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N Rajagopalan

Publications and source records attributed to N Rajagopalan.

18 recordsLinked to original sources
PubMed2005

Benign fibrous histiocytoma of the distal radius with congenital dislocation of the radial head: a case report.

Benign fibrous histiocytoma is such a rare tumour that only a few cases have been reported in the literature. A patient with an apparently benign lesion of the distal radius, along with congenital dislocation of the radial head, was presented at St. John's Medical College Hospital in Bangalore, India. Pain was the chief symptom. There were histological features of non-ossifying fibroma in the lesion. Because of its unusual radiological appearance and atypical clinical course, the lesion was diagnosed as fibrous histiocytoma. In this case report, we review similar cases in the literature and discuss an unusual association with congenital dislocation of the radial head.

Adolescent↗
PubMed2001

Comparison of new Doppler echocardiographic methods to differentiate constrictive pericardial heart disease and restrictive cardiomyopathy.

This study assesses how the newer modalities of tissue Doppler echocardiography and color M-mode flow propagation compare with respiratory variation of Doppler flow in distinguishing between constrictive pericarditis and restrictive cardiomyopathy. We studied 30 patients referred for further evaluation of diastolic function who had a diagnosis of constrictive pericarditis or restrictive cardiomyopathy established by diagnostic tests, including clinical assessment, magnetic resonance imaging, cardiac catheterization, endomyocardial biopsy, and surgical findings. Nineteen patients had constrictive pericarditis and 11 had restrictive cardiomyopathy. We performed 2-dimensional transesophageal echocardiography combined with pulsed-wave Doppler of the pulmonary veins and mitral inflow with respiratory monitoring, tissue Doppler echocardiography of the lateral mitral annulus, and color M-mode flow propagation of left ventricular filling. Respiratory variation of the mitral inflow peak early (peak E) velocity of > or =10% predicted constrictive pericarditis with 84% sensitivity and 91% specificity and variation in the pulmonary venous peak diastolic (peak D) flow velocity of > or =18% distinguished constriction with 79% sensitivity and 91% specificity. Using tissue Doppler echocardiography, a peak early velocity of longitudinal expansion (peak Ea) of > or =8.0 cm/s differentiated patients with constriction from restriction with 89% sensitivity and 100% specificity. A slope of > or =100 cm/s for the first aliasing contour in color M-mode flow propagation predicted patients with constriction with 74% sensitivity and 91% specificity. Thus, the newer methods of tissue Doppler echocardiography and color M-mode flow propagation are equivalent and complimentary with Doppler respiratory variation in distinguishing between constrictive pericarditis and restrictive cardiomyopathy. The additive role of the new methods needs to be established in difficult cases of constrictive pericarditis where respiratory variation may be absent or decreased.

Adult↗
PubMed2001

Respiratory variation of mitral and pulmonary venous Doppler flow velocities in constrictive pericarditis before and after pericardiectomy.

The objective of this study was to determine whether Doppler echocardiography is useful in assessing the effects of pericardiectomy in patients with constrictive pericarditis by studying the postoperative change in the respiratory variation of mitral inflow and pulmonary venous Doppler flows. The study population consisted of 35 cases with surgically proven constrictive pericarditis. Thirty-five patients had preoperative Doppler echocardiography, whereas 4 patients died of non-cardiac causes and 1 patient had a heart transplant before follow-up. Postoperative studies were performed at a mean of 1081 +/- 84 days (range 120-2700 days) after pericardiectomy. The mean (+/- SD) respiratory variation changed after surgery from a baseline value of 17% +/- 14% to 8% +/- 8% for peak mitral E velocity (P <.01); from 25% +/- 18% to 7% +/- 13% (P <.001) for pulmonary venous (PV) peak diastolic flow velocity, and from 21% +/- 13% to 11% +/- 13% (P =.009) for PV peak systolic flow velocity. The 23 patients who became asymptomatic after surgery had a significantly lower mean mitral and PV respiratory variation than the 7 patients who were NYHA class II (4% +/- 4% and 6% +/- 4% vs 21% +/- 6% and 19% +/- 10%, respectively, P <.0001 for both). Pulsed Doppler echocardiographic assessment of respiratory variation is useful for evaluating the outcome of pericardiectomy.

Aged↗
PubMed1999

Role of transesophageal echocardiography in assessing diastolic dysfunction in a large clinical practice: a 9-year experience.

BACKGROUND: Two-dimensional transthoracic echocardiography with respiratory monitoring has been used to characterize diseases that impair diastolic function. Transesophageal echocardiography (TEE) has emerged as a complementary technique to evaluate patients with these diseases. The purpose of this study was to evaluate in a large clinical practice the utility of TEE with respiratory monitoring for classification of patients with diastolic dysfunction. METHODS: Over a 9-year period TEE was used to examine 192 patients referred to an echocardiography laboratory for additional evaluation of abnormal diastolic function. We performed pulsed-wave Doppler TEE of the left ventricular inflow and pulmonary veins and respiratory monitoring to categorize patients as showing restrictive physiologic features, constriction with or without effusion, mixed constriction and restriction, abnormal relaxation, pseudonormalization, large pericardial effusion or tamponade, or normal diastolic function. RESULTS: Patients with diastolic dysfunction underwent 3% of the total number of transesophageal studies conducted during the study period. Among the 192 patients referred for TEE, abnormal diastolic function was found in 181 (94%); 11 (6%) had normal diastolic function. Seventy-one (39%) of the 181 patients had restrictive physiologic features. Constrictive pericarditis was found in 54 (30%) of the patients and was confirmed for all 31 patients who underwent pericardiectomy. Mixed constriction and restriction was present in 21 (12%) of the patients. The other 35 patients (19%) had abnormal relaxation, pseudonormalization, or large pericardial effusion or tamponade. The cause of diastolic dysfunction was idiopathic for 32% of the patients, previous cardiac operation for 26%, cardiac amyloidosis for 23%, radiation therapy for 11%, and hypertension or advanced ischemic heart disease for 8%. CONCLUSION: Two-dimensional and Doppler TEE with respiratory monitoring is useful in categorizing patients with impaired diastolic function, primarily into those with restrictive physiologic features or constrictive pericarditis.

Adult↗
PubMed1999

Cloud point of nonionic surfactants: modulation with pharmaceutical excipients.

PURPOSE: To determine the cloud point of a variety of nonionic surfactants and to search for means to raise the surfactant cloud point in liquid formulations. METHODS: Cloud points of nonionic surfactants were determined visually in a water bath. Organic compounds, many of which have been used as pharmaceutical excipients, were tested initially for effect on the cloud point of poloxamine 908. Four effective cloud point boosters (CPBs) from different structural classes were further tested on additional surfactants. RESULTS: A number of compounds can raise the cloud point of nonionic surfactants. These cloud point boosters are classified into two categories: nonionic and ionic. The nonionic CPBs include poly(ethylene glycols), propylene glycol, methanol, ethanol, isopropanol, and 2-hydroxypropyl-beta-cyclodextrin. They are effective at molar concentrations. The ionic CPBs include anionic and cationic surfactants, charged phospholipids, long chain fatty acids, and bile salts. They are effective at millimolar concentrations. CONCLUSIONS: The cloud point of nonionic surfactants used in liquid formulations can be modulated through the proper choice of excipient.

Alcohols↗
PubMed1999

Physical stability of ethyl diatrizoate nanocrystalline suspension in steam sterilization.

PURPOSE: To study the effects of formulation variables on the physical stability of a submicron crystal (nanocrystal) suspension under steam sterilization conditions. METHODS: Suspensions of ethyl diatrizoate nanocrystals were prepared by wet milling in the presence of the surfactant poloxamine 908. Particle size distribution and zeta potential were measured by photon correlation spectroscopy. RESULTS: On heating, the mean particle size of the nanocrystal suspension remained essentially unchanged up to 110 degrees C, the cloud point of the stabilizing surfactant, but increased significantly above that temperature. The increase in particle size was a result of particle aggregation rather than crystal growth. Adding a cloud point booster to the suspension significantly minimized the particle aggregation at high temperatures. The purity of poloxamine 908 and the tonicity agent and buffer salt used also affected the heat stability of the suspension, the latter agents apparently through altering the surfactant cloud point. CONCLUSIONS: The aggregation of the ethyl diatrizoate nanocrystalline suspension under steam sterilization conditions was a result of phase separation of the stabilizing surfactant at its cloud point. When formulated with a cloud point booster to prevent the phase-separation, the suspension maintained its physical stability under steam sterilization without any significant change in particle size distribution.

Buffers↗
PubMed1996

Cytolytic therapy for the treatment of bronchiolitis obliterans syndrome following lung transplantation.

Bronchiolitis obliterans syndrome (BOS) is a common occurrence following lung transplantation and is one of the most important impediments to long-term graft viability. Cytolytic therapy has been used as treatment for BOS, but there is little data documenting efficacy. Furthermore, these agents have been associated with significant adverse effects. Charts of 15 patients who received an antilymphocyte preparation (ALP) for BOS were reviewed. Forced expiratory volume-1 second (FEV1) and stage of BOS were compared before and after treatment. Complications of ALP were recorded from the charts. Two of 15 patients had an improvement in FEV1, 5/15 exhibited no change, and 8/15 continued to decline. There was no pattern associating stage of BOS with likelihood of response to ALP. All patients received antimicrobial prophylaxis and did not experience infectious complications following administration of the ALP. ALP for the treatment of BOS results in an arrest or improvement of FEV1 in approximately 50% of patients. Infectious complications are uncommon when antimicrobial prophylaxis is administered.

Adult↗
PubMed1996

Bronchodilator response at low lung volumes predicts bronchiolitis obliterans in lung transplant recipients.

BACKGROUND: Bronchiolitis obliterans syndrome (BOS) is the major obstacle to long-term lung allograft viability. The diagnosis often occurs after significant organ dysfunction is present, and BOS is often unresponsive to standard immunosuppressive agents. We have observed bronchodilator responses (BRs) at low lung volumes in many of our patients who have developed BOS. We therefore assessed whether BR could predict the development of BOS. METHODS: We conducted a retrospective review of the clinical and pulmonary function laboratory records of 146 patients who underwent transplantation between March 1983 and November 1993. BR was defined as 25% or more increase in forced expiratory flow at 50% of vital capacity or 30% or more increase in forced expiratory flow at 75% of vital capacity. BOS was defined according to recently published FEV1 criteria. Bronchiolitis obliterans was defined histologically according to criteria of the Lung Rejection Study Group. RESULTS: Of the total population, 52 were excluded because of death or insufficient information. BRs of the small airways were seen in 31 patients (33%), 25 of whom developed BOS (83%). Approximately half of those with BR who developed BOS had evidence of acute rejection in the month prior to the onset of BR. Two thirds (four of six) of patients with BR not developing BOS had acute rejection in the previous month. The sensitivity of BR in predicting BOS was 51% with a specificity of 87%. The positive predictive value was 81%. CONCLUSIONS: BR appears to be useful as an early marker of BOS. The development of BR in selected patients should lead to closer monitoring and possibly a trial of augmented immunosuppression to arrest the establishment of BOS.

Adolescent↗
PubMed1994

Hemothorax following uncomplicated sclerotherapy for esophageal varices.

Although pleural effusion as a complication of esophageal manipulation is well described in the literature, the fluid is usually nonhemorrhagic. We describe the first patient who had uncomplicated sclerotherapy with ethanolamine for esophageal varices, and on two occasions this patient developed left-sided bloody pleural effusion within 12-72 h after sclerotherapy. The effusion resolved spontaneously within 4 weeks. This case illustrates that hemothorax should be included in the pulmonary complications of sclerotherapy for esophageal varices.

Adult↗
PubMed1994

Astrocytoma presenting with apnea and sinus arrest.

Although some vascular lesions of the central nervous system are known to cause abnormalities in the control of breathing, association between astrocytoma and combined cardiorespiratory abnormalities in the adult is distinctly unusual. We present a case of a 52-year-old man whose only features of astrocytoma consisted of episodes of apnea and sinus arrest followed by prolonged alveolar hypoventilation. These abnormalities resolved after resection of the tumor. We conclude that in patients presenting with respiratory and sinus arrest, the search for a cause should not be limited to the cardiac and pulmonary systems, but it must include a possibility of a brain tumor.

Apnea↗
PubMed1991

Pneumocystis carinii pneumonia in thymoma with hypogammaglobulinaemia: successful outcome of therapy including i.v. IgG replacement.

A 66-year-old patient presented with Pneumocystis carinii Pneumonia (PCP) and was found to have hypogammaglobulinaemia, associated with a thymoma that had been resected 17 months earlier. Only one previous case of PCP in association with a thymoma and hypogammaglobulinaemia has been reported, in which the patient died. We report another such patient who was successfully treated with a combination of intravenous immunoglobulin and high dose cotrimoxazole.

Agammaglobulinemia↗
PubMed1989

Torticollis and blepharospasm in systemic lupus erythematosus.

A case of torticollis and blepharospasm as the major manifestation of neurological involvement in systemic lupus erythematosis (SLE) is presented. A 56-year-old woman presented with blepharospasm in February 1985 and with torticollis in April 1985. She was diagnosed as having SLE in 1966, on the basis of positive LE cells, when she presented with fever and joint pains. There was no evidence that she had ever been on major tranquilizers. An attempt has been made to correlate the level of antibody titres and exacerbation of these movements with response to steroids. The possibility of an association between blepharospasm, torticollis, and autoimmune disorders has recently been considered.

Blepharospasm↗
PubMed1984

Kinetics and thermodynamics of the formation of mixed micelles of egg phosphatidylcholine and bile salts.

The kinetics of dissolution of dispersions of egg phosphatidylcholine (lecithin) by bile salts was studied by observing the decrease in turbidity as mixed micelles of lecithin and bile salt were formed. The rate of dissolution of lecithin corresponding to the formation of mixed micelles was studied in the presence of dihydroxy bile salts, sodium deoxycholate, sodium chenodeoxycholate, sodium ursodeoxycholate, and one trihydroxy bile salt, sodium cholate. The rate of dissolution of lecithin and mixed micelle formation decreased in the order: chenodeoxycholate greater than deoxycholate greater than cholate greater than ursodeoxycholate. Kinetic solvent isotope studies in D2O, along with measurement of enthalpies of mixed micelle formation both in H2O and D2O, appear to indicate that the formation and stabilization of mixed micelles is related to "hydrophobicity" as estimated by high performance liquid chromatography retention factors.

Bile Acids and Salts↗
PubMed1982

The binding of Ca2+ to taurine and glycine-conjugated bile salt micelles.

The binding of Ca2+ to micelles of glycine and taurine bile acid conjugates was studied using a Ca2+-specific electrode. An investigation of the effect of buffer concentration, pH, added electrolyte and lecithin was also carried out. The observed results indicate that the binding of Ca2+ to bile salt micelles is dependent on both the number of hydroxyl groups on the steroid nucleus as well as on the nature of the head conjugating group, viz. glycine or taurine. It is speculated that the binding of Ca2+ to bile salt micelles may act as one of the mechanisms to lower Ca2+ activity in bile and thus reduce its tendency to precipitate as insoluble calcium salts and further growth into gallstones.

Bile Acids and Salts↗
PubMedDate not supplied

Counter-ion binding by bile acid solutions.

The binding of Ca2+ to micelles of glycine and taurine bile acid conjugates was studied using a Ca2+-specific electrode. An investigation of the effect of buffer concentration, pH, added electrolyte and lecithin was also performed. The results indicate that the binding of Ca2+ to bile salt micelles is dependent on the number of hydroxyl groups on the steroid nucleus and on the nature of the head conjugating group, namely, glycine or taurine. It is speculated that the binding of Ca2+ to bile salt micelles may act as one mechanism to lower Ca2+ activity in bile and, thus, reduce its tendency to precipitate as insoluble calcium salts and further growth into gallstones.

Bile Acids and Salts↗
PubMedDate not supplied

Kinetics and thermodynamics of dissolution of lecithin by bile salts.

The kinetics of dissolution of dispersions of egg phosphatidylcholine (lecithin) by bile salts was studied by observing the decrease in turbidity as mixed micelles of lecithin and bile salts were formed. The rate of dissolution of lecithin corresponding to formation of mixed micelles was studied in the presence of dihydroxy bile salts, sodium deoxycholate, sodium chenodeoxycholate, sodium ursodeoxycholate and one trihydroxy bile salt, sodium cholate. The rate of dissolution of lecithin and mixed micelle formation decreased in the order: chenodeoxycholate greater than deoxycholate greater than cholate greater than ursodeoxycholate. Kinetic solvent isotope studies in D2O, along with measurement of enthalpies of mixed micelle formation both in H2O and D2O, suggest that formation and stabilization of mixed micelles are related to "hydrophobicity" as estimated by high performance liquid chromatography retention factors.

Bile Acids and Salts↗