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Biomedical subjects

L Morales

Publications and source records attributed to L Morales.

At least 73 records · Page 4Linked to original sources
PubMed1998

[Skeletal muscle graft on the terminal ileum as a substitute for ileocecal valve: experimental study].

Behavior of a free skeletal muscle graft in contact with intestinal wall is analyzed in rats. On first phase, survival of the graft muscle in relation with previous denervation is studied. Nondenervated muscles suffer necrosis and fibrosis, whereas when denervated 4 weeks before grafting, the muscles are viable. On a second phase, the grafted muscle was studied on the long term. From 8th post-transplant week on, the structural and metabolic features of the graft were similar to normal. On the third phase the efficacy of the muscle implant as a substitute of the ileocecal valve is checked. Germs on either side of the valve (ileum and cecum) are counted in normal rats, rats after valve excision and rats with substitution of the valve by a free skeletal muscle implant. There haven been significant differences between normal and no-valve rats (P < 0.001) and between no-valve and artificial valve rats (P < 0.005). There has not been significant difference between normal rats and artificial valve rats. We conclude that free skeletal muscle survives transplant to intestine, and it prevents bacterial reflux from colon to ileum.

Animals↗
PubMed1998

[Urinary obstruction in fetal rabbits. An experimental model].

An original model of urethral ligation on 23 gestational-day fetal rabbits is described, that can be applied in studies of both urinary obstruction and oligohydramnios. The surgical technique is detailed and subsequent urinary obstruction is assessed, as well as the lung weight. In conclusion, this is an easy, mildly aggressive, inexpensive and fast model that can be used to investigate the pathophysiology of urinary obstruction and that of oligohydramnios.

Animals↗
PubMed1997

Effect of the environment on fetal skin wound healing.

Skin wound healing has been shown to be a different process in the fetus than in the adult animal. Some of these differences have been attributed to the unique fetal environment (i.e., amniotic fluid). The aim of the present study is to compare fetal skin healing in intraamniotic and extraamniotic wounds. A fetal rabbit model has been used in which three types of skin wounds were induced on 23-day-old fetuses in contact with either amniotic fluid or maternal peritoneal fluid. The wounds consisted of a sutured skin incision, a nonsutured incision, and an electrocautery burn. Seven days later all wounds were examined mechanically (scar resistance), biochemically (collagen and noncollagen protein concentration), and histologically. Biochemical and growth factor studies of both environments, the amniotic and the peritoneal fluids, were also conducted. The results showed excellent healing by first intention and absence of healing by second intention in both environments, greater scar resistance in the intraperitoneally positioned fetal wounds, and a higher concentration of insulin-like growth factor-1 (IGF-1) in the peritoneal fluid than in the amniotic fluid. It can be concluded that fetal skin wounds in contact with peritoneal fluid show the same healing pattern as in the natural fetal environment (amniotic fluid). The higher concentration of IGF-1 in the peritoneal fluid suggests that this growth factor, through its relationship with the growth hormone, plays a role in increasing the scar resistance of fetal skin wounds in contact with maternal peritoneal fluid.

Amniotic Fluid↗
PubMed1997

Endoscopic approach for benign tumor ablation of the forehead and brow.

Resection of benign tumors of the forehead and brow raises aesthetic concerns. An endoscopic subperiosteal approach to benign bony and soft-tissue tumors in the supraorbital and frontotemporal regions permits extirpation of these masses without producing visible facial scars. Therefore, this technique was used for tumor resection in 4 patients. This procedure demonstrated magnified visualization of the masses, and safe access for excisional biopsy and bony contouring. In addition to more acceptable surgical scars, patients experienced no significant postoperative morbidity and a reduced incidence of swelling, discomfort, and scalp anesthesia. Therefore, we conclude that the endoscopic subperiosteal approach is a favorable alternative for resection of suitable tumors.

Adult↗
PubMed1997

Ocular staphyloma associated with facial clefting.

A staphyloma is an uncommon ocular lesion consisting of an attenuation in the sclera, which, along with the underlying uveal tissue, bulges to form a raised pigmented area on the eye. The scleral defect predisposes the globe to rupture under conditions of increased intraocular pressure, which might occur while retracting the eye during cranio-orbital surgery. We report a case of a staphyloma in a child with bilateral facial clefts. Before hypertelorism correction, she underwent scleral repair with a cadaveric graft. Her orbital repositioning was performed without incident 10 months later. The significance of a possible association between facial clefting and staphyloma is discussed.

Cadaver↗
PubMed1997

Bioabsorbables: their use in pediatric craniofacial surgery.

The need to provide rigid bony fixation in the surgical treatment of craniofacial disorders has inspired an evolution of operative techniques and fixation devices over the past two decades, with the recent development of an absorbable miniplate fixation system. We present features of the LactoSorb absorbable system (Biomet, Inc., Warsaw, IN) and our initial experience in 35 pediatric craniofacial patients over a 10-month period.

Absorbable Implants↗
PubMed1997

[Experimental free muscle transplantation. Is autologous graft on the distal esophagus viable?].

UNLABELLED: Experimental free muscle transplantation has resulted in some successful clinical applications. AIM: The possibility that this type of transplantation could act as a sphincteric mechanism motivated us to start by assessing the viability of autologous skeletal grafts on the distal esophagus of laboratory animals. MATERIAL AND METHODS: Twenty transplants of previously denervated free plantaris muscle grafted on the distal esophagus of Sprague-Dawley rats were evaluated at the 1st, 2nd, 4th, 8th and 16th posttransplant week. Histological and histochemical studies were performed to evaluate general features of the grafts and the muscle fibers condition. RESULTS: One and two weeks after transplant the grafts show large areas of necrosis with inflammatory infiltrate. Between the 2nd and the 4th week, as revascularization and motor endplates become significant, the areas of necrosis begin to regress and they almost disappear by the 8th week. Since the 4th week after transplant, regenerated muscle fibers demonstrate morphological and biochemical features similar to normal. CONCLUSIONS: Experimental free plantaris muscle transplantation on the distal esophagus is viable and shows revascularized and reinnervated muscle fibers from the 8th week after transplant on, and at least until the 16th. These fibers have the structural and metabolic properties enabling contractile function. This original model may allow further investigation of some features related to pathophysiology and therapy of gastroesophageal reflux.

Animals↗
PubMed1997

[Laparoscopic Nissen fundoplication in children with encephalopathy].

Conventional management of gastroesophageal reflux (GER) and hiatus hernia in children affected with encephalopathy can deteriorate their pulmonary function, already compromised by their leaning position and their spine deformations. The results after laparoscopic surgery for GER in 6 encephalopathy children are reviewed; their ages ranged from 9 to 14 years, their accompanying diseases were: spastic tetraparesia, hydrocephalus, scoliosis, epilepsy and Reye's syndrome. The laparoscopy procedures followed the same surgical steps as open surgery; the surgical time was 3 to 5 hours; the average hospital stay was 3 days. Oral intake started 8 hours after surgery. The successful results of these first cases in this group of patients with neurologic anomalies, suggest that laparoscopic Nissen funduplication is the treatment of choice for GER and hiatus hernia.

Adolescent↗
PubMed1996

Comparison of ossification of demineralized bone, hydroxyapatite, Gelfoam, and bone wax in cranial defect repair.

Demineralized bone allografts in the repair of calvarial defects are compared with other common bone fillers. This study uses a video-digitizing radiographic analysis of calvarial defect ossification to determine calcification of bone defects and its relation to postoperative clinical examination and regional controls. The postoperative clinical results at 3 months demonstrated that bony healing was greatest in bur holes filled with demineralized bone and hydroxyapatite. Radiographic analysis demonstrated calcification of demineralized bone-filled defects compared to bone wax- and Gelfoam-filled regions. Hydroxyapatite granules are radiographically dense, thus not allowing accurate measurement of true bone healing. The results suggest that demineralized bone and hydroxyapatite provide better structural support via bone healing to defined calvarial defects than do Gelfoam and bone wax.

Bone Regeneration↗
PubMed1996

Frontonasal malformation and the oculoauriculovertebral spectrum: the oculoauriculofrontonasal syndrome.

Frontonasal malformation (FNM) is a developmental field defect representing abnormal morphogenesis of the frontonasal eminence. The oculoauriculovertebral spectrum (OAVS) has been used to describe a broader range of first and second branchial-arch defects including hemifacial microsomia and Goldenhar's syndrome. A combination of FNM and OAVS has been described in the literature in 13 cases. This condition has been labeled as the oculoauriculofrontonasal syndrome, as well as ophthalmofrontonasal dysplasia. We have evaluated four patients with both FNM and OAVS. The pattern of malformation involves only the craniofacies: they have no vertebral defects, heart disease, or encephaloceles. The categorization of these four individuals and those in the literature raises interesting issues regarding syndrome classification. Originally, it was suggested that perhaps this disorder was a variation of Goldenhar's syndrome. However, now that it has become evident that FNM and OAVS are malformation patterns of etiologic and presumably pathogenetic heterogeneity, a more likely hypothesis is that when these two defects occur together, this represents a unique syndrome pattern. The purpose of this article is to suggest that the combination of OAVS and FNM may be a distinct entity, representing a discreet subset of patients.

Adolescent↗
PubMed1996

[The profile surgery. Mandibular osteotomies].

During the years 1987-1994, 31 mandibular osteotomies have been performed in 25 patients, 15 had mandibular alteration alone, 10 of them with prognatism, 2 with microretrognatia and 3 with chin hipoplasia. The other 10 had a combined maxillary-mandibular alteration with hipoplasia and maxillary retrussion. The preoperative work-up included cephalometric and dental study, and a cast model was done to asses the theoretical benefic of the osteotomy. All these patients underwent orthodontic treatment before and after surgery. The results have been good or very good in 96% of the cases. The ortognatic surgery offers significant aesthetic and functional improvement to these patients.

Adolescent↗
PubMed1995

Optic nerve decompression in cranial base fibrous dysplasia.

Fibrous dysplasia of the anterior cranial base involves the bony orbit and optic canal. Although fibrous dysplasia is benign, it may produce a mass effect along the course of the optic nerve, inducing visual disturbances. Optic canal decompression in patients without clinical signs of optic neuropathy is controversial. We describe five patients with extensive fibrous dysplasia of the anterior cranial base involving the orbit and optic canal. These patients underwent transcranial optic canal decompression before signs of severe visual loss during correction of dystopias and craniofacial deformity induced by fibrous dysplasia. Cranial orbital reconstruction was performed by means of split rib and cranial bone grafts. Postoperative follow-up did not reveal disturbances in visual function, extraocular motility, or evidence of cerebrospinal fluid fistulas. This suggests that early, radical resection of orbital fibrous dysplasia with optic canal decompression may be effective in preventing visual loss with minimal risk of other neurological sequelae. Subsequent orbital reconstruction involving split-thickness rib and cranial bone grafting yields satisfactory cosmetic results.

Adolescent↗
PubMed1995

"False" migration of rigid fixation appliances in pediatric craniofacial surgery.

Osseous fixation techniques have been widely used to provide rigid stabilization in the craniofacial skeleton. Reported sequelae of its usage has been limited to palpation of the screw-plate system and radiological imaging artifacts. Over the past 3 years we have identified miniplates, microplates, and wire sutures on the inner cranial table of the growing child. The observation of "false" migration of these appliances has provided the impetus to review these patients in more detail. Twenty patients underwent secondary cranial remodeling within a two-year period; 7 of these patients were seen to have "false" migration. There were no untoward sequelae in removal of these appliances, and no adverse neurological symptoms were seen.

Bone Plates↗
PubMed1994

Streptomycin and alternative agents for the treatment of tularemia: review of the literature.

Because of the recent lack of availability of streptomycin--currently considered the drug of choice for the treatment of tularemia--we reviewed the literature on alternative drugs that have been used for this purpose. In addition, we reviewed data on the in vitro susceptibility of Francisella tularensis to a wide variety of agents. The rate of cure for streptomycin was 97%, with no relapses. For gentamicin and tetracycline, respectively, the rates of cure were 86% and 88%, the rates of relapse were 6% and 12%, and the rates of failure were 8% and 0. The duration of therapy with gentamicin and a delay in its initiation may have affected outcome in severe cases. For chloramphenicol and tobramycin, cure rates were 77% and 50%, respectively; relapse rates were 21% and 0; and failure rates were 2% and 33%, respectively. Treatment with imipenem/cilastatin was successful in one case, and that with ciprofloxacin or norfloxacin was successful in six cases; in contrast, therapy with ceftriaxone was ineffective in eight cases. On the basis of this review, we conclude that gentamicin is an acceptable alternative to streptomycin for the treatment of tularemia.

Francisella tularensis↗
PubMed1994

Congenital hypertrophy of the retinal pigment epithelium associated with familial adenomatous polyposis.

PURPOSE: Multiple, bilateral areas of congenital hypertrophy of the retinal pigment epithelium (CHRPE) have been described in association with familial adenomatous polyposis (FAP). Histopathologic findings have suggested a generalized effect of the FAP gene on the RPE, which could impair the functional integrity of the RPE. The clinical, psychophysical, electrophysiologic, and fluorescein angiographic findings in CHRPE in subjects with FAP were assessed. METHODS: RPE function was assessed in 7 subjects with CHRPE and a family history of FAP. Four had documented FAP (mean age = 22.25 years) and the other three were siblings of affected subjects, with a 50% risk of developing FAP (mean age = 6.33 years). All subjects underwent comprehensive ophthalmologic examination. RESULTS: All subjects showed mild hyperopia (mean, +1.13 D; best corrected visual acuity, 20/20 or better). On perimetry, there were scotomas corresponding to some lesions. ERG showed normal rod, maximal, single-flash cone, and flicker responses. Light-dark ratio was within the normal range on EOG. Fluorescein angiography demonstrated normal retinal vasculature overlying the CHRPE lesions, which blocked background choroidal fluorescence. A normal choriocapillaris was observed through some hypopigmented lacuna. CONCLUSION: CHRPE has been related to generalized expression of an abnormal gene in RPE, but its functional abnormalities tend to be localized.

Adenomatous Polyposis Coli↗
PubMed1994

Presurgical orthopedic premaxillary alignment in cleft lip and palate reconstruction.

Premaxillary malposition is a difficult problem in cleft lip and palate repair. Orthopedic palatal devices are excellent in positioning the premaxilla, though they are somewhat cumbersome and require complex techniques in adjusting precisely the position of the premaxilla prior to repair. A new technique has been developed for premaxillary repositioning in conjunction with palatal shelf expansion and obturation. The procedure implements microplate fixation anterior to the premaxillary segment and linked to a palatal splint by adjustable elastics. The microplate is inserted through a nasal floor incision and secured by a tight submucosal tunnel through minimal dissection between the prolabium and premaxilla. The last hole of each microplate protrudes through the mucosa and is attached to a pin-retained palatal splint by an elastic chain. Differential tension is applied to the chains to allow gradual repositioning of the protruding maxilla while the splint expands and maintains positioning of the lateral palatal segments. These elastic retractors can be adjusted by staff in the outpatient office. During the past 2 years, this technique has been used successfully in 21 consecutive patients with unilateral or bilateral cleft lip and palate. Its technical ease and design allows simple adjustments to control premaxillary positioning and growth before definitive surgical closure.

Bone Plates↗
PubMed1994

[Experimental alkaline reflux esophagitis. Role of the refluxed material].

Alkaline reflux is new recognised to play an important place in gastroesophageal reflux disease. In order to investigate the role of refluxate in the development of esophagitis we have performed an experimental study in laboratory animals submitted to alkaline reflux inducing operations. We produced esophagitis in two experimental groups of Sprague-Dawley rats: group I, end-to-side esophagojejunostomy (EY) and group II, esophagojejunostomy with partial derivation of afferent loop by an omega-like conduit (EO) designed to attain lesser reflux. Group III consisted of sham laparotomized animals (L). RESULTS. At day 14, all the animals of experimental groups have developed esophagitis, but the macroscopic extent and histological grade in group EO (med: 27 mm; grade 2) were significantly lower than in group EY (med: 35 mm; grade 3). Biochemical measurements (med) in esophageal washout revealed: a) pH were alkaline in all groups with a decrease in experimental groups that was only significant in group EY; b) Amylase, lipase and bile acids in groups EY (8090; 498; 32) and EO (12840; 449; 50) were similar, but significantly more higher than in group L (920; 24; 0). The analysis of correlation between esophagitis parameters and biochemical measurements revealed no significant ones except for pH (r = -.437 and -.417). CONCLUSIONS. 1- The alternative model (EO) presents lesser grade and extent of esophagitis. 2) The refluxate was rich in bile acids and pancreatic enzymes what is proof of the actual occurrence of reflux and supports its determinant contribute to the development of esophagitis. 3) Esophagitis has developed at alkaline pH but with no alkalinity increase in the experimental groups what indicate that "alkaline reflux esophagitis" is not an appropriate denomination. 4) The discrepancy between the biochemical analysis in esophageal washout and the extent and grade of esophagitis suggests that others than the nature and amount of refluxate (e.g. mucosal resistance) could play a role in reflux esophagitis.

Amylases↗