 0.739 +/- 0.166 x 10 mm/s and 1.123 +/- 0.185 x 10 mm/s respectively. The ADC from the lesions in group 1 was significantly lower compared with group 2 (P value <0.05) while it was higher in group 3 lesions compared with the other two groups. There was a significant direct correlation of ADC values with the disease duration in these cases (r=0.847, P <0.01). CONCLUSIONS: DWI is helpful in early diagnosis and characterization of the duration of the lesions in JE.

Adolescent↗

PubMedDate not supplied

An evaluation of salmeterol in the treatment of chronic obstructive pulmonary diseases.

BACKGROUND: Salmeterol has been shown a useful drug for the treatment of chronic obstructive pulmonary disease (COPD). However, its positioning in the current treatment of COPD remains to be defined. The present study was carried out to evaluate its role as an add-on drug to the current first-line drug, ipratropium. METHODS: A double-blind randomized, parallel group, placebo-controlled design was used in an outpatient setting. Thirty-three patients with moderate or severe COPD were included. After a run-in period of two weeks on 40 microg four-times-daily ipratropium and 400 microg twice-daily beclomethasone dipropionate, they were randomized into two groups to receive either salmeterol (50 microg twice daily) or placebo for eight weeks. The outcome parameters were: (i) spirometry, (ii) six-minute walking test, (iii) SF-36 health-related quality of life (HRQoL) questionnaire score, (iv) baseline dyspnoea index (BDI), (v) patient's self-assessment and (vi) supplemental use of salbutamol. RESULTS: The mean FEV1 and FVC increased significantly over the initial values in the salmeterol group but not in the placebo group. Salmeterol produced greater improvements in almost all the dimensions of HRQoL as well as in the BDI and the supplemental use of salbutamol was lower in this group. However, the six-minute walk distance was similar in the two groups. CONCLUSIONS: The present study shows that eight weeks treatment with salmeterol 50 microg twice-daily added to the existing regimen of ipratropium bromide and beclomethasone dipropionate provides greater symptomatic relief and improvement in lung function than placebo. This is accompanied by an improvement in the health-related quality of life.

Adult↗