Development of tooth germ heterotopically grafted within the ear skin. An histological study in the rat.
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The main goal of this study was the analysis of the developmental potentiality of tooth germ from late bell stage on, after its heterotopic placement within the skin. Teeth germs of newborn rats were grafted within a skin pouch of the ear of adult rats. Seven to fourteen days after grafting, dental germs developed normal dental structures in which ameloblasts and odontoblasts were well differentiated. Twenty to forty-one days after graft, the inflammatory host reaction destroyed the dental developed tissues by cell infiltration. The dentin of the grafts was of osteoid characteristics, and its size increased depending on grafting time until the complete substitution of all dental tissues. This atypical dentin showed several degrees of polymerisation from collagen fibres smooth dentin devoid near the graft a to fibres rich dentin far from the dental germ. Present results suggest that this type of dental graft could be a valuable model to study the self-development of dental tissues and the reactive mechanisms taking place after dental injuries. (+info)
Development of a conjunctival epithelial equivalent with improved proliferative properties using a multistep serum-free culture system.
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PURPOSE: To investigate the use of a multistep serum-free culture system in developing a conjunctival epithelial equivalent with improved in vitro and in vivo proliferative properties and to evaluate the effect of serum supplementation and culture conditions on the proliferative capacity of these cells. METHODS: Conjunctival epithelial cells were cultivated on human amniotic membrane (HAM) in a multistep serum-free culture system, under submerged and air-lifted conditions. The bromodeoxyuridine (BrdU) ELISA proliferation assay, colony-forming efficiency (CFE), and number of cell generations were compared with those in serum-containing medium. The in vivo proliferative capability of the tissue-constructs were evaluated by xenotransplantation to SCID mice. Cultured cells were evaluated for the expression of keratin-4, -19, and -3, as well as MUC5AC goblet cell mucin. RESULTS: The epithelial cells cultivated in serum-free medium (BrdU absorbance, 1.91 +/- 0.08; cell generations, 25.6 +/- 4.5) were more proliferative than those cultivated in serum-containing medium (BrdU absorbance, 1.06 +/- 0.08; cell generations, 12.1 +/- 3.0). The serum-free-derived epithelial equivalents demonstrated a significant increase in proliferation and stratification after transplantation. Cells that were air lifted for 6 and 12 days had a reduced proliferative capacity in vitro and in vivo compared with submerged cultures. Cultured cells expressed keratin-4 and -19, and MUC5AC mRNA was detected by RT-PCR. Electron microscopy demonstrated a basal lamina with numerous hemidesmosomes. CONCLUSIONS: This is a multistep serum-free culture system for developing a conjunctival epithelial equivalent with improved proliferative and structural properties, which are crucial for enhancing graft survival and regeneration of the conjunctival surface after clinical transplantation. (+info)
Laser Doppler flowmetry in evaluation of cutaneous wound blood flow using various suturing techniques.
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Measurements of blood flow on either sides of abdominal incisions and of uninjured control skin in 63 patients with three kinds of suturing techniques (clips in 21 patients, mattress in 21 patients, and subcuticular suture in 21 patients) on the 1st and 5th postoperative day were made, using an infrared laser Doppler flowmeter. There was a significantly higher flow on the 1st versus the 5th postoperative day. There is statistically higher blood flow in wounds sutured with subcuticular sutures in comparison with the two other groups. The method may allow the relationship of blood flow to wound healing to be evaluated. (+info)
Incidence of cranial nerve injuries after carotid eversion endarterectomy with a transverse skin incision under regional anaesthesia.
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OBJECTIVES: The objective of this prospective study was to evaluate the incidence and distribution of cranial nerve injuries after carotid eversion endarterectomy (EEA) performed under regional anaesthesia using a transverse skin incision. PATIENTS AND METHODS: The study included 165 patients and 180 carotid arteries. All patients had a standard pre-operative assessment performed by a neurologist and ENT specialist. All carotid endarterectomies were performed by the eversion technique under regional anaesthesia. RESULTS: Ten cranial nerve injuries were observed. Seven patients had injuries of the marginal mandibular branch of the facial nerve, two patients had lesions of the hypoglossal nerve, and one patient had an injury of the recurrent laryngeal nerve. Eleven patients developed hoarseness without cranial nerve injury. Injuries of the marginal mandibular branch recovered after 3-8 months (mean 5.2 months). Both hypoglossal nerve injuries recovered after 4 months. The patient with the recurrent laryngeal palsy had no improvement after 19 months. Patients with hoarseness secondary to laryngeal haematoma recovered within 1 month. CONCLUSION: The incidence of cranial nerves injury after carotid EEA under regional anaesthesia is comparable to that reported for conventional carotid surgery. Postoperative hoarseness is most frequently due to laryngeal haematoma. (+info)
Recurrent meningioma with metastasis to the skin incision--case report.
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A 70-year-old woman presented with meningioma with metastasis to the skin incision. Neuroimaging demonstrated a tumor of the falx extending to the frontal bone. The tumor was grossly totally resected through a coronal skin incision. The histological diagnosis was meningotheliomatous meningioma. The tumor recurred in the ethmoid sinus 2 years later, and was resected through the transfacial approach. One year later, the tumor recurred in the ethmoid sinus and orbit, and was resected through the transcranial approach. Six months later, she noticed an isolated small mass under the skin incision, distant from a further recurrence of the tumor. Both tumors were resected. The histological diagnosis was atypical meningioma. Resection of atypical meningioma carries the risk of iatrogenic metastasis. Surgeons should wash out the operative field carefully and change surgical tools frequently. (+info)
Modified Burow's advancement flaps for two circular adjoining cutaneous defects: the "8"-to-"S"-plasty.
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The traditional method to close two closely approximated cutaneous defects (i.e., a figure "8"-shaped defect) sacrifices healthy skin and does not give optimal aesthetic results. We report a case with modified Burow's advancement flaps describing less sacrificed skin and shorter scars. Modified Burow's advancement flaps ("8"-to-"S" plasty) were applied, sparing two Burow skin triangles. Application of that modified operation technique leads to shorter scars in comparison to traditional Burow's advancement flaps. A modified technique is presented here for skin defects shaped like an "8"--namely, two similar round and adjoining lesions. The suture line after closing resembles an "S". With this 8-to-S plasty no additional incisions are necessary. (+info)
Acetylcysteine in random skin flap in rats.
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PURPOSE: Analyze the ability of Acetylcysteine to reduce distal necrosis in a random skin flap, in the rat. METHODS: The present study utilized 28 adult male Wistar-EPM rats distributed, at random, in two groups of 14 animals. Control group rats (CG) received distilled water and Acetylcysteine group animals (NACG) received NAC (300 mg/kg) by oral infusion, 15 minutes before flap elevation. On the seventh postoperative day, percentage of distal necrosis was determined and skin samples collected in order to allow determination of MDA levels. RESULTS: The mean necrotic area in CG group (control) was 66% and in NACG group (Acetylcysteine) 52%, a statistically significant difference according to the Mann-Whitney test (U calc = 25; U crit = 45). MDA levels were lower in the CG flap skin samples than in the NACG samples (U calc = 24; U crit = 45), the oposite being true in the normal skin samples (U calc = 10; U crit = 45). CONCLUSION: Acetylcysteine was effective, according to the model used, reducing the percentage of distal necrosis in NACG rats. (+info)
Best evidence topic report. Topical anaesthetic versus lidocaine infiltration to allow closure of skin wounds in children.
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A short cut review was carried out to establish whether topical anaesthetics are an acceptable alternative to lidocaine infiltration in children. A total of 54 papers were found using the reported search, of which seven represented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results, and study weaknesses of these best papers are tabulated. A clinical bottom line is stated. (+info)