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Biomedical subjects

B Rajeev

Publications and source records attributed to B Rajeev.

13 recordsLinked to original sources

Everett Kinsey lecture. The elusive causes of keratoconus: a working hypothesis.

PURPOSE: Keratoconus is a diseasethat has been recognized clinically for many years. However, it is only more recently that a better understanding has been achieved in the area of keratoconus pathogenesis. The purpose of this paper is to summarize the completed research, review ongoing studies, and present a hypothesis for keratoconus pathology. METHODS: We used immunochemistry and molecular techniques to characterize keratoconus corneas. RESULTS AND CONCLUSIONS: Our hypothesis attempts to incorporate many of the recognized biochemical and molecular abnormalities found in the keratoconus corneas. Our hypothesis states: 1) there is abnormal processing of the free radicals and superoxides within the keratoconus corneas; 2) there is a build-up of destructive aldehydes or peroxynitrites within the corneas; 3) the cells that are damaged irreversibly undergo the process of apoptosis; and 4) the cells that are damaged reversibly undergo wound healing or repair. As part of the wound healing process, various degradative enzymes and wound healing factors are upregulated, which leads to focal areas of corneal thinning and fibrosis. Future studies will be directed to testthis working hypothesis and determine if these theories are valid.

Apoptosis↗

Computers in ophthalmology practice.

Computers are already in widespread use in medical practice throughout the world and their utility and popularity is increasing day by day. While future generations of medical professionals will be computer literate with a corresponding increase in use of computers in medical practice, the current generation finds itself in a dilemma of how best to adapt to the fast-evolving world of information technology. In addition to practice management, information technology has already had a substantial impact on diagnostic medicine, especially in imaging techniques and maintenance of medical records. This information technology is now poised to make a big impact on the way we deliver medical care in India. Ophthalmology is no exception to this, but at present very few practices are either fully or partially computerized. This article provides a practical account of the uses and advantages of computers in ophthalmic practice, as well as a step-by-step approach to the optimal utilization of available computer technology.

Computers↗

Molecular biologic techniques in ophthalmic pathology.

The polymerase chain reaction (PCR) and nucleic acid hybridization assays are recently introduced molecular techniques that allow for the identification of extremely small quantities of specific nucleic acids. These techniques have significant advantages over more conventional laboratory techniques, but also have some limitations. They are bound to have tremendous potential in diagnostic ophthalmic pathology and also in investigative pathology for deciphering the pathophysiology of ocular diseases. Despite their increased sensitivity and specificity, the results will still have to be co-related with clinical findings for maximum impact. For an ophthalmologist to derive maximum benefit, knowledge of these techniques, and their advantages, and limitations is essential. This article describes the basic concepts of molecular biology and the techniques of PCR, nucleic acid hybridization, and immunohistochemistry.

Animals↗

Vascular endothelial growth factor is a potent angiogenic factor in AIDS-associated Kaposi's sarcoma-derived spindle cells.

Angiogenesis is one of the most important features of AIDS-associated Kaposi's sarcoma (AIDS-KS). Our studies suggested that spindle-shaped AIDS-KS cells from various AIDS-KS lesions play important roles in the development of KS lesions. Basic fibroblast growth factor (bFGF) has been reported to be a predominant angiogenic factor expressed in AIDS-KS cells. However, our data from ELISA revealed the presence of the vascular endothelial growth factor (VEGF) molecule in large quantities in AIDS-KS cell-derived conditioned medium (AIDS-KS-CM) (12.1-21.4 ng/ml). In contrast, small amounts of bFGF were detected in AIDS-KS-CM (76-245 pg/ml). The combination of anti-VEGF and anti-bFGF IgGs completely inhibited endothelial cell growth-promoting activities in AIDS-KS-CM, while activities partially remained in the presence of anti-bFGF IgG or anti-VEGF IgG alone. VEGF and bFGF in AIDS-KS-CM were distinguished by heparin-affinity chromatography. Furthermore, the combination of VEGF and bFGF synergistically augmented the growth of endothelial cells. Both VEGF and bFGF revealed an angiogenic property that was inhibited by specific Abs, when applied to the rabbit cornea and chicken chorioallantoic membrane. On Western blots, anti-VEGF IgG gave two major bands of 22 and 24 kDa, similar to those of recombinant VEGF165. As detected on Northern blots, AIDS-KS cells expressed major 3.9-kb VEGF-specific mRNA. Thus, VEGF, in concert with bFGF, may play a crucial role in the angiogenesis of AIDS-KS lesions.

Animals↗

Postsurgical endophthalmitis: diagnosis and management.

Infectious endophthalmitis following intraocular surgery is a complication that could cause severe visual loss or loss of the eye. The categorisation of the event that led to intraocular infection will help the clinician to predict the infectious agent and begin appropriate therapy. Most of the cases of postsurgical endophthalmitis are seen following cataract surgery. It is important for all ophthalmologists, irrespective of specialisation and areas of interest, to be familiar with the management of endophthalmitis. This review briefly describes the facets of clinical and laboratory diagnosis, pathology, and management. While the different viewpoints in the management of endophthalmitis are mentioned in appropriate places, more attention is paid to present a rational approach to the management of endophthalmitis.

Anti-Bacterial Agents↗

Incidence and management of cataracts in Vogt-Koyanagi-Harada syndrome.

Of 65 consecutive patients (130 eyes) with Vogt-Koyanagi-Harada syndrome, 26 (40%) developed cataracts (49 eyes, 38%). Twenty-eight cataracts were posterior subcapsular, six nuclear, 14 combined nuclear and posterior subcapsular, and one anterior cortical. Risk factors for the development of cataracts included age (P = .003), long-standing recurrent anterior segment inflammation (P < .001), and systemic corticosteroid therapy for six months or more (P < .001). After at least three months of minimal to no intraocular inflammation, 19 eyes underwent cataract extraction, of which 11 also had posterior chamber intraocular lens implantation. Median visual acuity improved significantly from 20/400 to 20/40 (P < .01) after a median follow-up time of 13 months. Route of preoperative corticosteroids, pars plana vitrectomy, and glaucoma surgery did not markedly affect visual prognosis. If preoperative intraocular inflammation is rigorously controlled, cataract surgery can be performed safely and can result in significant visual improvement in patients with Vogt-Koyanagi-Harada syndrome.

Adult↗

Treatment of uveitis with immunosuppressive agents.

The spectrum of uveitis constitutes one of the major causes of blindness. Advances in our understanding of the underlying mechanisms have altered the diagnostic and therapeutic approaches. The most notable development is the increasing usage of several immunosuppressive agents. A systematic approach in making accurate diagnosis is central to employment of specific, more effective treatment. One should be cognizant of the potential benefits and risks of each of these agents before exposing the patients to these very potent drugs.

Humans↗

Botulinum toxin in the treatment of paralytic strabismus and essential blepharospasm.

As an alternative to conventional medical and surgical modalities that have met little success in the treatment of paralytic strabismus and essential blepharospasm, we explored the use of botulinum toxin as a treatment of choice in these two disorders. We used botulinum toxin in three patients with paralytic strabismus and in nine patients with essential blepharospasm. In three patients with paralytic strabismus, the botulinum toxin was injected into the ipsilateral antagonist of the paralysed muscle. The preinjection deviations ranged from 18 to 60 prism diopters. Two of these three patients achieved orthotropia around the thirtieth day and thereafter maintained it. The third patient became orthotropic on the eighteenth day, but deviation recurred and therefore required another injection of toxin. In nine patients with essential blepharospasm, botulinum toxin was injected into the orbicularis oculi muscles. Both objective and subjective improvement occurred in all nine patients within seven days and the effect lasted 12 to 15 weeks. Further injection of the toxin produced extremely beneficial results. However, the only significant complication that we encountered in both groups of strabismus and blepharospasm was ptosis, which was usually partial and temporary. From our experience, we advocate the use of botulinum toxin in the treatment of essential blepharospasm.

Adult↗

Corneal hazards in use of Simmons shell.

A Simmons tamponade shell was used in 10 cases of post-trabeculectomy overfiltration leading to shallow (iridocorneal touch) or flat anterior chamber. The Simmons shell was an unqualified success in only three cases. Corneal abscess (one case) and corneal abrasion/epithelial loss (four cases) necessitated premature removal of the shell. Three of the patients with corneal abrasions had a formed anterior chamber at the time of shell removal but this shallowed again within 12 hours. Two of these required surgical reformation of the anterior chamber and one reformed spontaneously. Air entrapment causing corneal dessication was probably responsible for the abrasion/epithelial loss. The patient who developed a corneal abscess was grossly malnourished. Use of the Simmons shell needs close monitoring and it should be removed at the first sign of corneal toxicity (abrasion/epithelial loss). Extreme care is necessary in malnourished cases.

Adolescent↗