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Biomedical subjects

R Rajagopal

Publications and source records attributed to R Rajagopal.

At least 37 records · Page 2Linked to original sources
PubMed2001

Adenovirus-mediated antisense urokinase-type plasminogen activator receptor gene transfer reduces tumor cell invasion and metastasis in non-small cell lung cancer cell lines.

The urokinase-type plasminogen activator (uPA) and its receptor (uPAR) play an important role in the proteolytic cascade involved in the metastasis of lung and other cancers. We report that the reduction in uPAR levels produced by an antisense strategy using an adenovirus construct (Ad-uPAR) in H1299 cells, an invasive human lung cancer cell line that produces high levels of uPAR, resulted in a decrease of uPAR levels to 80-90% of those seen in cells infected with mock or adenovirus (Ad)-cytomegalovirus vector controls. In addition, increasing the multiplicity of infection from 25 to 200 caused a corresponding decrease in the level of uPAR protein within 5 days of treatment, as shown by Western blot analysis. Furthermore, the in vitro translation of total RNA levels of Ad-uPAR-infected H1299 cells in a rabbit reticulocyte lysate system caused a 50-70% decrease in uPAR immunoprecipitate in Ad-uPAR-infected cells relative to the levels in cells of mock and vector controls. The Matrigel invasion assay showed the invasion of H1299 cells and A549 cells infected with Ad-uPAR to be decreased by 70% relative to mock- and vector-infected controls. Infection of tumor cells with Ad-uPAR before implantation significantly reduced the incidence of lung metastasis by 85% as compared with the control virus-infected cells injected into nude mice through the tail vein. Our collective results show that the uPAR system is a potential target of treatment for lung cancers.

Adenoviridae↗
PubMed2000

Postoperative Mycobacterium chelonae endophthalmitis after extracapsular cataract extraction and posterior chamber intraocular lens implantation.

OBJECTIVE: To describe a case of postoperative endophthalmitis caused by Mycobacterium chelonae after extracapsular cataract extraction with posterior chamber intraocular lens implantation. DESIGN: Interventional case report. METHODS: The history and clinical presentation of a 66-year-old female patient, in whom a low-grade delayed-onset endophthalmitis and keratitis developed after extracapsular cataract extraction with posterior chamber intraocular lens implantation, is described. Microbiologic investigations of the scrapings of corneal infiltrate at the cataract incision site, aqueous humor and eviscerated material, and histopathologic study of eviscerated material and an enlarged cervical lymph node were performed. MAIN OUTCOME MEASURES: The clinical, histopathologic, and microbiologic findings in a case of low-grade delayed-onset endophthalmitis. RESULTS: Analysis of the direct smear of both the corneal infiltrate as well as the eviscerated material revealed acid-fast bacilli. M. chelonae was isolated from these specimens. Direct smear and culture of the aqueous humor were negative for bacteria (including mycobacteria) and fungus. Histopathologic examination of the eviscerated material showed a dense infiltration of polymorphonuclear leukocytes in the uveal tissue, extensive necrosis and hemorrhage, and exudates with hemorrhage in the vitreous cavity. Histopathologic examination of the lymph node revealed granulomatous inflammation with caseation necrosis, but did not reveal acid-fast bacilli. CONCLUSIONS: M. chelonae, although infrequent, should be considered an etiologic agent of delayed-onset, postoperative endophthalmitis and early bacterial diagnosis should help in institution of appropriate therapy.

Abscess↗
PubMed2000

Bilateral corneal infiltrates after excimer laser photorefractive keratectomy.

A 26-year-old man developed painless inferior subepithelial infiltrates away from the site of ablation in both eyes after excimer laser photorefractive keratectomy (PRK) for myopia. Clinical characteristics of the corneal infiltrates resembled staphylococcal-immune infiltrates. The condition responded to treatment with topical diluted steroids and antibiotics. There was no residual corneal scarring. The infiltrates did not affect the refractive outcome of the surgery. Recognition of this rare entity will help clinicians avoid aggressive investigative and treatment modalities that can affect the results of PRK.

Adult↗
PubMed2000

Partial flap during laser in-situ keratomileusis: pathogenesis and timing of retreatment.

PURPOSE: To report the timing of retreatment and clinical outcomes in patients with a partial corneal flap during laser in-situ keratomileusis (LASIK), and to describe the causes of this complication. METHODS: Retrospective review of case records of four patients (4 eyes) who had a partial corneal flap during LASIK. RESULTS: The mean age of the four patients was 23 +/- 4.7 years, and mean preoperative spherical equivalent (SE) refraction was -9.1 +/- 3.1 D (range, -5.5 to -13 D). A 160 microns corneal flap was attempted during the initial treatment. Retreatment with a 180 microns corneal flap was performed at a mean of 5.1 +/- 1.6 weeks (range, 4 to 7.5 weeks) after the initial procedure. There were no intraoperative complications during retreatment. Post-LASIK mean SE refraction was -1.0 +/- 1.1 D (range, +0.38 to -2.0 D), after a mean follow up of 19 +/- 15.7 weeks (range, 7 to 42 weeks). Best spectacle-corrected visual acuity decreased in one eye from 6/5 to 6/6 and was maintained in the others. CONCLUSION: LASIK retreatment can be performed as early as one month after a partial flap, if the refraction is stable and a thicker corneal flap is created.

Adult↗
PubMed1999

Limbal allografting from related live donors for corneal surface reconstruction.

OBJECTIVE: To report the results of limbal allograft transplantation, from human leukocyte antigen (HLA)-matched and -unmatched related live donors, in patients with ocular surface disease due to chemical burns and Stevens-Johnson syndrome. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Eight patients (nine eyes) with severe chemical burns (n = 7 eyes) and Stevens-Johnson syndrome (n = 2 eyes). INTERVENTION: Recipient eyes were treated with excision of cicatricial tissues. Transplantation of superior and inferior limbal grafts was performed from related live HLA-matched (n = 7) and -unmatched donors (n = 2). Systemic cyclosporine was not used in any of the recipients. MAIN OUTCOME MEASURES: Reconstruction of corneal surface epithelium, restoration of avascularity, increase in ocular comfort, and improvement in visual acuity. RESULTS: With a mean observation period of 17.2 months, phenotypically corneal epithelium, decreased vascularization of the corneal surface, and improved ocular comfort were seen in seven (77.8%) eyes. In all seven eyes, gradual recurrence of peripheral corneal vascularization occurred during the follow-up period. Features of graft rejection developed in three (42.9%) of these seven eyes. In two eyes, limbal transplantation from HLA-unmatched donors failed to reconstitute the corneal surface. Limbal allograft transplantation resulted in visual acuity of 20/400 or greater in only two (22.2%) eyes at last follow-up. Corneal grafts performed 7 and 16 months after successful limbal transplantation in two eyes developed recurrent epithelial breakdown and superficial corneal scarring. None of the donor eyes in this study had any complication. CONCLUSION: Transplantation of limbal tissue from related live donors successfully reconstructs the corneal surface in HLA-matched recipients. Recurrence of vascularization on long-term follow-up probably results from inadequate stem cell transfer, immune-mediated stem cell damage, or both. Limbal allografting is best performed by transplanting the entire limbus from a cadaveric donor eye with systemic immunosuppression of the recipient, even if the donor is HLA-compatible.

Adolescent↗
PubMed1999

Bilateral penetrating keratoplasty--indications, results and review of literature.

PURPOSE: To analyze the indications, functional results, and rates of graft rejection and failure after bilateral penetrating keratoplasty (PK) in a major eye care hospital and research center in India. METHODS: Retrospective review of the case records of 38 patients who underwent bilateral PK and had at least 6 months follow-up after corneal transplantation in the second eye. RESULTS: The mean age of the 38 patients (20 M, 18 F) was 35 +/- 25 years (range, 0.5 to 79 years). Mean follow-up was 49 +/- 23 months (range, 13.4 to 116.4 months) after surgery in the first eye and 31 +/- 22 months (range, 6.6 to 103.6 months) after surgery in the second eye. The average time interval between surgery in the first and second eye was 18 +/- 10 months (range, 0 to 38 months). The commonest indications for surgery were corneal dystrophies (50%), aphakic bullous keratopathy (21%), and keratoconus (11%). Postoperatively, secondary glaucoma occurred in 2 first and 3 second eyes. Best-corrected visual acuity at last follow-up was > 6/12 in 34% of first eyes and 50% of second eyes, and was < 6/60 in 26% and 18% of first and second eyes respectively. Allograft rejection occurred in 4 of the first eyes and 3 of the second eyes. The two-year graft survival rate in first eyes was 70% and in second eyes was 83%. Worse outcomes were noted in grafts performed for secondary endothelial failure. Earlier graft failure occurred in first eyes (54 +/- 5 months) compared to second eyes (79 +/- 10 months) (Logrank Test p = 0.2311). CONCLUSIONS: Bilateral penetrating keratoplasty has reasonable success in selected patients. Corneal transplantation in the second eye does not seem to increase the risk of graft rejection in either eye.

Adolescent↗
PubMed1999

Limbal autografting: comparison of results in the acute and chronic phases of ocular surface burns.

PURPOSE: To compare outcomes of limbal autograft transplantation (LAT) in the acute and chronic phases of ocular surface burns. METHODS: Retrospective analysis of case records of 16 consecutive patients who underwent LAT for ocular surface burns, at our institute, between April 1994 and March 1997. RESULTS: Limbal autograft transplantation was successful in reconstructing the corneal surface and restoring ocular comfort in 15 (93.8%) eyes. Limbal autografting failed to reconstruct the ocular surface in one patient undergoing surgery 2 weeks after grade IV alkali burns. In 13 eyes with counting fingers or worse vision, functional success (visual acuity >20/400) was attained after LAT in nine (69.2%) eyes. Visual acuity > or = 20/80 was achieved in two (25%) of eight eyes undergoing surgery for a persistent epithelial defect (PED) and five of six (83.3%) eyes undergoing surgery after the epithelial defect had healed (p = 0.03). Nine patients underwent simultaneous superior and inferior limbal autografting. Mean epithelial healing time in six of these patients undergoing surgery in the acute phase of injury (<4 months) was 15+/-6.1 days. In three patients undergoing a similar procedure in the chronic phase of injury, the healing time was 8.3+/-6.7 days. CONCLUSIONS: Limbal autograft transplantation is successful in reconstructing the corneal surface and restoring ocular comfort after ocular surface burns. Surgery in the acute phase of injury (<4 months), in the presence of a PED, could result in delayed corneal reepithelialization and poorer visual prognosis. If performed in the acute phase of injury, LAT should be performed after adequate limbal vascularization and resolution of surface inflammation in the recipient eye, avoiding graft placement over ischemic limbus.

Acids↗
PubMed1993

Present perspectives of malaria transmission in Boko area of Assam.

A longitudinal study on malaria transmission was conducted from January 1984 to December 1988 in three villages in Boko PHC of Assam, where indoor residual DDT spray was withdrawn during the period of study. Anopheline fauna comprising of 19 species was identified and their seasonal density estimated. Anopheles philippinensis was the predominant species followed by An. minimus. The principal role of An. minimus in the transmission of malaria and predilection for indoor resting in this area was clearly evident. Though An. dirus and An. fluviatilis were found in low density, sporozoite infection was detected in them along with An. minimus. The high malaria incidence predominantly with Plasmodium falciparum was closely related to sporozoite infection in the vectors and their densities. The biting cycle of An. minimus was maximum in the first half of the night.

Animals↗
PubMed1993

Malaria transmission in Nagaland, India. Part-I--Anophelines and their seasonality.

A longitudinal study on malaria transmission was conducted from January 1983 to December 1988 in two villages of Dimapur PHC in Nagaland. A diverse anopheline fauna comprising of 23 species was identified including three species viz. An. aitkeni, An. bengalensis and An. insulaeflorum which were observed in larval stages only. An. vagus was the predominant species followed by An. philippinensis, An. culicifacies and An. minimus. An. minimus though maintained relatively high density throughout the year manifested two peaks in June and October. An. fluviatilis and An. dirus though found in relatively low density their seasonal prevalence was suggestive of a post-monsoon and monsoon species respectively.

Animals↗
PubMed1991

Monoclonal antibodies toward a stable cyclic AMP-C8 antigen.

A cyclic AMP antigen was prepared utilizing a stable thioether linkage from C8 of the purine moiety. Monoclonal antibodies were raised toward the cyclic AMP-C8-diphtheria toxoid antigen and found to be of high specificity, with only very low cross-reactivity against related compounds, less than 0.03% against cGMP being the most significant cross-reaction. The stability of the thioether linkage enabled the preparation of an enzyme tracer, which was used in an ELISA. The assay had an effective working range from 0.1 to 100 pmol cAMP. Due to the structure of the antigen, the need for sample derivatization was eliminated.

Animals↗
PubMed1989

Preparation and Properties of Antibodies against Indoleacetic Acid (IAA)-C5-BSA, a Novel Ring-Coupled IAA Antigen, as Compared to Two Other Types of IAA-Specific Antibodies.

Two types of indoleacetic acid (IAA) antigens have been described in the literature which show marked differences with respect to antibody specificity. In this communication an alternative antigen design is described. In the so-called IAA-C5-BSA conjugate, both the acetic acid group and the pyrrole moiety are presented free, as the covalent linkage between IAA and the carrier molecule is introduced in the benzene moiety. Antibodies were elicited in rabbits against this novel antigen. Using cross-reactivity data and the strategy of successive approximation for the measurements of auxin levels in the internodes of light-grown broad bean (Vicia faba L. cv Superfine), the three types of antibodies are compared.

Journal Article↗