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Biomedical subjects

R Diwan

Publications and source records attributed to R Diwan.

12 recordsLinked to original sources
PubMed2001

Continuous axillary block for upper limb surgery in a patient with epidermolysis bullosa simplex.

We report the use of continuous regional block with light general anaesthesia in epidermolysis bullosa simplex. A 4-year-old girl suffering from florid epidermolysis bullosa simplex was scheduled for external fixator (JESS) for manus valgus deformity of the left forearm. Haemoglobin was 7.6 g.dl(-1) and blood chemistry was normal. She had no history of oral bullae, although a younger sibling had died of Bart syndrome with oral lesions. She was sedated with nasal midazolam 0.5 mg.kg(-1). All pressure points were cushioned. Inhalational anaesthesia was given by holding a mask above her face. Only oximetry and capnography were monitored. ECG and noninvasive blood pressure monitoring were avoided. The intravenous cannula was fixed by sutures. An epidural catheter of 0.63 mm OD (21-G) was passed into the axilla for continuous axillary block. Intra- and postoperative course was uneventful with slight bullae at the i.v. site and at the fixator which healed without further damage. The axilla remained free of problems. Continuous peripheral plexus or nerve blocks can be an option in these difficult patients, and can minimize the amount of general anaesthesia along with problems of airway handling and potential subsequent mucosal lesions. The postoperative period was pain free and comfortable.

Anesthesia, Conduction↗
PubMed2001

Continuous caudal epidural analgesia for congenital lobar emphysema: a report of three cases.

IMPLICATIONS: In congenital lobar emphysema, positive pressure ventilation can expand the emphysematous lobe, compressing the normal lung during anesthesia induction. We managed the dual challenges of safe induction and analgesia for thoracotomy by placing thoracic epidural catheters via the caudal insertion site and retaining spontaneous ventilation until thoracotomy.

Anesthesia, Caudal↗
PubMed1997

Pattern waxes and inaccuracies in fixed and removable partial denture castings.

It is the desire of every dentist and dental technician to produce a restoration that will fit the patient with a minimum of adjustments and certainly one that does not require remaking. Yet many abuse the materials with which they work, either through improper manipulation, lack of familiarity with their properties, or by attempting to reduce laboratory time by taking short cuts. Wax is one of the materials that requires more knowledge and skill to manipulate accurately because it has a considerably higher coefficient of thermal expansion (and contraction) than any other dental material. It often contributes considerably to the inaccuracies of cast dental restorations. This article provides a review of dental waxes used to make prosthodontic castings and points out some of the properties of waxes that must be controlled to make accurate restorations.

Dental Casting Investment↗
PubMed1997

The effect of storage time of removable partial denture wax pattern on the accuracy of fit of the cast framework.

STATEMENT OF PROBLEM: Situations may arise in dental laboratories that could result in a time lapse between preparing the wax pattern of the removable partial denture framework and its casting into the cobalt-chromium alloy. PURPOSE: This study investigated the effect of storage time of the wax pattern before casting and the influence of the palatal major connector design on the accuracy of its fit on the master casts. MATERIAL AND METHODS: Forty-two frameworks were prepared with two designs of major connectors, which were divided into three subgroups according to the storage time of the wax patterns: 24 hours, 1 week, and 1 month. Discrepancies in the fit of the connectors to their respective casts were measured at specific locations for both connector designs. RESULTS: In both framework design groups, there was a significant deterioration in fit (p < 0.0005) of the major connectors with the increase in storage time of their wax patterns on their respective refractory casts. Gap discrepancies were more pronounced towards the center of the palate. CONCLUSIONS: The greatest discrepancies appeared at the middle sections of the connectors more than at the lateral section (p < 0.0005). Furthermore, frameworks with modified palatal plate major connectors exhibited greater inaccuracies in their fit than those with the anterior posterior palatal strap design, as evidenced by the increase in mean gap discrepancies under the palatal plate design (p < 0.0005).

Analysis of Variance↗
PubMed1993

The use of microwave energy to cure denture acrylic resins.

Experiments have been carried out on the curing of poly(methyl methacrylate) denture base material in a microwave oven, using conventional dental flasks and flask clamps. It has been shown that it is important (a) to maintain sufficient pressure on the materials, (b) to avoid gaseous porosity by not heating too rapidly initially, and (c) to ensure that all metal is protected from exposure to microwaves. When the appropriate conditions of polymerisation were used, microwave-cured samples had satisfactory physical and mechanical properties according to American Dental Association specification number 12.

Acrylic Resins↗
PubMed1992

Cellular localization of retinoic acid receptor-gamma expression in normal and neoplastic skin.

Retinoids profoundly affect the normal growth and differentiation of epithelial tissues. Retinoic acid receptor-gamma (RAR-gamma) is a member of a family of retinoid receptors, and has been shown to be expressed almost exclusively in skin. However, little is known about the cellular localization of this receptor in human skin. The authors studied the expression of RAR-gamma in normal skin and human skin tumors by Northern blot analysis and in situ hybridization. RAR-gamma mRNA was detected in normal skin as well as in cultures of neonatal keratinocytes. Using an oligonucleotide specific for the RAR-gamma cDNA isoform 1 (RAR-gamma 1), RAR-gamma 1 mRNA was localized to all layers of the epidermis, the outer root sheath of hair follicles, follicular hair bulbs, eccrine and sebaceous glands. Basal cell carcinoma constitutively expressed gamma-1 mRNA and one of seven squamous cell carcinomas showed loss of gamma-1 mRNA expression, relative to adjacent epithelium. By contrast, normal melanocytic nevi and tumor-associated lymphocytes expressed little or no RAR-gamma mRNA. These results suggest that RAR-gamma 1 may play an important role in the maintenance and differentiation of normal epidermis and skin appendages.

Blotting, Northern↗
PubMed1990

A comparative study between three ethnic groups to derive some standards for maxillary arch dimensions.

A sample of 91 adult Philippinos, 45 males and 46 females, were selected for maxillary arch measurements. The intercanine width (C-C), intermolar width (M-M), molar incisor (M-I) and molar canine (M-C) length were measured. The measurements were compared to previous studies of maxillary arch dimensions for adult male and female Egyptians and Saudi Arabians. The results showed wider (M-M) measurements for the Egyptians than for the Philippinos, who also showed wider (C-C) arch dimensions than the Saudi Arabians.

Adult↗
PubMed1990

Laser therapy in the treatment of congenital vascular abnormalities.

Portwine stains, especially on the face, have serious psychological and emotional impact for affected children. Laser therapy has been the only effective means for treating these lesions. The argon laser has been the mainstay, but more recently the flashlamp-pumped pulsed dye laser has added significantly to the management of portwine stains as well as to the effective treatment of other vascular lesions such as telangiectasias and angiomas.

Adolescent↗
PubMed1989

Secondary intention healing. The primary approach for management of selected wounds.

Secondary intention healing is an ancient and well-established method of wound management. Since the advent of various reconstructive techniques, it is often forgotten as a valuable alternative to immediate surgical reconstruction of wounds. In certain situations the cosmetic and functional results of secondary intention healing are equal to the results of more complex reconstructive surgery. We describe a case in which remarkable results were obtained from spontaneous healing of a facial wound.

Aged↗