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Biomedical subjects

S Gupta

Publications and source records attributed to S Gupta.

At least 739 records · Page 41Linked to original sources
PubMed1997

Mycophenolate mofetil for obliterative bronchiolitis syndrome after lung transplantation.

BACKGROUND: The development of obliterative bronchiolitis after lung transplantation portends a poor long-term outcome because of progressive decline in allograft function. There are currently no effective means of treating this condition. METHODS: Thirteen patients in whom obliterative bronchiolitis syndrome developed after lung transplantation were treated with mycophenolate mofetil, an antimetabolite immunosuppressant, at a dose of 1.5 g orally twice daily. Patients were followed up clinically and with pulmonary function testing. RESULTS: Duration of mycophenolate mofetil therapy ranged from 1 week to 24 months (mean duration, 11.4 months). Pulmonary function test results stabilized in the majority of patients with no significant further decline in forced expiratory volume in 1 second. Two patients died of progressive obliterative bronchiolitis, 1 patient is alive with progressive disease, and 1 patient died of an acute infection. The drug was discontinued in 2 additional patients. In no patient did severe leukopenia or cytomegalovirus infection develop; 1 patient had a fungal infection, and 7 patients experienced gastrointestinal side effects. CONCLUSIONS: In the setting of obliterative bronchiolitis syndrome, mycophenolate mofetil is generally well tolerated and is associated with stabilization of pulmonary function test results. These findings suggest that the otherwise progressive process of obliterative bronchiolitis can be slowed.

Adult↗
PubMed1997

Ilio-psoas abscesses: percutaneous drainage under image guidance.

Over a 5-year period, 56 psoas abscesses occurring in 51 patients were managed by image-guided percutaneous drainage, either by needle aspiration (n = 10) or by catheter drainage (n = 46) in conjunction with medical therapy. Twenty-seven patients had tuberculous abscesses (bilateral in five) while 24 patients had pyogenic abscesses. Percutaneous treatment was successful in 16 of the 24 patients (66.7%) with pyogenic abscesses. The reasons for failure were co-existent bowel lesions, phlegmonous involvement of muscle without liquefaction, multiloculated abscess cavity and thick tenacious pus not amenable to percutaneous drainage. Surgery was required in seven patients, either for failed percutaneous drainage or for the management of co-existent disease. Percutaneous drainage was initially successful in all 27 patients of tuberculous psoas abscesses. However, eight patients presented with recurrence requiring repeat intervention. The average duration of catheter drainage was longer in patients with tuberculous abscess (11 days) than in patients with pyogenic abscess (6 days). Percutaneous drainage under image guidance provides an effective and safe alternative to more invasive surgical drainage in most patients with psoas abscesses.

Adolescent↗
PubMed1997

Intracavernosal forskolin: role in management of vasculogenic impotence resistant to standard 3-agent pharmacotherapy.

PURPOSE: We investigated forskolin, a direct adenylate cyclase activator, as an intracavernosal vasoactive agent in management of vasculogenic impotence. MATERIALS AND METHODS: Concentration responses for forskolin and prostaglandin E1 induced relaxation of phenylephrine precontracted strips of human corpus cavernosum smooth muscle were constructed in vitro. Cyclic adenosine monophosphate (cAMP) synthesis was determined with papaverine, phentolamine, prostaglandin E1 and forskolin in human corpus cavernosum smooth muscle cell cultures. Dose-dependent hemodynamic responses to intracavernosal forskolin (5 to 20 micrograms) were evaluated in a New Zealand White rabbit model. Safety and efficacy outcome data were obtained in vasculogenically impotent patients who signed informed consent and met strict inclusion and exclusion criteria that included having had standard self-injection therapies fail. RESULTS: In vitro forskolin and prostaglandin E1 alone caused concentration dependent relaxation with an EC50 of approximately 200 nm. and 16 nm., respectively. When the 2 agents were combined, the concentration response curve for relaxation shifted to the left. cAMP production was highest in cells treated with prostaglandin E1 and forskolin and was unaffected by papaverine or phentolamine. In 3 animals, equilibrium intracavernosal pressure and duration of erection had a dose dependent increase. Clinical investigation in 31 patients showed no adverse events with a mean of 14 +/- 4, range 11 to 18 months of followup. Overall 61% reported improvement in rigidity and/or erection duration using intracavernosal forskolin (98 micrograms./ml.), papaverine (29 mg./ml.), phentolamine (0.98 mg./ml.) and prostaglandin E1 (9.8 micrograms./ml.). CONCLUSIONS: Forskolin is a United States Food and Drug Administration nonapproved vasoactive agent that acts in synergism with prostaglandin E1 to induce smooth muscle relaxation. In combination with other vasoactive agents, forskolin has demonstrated preliminary safety and efficacy in patients with vasculogenic impotence resistant to standard 3-agent pharmacotherapy.

Alprostadil↗
PubMed1997

Role of iron and iron chelation therapy in oxygen free radical mediated tissue injury in an ascending mouse model of chronic pyelonephritis.

The contribution of iron towards the free radical generation leading to renal tissue damage was assessed using a non-obstructive ascending mouse model for chronic pyelonephritis. The parameters studied include luminol dependent chemiluminescence (LDCL), histopathology and some biochemical investigations. We found that iron enhanced the renal tissue damage and led to renal scarring, and end point in chronic renal inflammation, irrespective of the bacterial strain studied. In addition a role of iron chelation therapy as a treatment for chronic renal inflammation is also suggested.

Animals↗
PubMed1997

Secondary capsule-supported intraocular lens implantation in children.

PURPOSE: To evaluate surgical problems, postoperative complications, and visual results of secondary posterior chamber intraocular lens (IOL) implantation in children. SETTING: L.V. Prasad Eye Institute, Hyderabad, India. METHODS: A retrospective study was done of secondary IOL implantation in 27 children (35 eyes) who were not satisfied with aphakic glasses and were intolerant of or reluctant to use contact lenses. The extent of posterior capsular support was assessed prior to surgery. Additional surgical procedures were posterior synechiolysis (11 eyes), anterior vitrectomy (8 eyes), pupilloplasty (2 eyes), and membranectomy (2 eyes). RESULTS: Postoperative complications included wound leak (1 eye), uveitis (5 eyes), peripheral anterior synechias (2 eyes), and retinal detachment (1 eye). Visual acuity improved or remained at the preoperative level in 34 eyes. CONCLUSION: Secondary posterior chamber IOL implantation is an effective optical modality for managing pediatric aphakia. Observation must continue to determine the long-term safety of the procedure.

Adolescent↗
PubMed1997

Management of traumatic cataract in children.

PURPOSE: To evaluate the presentation, mode of management, and clinical outcome of traumatic cataract in children. SETTING: L.V. Prasad Eye Institute, Hyderabad, India. METHODS: One hundred thirty-seven children (< 16 years) who developed traumatic cataract, seen between January 1988 and December 1993, were retrospectively analyzed. Nature of injury, type of cataract, management, and outcome were evaluated. RESULTS: The study group comprised 110 boys and 27 girls. Average follow-up was 11.7 months (range 1 week to 60 months). Most injuries (54.7%) were caused by a stick or a bow and arrow. Most (53.2%) of the cataracts were total. Corneal scarring (60.5%) and iris-related problems (49.6%) were the most common associated findings. Extracapsular cataract extraction with intraocular lens (IOL) implantation was performed in 65.67% of patients. Visual acuity improved form 20/200 or worse in 97.7% of patients preoperatively to 20/60 or better in 74.1% or patients postoperatively. Seventeen patients had associated posterior segment insult; most failed to recover satisfactory vision. Posterior capsule opacification (PCO) was noted in 42.9% of patients. CONCLUSIONS: Extracapsular cataract extraction with IOL implantation provides satisfactory results in children with traumatic cataract. Associated posterior segment complications and development of PCO are the major obstacles to visual rehabilitation.

Adolescent↗
PubMed1997

Etiology of ptosis after cataract surgery.

PURPOSE: To determine whether using a lid speculum with a superior rectus bridle suture in cataract surgery results in levator rectus aponeurosis dehiscence caused by strong fascial attachments between the levator and superior rectus muscles. SETTING: L.V. Prasad Eye Institute, Hyderabad, India. METHODS: This study comprised 220 patients having cataract extraction with posterior chamber intraocular lens implantation. The patients were randomly assigned to one of two groups. In the first group (n = 108), a lid speculum was used during surgery. In the second group (n = 112), no speculum was used. All patients had a superior rectus bridle suture. The occurrence of ptosis was analyzed by a masked observer who was not involved in the surgery. RESULTS: The incidence of ptosis was significantly higher in the speculum (44.4%) than in the no-speculum (23.3%) group (P = .0009). CONCLUSION: The results indicate that the opposing forces created by the lid speculum and bridle suture can cause levator aponeurosis dehiscence because of the strong fascial attachments between the superior rectus and levator muscles. The occurrence of ptosis in the no-speculum group implies a multifactorial etiology, however.

Blepharoptosis↗
PubMed1997

Cataract formation after penetrating keratoplasty.

PURPOSE: To assess the incidence and risk factors for developing cataract after penetrating keratoplasty (PKP). SETTING: L.V. Prasad Eye Institute, Hyderabad, India. METHODS: This retrospective analysis of 251 phakic patients who had PKP between 1987 and 1994 assessed the incidence of and risk factors for cataract formation. Patients were assigned to one of two groups: Group 1 (n = 96), patients with keratoconus and corneal dystrophy; Group 2 (n = 88), patients with corneal scar and adherent leucoma. Preoperative, intraoperative, and postoperative lens details were noted. Data on intraoperative iris procedures (excess manipulation, pupilloplasty, synechiolysis, peripheral iridectomy) and postoperative topical steroid usage were assessed. RESULTS: Sixty-seven patients were excluded because of incomplete lens status data. Of the remaining 184 patients, 45 (24.45%) developed cataract. Most cataracts (n = 31) developed within the first year of surgery. The incidence of cataract was significantly higher in Group 2 (n = 29) than in Group 1 (n = 16) (P = .0102). There was no significant between-group difference in mean steroid dose (P = .7064); however, the mean dose was significantly higher in eyes with cataracts (563 +/- 234 units) than in those without (479 +/- 127 units) (P = .0352). In Group 2, 9 of 20 patients who had synechiolysis, 1 of 3 who had pupilloplasty, and 2 of 5 who had peripheral iridectomy developed cataract. In Group 1, no patient had iris-related procedures. CONCLUSION: Excessive steroid use and intraoperative iris manipulations are major risk factors for cataract formation after PKP.

Adolescent↗
PubMed1997

Globe rupture during digital massage after peribulbar anesthesia.

A 75-year-old woman developed globe rupture with extrusion of intraocular contents during digital massage after periocular injection of an anesthetic. The rupture was repaired. At the last follow-up 6 months after surgery, visual acuity was 20/160. The retina was attached, and the vitreous hemorrhage was resolving. This complication of peribulbar anesthesia and digital massage highlights the importance of using quantitative techniques to induce hypotony during peribulbar anesthesia.

Aged↗
PubMed1997

Pressure modulates monocyte migration.

Migration of monocytes into the subendothelial space of the aorta has been considered to be an important event in the development of atherosclerosis. Because hypertension is commonly associated with atherosclerosis, we studied the effect of applied pressure on the migration of monocytes. Direct applied pressure increased the migration (P < .001) of monocytes across a filter when compared with normal atmospheric pressure. The migration of monocytes was found to be directly related to the amount of the applied pressure. Amlodipine, a calcium channel blocker, attenuated the migration of monocytes under normal as well as increased pressure conditions in a dose-dependent manner. These studies provide a basis to speculate on the role of direct pressure in the migration of monocytes into the subendothelial space and the possibility that vasoactive agents may modulate the migration of monocytes independent of their pressure-lowering effect.

Amlodipine↗
PubMed1997

Serological diagnosis of childhood tuberculosis by estimation of mycobacterial antigen 60-specific immunoglobulins in the serum.

SETTING: An ELISA assay based on mycobacterial antigen 60 (A60) for the estimation of specific immunoglobulins in the serum has been used successfully for the rapid diagnosis of tuberculosis in studies done predominantly in Western countries. In a recent Indian study, encouraging results were reported in adult tuberculosis. OBJECTIVE: To evaluate the utility of this ELISA test for rapid diagnosis of different clinical forms of tuberculosis in Indian children. DESIGN: ELISA test based on mycobacterial A60 was used to estimate specific IgM, IgA and IgG antibodies in the sera obtained from 452 cases of tuberculosis and 161 controls in the paediatric population of Delhi, India. RESULTS: Of the 161 controls, only 7.4% were positive for IgM, 4.3% for IgG, 3.7% for IgA and 8% when a combination of IgM and IgA was considered. Of 58 cases of definite pulmonary tuberculosis, 55.2% were positive for IgM, 32.7% for IgG, 36.2% for IgA and a high positivity of 72.4% was seen when IgA and IgM estimations were combined. The corresponding figures in 150 cases of definite extrapulmonary tuberculosis were 57.3%, 36.6%, 38% and 76.6%. A relatively weak serology was observed in 244 cases of probable tuberculosis. A very high positivity (95%) was seen in acid-fast bacilli-positive cases of tuberculosis. CONCLUSIONS: Our findings point to a very good specificity (92%) and a reasonably good sensitivity (75.5%) of the test when combined IgM and IgA antibody titres are considered in the diagnosis of childhood tuberculosis.

Antibodies, Bacterial↗
PubMed1997

Expression of arginine decarboxylase in seedlings of indica rice (Oryza sativa L.) cultivars as affected by salinity stress.

The effect of salinity stress on the activity of arginine decarboxylase (ADC, EC 4.1.1.19), the first enzyme in biosynthesis of polyamines (PA) from arginine, as well as its transcript level has been compared in salt-sensitive (M-1-48) and salt-tolerant (Pokkali) rice cultivars. Treatment of 72 h grown seedlings either with increasing concentrations of NaCl or with 150 mM NaCl for different time periods, showed a gradual increase of activity in Pokkali. In M-1-48 an immediate increase followed by sharp decrease was observed on prolonged treatment beyond 6 h or above 150 mM NaCl. To generate a DNA probe for ADC, the polymerase chain reaction was used with oat genomic DNA and sequence-specific primers. A region of oat genomic DNA containing a coding sequence for 166 amino acids of the C-terminal part of the ADC enzyme was amplified and called OAD1. Southern analysis of EcoRI- or BamHI-cut genomic DNAs from different cultivars of rice with OAD1 as the probe revealed strong hybridization with one DNA fragment of rice and restriction fragment length polymorphism (RFLP) was noticed. Northern analysis of total RNA of rice with OAD1 as the probe revealed hybridization with a transcript of similar size to the ADC transcript in oat. While in Pokkali, at least a 20-fold accumulation of OAD1 homologous transcript was detected after treatment with 200 mM NaCl, only a seven-fold increase in transcript level was found in M-1-48 after 150 mM NaCl treatment. Results suggest that in the salt-tolerant rice cultivar Pokkali, ADC enzyme activity increases and its transcript also accumulates during the prolonged salinity stress, this mechanism is absent in the salt-sensitive rice cultivar M-1-48 where a prolonged period of salinity stress down-regulates both ADC activity and its transcript level.

Carboxy-Lyases↗
PubMed1997

Programmed cell death (apoptosis) in cord blood lymphocytes.

Cord blood lymphocytes are functionally immature and have deficient immune responses. In order to determine whether the process of programmed cell death is distinct between cord blood and peripheral blood lymphocytes, we analyzed the expression of fas and bax (apoptosis promoting genes) and bcl-2 and bcl-xL (apoptosis inhibiting genes) at protein or mRNA levels using flow cytometry and quantitative PCR methods, respectively. The susceptibility of T cell subsets from cord blood and adult peripheral blood to undergo apoptosis following restimulation with anti-CD3 or anti-Fas monoclonal antibodies was also studied. We observed that cord blood T cell subsets expressed lower levels of Fas and Bcl-2, a low bcl-2/bax ratio, and higher bcl-xL compared to peripheral blood. Additionally, upon primary stimulation with anti-CD3, cord blood T cell subsets were more resistant to apoptosis compared to peripheral blood. In contrast, rechallenge of previously stimulated lymphocytes with anti-CD3 monoclonal antibody triggered apoptosis in a larger proportion of T cells from cord blood as compared to peripheral blood, whereas the number of T cells undergoing anti-Fas-induced programmed cell death were lower in cord blood compared to peripheral blood.

Adult↗
PubMed1997

Altered expression and function of P-glycoprotein (170 kDa), encoded by the MDR 1 gene, in T cell subsets from aging humans.

Aging is associated with progressive T cell-mediated immune deficiency, increased frequency of infections, and autoimmune phenomena. P-glycoprotein (P-gP), a 170-kDa glycoprotein, is a member of a superfamily of ATP-binding cassette transport proteins that has been shown to express on cells of the immune system and suggested to play a role in secretion of certain cytokines and cytotoxic molecules. Because aging is associated with altered secretion of cytokines, in this investigation we examined the expression and function of P-gP in CD4+ and CD8+ T cells and their "memory" and "naïve" subpopulations in peripheral blood from healthy aging and young subjects. P-glycoprotein expression was analyzed at the protein levels by dual- or triple-color flow cytometric analysis, using monoclonal antibodies against P-gP (MRK16), and at the mRNA level by quantitative reverse-transcriptase polymerase chain reaction. The efflux function of P-gP was measured by intracellular accumulation of rhodamine-123 (Rh123; a substrate for P-gP) in the presence or absence of cyclosporin A (which binds to P-gP and inhibits its efflux function). The data show increased expression of P-gP at both the protein and the mRNA levels in aging lymphocytes. Increased P-gP expression, at the protein level, was also observed in naïve cell subpopulations from aging CD4+ and CD8+ T cell subsets compared to those from young controls. An increase in P-gP function, as measured by the ability of T cell subsets to efflux Rh123, was observed in aging CD4+ and CD8+ T cell subsets and their naïve and memory subpopulations. These data suggest that altered P-gP expression and function in aging may play a role in changes in immune response, including cytokine secretion, associated with human aging.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

Phyllanthus amarus suppresses hepatitis B virus by interrupting interactions between HBV enhancer I and cellular transcription factors.

The Phyllanthus amarus plant suppresses HBV mRNA transcription in vitro and exhibits therapeutic potential in chronic HBV carriers, although further work is necessary to define its mechanism of action. Analysis in HuH-7 cells with transfected plasmids using a luciferase reporter showed that P. amarus specifically inhibited HBV enhancer I activity. To identify the mechanism of this HBV enhancer I inhibition, liver-enriched cellular transcription factors were co-expressed in HuH-7 cells. The C/EBP alpha and beta, as well as HNF-3 alpha and beta transcription factors, significantly up-regulated the HBV enhancer I activity. In contrast, co-transfection of HNF-I alpha or beta had no effect upon the HBV enhancer I activity. Exposure to P. amarus inhibited C/EBP alpha- and beta-mediated up-regulation of HBV enhancer I activity in a dose-dependent manner, whereas HNF-3 alpha- and beta-mediated up-regulation of HBV enhancer I was unaffected. In vitro gel shifts showed that P. amarus inhibited complexing of C/EBP transcription factors to a consensus oligonucleotide sequence, whereas DNA binding of AP-1 and SP-1 transcription factors was unaffected. As P. amarus down-regulates HBV mRNA transcription by a specific mechanism involving interactions between HBV enhancer I and C/EBP transcription factors, purification and further analysis of the active P. amarus component will advance insights into its antiviral activity.

Antiviral Agents↗
PubMed1997

Percutaneous nephrostomy with real-time sonographic guidance.

PURPOSE: Percutaneous nephrostomy (PCN) is an effective method for achieving temporary drainage of the obstructed urinary system and is usually performed under fluoroscopic guidance alone or more commonly under combined sonographic and fluoroscopic guidance. We undertook a retrospective analysis of 273 PCNs performed solely under ultrasound (US) guidance with the aim of evaluating the technique and the safety and efficacy of the procedure. MATERIAL AND METHODS: A total of 273 PCN procedures in 267 patients were performed under real-time US guidance using the Seldinger technique. The indications for PCNs comprised benign (n = 215) and malignant (n = 46) urinary obstruction, and urinary fistulae (n = 6). RESULTS: PCN was successful in 269 of the 273 attempts (98.5%). Satisfactory catheter placement was achieved in 245 of the 269 procedures (91.1%) under US guidance. Fluoroscopic assistance for catheter repositioning was required in 24 PCNs owing to the unsatisfactory position of the catheter tip. Major complications occurred in 15 patients (5.6%). Catheter dislodgement and catheter blockage was seen in respectively 12.6% and 3.3% of procedures. CONCLUSION: In most patients, PCN can be performed safely using real-time sonographic guidance.

Adolescent↗
PubMed1997

Effect of incremental doses of sevoflurane on cerebral pressure autoregulation in humans.

We have examined cerebral pressure autoregulation while awake, and during 0.5 and 1.5 MAC of sevoflurane anaesthesia in 10 patients undergoing non-intracranial neurosurgical procedures. All patients received a standardized anaesthetic comprising premedication with temazepam 20 mg orally, a sleep dose of propofol, fentanyl 1 microgram kg-1 and vecuronium 0.1 mg kg-1. After tracheal intubation, the lungs were ventilated with a mixture of air and oxygen to mild hypocapnia. Routine monitors included ECG, continuous and intermittent non-invasive arterial pressure, pulse oximetry and end-tidal capnography. In addition, blood flow velocity (vmca) was measured by insonating the middle cerebral artery transtemporally using a 2-MHz transcranial Doppler probe. Cerebral pressure autoregulation was tested by increasing mean arterial pressure (MAP) by approximately 20 mm Hg using an infusion of phenylephrine and simultaneously recording vmca. The index of autoregulation (IOR) during each period of the study, calculated as the ratio of percentage change in estimated cerebral vascular resistance (CVRe = MAP/vmca) to percentage change in MAP, was compared using ANOVA. vmca during 0.5 and 1.5 MAC of sevoflurane anaesthesia was significantly lower than that while awake (mean 79 (SD 24), 54 (15) and 51 (12) cm s-1, respectively; P < 0.05). There was no significant change in vmca with the increase in MAP while awake, or during 0.5 or 1.5 MAC of sevoflurane anaesthesia and IOR was similar under the three conditions (0.82 (0.11), 0.83 (0.04) and 1.0 (0.03), respectively). We conclude that cerebral pressure autoregulation remained intact during sevoflurane anaesthesia in humans.

Adult↗