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Biomedical subjects

R K Aggarwal

Publications and source records attributed to R K Aggarwal.

At least 37 records · Page 2Linked to original sources
PubMed1996

A survey of ocular perforation during ophthalmic local anaesthesia in the United Kingdom.

A survey of local anaesthetic related ocular perforation in the United Kingdom is reported. A total of 531 consultant ophthalmologists were sent a postal questionnaire and there was a 71% response rate. Thirty respondents reported 39 perforations occurring under their care during the previous year. Details of the cases are presented. The rate of local anaesthetic related ocular perforation is higher than in previous reported series. Efforts to reduce the incidence will require consideration of alternative techniques, audit, and training.

Anesthesia, Local↗
PubMed1996

Stent thrombosis revisited.

The choice of antithrombotic regimes after stent implantation has increased. Complication rates have improved and in-hospital stay is reduced with the less aggressive regimes. For de novo stenting in large vessels with a good result, ticlopidine plus aspirin or even aspirin alone appears attractive. The successful use of such a regimen may depend on complying with published intravascular ultrasound criteria. For patients who are at higher risk, the option appears to be ticlopidine and aspirin either alone or combined with subcutaneous low molecular weight heparin. In patients selected for established or threatened vessel closure, the old regimen using full anticoagulation should still be considered. Operators should deploy stents earlier to avert the need for true bailout stenting. We still await the truly non-thrombogenic stent that can be used in small vessels under any circumstances.

Anticoagulants↗
PubMed1996

Trends in pacemaker mode prescription 1984-1994: a single centre study of 3710 patients.

OBJECTIVE: To evaluate trends in pacemaker mode prescription from 1984 to 1994 with particular reference to the changes in pacemaker mode prescription for patients aged 80 years and older at implant. DESIGN: Prospective evaluation of indications for pacing and pacemaker mode prescription in all patients undergoing new pacemaker implantation from 1992 to 1994. Comparison with retrospectively obtained data for patients paced from 1984 to 1991. SETTING: Tertiary referral cardiothoracic centre. PATIENTS: Group 1: 2622 patients paced at one centre and entered into the national pacing database from 1984 to 1991. Group 2: 1088 consecutive patients paced from 1992 to 1994. RESULTS: Use of atrial (AAI) and dual chamber (DDD) pacemakers increased progressively in patients of all ages from 1984 to 1994. There was an increase in the proportion of patients aged 80 years and older from 25.4% (group 1) to 40.5% (group 2). Patients of all ages in group 2 were more likely to receive DDD units for atrioventricular block (odds ratio (95% confidence interval) (CI) 9.0 (7.0 to 11.5)) and AAI or DDD units for sinus node disease (odds ratio (95% CI) 11.0 (7.7 to 15.8)) than those in group 1. Elderly patients (age > or = 80 at implant) with atrioventricular block or sinus node disease and a suitable atrial rhythm were less likely to receive DDD or AAI pacemakers than younger patients in both groups. CONCLUSIONS: Use of atrial and dual chamber pacing modes has increased substantially in patients of all ages over the last decade. Although elderly patients represent an increasing proportion of the paced population, they remain less likely to receive atrial or dual chamber pacemakers than younger patients.

Age Factors↗
PubMed1996

Myocardial infarction following sternal surgery.

We report a case of myocardial infarction in a 32-year-old man undergoing sternal surgery. Thrombotic occlusion of the right coronary artery with no underlying atheromatous disease was demonstrated angiographically and successfully treated with intracoronary thrombolysis.

Adult↗
PubMed1996

Low prevalence of human immunodeficiency virus type-1 (HIV-1) infection in population attending a major hospital in New Delhi, India.

During 4 year period between April 1990 and March 1994, 4120 specimens from the patients attending out patient departments of Medical, Surgical and Antenatal units of a major city hospital were tested for HIV infection as a part of an on-going sentinel surveillance programme. In addition, 1440 specimens from the patients attending STD clinic of the same hospital and 862 females seeking termination of pregnancy from a near by hospital were included for comparison. It was found that only 3 individuals with high risk behaviours out of 2002 females attending antenatal clinic showed evidence of HIV infection (rate 1.49 per 1000). The corresponding rate for the group of patients attending STD clinic and seeking termination of pregnancy were 3 out of 1440 (rate 2.15 per 1000) and 1 out of 862 (rate 1.16 per 1000) respectively. It was noted that prevalence of HIV infection in the hospital attending population with unspecified risk factor (medical, surgical and antenatal clinics) was not a matter of serious concern. The importance of finding out risk factors in females attending antenatal clinic is evident from the study.

Adolescent↗
PubMed1996

Further evaluation of alternative strategy for HIV testing in India.

A total 320 sera from groups at risk for HIV were evaluated by two (198 specimens) or three (122 specimens) screening tests for confirmatory anti-HIV testing in comparison to Western Blot as gold standard. Sera positive by both screening tests showed 100% correlation with Western Blot although with a false positivity rate of 3.2%. In specimens positive by 1st screening test but negative by the second, (considered negative for anti-HIV antibody as per WHO algorithm), 8.7% were found to be Western Blot positive showing the serious problem of false negativity of the proposed WHO algorithm. Employing the system of three screening test systems did not provide additional benefit for the specimens positive by initial two screening tests since all of them were positive by third test also. However, the study involving three screening tests substantiated the need for Western Blot in discordant specimens (i.e. positive by first test but negative by second), since in this group one out of 22 (4.6%) such specimens were Western Blot positive. Considering the serious consequences of both false positive and false negative results, it is felt that alternative strategy of confirmatory anti-HIV serology, although economical may not be suitable substitute for Western Blot in India at this juncture when the prevalence of HIV infection is relatively low.

AIDS Serodiagnosis↗
PubMed1995

A rapid test for measuring the infectivity of Yellow Fever vaccine.

An in-house reference preparation of 17D-204 Yellow Fever vaccine was tested 60 times using LD50 mouse assay and CCID50 method. The mean virus titre, standard deviation and coefficient of variation obtained were comparable. Student's t-test indicated that there was a statistically insignificant difference between the two methods (p > 0.05) used for potency test with a correlation coefficient of 0.666 (p < 0.05). CCID50 assay for measuring the infectivity of Yellow Fever vaccine is rapid, sensitive and reproducible.

Animals↗
PubMed1995

Surgical management of ocular surface disorders using conjunctival and stem cell allografts.

AIMS: The aim of this work was to investigate different surgical options for the repair of the ocular surface, using various extensions of the procedure of limbal stem cell allotransplantation. METHODS/RESULTS: Straightforward lamellar limbal transplantation was performed in one patient with contact lens induced limbal stem cell failure. A second patient with a neoplastic corneal lesion underwent limbal allotransplantation, followed later by a second procedure in which 360 degrees of limbus and the entire ocular surface was transplanted. A third patient who had suffered extensive chemical burns was treated by penetrating keratoplasty to restore central corneal clarity, followed later by a lamellar allograft comprising a 360 degrees annulus of peripheral cornea to repair the ocular surface. A fourth patient with long standing, chronic trachomatous eye disease underwent allotransplantation of the upper lid tarsal plate and conjunctiva, with reconstruction of the fornix. Finally, a child with Goldenhar's syndrome underwent reconstruction of the medial fornix with autologous buccal mucosa, followed by a lamellar corneal and conjunctival allograft. A stable ocular surface has been achieved in each case and there have been no obvious rejection episodes. CONCLUSION: Limbal allotransplantation can be extended to engraftment of the entire superficial cornea, limbus, conjunctiva, and tarsal plate in patients with a range of pathologies. We have described the surgical management of five cases which demonstrate the potential of the technique, but which raise questions which still need to be explored.

Adult↗
PubMed1995

Simultaneous bilateral cataract extraction in the UK.

AIMS/BACKGROUND: Simultaneous bilateral extracapsular cataract extraction (SBCE) is not routinely performed in the developed world. This study investigated the safety and efficacy of this procedure as performed in the UK. METHODS: A review of 319 consecutive patients (638 eyes) who underwent SBCE with posterior chamber intraocular lens implantation is presented. RESULTS: The incidence of intraoperative complications was 7.7%. These included posterior capsule rupture (0.8%) and vitreous loss (0.3%). Postoperative complications were seen in 8.7% of operated eyes and included iris prolapse (0.3%) and raised intraocular pressure (3.0%). Endophthalmitis occurred in one eye (0.15%). There were no major bilateral complications, and, in particular, no cases of bilateral endophthalmitis. Final visual acuities compared favourably with reports for unilateral surgery. Eighty two per cent achieved a final visual acuity of 6/12 or better, and 41% tested 6/6 or better. CONCLUSION: This study illustrates that SBCE is not associated with an increased incidence of complications and that the visual results are good. Where indicated, and under strict surgical protocol, this procedure is safe.

Aged↗
PubMed1995

Early complications of permanent pacemaker implantation: no difference between dual and single chamber systems.

OBJECTIVE: To evaluate the incidence of intraoperative and early postoperative complications (up to two months after implant) of endocardial permanent pacemaker insertion in all patients under-going a first implant at a referral centre. METHODS: Prospective evaluation of all endocardial pacemaker implantation procedures performed from April 1992 to January 1994 carried out by completion of standard audit form at implant. Patients' demographic data, medical history, details of pacemaker hardware used, and any complications were noted. Follow up information was also collected prospectively onto standard forms at pacemaker outpatient clinic. SETTING: United Kingdom tertiary referral cardiothoracic centre. PATIENTS: 1088 consecutive patients underwent implantation of their first endocardial permanent pacemaker from April 1992 to January 1994. Implant and follow up data were available for 1059 (97.3%) patients at analysis. The median (range) age was 77 years (16-99); 51.2 % were male. RESULTS: Dual chamber units were implanted in 54.1% of patients, single chamber atrial in 5.2%, and ventricular in 40.7%. A temporary pacing lead was present at implant in 22.9% of patients. Most (93.6%) implants were performed via the subclavian vein. Immediate complications were rare: eight (0.8%) patients developed pneumothorax requiring medical treatment and 11 (1.0%) an insignificant pneumothorax. There was no significant difference in the pneumothorax rate for dual chamber (DDD) compared with single chamber systems. Arterial puncture without sequelae was documented in 2.7% of attempts at subclavian vein cannulation. A total of 35 patients (3.3%) required reoperation; the reoperation rate for dual chamber (3.5%) was similar to that for single chamber (3.1%) systems. Electrode displacement (n = 15, 1.4%) was the most common reason for reoperation. Atrial lead displacement (n = 10, 1.6% of atrial leads) was significantly more common than ventricular lead displacement (n = 5, 0.5% of ventricular leads, P = 0.047). There was no difference in electrode displacement rates for dual (1.6%) compared with single (1.2%) chamber systems. Pacemaker pocket infection led to reoperation in 10 patients (six dual, four single chamber, P = not significant) and was significantly more common in patients who had a temporary pacing lead in place at implant (2.9%) than in those who did not (0.4%, P = 0.0014). Five patients (0.5%) required reoperation for generator erosion (two dual, three single chamber, P = not significant). and a further five for drainage of haematoma or a serous fluid collection (three dual, two single chamber, P = not significant). Complications that did not require reoperation were also rare. Undersensing occurred in 10 patients (0.9%). Atrial undersensing (n = 8) was significantly more common than ventricular undersensing (n = 2, P = 0.017). All patients were successfully treated by reprogramming of sensitivity. Superficial wound infection was treated successfully with antibiotics in nine patients (six dual, three single chamber, P = not significant). Three patients with DDD generators developed sustained atrial fibrillation: two required reprogramming to VVI mode and one required cardioversion. CONCLUSIONS: Permanent pacing in a large tertiary referral centre with experienced operators carries a low risk. Infection rates are low, < 1% overall but significantly higher in patients who undergo temporary pacing before implantation. Lead displacement and undersensing are more likely to occur with atrial than ventricular leads. The overall complication rate for dual chamber pacing, however, is no higher than for single chamber pacing.

Adolescent↗
PubMed1994

Generic affinities among crocodilians as revealed by DNA fingerprinting with a Bkm-derived probe.

Genetic fingerprint profiles have been successfully used for establishing biological relationships, in linkage analysis, and in studies of population structure but have not so far been used for ascertaining phylogenetic relationships among related groups of species and genera. This is largely because these profiles are thought to evolve too rapidly to be informative over large time intervals. However, we show here that among the Crocodilia, whose phylogeny is a debated issue, these profiles can provide phylogenetically useful information. By using the probe Bkm-2(8), DNA fingerprints with distinct bands distributed in the size range 0.5-23.0 kb were obtained for individuals of 18 species belonging to seven of the eight genera of crocodilians. These genetic profiles showed individual-, species-, and restriction enzyme-specific patterns. In addition, striking differences were observed in the copy number of Bkm-related sequences in genomes of different crocodilian species. The qualitative data from DNA fingerprint profiles, and quantitative data on copy number variation in Bkm-related sequences, suggest that these genera belong to two distinct groups, one of which includes Alligator, Paleosuchus, and Caiman; the other includes Crocodylus, Osteolaemus, Tomistoma, and Gavialis. A close relationship between Tomistoma and Gavialis is also suggested by these results.

Alligators and Crocodiles↗