Search PubMed⌕ Search

Biomedical subjects

A Sethi

Publications and source records attributed to A Sethi.

68 records · Page 4Linked to original sources
PubMedDate not supplied

A modified technique for RF-LCF interstitial hyperthermia.

To provide uniform heating of a tumour, it is necessary to establish sufficient volumetric control of power deposition. The interstitial Radio-Frequency Localized Current Field (RF-LCF) technique may provide such control when segmented electrodes are used. The length of segments is equal to 1-1.5 cm. Each segment is connected to a separate power source. However, this technique requires an additional implant for interstitial radiotherapy, because the lumen of segmented electrodes is filled with wires necessary to connect each segment to a separate power source. In this work, a modified method of implant that allows delivery of sequential and concomitant controlled thermoradiotherapy was investigated. In this method, each segmented electrode is surrounded by four continuous electrodes. Continuous electrodes pass through vertices of 1.5 x 1.5 cm square and a segmented electrode passes through the centre of the square. The distance between segmented and continuous electrodes is 1.06 cm. The electric field induced between an electrically interacting segment and continuous electrodes is concentrated primarily between this segment and its projection on continuous electrodes. Therefore, control of temperature distribution achieved with a modified implant is similar to that achieved with an implant containing only segmented electrodes. For temperature control during treatment, plastic catheters are inserted at a 0.5 cm distance from each segmented electrode. Temperature is monitored using multisensor temperature probes. The continuous electrodes are also used for placement of radioactive sources. The lateral distance between radioactive sources is equal to 1.5 cm. Besides allowing a sequential and concomitant thermoradiotherapy, the modified method is simpler to implement because it uses several fold less amount of segmented electrodes and power sources.

Biosensing Techniques↗
PubMedDate not supplied

Efficacy of induction chemotherapy in retinoblastoma, alone or combined with other adjuvant modalities.

BACKGROUND: There are not much data available on the use of newer antimetabolites as an initial treatment modality in retinoblastoma, or their effect on vitreous seedings and de novo foci, especially in the Indian subcontinent. METHODS: To evaluate the efficacy of newer agents as induction chemotherapy, 34 tumors in 22 eyes of 19 children with bilateral retinoblastoma were treated with 2 cycles of carboplatin, etoposide, vincristine, and cyclophosphamide; each cycle was of 1 month duration. The tumor response was evaluated at 2 months and adjuvant salvage modalities (ie, cryotherapy, laser, and/or external beam radiotherapy) were added as needed. The cycles were continued and ophthalmoscopic and ultrasonographic monitorings were performed to determine further tumor response, tumor height regression, effect on vitreous seeds, and other ocular changes. RESULTS: Mean tumor height at presentation was 4.2 mm, which regressed to 2.61 mm at 6 months (P=0.000). The biggest tumor to respond was 12.5 mm, although smaller multiple tumors regressed better. Adjuvant modalities were used in 28 tumor foci in 16 eyes. A follow up of 6 to 24 months (mean, 12.8+/-6.21 months), showed complete regression in 12/34 tumors, partial regression in 15/34, stable disease in 6/34, and 1 tumor progressed despite all therapy. Results in all 6 eyes with vitreous seeds were most gratifying; at 1 year vitreous seeds disappeared in 4 eyes and showed complete calcification in 2. Fresh new lesions were not seen in any eye with complete response after the first 2 cycles of chemotherapy. Recurrences were nil and complications minor. CONCLUSIONS: The overall tumor response (complete and partial) of more than 80% indicates that chemoreduction is an effective modality alone and combined with adjuvant salvage modalities. The results with our treatment regime, even in cases with advanced intraocular retinoblastoma, are encouraging.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

Extended survival of carcinoma head of pancreas following palliative treatment.

A 48 year old woman presented with obstructive jaundice 10 years back. Upper gastrointestinal endoscopy revealed a growth infiltrating the ampulla of Vater, which was confirmed to be adenocarcinoma on cytology. At laparotomy, a large nodular growth was seen in the head of pancreas. Surgical resection could not be done because of encasement of superior mesenteric vessels, hence a cholecystojejunostomy was performed. The patient remained asymptomatic for 9 years, when she developed cholangitis. Duodenoscopy at this stage revealed an ulcerated growth at the ampulla and biopsy from the growth confirmed a well differentiated adenocarcinoma. A straight flap 10 F stent was placed in the common bile duct. Thereafter the patient has remained asymptomatic for more than a year.

Adenocarcinoma↗
PubMedDate not supplied

Maxillary ridge expansion with simultaneous implant placement: 5-year results of an ongoing clinical study.

With the technique of maxillary ridge expansion, 449 implants were placed in 150 patients and observed over a period of up to 93 months. Thin maxillary ridges of adequate height and comprising 2 separate cortical plates with intervening cancellous bone were selected for maxillary ridge expansion and simultaneous implant placement. Two-stage implants were used and allowed to heal in a closed environment for 6 months prior to loading. Single and multiple teeth were replaced using this technique, and an estimated mean survival rate better than 97% after a 5-year observation period was calculated (95% confidence interval of the mean survival estimation: 98% +/- 1%). Good esthetic and functional outcomes were observed.

Alveolar Ridge Augmentation↗
PubMedDate not supplied

The use of angulated abutments in implant dentistry: five-year clinical results of an ongoing prospective study.

A total of 2,261 2-stage implants was placed in 467 patients in combination with angled abutments ranging from 0 to 45 degrees. These were observed over a period of up to 96 months, with a mean observation time of 28.8 months. Single and multiple teeth were replaced and restored using angled abutments. For patients who contributed multiple survival data, the data were considered dependent. Therefore, a mean survival estimation was performed. With a certainty of 95%, an estimated mean survival rate better than 98.6% after a 5-year observation period was calculated. The statistical comparison of 2 independent, randomized implant groups (with abutments angled between 0 and 15 degrees and between 20 and 45 degrees) by means of a log-rank test showed a probability of 0.84 (P value) that the survival functions are the same for both groups. Good esthetic and functional outcomes were observed.

Adolescent↗
PubMedDate not supplied

Ridge augmentation using mandibular block bone grafts: preliminary results of an ongoing prospective study.

The aim of the current ongoing study is to evaluate the long-term results of endosseous implants placed into autogenous bone grafts from intraoral donor sites. Patient selection for the correction of bone deficiencies was based on biomechanical and esthetic needs. Donor site selection was dependent upon the type of deficiency and the graft shape needed. Two-stage implants were placed after a healing period of 3 to 6 months, based on an assessment of the graft viability with radiographic and clinical parameters. Thus far, 118 implants have been placed in 60 patients whose alveolar ridges were deficient in height, width, or both height and width and were augmented. The patients were observed for up to 77 months. Two implant failures were encountered before implant exposure (1.7%). No further implants have been lost in function.

Adolescent↗
PubMedDate not supplied

Antimicrobial utilization pattern in out patient services of ENT department of tertiary care hospital of Eastern Nepal.

OBJECTIVE: The objective of this study was to monitor the antimicrobial utilization in ENT out patient services in a tertiary care hospital of Nepal. MATERIALS & METHODS: A total of 191 prescriptions were randomly audited at varying time interval from the department of ENT in the year 2003. The data was collected in customized Performa in the form of antibacterial audit questionnaires. It also contained Patient particulars, diagnosis, investigations, drug details and information from the prescriber regarding the indication for prescribing antimicrobial agent, suspecting organism underlying infection, duration of therapy and details of any concomitant medications. RESULTS: The incidence of use of antimicrobial agents (AMA) in 191 prescriptions was analyzed from the enrolled prescriptions, a total of 218 antimicrobials i.e.1.4 antimicrobial agent per patient were prescribed. . The AMAs were indicated therapeutically in 73.29% of patients & 19.37% patients for prophylaxis. The AMAs were advised for more than 72 hours for prophylaxis in 86.48%. In the concomitant medications antihistaminic were prescribed in 32.62% and NSAIDS in 21.98% cases. Most of patients reported with upper respiratory tract infections (URTI-32.56%), Chronic Suppurative otitis Media (CSOM-18.3%), sinusitis (6.28%), tonsillitis (5.75%),. Pharyngitis (3.66%), Acute Suppurative Otitis Media (ASOM-2.61%) and others. The diagnosis was established clinically in 42.40% and confirmative in 35.60%. In 21.46% the diagnosis was not disclosed. Out of 191 patients, culture sensitivity tests were performed for only 31 patients and 13 patients depicted a positive culture sensitivity tests. The common microbes isolated from the culture were staphylococcus aureus (69.2%). Streptococcus (7.7%), Enterobacteriacae (7.7%), Pseudomonas auroginosa (7.7%) & psendomanas mirabilis (7.7%). Clinically suspected organism were mentioned in only 32 prescriptions and most prescriber presumed the infections due to staphylococci & pseudomonas (43.75%), streptococci (21.8%),Gram negative organisms (12.5%) and H influenza (9.3%). The use of a single drug was abundant (89.52%), two drugs (9.94%), and three drugs (0.52% )prescriptions. Ciprofloxacin (23.85%) was preferred, followed by amoxycillin (20.06%), combination of ampicillin + cloxacillin( 9.17%), doxycyclin (5.96%). Erythromycin (4.58%) and cotimoxazole (4.58%). Expensive drugs i.e azithromycin (2.75%), roxithromycin (1.37%) and cephalosporins (3.21%) were also prescribed. The causative microbes were sensitive to amoxycillin (53.84%), cloxacillin (53.84%) ciprofloxacin (46.15%), gentamicin (46.15%), and cephalosporin (46.15%). But resistant to erythromycin, tetracycline, cotrimoxazole and norfloxacin) CONCLUSIONS: Majority of patients were prescribed drugs irrationally with misleading indications without confirming the bacteriological culture and sensitivity.

Ambulatory Care↗
PubMedDate not supplied

Predicting esthetics in implant dentistry using multiplanar angulation: a technical note.

Although the permucosal site of implants can be made to coincide with tooth position, the problem of aligning multiple abutments remains. To use the maximum amount of available bone, an implant must often be placed at an angle to the long axis of the prosthetic replacement tooth, and it also can deviate mesiodistally. This paper discusses a technique using trial abutments to create parallelism while ensuring that each abutment is ideally positioned with respect to the final restoration. The procedure also encourages patient acceptance by transferring the appearance created by a preliminary diagnostic waxup through to the finished prosthesis.

Contrast Media↗