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Biomedical subjects

S Verma

Publications and source records attributed to S Verma.

296 records · Page 17Linked to original sources
PubMedDate not supplied

Loss and recovery of corneal sensitivity following photorefractive keratectomy for myopia.

BACKGROUND: Photorefractive keratectomy affects corneal innervation in a new, and drastic, way. This inevitably results in a significant loss of corneal sensitivity. This paper investigates the pattern of sensitivity loss and recovery following PRK for low to moderate myopia. METHODS: Patients were recruited for two separate studies. Longitudinal Study: 10 patients, treated with a -6.00 D/6 mm PRK ablation, were examined over a 1-year period. Transverse Study: A comparison was made between 35 non-contact lens wearers, 80 contact lens wearers, and 60 patients who underwent five different PRK treatments, 1 year previously. Corneal sensitivity was assessed using the Non-Contact Corneal Aesthesiometer at four corneal locations: centrally, temporally, medially, inferiorly, on all patients. RESULTS: Longitudinal Study: Corneal sensitivity was significantly reduced at week 1, with a further significant reduction at week 2. A gradual recovery in sensitivity then followed to reach preoperative levels by 1 year. Transverse Study: There was no significant difference in corneal sensitivity found as a result of different PRK ablation depths. The depth of ablation was not a factor in corneal sensitivity recovery in low to moderate myopic corrections. Corneal sensitivity in the PRK treated eyes was significantly lower than in the control groups. CONCLUSION: The immediate loss of corneal sensitivity after surgery was due to the total removal of the corneal epithelial nerve supply and a substantial portion of the underlying stromal nerves. The further decrease at week 2 was probably due to the new epithelium acting as barrier to stimulation. The gradual recovery of corneal sensitivity was most likely caused by epithelial reinnervation within the ablation zone, but this was still below normal levels at 1 year after surgery. Corneal nerve function demonstrates a biphasic pattern of loss and recovery following the excimer laser correction of low to moderate myopia.

Adult↗
PubMedDate not supplied

Analysis of the clinical profile, autoimmune phenomena and T cell subsets (CD4 and CD8) in Takayasu's arteritis: a hospital-based study.

OBJECTIVE: To evaluate clinical and immunological abnormalities in patients with Takayasu's arteritis (TA) from India, with particular reference to autoimmune perturbations and abnormalities in T cell subsets (CD4 and CD8 cells). METHODS: 16 consecutive patients with TA (11 females and 5 males) underwent clinical and laboratory evaluation inclusive of flow cytometric analysis of T cell subsets (CD4 and CD8). A control population of 94 age- and sex-matched blood donors was used to determine the normal T cell subsets. Student's t-test was used to compare the means. RESULTS: The mean age at onset was 23.4 + 2.3 yrs. Common symptoms observed were headache, limb claudication, abdominal pain and visual disturbance/blackout. Common clinical signs observed included reduced arterial pulsations, bruits, and a BP difference > 10 mm Hg in the upper limbs. Systemic hypertension was documented in 12 patients. The mean absolute lymphocyte count in the patients was 2289/mm3. The mean CD4 count and CD4% were 1003 and 41 respectively; the mean CD8 count and CD8% were 755 and 34, respectively; and the mean CD4/8 ratio was 1.41. The patients had statistically significantly higher CD8 but not CD4 T cell values than controls. IgG and IgM immunoglobulin levels were increased. The mean multi-test CMI score in patients using CMI multi-test device of Pasteur Merieux was 14.6 mm. Two patients had an anergic response, 4 a partial response (1-13 mm), and 6 a full response of > 13 mm. Four patients hyper-responded with a score of > 20 mm. ANCA was positive in 2 patients. ANA was positive in 3 patients. IgG anticardiolipin was positive in 12 patients and IgM in 3; overall 12 patients were anticardiolipin positive by ELISA. Anti-beta 2GPI of the IgG variety was found to be positive in 3 patients and IgM in 2 patients; overall 3 patients being positive for the same. Nine of the patients with active disease were started on a combination of moderate dose prednisolone (20-40 mg once daily) along with weekly oral methotrexate (7.5-15.0 mg). Surgical intervention was required in 6 patients. CONCLUSION: This study found an increase in CD8 positive T cell subsets, increased IgG and IgM immunoglobulin levels, and the presence of autoantibodies including ANA, ANCA, anticardiolipin and anti-beta 2GPI antibodies in TA patients. TA may be an autoimmune disorder with T cell aberrations. The relationship with antiphospholipid antibodies and anti-beta 2GPI needs to be explored and confirmed by other larger studies. The strikingly positive responses to tuberculin, as well as the multi-test CMI also indicate exaggerated T cell responses and cell mediated immunity in Takayasu's arteritis. Immunosuppressive therapy was successful in controlling disease activity in the majority, but surgery was needed for irreversible stenotic lesions.

Adult↗
PubMedDate not supplied

Treatment of alopecia areata in the DEBR model using Cyclosporin A lipid vesicles.

Alopecia areata (AA) is a chronic cutaneous disease with a suspected autoimmune origin. We evaluated the efficacy of 0.5% Cyclosporin A (CyA) in a topically applied liposomal formulation as a potential treatment for AA using the Dundee Experimental Bald Rat (DEBR) model. The vehicle consisted of liposomes (75% phosphatidylcholine, 5% lysophosphatidylcholine, 5% sterol, natural oils) of 10% wt. in ethanol with and without 2% wt. terpenes (d-limonene: citral: cineole, 10:45:45) as a penetration enhancer (PE). Fifteen DEBR were allocated to 3 groups of 5. Groups I, II and III received CyA vesicles with PE, CyA vesicles without PE, and CyA in ethanol respectively. All rats were treated twice a day for 6 weeks within a 4 cm2 area on one bald flank with CyA while the contralateral flank received an equivalent control formulation. Rats in group I exhibited visible hair regrowth on the drug treated site after one week of drug application. Group II rats had visible hair regrowth by the end of the second week. The hair growth was progressive and reached a maximum density at the site of application after six weeks in both groups. Histological examination revealed a reduced inflammatory infiltrate and improved hair follicle morphology within the drug treated area as compared to the contralateral vehicle treated skin. Group III rats showed neither visible signs of hair growth nor reduction of hair follicle inflammation. The results of this proof of concept preliminary study suggest that CyA vesicle formulations with and without PE have promising potential as a topical treatment for AA in humans.

Administration, Cutaneous↗
PubMedDate not supplied

Psychiatric and behavioural manifestations of normal-pressure hydrocephalus.

Seven patients with psychiatric and behavioural manifestations of normal-pressure hydrocephalus are described. There is little disagreement about the classical triad of symptoms. However, it requires a high index of suspicion when a patient presents with non-specific psychiatric and behavioural symptoms. Clinicians must be alert to the possibility when positive findings point to the diagnosis of normal-pressure hydrocephalus, namely gait disturbance, incontinence, soft neurological signs, history of hypertension and no previous psychiatric history.

Aged↗
PubMedDate not supplied

Sigmoidopexy (tube sigmoidostomy) as definitive surgical procedure for sigmoid volvulus.

BACKGROUND: Volvulus of the sigmoid colon is associated with high mortality and high recurrence rate following nonoperative decompression of the colon. Therefore definitive surgery is required for its management. AIM: To evaluate the outcome following sigmoidopexy (tube sigmoidostomy) as a definitive surgical procedure to prevent recurrence of disease. METHODS: Seventeen patients with sigmoid volvulus who presented with features of large gut obstruction were studied; 12 patients underwent elective and 5 underwent emergent exploratory laparotomy. Malecot catheter fixed to the sigmoid colon and abdominal wall acted as fixator for the colon and rent for drainage of fecal matter. RESULTS: Sigmoidostomy started functioning the day following surgery and the stoma remained patent for approximately 12 days, although discharge started decreasing by the 5th postoperative day. No recurrence was noted over a period of 18 (5) months (range 13-23). CONCLUSIONS: Tube sigmoidostomy is an alternative effective procedure to prevent recurrence of sigmoid volvulus in patients who present without gangrene.

Endoscopy↗