Browsing by Author "Fernandez, AC"

Now showing 1 - 5 of 5
  • Item
  • Item
    Evaluation of the effect of incorporation of dibutyryl cyclic adenosine monophosphate in an in situ-forming hydrogel wound dressing based on oxidized alginate and gelatin
    (BIOMATERIALS, 2006)
    Cyclic adenosine monophosphate (cAMP) has long been regarded as a second messenger and a regulator of human keratinocyte proliferation. To explore more effective wound management, dibutyryl cyclic adenosine monophosphate (DBcAMP), a lipophilic analog of cAMP was incorporated into an in situ-forming hydrogel wound dressing based on periodate-oxidized alginate and gelatin. In vitro release of DBcAMP from the matrix into phosphate buffered saline was slow and increased with time. Only 50-60% of the compound was released into the medium over a period of 2 days suggestive of a sustained release into the wound bed over a period of few days. The wound-healing efficacy of the DBcAMP-incorporated dressing was evaluated on experimental full-thickness wounds in a rat model. It was found that dressing promoted wound healing leading to complete re-epithelialization of wounds within 10 days, whereas control wounds took 15 days for complete re-epithelialization. Data obtained in this Study showed that the presence of DBcAMP accelerated healing and re-epithelialization of full-thickness wounds. (c) 2005 Elsevier Ltd. All rights reserved.
  • Item
    Incidence of Chirodiscoides caviae in Laboratory Rats-Screening, Identification and Treatment
    (SCANDINAVIAN JOURNAL OF LABORATORY ANIMAL SCIENCE, 2009) Harikrishnan, VS; Ranaraj, VR; Fernandez, AC
    This is a report on the incidence and treatment of the guinea pig fur mite Chirodiscoides caviae, which was so far considered as host specific, in a conventional colony of laboratory rats. Chirodiscoides caviae infestation in laboratory rats was accidentally observed during the screening of Syphacia obvelata by the peri-anal cellophane tape test (CTT). The organism was identified by comparing the morphology described by various researchers and was differentially diagnosed from other common mites of rat, Radfordia ensifera and Notoedres muris. The adult male mites (n=15) were of 330.2+/-13.3 mu m long and the females (n=15) 495.5+/-25.2 mu m. Later on, the entire rat colony consisting of Wistar, Sprague Dawley and Spontaneously Hypertensive Rats (SHR) and the mice colony of Balb/c and Swiss Albino were randomly sampled and screened for the presence of the mite by the cellophane tape technique. All the rat strains were found positive for C caviae infestation, which was more concentrated towards the posterior region of the body and, collectively, the screening results of C. caviae revealed that the posterio-dorsal and peri-anal regions are most suitable for sampling-suggesting that, the infestation pattern of C. caviae in rats has similarities to that of guinea pigs. Interestingly the mice colony was found free from the infestation. The Cellophane tape test was found to be an easier method than fur examination by hair plucking and equally accurate for screening of fur mite in a colony of laboratory rats. No clinical symptoms were observed in any of the animals in the colony, which possessed infestation. The facility strictly practised physical separation of animals by species, which pointed to the only possibility of cross infestation being through indirect contact between guinea pigs and laboratory rats and thereby questioning previous reports on the mode of transmission of C caviae. The entire colony was effectively treated with 0.2% lvermectin spray followed by 1% spray in an interval of 2 weeks. This report is the first one, which demonstrates the guinea pig fur mite in laboratory rats. It also questions the so far documented "host specificity" and "direct contact" mode of transmission and demonstrates indirect contact as a possible mode of transmission.
  • Item
    Orchidectomy Reduced Abdominal Aorta Relaxation Response to Androgens in Sprague Dawley Rats Fed a High Salt Diet
    (FASEB JOURNAL, 2010) Oloyo, AK; Sofola, OA; Nair, R; Harikrishnan, VS; Fernandez, AC
  • Item
    Safety and efficacy of Chitra-CPC calcium phosphate cement as bone substitute
    (CURRENT SCIENCE, 2006) Fernandez, AC; Mohanty, M; Varma, HK; Komath, M
    Calcium phosphate cements (CPCs) have gained importance in orthopaedics and dentistry as repair materials for bony/dentinal defects. They are aqueous based, mouldable and osteoconductive materials which set into hydroxyapatite, the basic mineral of bone and teeth. A CPC product 'Chitra-CPC' has been developed. This communication compiles the safety and efficacy evaluation of Chitra-CPC. The evaluation plan consisted of acute systemic toxicity test (in mice for systemic response), intracutaneous reactivity test (in rabbits for skin response), pyrogen test (in rabbits for presence of pyrogens) and maximization sensitization test (in guinea pigs for allergic skin response). Soft tissue response was tested by implantation in rabbit paravertebral muscle, with histological evaluation at 1, 4 and 12 weeks post-implantation. The efficacy of the product to heal bone defects was investigated by implanting in rabbit femur with hydroxyapatite ceramic granules as the control. Local effects at macroscopic and microscopic levels were assessed at time periods of 4, 12, 26 and 52 weeks post implantation. The cement did not show any adverse effects in the acute systemic toxicity. Nor did it elicit any erythemic or edematous reactivity in the intracutaneous reactivity test. The maxindzation sensitization study did not show any adverse skin response and the pyrogen test did not evoke undue temperature rise. In the muscle implantaion test, there was no haemorrhage, infection or necrosis. Localized vascularization was present near the implanted region. Chronic inflammation was observed in 1 week, which became mild by 12 weeks with the evidence of repair. Bone implantation studies showed that efficacy of Chitra-CPC and hydroxyapatite granules in bone healing is comparable. Both materials were found to be osteoconductive, but with the difference that Chitra-CPC resorbed progressively allowing simultaneous new bone formation. This proves the osteotransductivity of Chitra-CPC, which is the ideal property for a bone substitute.