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Biomedical subjects

V Srinivasan

Publications and source records attributed to V Srinivasan.

At least 37 records · Page 2Linked to original sources
PubMed2005

In-vitro microleakage of repaired fissure sealants: a randomized, controlled trial.

UNLABELLED: The aim of this study was to investigate whether differences in surface treatment prior to repair influenced the seal of a resin fissure sealant placed on the occlusal surfaces of permanent molar teeth. SETTING: In-vitro study. SAMPLE AND METHODS: One hundred and twenty-eight extracted human first and second molars were randomly allocated to one of four groups of 32 teeth each. A light cured, unfilled, opaque resin fissure sealant (Delton) was placed on their occlusal surface following cleaning by prophylaxis and acid etching. Following storage in artificial saliva (Saliva Orthana) for a week, duplication of sealant failure was carried out. The teeth were then subjected to one of four different surface treatments: Group 1: with a slow-speed prophylaxis brush followed by acid etching (control method); Group 2: a slow-speed bur and acid etching; Group 3: air abrasion and acid etching; and Group 4: acid etching and application of a bonding agent. Following a further week of storage in artificial saliva two layers of impermeable varnish were applied to the nonocclusal surfaces of the teeth; their apices were then sealed with wax and the teeth were immersed in 1% methylene blue for 48 h. The teeth were then sectioned (ISOMET 1000) to achieve three cuts resulting in a maximum of four blocks, i.e. six surfaces per tooth. A total of 715 sections from 126 teeth were scored for microleakage on the intact and repaired side of the fissure sealant. RESULTS: Statistical analysis did not demonstrate any one single method of repair to be superior to the control method for reapplication of the sealant. CONCLUSION: All four techniques compared in this study seem to be acceptable for replacing or repairing lost or fractured fissure sealants. As prophylaxis with a brush rotating at slow speed followed by acid etching, which probably represents current practice, is also the simplest technique that can be practised on children, it is therefore recommended.

Acid Etching, Dental↗
PubMed2004

Recurrent periorbital cellulitis in a child. A random event or an underlying anatomical abnormality?

We present a case of recurrent periorbital cellulitis in a child. From the age of 2 years the child was admitted with periorbital cellulitis a total of six times with the first five episodes responding to conservative management with intravenous antibiotics. On the sixth admission endoscopic surgical treatment was carried out. Two abnormalities were noted: an anatomically abnormal uncinate process and an isolated abscess in an ethmoidal cell. It is believed that the abnormal uncinate process caused obstruction of the osteomeatal area, predisposing to recurrent peri-orbital cellulitis. We discuss the importance of early imaging and surgery in recurrent periorbital cellulitis.

Cellulitis↗
PubMed2004

Which is the real gold standard for small-volume renal tumors? Radical nephrectomy versus nephron-sparing surgery.

BACKGROUND AND PURPOSE: Until recently, the gold standard for treatment of localized renal-cell carcinoma with a normal contralateral unit was deemed to be a formal radical nephrectomy. Advocates of nephron-sparing surgery have recently challenged this concept; we wished to evaluate the evidence to determine which treatment is objectively superior for patients with renal tumors up to 4 cm. MATERIALS AND METHODS: MEDLINE, CANCERLIT, and EMBASE computer literature searches were performed to identify peer-reviewed papers pertaining to radical nephrectomy (RN), nephron-sparing surgery (NSS), or comparisons of these methods for tumors as large as 4 cm in maximum diameter. Review of the bibliographies of recovered articles and data in recent textbooks were used to supplement the computerized searches. There were a total of 797 cases in the RN group and 1211 in the NSS group. The parameters specifically evaluated were evidence of local recurrence, disease progression, and death within 33 months, this period being chosen primarily because it was the shortest follow-up in the studies evaluated. The data were then subjected to rigorous statistical analysis. Laparoscopic radical nephrectomy (LRN) and laparoscopic nephron-sparing surgery (LNSS) articles were also reviewed; however, current follow-up periods were considered too short to draw a statistically significant conclusion. RESULTS: Disease-specific survival rates (P=0.001; Mann-Whitney test) as well as the incidence of metastases (P<0.05; Mann-Whitney test) were significantly better in the NSS group. The incidence of local recurrence (P=0.22; Mann-Whitney test) was not significantly different. It should be borne in mind that there are different follow-up periods for each study, and this may have had an impact on the results. CONCLUSION: Nephron-sparing surgery seems to be as effective as RN in patients with renal cell tumours up to 4 cm, although only a large randomized controlled trial with long follow-up periods would provide a definite answer.

Carcinoma, Renal Cell↗
PubMed2003

Mycetoma leg a--case report.

One rare and peculiar result of repeated minor trauma to the leg is Madura foot. Caused by fungi or fungus-like bacteria, Madura foot is found mainly in the tropics. A report of a classic case with chronic indurated swelling involving the leg and a discharge of yellowish granules is presented. The case is reported to highlight the fact that though Maduramycosis needs prolonged intensive antibacterial chemotherapy, even extensive disease can be successfully managed with conservative therapy.

Journal Article↗
PubMed2002

Planning and implementing a program of renovations of emergency obstetric care facilities: experiences in Rajasthan, India.

Even though many governments and donors are now putting resources into upgrading facilities, the study of the renovation process is one of the most neglected aspects of quality improvement in emergency obstetric care (EmOC). In a previous publication, we discussed basic concepts and simple techniques to assess, plan and implement renovations. Here we focus on actual in-the-field experiences of the renovation process initiated by the health system in Rajasthan, India and the valuable lessons obtained from it. With the advice of the technical members of the Averting Maternal Death and Disability Program (AMDD) and the United Nations Population Fund (UNFPA), the facilities achieved noticeable changes in the physical infrastructure. As a result, the quality of EmOC services improved. We analyze these experiences critically and draw out lessons which may be instructive for future renovation efforts.

Emergency Medical Services↗
PubMed2002

Evaluation of extracorporeal shock wave therapy in Peyronie's disease.

OBJECTIVES: To evaluate the results of extracorporeal shock wave therapy (ESWT) in patients with Peyronie's disease. METHODS: This study included 42 patients (mean age 55.4 years, range 32 to 72, SD 9.92) with Peyronie's disease. The mean duration of disease was 16.5 months (range 3 to 60, SD 13.31). Before treatment, the degree of angulation was assessed artificially by injection of 10 to 20 microg alprostadil, and Polaroid photographs were taken. Patients were also questioned about pain on erection, whether sexual intercourse was possible, and the quality of erections. All were initially treated with three sessions of ESWT (3000 shock waves). After three sessions, patients who believed that improvement had resulted or who wanted to undergo additional treatment went on to have further sessions. The mean duration of follow-up was 5.9 months (range 2 to 18, SD 4.4), after which the results were analyzed. RESULTS: Those who believed that improvement in angulation had resulted were asked to provide Polaroid photographs to assess the improvement objectively. Six (14%) said that they had excellent results, 21 (50%) had significant improvement, 7 (17%) had slight improvement, and 8 (19%) had no change. Of the 25 who had pain on erection before treatment, 21 (84%) reported complete or near complete relief after treatment. Five patients said that the quality of the erections had improved after treatment. Eight patients complained of mild and one of severe pain during or immediately after treatment; 2 of these 9 patients had both pain and bruising. CONCLUSIONS: The initial results with ESWT are promising, with minimal complications. The long-term results need to be evaluated.

Adult↗
PubMed2002

Radioprotection, pharmacokinetic and behavioural studies in mouse implanted with biodegradable drug (amifostine) pellets.

PURPOSE: We evaluated the use of a subcutaneously (s.c.) implantable, biodegradable pellet as a drug delivery system for the radioprotector amifostine. MATERIALS AND METHODS: Mice were implanted s.c. with either the custom-made biodegradable amifostine drug pellet or the placebo pellet without amifostine, exposed to cobalt-60 gamma-radiation (bilateral, 1 Gy min(-1), 7-16 Gy), and the 30-day survival rate was monitored. The non-irradiated mouse was used for pharmacokinetic and behavioural tests. RESULTS: Significant radioprotection (85-95% survival) at 10 Gy was observed in the three-amifostine pellet implanted group 3-5 h after implantation. LD50/30 was 7.97, 8.74 and 16.64 Gy for the control, three-placebo pellet (dose reduction factor, DRF=1.10, p<0.01), and three-amifostine pellet (DRF=1.79, p<0.01) groups respectively in mouse exposed to radiation 2h after implantation. Radioprotection at 12 Gy was observed up to 4h after s.c. amifostine administration and up to 3h after implantation. Pharmacokinetic data revealed that the three-amifostine pellet group had sustained blood WR-1065 levels at 2 h after implantation, in contrast to the reported sharp peak at 30 min for s.c. administration. Although locomotor activity was significantly reduced (p<0.01) in the amifostine pellet group, the onset of the locomotor decrement was delayed as compared with groups that received 400 and 750 mg kg(-1) s.c. amifostine. CONCLUSIONS: Amifostine in biodegradable implant was effective. The radioprotection observed was comparable between conventional s.c. administration of the drug and implantation. Pharmacokinetic data and locomotor activity suggest that the implantation was beneficial though radioprotection data warrants formulation improvements in implants.

Amifostine↗
PubMed2002

Sterile abscess mimicking recurrent tumour in the cerebellopontine angle.

Vestibular schwannomas are the most common tumours encountered in the cerebellopontine angle (CPA) region, accounting for 90 per cent of all lesions. Early pyogenic abscess following surgery and delayed abscesses due to retained foreign bodies have been reported. We describe a case of sterile abscess of unknown aetiology in the CPA region, occurring 13 years after surgical excision of a vestibular schwannoma. The clinical and radiological features were suggestive of recurrent vestibular schwannoma or malignant transformation. We believe this is the first reported case of delayed occurrence of sterile abscess in the CPA region. Further the diagnostic difficulties of such rare lesions occurring in the CPA after vestibular schwannoma surgery are discussed.

Abscess↗
PubMed2002

High-dose antibiotic therapy is superior to a 3-drug combination of prostanoids and lipid A derivative in protecting irradiated canines.

There is an urgent need to develop non-toxic radioprotectors. We tested the efficacy of a 3-drug combination (3-DC) of iloprost, misoprostol, and 3D-MPL (3-deacylated monophosphoryl lipid A) and the effects of postirradiation clinical support with high doses of antibiotics and blood transfusion. Canines were given 3-DC or the vehicle and exposed to 3.4 Gy or 4.1 Gy of 60Co radiation. Canines irradiated at 4.1 Gy were also given clinical support, which consisted of blood transfusion and antibiotics (gentamicin, and cefoxitin or cephalexin). Peripheral blood cell profile and 60-day survival were used as indices of protection. At 3.4 Gy, 3-DC- or vehicle-treated canines without postirradiation clinical support survived only for 10 to 12 days. Fifty percent of the canines treated with 3-DC or vehicle and provided postirradiation clinical support survived 4.1-Gy irradiation. Survival of canines treated with vehicle before irradiation significantly correlated with postirradiation antibiotic treatments, but not with blood transfusion. The recovery profile of peripheral blood cells in 4.1 Gy-irradiated canines treated with vehicle and antibiotics was better than drug-treated canines. These results indicate that therapy with high doses of intramuscular aminoglycoside antibiotic (gentamicin) and an oral cephalosporin (cephalexin) enhanced survival of irradiated canines. Although blood transfusion correlated with survival of 3-DC treated canines, there were no additional survivors with 3-DC treated canines than the controls.

Animals↗
PubMed2001

Beneficial role of amino acids in mitigating cytoskeletal actin glycation and improving F-actin content: in vitro.

AIMS: The actin filaments present in circulating leukocytes facilitate their passage through microvenules and capillaries by helping in their deformability. Decreased deformability of granulocytes is now known to cause occlusion of the retinal microcapillaries leading to hypoxia and the subsequent development of diabetic retinopathy. Structural and functional loss of proteins, due to non-enzymatic glycation and glycoxidation, has been reported to cause diabetic pathogenesis. As amino acids have been earlier reported to have antidiabetic properties, the present study involves the investigation of the susceptibility of the cytoskeletal actin to glycation and its mitigation by free amino acids. This study also involves quantifying F-actin in cultured mononuclear cells obtained from diabetic and normal healthy volunteers and on the effect of glucose and free amino acids on F-actin content. METHODS: Commercial non-muscle actin and actin immuno-pre-cipitated from granulocytes obtained from (a) normal healthy human volunteers and (b) patients with type 2 diabetes mellitus were subjected to glycation studies using [U] (14)C glucose. The effect of free amino acids, as antiglycating agents, was determined using various concentrations of lysine, arginine, alanine, aspartic acid and glutamic acid. F-actin content in cultured mononuclear cells was estimated by flow cytometry using fluorescein isothiocynate (FITC)-Phalloidin. RESULTS: Commercial actin at physiological conditions of pH and temperature was found to undergo non-enzymatic glycation. The extent of in vitro glycation was significantly low (P<0.001) in actin isolated from patients with type2 diabetes when compared to the non-diabetic group, suggesting an increased in vitro structural modification of actin in patients with diabetes. All the free amino acids tested were found to have varying degrees of antiglycating effect. The F-actin content in the intact mononuclear cells obtained from diabetic patients was found to be low when compared with normal healthy volunteers (P<0.001). Similarly the F-actin content was significantly low when the normal mononuclear cells were incubated with glucose. This effect was reversed upon the addition of free amino acids to the incubation mixture. CONCLUSIONS: Free amino acids can play a positive role in improving leukocyte deformability by mitigating cytoskeletal actin glycation and improving F-actin content.

Actins↗
PubMed2001

Fowlpox virus encodes a novel DNA repair enzyme, CPD-photolyase, that restores infectivity of UV light-damaged virus.

Fowlpox virus (FPV), a pathogen of poultry, can persist in desiccated scabs shed from infected hosts. Although the mechanisms which ensure virus survival are unknown, it is likely that some type of remedial action against environmentally induced damage is required. In this regard, we have identified an open reading frame (ORF) coding for a putative class II cyclobutane pyrimidine dimer (CPD)-photolyase in the genome of FPV. This enzyme repairs the UV light-induced formation of CPDs in DNA by using blue light as an energy source and thus could enhance the viability of FPV during its exposure to sunlight. Based on transcriptional analyses, the photolyase gene was found to be expressed late during the FPV replicative cycle. That the resultant protein retained DNA repair activity was demonstrated by the ability of the corresponding FPV ORF to complement functionally a photolyase-deficient Escherichia coli strain. Interestingly, insertional inactivation of the FPV photolyase gene did not impair the replication of such a genetically altered virus in cultured cells. However, greater sensitivity of this mutant than of the parental virus to UV light irradiation was evident when both were subsequently photoreactivated in the absence of host participation. Therefore, FPV appears to incorporate its photolyase into mature virions where the enzyme can promote their survival in the environment. Although expression of a homologous protein has been predicted for some chordopoxviruses, this report is the first to demonstrate that a poxvirus can utilize light to repair damage to its genome.

Amino Acid Sequence↗
PubMed2001

Renal artery embolization for benign obstructive uropathy.

PURPOSE: We demonstrate safety of renal artery embolization as an alternative to nephrectomy in symptomatic patients with obstructed, poorly functioning kidneys who are unfit for surgery. MATERIALS AND METHODS: We performed renal artery embolization in 2 medically unfit patients with benign obstructive uropathy and poorly functioning kidneys. The affected kidney was initially drained with a nephrostomy tube and the kidney was then selectively embolized using absorbable gelatin sponge particles and Gianturco coils. The nephrostomy tube was removed before hospital discharge. RESULTS: Urine production by the affected kidney ceased and symptoms resolved. CONCLUSIONS: Renal artery embolization with antegrade drainage is a safe alternative to surgery in unfit symptomatic patients with benign obstructive uropathy and poorly functioning kidneys.

Aged↗
PubMed2001

A study in two centres of variations in the time of apical barrier detection and barrier position in nonvital immature permanent incisors.

OBJECTIVES: To study barrier formation in nonvital, immature permanent incisors being treated using the apexification technique in two centres, and to establish the effect of the frequency of change of calcium hydroxide (CaOH) on barrier detection times. DESIGN: A retrospective study of the time of detection and the position of barriers. RESULTS: There were no significant differences between the two centres in terms of the average frequency of change of each CaOH dressing, the distribution of barrier detection times or the position of barriers (P > 0.05). There was a total of 107 teeth and the time of barrier detection was significantly earlier in more frequently dressed teeth (P = 0.013). Of the teeth with a barrier detection time of less than 9 months, 60.7% were dressed more frequently than every 3 months, as opposed to 39.1% of teeth with longer barrier times (P = 0.027). The mean time of barrier detection for all cases was 43.3 weeks. The majority of barriers were located at or near the apex. CONCLUSION: The frequency of change of CaOH can increase the speed of barrier detection but does not appear to affect the position.

Analysis of Variance↗