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Rajeev Kumar

Publications and source records attributed to Rajeev Kumar.

At least 55 records · Page 3Linked to original sources
PubMed2004

Benign brain tumours and psychiatric morbidity: a 5-years retrospective data analysis.

OBJECTIVE: To examine the psychiatric comorbidity in benign brain tumours. METHOD: A retrospective (5 years) data analysis at our 500 bed teaching hospital. The diagnoses of benign brain tumours were based on the record of final diagnoses in the case records confirmed by either CT or MRI scans. Case records of patients with clearly documented history of psychiatric symptoms of several weeks to several months duration were identified only if such symptoms had antedated a diagnosis of the brain tumour. Using a specially designed proforma, two psychiatrists rated the symptoms together. We also collected data on age, gender and CT/MRI findings. Consensus was reached on all cases in regard to the psychiatric phenomenology. The symptoms were divided according to their presentation into purely neurological or psychiatric symptoms. RESULTS: A total of 79 patients were identified as having a primary diagnosis of benign brain tumour. There were 56 female patients and 23 male patients. Seventy-two of these had meningiomas. Fifteen (21%) of 72 meningioma cases, eight men and seven women, presented with psychiatric symptoms in the absence of neurological symptoms. Affective disorders were a common presentation. There was no correlation between brain laterality and the psychiatric comorbidity. CONCLUSIONS: Psychiatric symptoms may be the only initial manifestations of meningiomas of the brain in a significant number of cases occurring in the fifth decade of life. Such patients must be investigated by brain imaging studies even if there are no neurological signs or symptoms.

Adult↗
PubMed2004

Should retroperitoneoscopic nephrectomy be the standard of care for benign nonfunctioning kidneys? An outcome analysis based on experience with 449 cases in a 5-year period.

PURPOSE: Laparoscopic nephrectomy has become a routine procedure at specialized centers with the advantages of less postoperative pain, minimal scars, rapid recovery and short convalescence. We report our experience with the establishment of retroperitoneoscopic nephrectomy as the standard of care for benign nonfunctioning kidneys. MATERIALS AND METHODS: We retrospectively compared the records of patients who underwent simple nephrectomy retroperitoneoscopically or by open surgery from January 1998 to October 2003 at our center. RESULTS: A total of 351 simple nephrectomies were done retroperitoneoscopically, while 83 were done as an open procedure. Mean operative time was significantly longer in the retroperitoneoscopic group. However, mean blood loss, complication rate, hospital stay and convalescence were significantly less in the retroperitoneoscopic group. CONCLUSIONS: Retroperitoneoscopic nephrectomy has become a standardized procedure. It should be offered as the primary treatment modality to patients with benign renal disease scheduled for elective nephrectomy except in those in whom it is contraindicated.

Blood Loss, Surgical↗
PubMed2004

Complications of laparoscopic radical cystectomy during the initial experience.

AIM: Radical cystectomy is the standard of care for patients with muscle invasive bladder cancer. While open radical cystectomy is now a standard procedure, laparoscopic radical cystectomy is still in its infancy. We performed this surgery laparoscopically in 11 patients and review the procedure specific complications. METHODS: Beginning in February 1999, 11 patients underwent laparoscopic radical cystectomy at the Department of Urology, All India Institute of Medical Sciences, New Dehli. Urinary diversion was performed by an open-hand sewn ileal conduit. RESULTS: There were three intraoperative complications specifically related to the laparoscopic radical cystectomy. These included injury to the external iliac vein in one patient and a small rectal tear in two. All were repaired with laparoscopic free hand suturing with normal postoperative recovery. Other laparoscopy-related complications were subcutaneous emphysema in one patient and hypercarbia necessitating conversion to open surgery in a patient who, four weeks after surgery, died of multiple organ failure. One patient had margins positive and received cisplatinum-based chemotherapy. All patients had normal renal function and preserved upper tracts with no evidence of metastasis at a mean of 18.4 months follow up (range 1-48 months). CONCLUSIONS: Though there were three complications specific to the laparoscopic radical cystectomy, none necessitated a conversion to open surgery or hampered the overall outcome. Absence of local recurrence or metastatic disease at four years of follow up suggests that the procedure is oncologically valid. Laparoscopic radical cystectomy is a new procedure and it is important to critically analyze the complications in order to reduce their occurrence and allow the development of a better technique.

Adult↗
PubMed2004

Post operative analgesia with continuous epidural infusion.

Forty eight ASA I or II patients of either sex between 20-70 years undergoing major upper abdominal surgery were grouped into sixteen each, on complaint of pain. They received an epidural bolus dose, followed by infusion of the assigned drug at 4ml per hour through BARD PCA I pump. Pain assessment, for the first four hours, was hourly, and subsequently at l0th, 16th, 22nd, 28th, 36th and 40th hour by VAS and VRS. The groups matched for demographic distribution. All groups had lower mean pain scores at first hour by VAS and VRS. In Group II and Group III, the difference was significant (<0.05) at the 2nd (VAS) and 4th (VRS) hours. From 16th (VAS) and 22nd (VRS) hours, the mean pain score was less and significant (<0.05) in Group III. In all groups sedation ranged from 0-1. There was hypotension in Group I (2/16).urinary retention in Group II (8/9 not catheterised); unilateral sensory impairment and motor weakness in Group I (3/16) and Group III (1/16). This study showed that continuous infusion of low dose morphine with bupivacaine provides better quality post operative analgesia with fewer side effects than bupivacaine or morphine alone.

Adult↗
PubMed2003

Long-term follow-up of thalamic deep brain stimulation for essential and parkinsonian tremor.

Thirteen consecutive patients with thalamic deep brain stimulation (DBS) were examined serially for 3 to 5 years. Initially, all demonstrated at least 50% improvement in contralateral tremor. At last follow-up, three of eight patients with Parkinson disease no longer used DBS because tremor had markedly improved, and for two, motor fluctuations and levodopa-induced dyskinesias became the major disability, with tremor less troublesome. Two of five patients with essential tremor had contralateral tremor improvement after ongoing stimulation for 2 years; two developed marked tolerance to DBS.

Adult↗
PubMed2003

Proton magnetic resonance spectroscopy with a body coil in the diagnosis of carcinoma prostate.

We evaluate the feasibility of proton magnetic resonance spectroscopy ((1)H MRS) using a spine coil receiver (body coil) in the diagnosis of carcinoma prostate. Seventeen patients with biopsy-proven prostate carcinoma, five patients of benign prostatic hyperplasia (BPH) and five healthy young volunteers underwent (1)H MRS investigation. MRS was performed at 1.5 Tesla using a spine receiver coil for signal reception. In vivo citrate levels are reported as a ratio of citrate peak area to the sum of the areas of choline and creatine peak. MRS spectrum with good sensitivity and signal to noise (S/N) ratio was obtained in all 27 subjects. The citrate to creatine plus choline ratio was 0.31+/-0.25 in patients with cancer, 1.43+/-0.58 in BPH and 2.16+/-0.56 in controls. The difference in ratios between cancer and BPH and cancer and control was statistically significant ( p<0.01). Within the cancer group, there was a statistically significant decline in levels with higher-grade malignancy ( p<0.05). There were no complications of the procedure. There is a statistically significant decline in the ratio of citrate to choline plus creatine in the regions of cancer prostate when compared with BPH or normal control. The study demonstrates that MRS data can be reliably acquired using a spine coil receiver. MRS may also play a role in differentiating well-differentiated tumors from the anaplastic variety.

Adult↗
PubMed2003

A model for antigen-specific T-cell anergy: displacement of CD4-p56(lck) signalosome from the lipid rafts by a soluble, dimeric peptide-MHC class II chimera.

Soluble, dimeric peptide-MHC chimeras were shown to induce Ag-specific T cell anergy in vitro and in vivo. In this study, we describe a mechanism by which a soluble, dimeric peptide MHC class II chimera (DEF) induces Ag-specific T cell anergy. The anergic cells showed a displacement of the CD4-p56(lck) signaling module from the GM1-rich plasma membrane microdomains (lipid rafts), and subsequently an increase in p59(fyn) kinase activity, a dominant expression of p21 inhibitory TCR zeta-chain, and a poor phosphorylation and recruitment of zeta-associated protein of 70 kDa kinase to the TCR's immunoreceptor tyrosine-based activation motifs. The Th1 and Th2 transcription was suppressed and the cells were arrested in the Th0 stage of differentiation. Recovery from DEF anergy occurred late and spontaneously at the expense of low thresholds for activation-induced cell death. In contrast to DEF, a combination of TCR and CD4 mAbs did not induce such alterations or anergy, indicating that the ligand-mediated topology of TCR and CD4 coengagement can differentially affect the T cell function. Our results argue for a model of anergy in which the defective partitioning of signaling molecules in lipid rafts is an early, negative signaling event in T cells. Physiological ligands like DEF chimeras may provide new tools for silencing the autoimmune processes, and may also help in deciphering new mechanisms of negative regulation in T cells.

Animals↗
PubMed2003

Calculation of coherence pathway selection and cogwheel cycles.

The selection of proper coherence pathways is a very important aspect of the design of NMR pulse sequences. This article describes a C++ program for the calculation of coherence pathway selection via phase cycles, including a module to calculate cogwheel cycles. Cogwheel phase cycles shorter than the original ones [M.H. Levitt et al., J. Magn. Reson. 155 (2002) 300] are derived and experimentally tested for the MQMAS experiment for 3/2 spins. Some other cogwheel cycles are derived for the MQNQMAS, the STMAS experiment, and a PFG diffusion pulse sequence. This program is publicly available through our website http://www.nyu.edu/projects/jerschow with additional documentation and examples.

Journal Article↗
PubMed2003

Complement component C1q induces endothelial cell adhesion and spreading through a docking/signaling partnership of C1q receptors and integrins.

The interaction of C1q with endothelial cells elicits a multiplicity of biologic responses. Although these specific responses are thought to be mediated by the interaction of C1q with proteins of the endothelial cell surface, the molecular identity of the participant(s) has not been clearly defined. In this study, we examined the role of two C1q-binding proteins, cC1q-R/CR and gC1q-R/p33, on C1q-mediated adhesion and spreading of human dermal microvascular endothelial cells (HDMVECs). A specific and dose-dependent adhesion and spreading was observed when HDMVECs were cultured in microtiter plate wells coated with concentrations of C1q ranging from 0 to 50 microg/ml. The extent of adhesion and spreading was similar to the adhesion seen on collagen-coated wells. Furthermore, the effect of C1q was mimicked by either polyclonal anti-cC1q-R or mAb 60.11, but not with isotype- and species-matched control IgG. More importantly, however, a 100% inhibition of spreading but not adhesion to C1q-coated wells was observed when HDMVECs were cultured in the presence of 30 mM of the peptide GRRGDSP but not GRRGESP. Furthermore, while anti-beta1 integrin antibody blocked adhesion and spreading, antialpha5 integrin only blocked spreading. Since earlier studies have shown that zinc induces the exposure of hydrophobic sites in the C-terminus of gC1q-R including the putative high-molecular weight kininogen (HK)-binding site corresponding to residues 204-218, we also examined the effect of zinc on antibody binding to cell surface gC1q-R. Flow cytometric data show that the binding of mAb 74.5.2, which recognizes residues 204-218, is greatly enhanced when endothelial cells were incubated in the presence of 50 microM zinc. In summary, our data show that: (a) C1q-mediated endothelial cell adhesion and spreading requires the cooperation of both C1q receptors and 1 integrins, and possibly other membrane-spanning molecules, and (b) zinc can induce the exposure of hydrophobic sites in the C-terminal domain of gC1q-R allowing a more efficient binding of mAb 74.5.2 and HK.

Antibodies, Monoclonal↗
PubMed2003

Laparoscopic radical cystectomy and ileal conduit reconstruction: preliminary experience.

PURPOSE: We present our preliminary experience with laparoscopic radical cystoprostatectomy for muscle-invasive carcinoma of the urinary bladder. Patient and operative data and the surgical technique are presented. PATIENTS AND METHODS: Laparoscopic radical cystoprostatectomy and bilateral pelvic lymph node dissection were performed using five or six ports by a transperitoneal approach. An ileal conduit urinary diversion was constructed at the site of specimen retrieval. RESULTS: The procedure was successful in nine of ten patients with a mean blood loss of 533 mL and an average transfusion of 1.3 units per patient. The mean operating time was 6.48 hours and an average of 33 mg of morphine equivalents was required for analgesia. The mean hospital stay was 10.8 days. One patient had surgical margins positive for cancer, while none had histologic evidence of pelvic nodal metastasis. There were five minor and major intraoperative and postoperative complications. The remaining patient, treated early in our experience, developed hypercarbia necessitating conversion to open surgery. No metastases have been seen after a mean duration of follow-up of 19 months. CONCLUSIONS: Laparoscopic radical cystoprostatectomy with open ileal conduit urinary diversion is a feasible alternative to traditional open radical cystectomy. Urinary diversion can be performed through the small incision necessary to extract the surgical (radical cystoprostatectomy) specimen from the abdomen. With our modified technique, it also is feasible to reduce the cost.

Adult↗
PubMed2003

High-throughput selection of effective RNAi probes for gene silencing.

RNA interference (RNAi) is a process of sequence-specific posttranscriptional gene silencing mediated by double-stranded RNA. RNAi has recently emerged as a powerful genetic tool to analyze gene function in mammalian cells. The power of this method is limited however, by the uncertainty in predicting the efficacy of small interfering RNAs (siRNAs) in silencing a gene. This has imposed serious limitations not only for small-scale but also for high-throughput RNAi screening initiatives in mammalian systems. We have developed a reliable and quantitative approach for the rapid and efficient identification of the most effective siRNA against any gene. The efficacy of siRNA sequences is monitored by their ability to reduce the expression of cognate target-reporter fusions with easily quantified readouts. Finally, using micro array-based cell transfections, we demonstrate an unlimited potential of this approach in high-throughput screens for identifying effective siRNA probes for silencing genes in mammalian systems. This approach is likely to have implications in the use of RNAi as a reverse genetic tool for analyzing mammalian gene function on a genome-wide scale.

Animals↗
PubMed2003

Subinguinal microsurgical varicocelectomy: evaluation of the results.

INTRODUCTION: Varicoceles have been established to be the commonest correctable cause of male infertility. Among the various methods available, microsurgical varicocelectomy has one of the lowest complication rates with low failure. PATIENTS AND METHODS: Over a 4-year period, 100 patients underwent microsurgical varicocelectomy at our center. One hundred and forty-four surgeries were performed on 90 of these patients through a subinguinal approach and these form the study group. Only clinically diagnosed varicoceles were operated. Pre-operative semen values were compared with the post-operative values and statistical analysis performed using a non-parametric test. All 90 patients provided at least 1 post-operative semen report 3 months after surgery while 50 are on complete follow-up. RESULTS: Sperm count improved in 71% patients, normal motility in 60% and normal morphology in 49%. Seventeen of the 50 patients on full follow-up (34%) achieved pregnancy, with 16 of these being spontaneous. All patients achieving pregnancy showed improvement in sperm count, 13 improved in motility and 12 in morphology. All improvements were statistically significant. There were 21 (14.6%) minor complications with no testicular atrophy and 1 recurrence. CONCLUSION: Microsurgical varicocelectomy is a safe and effective option for the management of varicocele-induced male infertility. It leads to improvement in all semen parameters and increases the possibility of spontaneous pregnancies.

Adult↗