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Biomedical subjects

A J Singh

Publications and source records attributed to A J Singh.

At least 19 recordsLinked to original sources
PubMed2004

Late onset vitreoretinal complications of regressed retinopathy of prematurity.

AIM: To report the clinical findings, management, and outcomes in eyes undergoing surgery for regressed retinopathy of prematurity (ROP) with vitreoretinal complications. METHOD: Retrospective review of 40 eyes of 32 patients with regressed ROP who presented between 1989 and 2001 at two UK referral centres. RESULTS: Of 29 eyes presenting with rhegmatogenous retinal detachment (RRD), 15 initially underwent a scleral buckling procedure and 14 initially underwent vitrectomy with or without additional buckling. Primary surgery was anatomically successful in 11/15 eyes that underwent a non-vitrectomy retinal detachment repair and 8/14 that required vitrectomy. The final reattachment rate after reoperation was 28/29 eyes. Median visual acuity improved from 6/60 to 6/36 following retinal detachment repair. A further 11 eyes of eight patients from this series underwent prophylactic surgery, laser, or cryotherapy for predisposing vitreoretinal pathology and/or retinal breaks, all of which were stabilised. CONCLUSIONS: In eyes with RRD and signs of regressed ROP successful reattachment of the retina can be achieved using either vitrectomy or external surgery with an associated overall improvement in visual acuity. A range of external and closed microsurgical approaches is required to effectively deal with the diverse manifestations of regressed ROP.

Adolescent↗
PubMed2003

A histological analysis of lens capsules stained with trypan blue for capsulorrhexis in phacoemulsification cataract surgery.

PURPOSE: Staining of anterior lens capsules with dye to facilitate completion of continuous curvilinear capsulorrhexis is now being used more frequently in phacoemulsification of white and mature cataracts with poor red reflexes. This study examined the histological characteristics of anterior lens capsules stained with trypan blue. The layer(s) of the lens capsule that stained with dye and the extent of accumulation of dye in these layers of the lens capsule were determined. To the best of our knowledge this has not been described before. METHODS: A series of 10 stained lens capsules were analysed histologically. The dye used in this study consisted of a standard sterile, noninflammatory, nonpyrogenic, 2 ml solution containing 0.6 mg/ml of trypan blue. Following capsulorrhexis, samples were sent to the laboratory for histological analysis. Frozen sections (8 microm) were prepared and examined with the light microscope. All 10 capsules were cut by frozen section to preserve trypan blue staining (which would be leached by processing) and then subjected to immunohistochemistry for collagen IV. Immunohistochemical analysis using markers for type IV collagen were done on formalin-fixed specimens for morphological comparison with the frozen sections. A counterstain highlighted the epithelium. RESULTS: Continuous curvilinear capsulorrhexis was successfully and easily completed in all cases without any complications. Frozen section analysis using light microscopy demonstrated accumulation of trypan blue dye in the basement membrane of the lens capsule. Staining was concentrated in the portion of the membrane adjacent to the lens epithelium. The lens epithelium could not be clearly identified on the frozen sections. Consequently, immunohistochemical analysis with markers for type IV collagen was performed. A counterstain highlighted the epithelium. This confirmed that the layer staining with trypan blue was the basement membrane, a consistent feature on all the specimens. CONCLUSION: Trypan blue selectively stains the basement membrane of the anterior lens capsule. There is a concentration of dye in the basement membrane adjacent to the lens epithelial cell layer. The lens cortex does not appear clinically to stain with trypan blue. This enables surgeons to distinguish the lens capsule from the cortex and provides sufficient contrast for successful completion of continuous curvilinear capsulorrhexis during cataract surgery.

Basement Membrane↗
PubMed2001

The influence of counselling on patient return following uncomplicated posterior vitreous detachment.

PURPOSE: To investigate the effect of patient counselling together with the use of information leaflets on the number of return visits for patients with acute, symptomatic, uncomplicated posterior vitreous detachment (PVD). METHODS: The study group comprised the first 50 patients diagnosed with uncomplicated PVD in 1998 when a standard protocol of structured patient counselling and leaflet distribution was employed following diagnosis of PVD. The control group comprised the first 50 patients in 1997 diagnosed with uncomplicated PVD before structured patient counselling was in place. A retrospective analysis of casualty case notes was made comparing the two groups. The number of eye casualty attendances within 1 year of first presentation with PVD was compared in the two groups. RESULTS: Seven patients from the control group returned because of photopsia or floaters; 3 of the 7 returned with no change in their original symptoms. Six patients from the study group returned. All had a definite change in their symptoms of photopsia or floaters. No patient in the study group who returned had old or persistent symptoms. Statistical analysis comparing return visits of patients with no change in symptoms in the two groups by Fisher's Exact Test gave a p value of 0.13. CONCLUSION: Patients counselled following uncomplicated PVD did not return to eye casualty in the absence of new symptoms. Patient counselling is an important part of the management of PVD because it makes patients aware of which symptoms are important predictors of serious vitreoretinal pathology.

Adult↗
PubMed2000

Cost-effectiveness of public-funded options for cataract surgery in Mysore, India.

BACKGROUND: In India 3.8 million people become blind due to cataracts every year. We assessed the cost-effectiveness of public-funded options for delivering cataract surgery in Mysore, Karnataka State, India. METHODS: Three types of delivery of cataract surgery were studied: mobile government camps, walk-in services at a state medical college hospital, and patients transported in from satellite clinics to a non-governmental hospital. We assessed outcomes in a systematic sample of patients operated on in 1996-97 by follow-up at home; average costs by provider derived from actual expenditures during the year. FINDINGS: Almost half the patients operated on in government camps were dissatisfied with the outcome (34/70, 49% [95% CI 36-61]). More than one third were blind in the operated eye (25/70, 36% [25-48]). User satisfaction was higher with other providers (medical college hospital 82% [63-94]; non-government hospital 85% [72-93]), and fewer patients remained blind. Camps were a low-cost option, but the poor outcomes reduced their cost-effectiveness to US$97 per patient. The state medical college hospital was least cost-effective, at US$176 per patient, and the non-governmental hospital was the most cost-effective at US$54 per patient. INTERPRETATION: The government of India should review its policy for government camp surgery, and consider alternatives, such as transporting patients to better permanent facilities. India and other developing countries should monitor outcomes in cataract surgery programmes, as well as throughput.

Blindness↗
PubMed1999

A new isolation method for rat intraepithelial lymphocytes.

Intraepithelial lymphocytes (IELs) play critical roles in gut immunity. In mice, gammadelta T cells are a large component of the IEL population. In the rat, gammadelta IELs are reportedly much less common, but technical issues suggest that previous analyses should be interpreted cautiously. The study of IELs in rats has been impeded by isolation procedures that are lengthy and complex, leading to small cell yields. For this reason, it is possible that rat IELs analyzed in previous studies have not been representative of the entire IEL compartment. We report a new method for the isolation of rat IELs that is based on the selective removal of intestinal epithelial cells under conditions that leave the basement membrane undisturbed. The method is rapid and requires neither enzymatic digestion, nor surgical removal of Peyer's patches, nor vigorous mechanical manipulation of the intestine. The yield of rat IELs using this method is 5- to 10-fold greater than that reported for other methods. Morphological and phenotypic analyses demonstrated that the purified cell population is comprised of IELs and is not contaminated with lamina propria or Peyer's patch lymphocytes. Phenotypic analysis revealed five major subsets of IELs based on differential cell surface expression of CD4, CD8, and alphabeta T cell receptor (TcR). Among the alphabetaTcR- cells was a population of gammadelta T cells present at levels not previously detected. The isolation of IEL sub-populations using this methodology should facilitate studies of the function of these cells in gut immunity.

ADP Ribose Transferases↗
PubMed1999

Partial liquid ventilation with and without inhaled nitric oxide in a newborn piglet model of meconium aspiration.

The object of this study was to determine the effects of partial liquid ventilation (PLV) with and without inhaled nitric oxide (NO) over a 4-h period on lung mechanics, gas exchange, and hemodynamics in an animal model of meconium aspiration syndrome (MAS). Twenty-four fentanyl-anesthetized piglets were instrumented and administered a slurry of human meconium to create a model with hypoxia, hypercarbia, acidosis, and pulmonary hypertension. They were then randomly assigned to conventional ventilation, conventional ventilation plus inhaled NO at 40 ppm, PLV using perfluorodecalin, or PLV plus inhaled NO. The perfluorocarbon was added until a meniscus was visible in the endotracheal tube during expiration. Hemodynamics, lung mechanics, and gas exchange were monitored for 4 h, and then the animals were killed. The conventionally ventilated animals continued to deteriorate, and three of the six died prior to 4 h. All the animals in the remaining groups survived. Oxygenation improved significantly immediately with the start of inhaled NO (from 43.8 SD 10.3 to 62.6 SD 11.7 mm Hg after 30 min) and stayed elevated compared with the control group for the remainder of the study (62.4 SD 21.8 mm Hg at 4 h compared with 44.9 SD 1.6 mm Hg for the control group, p < 0.05). Oxygenation improved more slowly in the PLV alone group, being slightly less than control at 30 min (p = NS) but increasing to 104 SD 34.9 after 4 h (p < 0.01 compared with the control group), at which time it was also greater than inhaled NO alone (p < 0.05). The combined group had an acute increase in oxygenation indistinguishable from the NO alone group and maintained this until the end of the study. Lung compliance was unaffected in the inhaled NO group. In both the liquid ventilation groups the lung compliance improved with the instillation of perfluorodecalin (from 0.46 SD 0.18 to 0.62 SD 0.09 ml/cm H(2)O/kg in the PLV alone group at 1 h, p < 0.05 compared with the control group) and remained stable for the remainder of the study. Cardiac output and pulmonary vascular resistance were not significantly affected by any of the treatments. It was concluded that in this animal model of MAS, inhaled NO led to an acute improvement in gas exchange and prolonged survival compared with conventional therapy. PLV improved lung mechanics, which was maintained over the course of the study. The combination of PLV and inhaled NO produced both effects, acutely improving both gas exchange and lung mechanics. Combined therapy with PLV and inhaled NO may have benefits in the MAS.

Administration, Inhalation↗
PubMed1996

Regulation of intracellular level of Na+, K+ and glycerol in Saccharomyces cerevisiae under osmotic stress.

The intracellular level of Na+ and K+ ofS. cerevisiae strain AB1375 revealed that under KCl as well as sorbitol stress, the cationic level was comparable to the level under no stress conditions. On the other hand, there was a sharp drop in the intracellular K+ content and increase in the Na+ content on addition of NaCl to the medium. However, the total cationic level was close to that under control conditions. In addition to changes in the cationic level, an enhanced production and accumulation of glycerol were also observed under osmotic stress. A regulatory mechanism co-ordinating the intracellular concentration of glycerol as well as Na+, K+ content under osmotic stress conditions has been proposed.

Glycerol↗
PubMed1996

Minor injuries in ninth class school children of Chandigarh and rural Haryana.

OBJECTIVE: To estimate the incidence of minor injuries and to study the wound care practices of school children. DESIGN: A fortnightly follow up of urban (n = 112) and rural (n = 110) high school children was done in Chandigarh and rural Haryana between 1990-1992. Initial point prevalence survey was followed by fortnightly follow up survey involving interview for assessing incidence and wound care practices among students. SETTING: Government high schools of Chandigarh and rural Ambala in between 1990 to 1992. SUBJECTS: Ninth class school children from urban (n = 112) and rural (n = 110) areas. RESULTS: Average episodes of minor injuries per year were 2.9 in rural and 2.1 in urban area, point prevalence was higher in urban area. First-aid training of teachers or the students was lacking in both the areas. Many of the injuries (41-46%) occurred during the school time. Fingers/hand or feet were affected most. Main sources of injuries were farm implements, thorn, blade and stick in rural area and finger nails, kitchen appliances and furniture in urban area. Rural students were more tolerant to minor injuries. Lesser number of rural students had taken tetanus toxoid. Wound washing with water as the first action was reported by 20-22% students in both the areas. Application of urine or chewed grass was reported by rural students only, whereas use of ointment, tablet, bandage, injection as the first action was observed in urban students only. CONCLUSIONS: Incidence of minor injuries was higher in rural area as compared to urban area. Training of students on elementary hygienic wound care is recommended.

Adolescent↗
PubMed1995

Evaluation of cold chain system in rural areas of Haryana.

Evaluation of cold chain system was done in a time bound study during August and September months of 1992 in two districts of Haryana as there were frequent breakdowns of icelined refrigerators during the previous year. The study revealed that defective stabilizers and electricity plugs and sockets were the reason of breakdown in many cases. Temperature maintenance and functioning of deep freezers was satisfactory. Retrospective analysis showed that the polio vaccine samples picked up during 1990-92 were found to be satisfactory by CRI, Kasauli. Use of two ice-pick carrier and thermos flasks was associated with poor temperature maintenance. Seven vaccine carriers out of 25 examined had cracked wall lining. Lids of carriers were also not kept tight during vaccination sessions. Response lag of the health workers and medical officers in case of breakdowns was delayed. A one day refresher course exclusively on cold chain maintenance at community health centre level is recommended.

Drug Storage↗
PubMed1994

An epidemiological study of congenital malformations in rural children.

Children between 0-6 years of age from six villages of Ambala District were screened for congenital malformations. Of 1371 children, malformations were observed in 30 (prevalence 22/1000). Twenty children had major malformations and six had multiple anomalies. Cardiovascular malformations were the commonest (37%) followed by musculoskeletal (30%), gastrointestinal (23%), central nervous system (13%) and genitourinary anomalies (6.6%). An etiological factor (maternal rubella infection or drug exposure during early pregnancy) could be ascertained in only 3 cases. Traditional birth attendents (TBA) and Anganwadi workers (AWW) were helpful in identifying 95% of the cases with externally visible malformations in rural areas. In majority of cases no remedial measures were taken by the parents.

Adult↗