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Biomedical subjects

M Ramchandani

Publications and source records attributed to M Ramchandani.

16 recordsLinked to original sources
PubMed2004

Integrated portable genetic analysis microsystem for pathogen/infectious disease detection.

An integrated portable genetic analysis microsystem including PCR amplification and capillary electrophoretic (CE) analysis coupled with a compact instrument for electrical control and laser-excited fluorescence detection has been developed. The microdevice contains microfabricated heaters, temperature sensors, and membrane valves to provide controlled sample positioning and immobilization in 200-nL PCR chambers. The instrument incorporates a solid-state laser and confocal fluorescence detection optics, electronics for sensing and powering the PCR reactor, and high-voltage power supplies for conducting CE separations. The fluorescein-labeled PCR products are amplified and electrophoretically analyzed in a gel-filled microchannel in <10 min. We demonstrate the utility of this instrument by performing pathogen detection and genotyping directly from whole Escherichia coli and Staphylococcus aureus cells. The E. coli detection assay consists of a triplex PCR amplification targeting genes that encode 16S ribosomal RNA, the fliC flagellar antigen, and the sltI shigatoxin. Serial dilution demonstrates a limit of detection of 2-3 bacterial cells. The S. aureus assay uses a femA marker to identify cells as S. aureus and a mecA marker to probe for methicillin resistance. This integrated portable genomic analysis microsystem demonstrates the feasibility of performing rapid high-quality detection of pathogens and their antimicrobial drug resistance.

Animals↗
PubMed2004

Penetrating keratoplasty in adults with congenital glaucomas.

PURPOSE: To report the problems and outcomes of penetrating keratoplasty (PKP) in patients with corneal oedema due to congenital glaucoma. METHOD: Case note review of nine such consecutive patients treated with PKP. A Kaplan - Meir survival curve was plotted for the series. RESULTS: Nine patients, ranging in age from 27 to 71 years at the time of their surgery were followed up for a mean of 28 months. All had undergone previous surgery for glaucoma. Preoperatively all patients had controlled intraocular pressures, and four were on ocular hypotensives. Two patients developed corneal graft failure at 15 and 41 months postoperative. Raised pressure was the cause in both. Final visual acuity improved in five patients, was the same in three, and deteriorated in only one. Complications included raised intraocular pressure, cataract, retinal detachment, and endophthalmitis secondary to an infected Molteno implant. CONCLUSION: Despite multiple impediments to good postoperative vision including previous surgery and pre-existing glaucomatous damage, a successful outcome was achieved by careful patient selection, and an awareness of, and meticulous attention to postoperative complications.

Adult↗
PubMed2004

Are patient information leaflets contributing to informed consent for cataract surgery?

AIM: To assess, against a checklist of specific areas of required information and using standard published criteria, to what extent leaflets given before cataract surgery provided patients with enough information to give adequately informed consent. METHOD: Twelve ophthalmology departments in the West Midlands region were asked to submit the cataract information leaflets given to their patients at the preoperative assessment for analysis. Using criteria published by the General Medical Council, British Medical Association, and Medical Defence Union the leaflets were assessed for their contribution to informed consent for patients considering cataract surgery. Leaflets were scored according to the information they provided on: diagnosis, prognosis, treatment options, costs to the patient, details about the procedure, its purpose, likely benefits, how to prepare for it, what to expect during and after the operation, and the common as well as serious complications that may occur. The readability of the information was also assessed. RESULTS: All the units' leaflets provided information on diagnosis, the lifestyle changes required postoperatively, and cost involved to the patient. Only five units had leaflets that mentioned the risks involved in cataract surgery. The other areas of information were covered by 50-75% of the leaflets. Fifty per cent of the leaflets included a diagram. The average SMOG readability score was high. CONCLUSION: Although present cataract information leaflets make some contribution to the process of informed consent, most do not address important areas outlined by the General Medical Council. Many of the areas of information that are required for informed consent could easily be covered, and should be borne in mind when designing patient information leaflets. Resources are available on the internet including toolkits, guides, and means of assessment for the production of patient information leaflets.

Cataract Extraction↗
PubMed2001

Pars plana vitrectomy with silicone oil in the management of combined rhegmatogenous retinal and choroidal detachment.

PURPOSE: Rhegmatogenous retinal detachment combined with spontaneous pre-operative choroidal detachment (RDCD) represents a rare but specific entity, which has in the past been associated with a poor prognosis. This study was designed to determine the efficacy of pars plana vitrectomy with silicone oil injection in the management of this very difficult vitreoretinal problem. METHODS: A retrospective analysis was carried out of 13 eyes of 13 consecutive patients who underwent vitrectomy and silicone oil exchange. RESULTS: In a total of 10 eyes (77%) the first procedure produced anatomical success. Two eyes required a further procedure to achieve retinal reattachment, producing a final anatomical success rate of 92%. CONCLUSION: Pars plana vitrectomy with silicone oil exchange is an effective technique for managing RDCD.

Adult↗
PubMed2000

Labial adenocarcinoma after treatment with cyclosporin a in a patient with panuveitis.

PURPOSE: To report a case of labial basal cell adenocarcinoma in a patient with uveitis on treatment with cyclosporin A. METHOD: Case report. A 73-year-old woman with panuveitis and retinal vasculitis presented with a lump on her lip after 52 months of treatment with cyclosporin A. RESULT: Excision biopsy showed a labial adenocarcinoma. CONCLUSION: Malignancy can occur after long-term cyclosporin A treatment for uveitis.

Adenocarcinoma↗
PubMed1998

In vitro and in vivo release of ciprofloxacin from PLGA 50:50 implants.

Poly(lactides-co-glycolides) [PLGA] are widely investigated biodegradable polymers and are extensively used in several biomaterials applications as well as drug delivery systems. These polymers degrade by bulk hydrolysis of ester bonds and break down into their constituent monomers, lactic and glycolic acids which are excreted from the body. The purpose of this investigation was to develop and characterize a biodegradable, implantable delivery system containing ciprofloxacin hydrochloride (HCl) for the localized treatment of osteomyelitis and to study the extent of drug penetration from the site of implantation into the bone. Osteomyelitis is an inflammatory bone disease caused by pyogenic bacteria and involves the medullary cavity, cortex and periosteum. The advantages of localized biodegradable therapy include high, local antibiotic concentration at the site of infection, as well as, obviation of the need for removal of the implant after treatment. PLGA 50:50 implants were compressed from microcapsules prepared by nonsolvent-induced phase-separation using two solvent-nonsolvent systems, viz., methylene chloride-hexane (non-polar) and acetone-phosphate buffer (polar). In vitro dissolution studies were performed to study the effect of manufacturing procedure, drug loading and pH on the release of ciprofloxacin HCl. The extent of penetration of the drug from the site of implantation was studied using a rabbit model. The results of in vitro studies illustrated that drug release from implants made by the nonpolar method was more rapid as compared to implants made by the polar method. The release of ciprofloxacin HCl. The extent of the penetration of the drug from the site of implantation was studied using a rabbit model. The results of in vitro studies illustrated that drug release from implants made by the nonpolar method was more rapid as compared to implants made by the polar method. The release of ciprofloxacin HCl from the implants was biphasic at < or = 20% w/w drug loading, and monophasic at drug loading levels > or = 35% w/w. In vivo studies indicated that PLGA 50:50 implants were almost completely resorbed within five to six weeks. Sustained drug levels, greater than the minimum inhibitory concentration (MIC) of ciprofloxacin, up to 70 mm from the site of implantation, were detected for a period of six weeks.

Animals↗
PubMed1998

trans-3-Benzyl-4-hydroxy-7-chromanylbenzoic acid derivatives as antagonists of the leukotriene B4 (LTB4) receptor.

The SAR of a series of 2-(7-chromanyl)benzoic acids has been investigated with the aim of identifying potent and selective LTB4 receptor antagonists that maintain potency in complex biological fluids. We found optimal activity in derivatives with electron-withdrawing groups in the benzoic acid ring and with an unsubstituted C-3 benzyl group on the chromanol nucleus. While compounds containing a 3-(4-phenyl)benzyl chromanol substituent were potent LTB4 receptor antagonists, the increased lipophilicity imparted by the additional phenyl substituent led to decreased potency in the presence of plasma proteins. From among the potent compounds identified, CP-195543, the 5'-trifluoromethyl 3-benzyl chromanol, was selected for development.

Animals↗
PubMed1998

Synthetic approaches to 2-(4-hydroxy-7-chromanyl)benzoic acids as antagonists of leukotriene B4.

Structural modification of 1 led to a series of 2-(4-hydroxy-7-chromanyl)benzoic acid LTB4 antagonists exemplified by 2 and 3. The use of an organostannane biaryl coupling, a non steroselective reduction and a chromatographic resolution limited the utility of this synthetic route. To address these issues, a new synthetic route was developed utilizing a palladium catalyzed coupling of aryl oxazolines in tandem with a stereospecific enone reduction as key synthetic steps. Resolution was achieved by fractional crystallization of a (S)-(-)-alpha-methylbenzylamine salt.

Benzoates↗
PubMed1997

Diagnosis and operation for anomalous circumflex coronary artery.

BACKGROUND: Origin of the left circumflex coronary artery from the right sinus of Valsalva is the most common anatomic variation of the coronary artery circulation. However, there are few reports about the operative approach to this anomalous vessel. METHODS: Forty patients having this anomaly were identified from 10,216 adult cardiac catheterization procedures. Forty percent of the anomalous circumflex coronary arteries (ACCAs) had critical atherosclerotic lesions. Eighty cases needed bypass grafting. RESULTS: For diagnosis of ACCA, the aortic root sign was positive in 94.9% of the diagnosed patients and the nonperfused myocardium sign was found in 92.5%. Eighty percent of ACCAs were larger than 2 mm in radiographic diameter before their passage into the atrioventricular groove. However, after emerging from the atrioventricular groove, 70% measured less than 1.5 mm. Consequently, a technique was developed to bypass the proximal ACCA and was used in 2 cases. Six other patients with more distal disease and larger vessels underwent conventional bypass grafting. CONCLUSIONS: The aortic root sign and nonperfused myocardium are useful in diagnosing ACCA. The ACCA is usually too small for use of the conventional graft technique. Therefore, a technique was developed to graft more proximally and was applied successfully in 2 cases.

Adult↗
PubMed1997

Clinical variables influencing the appearance of right bundle branch block after cardiac surgery.

Right bundle branch block following coronary surgery is a common occurrence. Among 759 coronary surgery cases, 104 patients (13.7%) had a new right bundle branch block. Of these right bundle branch blocks, 62 were transient, and 42 (40.4%) were permanent. The large number of bypasses (3.20 versus 2.75, P = 0.0001) and stenosis of the right coronary artery (81.7% versus 66.5%, P = 0.003) was strongly associated with a new right bundle branch block. In the analysis of the permanent right bundle branch block, blood cardioplegia prevented the block from becoming permanent (35.7% versus 75.8%, P = 0.0001). Therefore, it is concluded that perioperative right bundle branch block occurs predominantly in patients who have a critical stenosis in an artery which supplies the conduction system and in those undergoing more extensive procedures. In addition, blood cardioplegia affects the conduction system less severely than does crystalloid cardioplegia.

Adult↗