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A surgical technique to avoid postoperative enophthalmos in the cranioorbital approach. Technical note.

The authors describe a surgical technique to avoid postoperative enophthalmos when using the cranioorbital approach. To perform osteotomies with a less demanding technique, two separate bone flaps were created: 1) a free frontotemporal bone flap and 2) en bloc removal of the superior and lateral orbital rims: Because the latter bone flap includes both the orbital roof and the posterolateral wall of the orbit with the greater wing of the sphenoid bone, unnecessary bone defects in the lateral orbital wall are avoided. The technique has been performed in seven patients treated for medially located skull base neoplasms or complex anterior circulation aneurysms without postoperative enophthalmos or other cosmetic problems. The authors believe this cranioorbital approach, with its simpler, less invasive surgical technique, offers a definite advantage by avoiding postoperative enophthalmos.

Enophthalmos↗

Autologous chondrocyte transplantation for reconstruction of isolated joint defects: the Assaf Harofeh experience.

BACKGROUND: Articular cartilage is incapable of undergoing self-repair since chondrocytes lose their mitotic ability as early as the first year of life. Defects in articular cartilage, especially in weight-bearing joints, will predictably deteriorate toward osteoarthritis. No method has been found to prevent this deterioration. Drilling of the subchondral bone can lead to fibrocartilage formation and temporary repair that slowly degrades. Animal experiments indicate that introducing proliferating chondrocytes such as cultured articular chondrocytes can reliably reconstruct joint defects. OBJECTIVES: To describe our clinical experience in culturing and transplanting autologous chondrocytes. METHODS: Biopsies were obtained from 10 patients, aged 18-45, undergoing a routine arthroscopy in which a cartilage defect was identified with indications for cartilage transplantation. The biopsies were further processed to establish chondrocyte cultures. ACT was performed in 8 of the 10 patients because of persistent symptoms for at least 2 months post-arthroscopy. All patients (6 men and 2 women) had a grade IV cartilage defect in the medial or lateral femoral condyle, and three had a defect in the trochlear region as well. Biopsies were removed from the lateral rim of the superior aspect of the femur, and cells were cultured in a clean room. Following a 2 order of magnitude expansion, cells were implanted under a periosteal flap. RESULTS: The eight patients implanted with autologous cells were followed for 6 months to 5 years (average 1 year). Complaints of giving-way, effusion and joint locking resolved in all patients, and pain as assessed by the visual analogue score was reduced by an average of 50%. Follow-up magnetic resonance imaging studies in all patients revealed that the defects were filled with tissue having similar signal characteristics to cartilage. CONCLUSIONS: Chondrocyte implantation is a procedure capable of restoring normal articular cartilage in cases with isolated joint defects. Pain can be predictably reduced, while joint locking and effusion are eliminated. The effect on osteoarthritis progression in humans has not yet been elucidated.

Adolescent↗

Spontaneous cerebrospinal fluid rhinorrhoea due to temporosphenoidal encephalocele.

A 57-year old man was referred to our hospital with spontaneous cerebrospinal fluid (CSF) rhinorrhoea of 6 years duration. He had an episode of meningitis 2 months previously. CT cisternography and cranial MRI revealed a defect in the lateral wall of the sphenoid sinus, with an anteromedial temporosphenoidal encephalocele. Surgery was performed transcranially through a pterional approach. The temporal encephalocele was amputated, the sphenoid sinus obliterated and the dural defect repaired. Lumbar drainage was used for 5 days after surgery. Spontaneous CSF rhinorrhoea is only infrequently due to temporal encephalocele. Anteromedial temporosphenoidal encephaloceles are the least common type of temporal encephalocele, with only 12 reported in the literature.

Cerebrospinal Fluid Rhinorrhea↗

Knee arthroscopy in Chinese children and adolescents: an eight-year prospective study.

In the period January 1985 to December 1992, 69 Chinese boys and 20 Chinese girls (average 14.6 years, age range 6 to 16 years) with a total of 92 involved knees underwent examination under anaesthesia and knee arthroscopy. Two thirds of the patients were engaged in sports activities. A haemarthrosis was present in 51 patients. In one patient, Staphylococcus aureus was shown, and in two children a serous-purulent aspirate grew Mycobacterium tuberculosis. The lateral meniscus was torn in four knees and the medial meniscus in six. An intact discoid lateral meniscus was found in five girls. Three partial anterior cruciate ligament (ACL) tears, three complete ACL tears and two posterior cruciate ligament tears were diagnosed. One child had an osteochondral defect of the lateral femoral condyle accompanying an ACL and a lateral meniscal tear. Nonspecific synovitis of unknown etiology was diagnosed in six patients who had presented subacutely with at least a 2-month history of a symptomatic monoarticular knee effusion with low grade local inflammation and no history of major trauma. The synovitis gradually resolved over a 6- to 10-month period after arthroscopy. Knee arthroscopy in children and adolescent patients is safe, gives a high diagnostic accuracy, and allows treatment of a variety of intraarticular conditions. This study also demonstrates that the range of intraarticular knee problems found in Chinese children and adolescents differs from that described in their Western counterparts.

Adolescent↗

Transection and occlusion of lateral semicircular canal in guinea pigs.

Audiologic and histopathologic examinations were made after occlusion of the lateral semicircular canal in eight guinea pigs. The lateral semicircular canal was drilled out, and then the canal lumens were plugged with muscle pieces. After a serial recording of auditory brain stem responses for 2 months, histologic specimens of the temporal bones were prepared in the lateral semicircular canal plane. One animal developed profound hearing loss due to suppurative labyrinthitis. The other seven animals showed no significant threshold elevation during this period. Histopathologic examination revealed that the bone defect on the lateral canal was replaced with newly formed bone; the perilymphatic and endolymphatic spaces maintained their compartmentalization; and the membranous endolymphatic canal healed to form complete blind ducts. These findings suggest that proper management of the injured semicircular canal is important for maintenance of postoperative hearing.

Animals↗

Free physeal transplantation in the rabbit. An experimental approach to focal lesions.

UNLABELLED: We have developed a procedure to transplant free autogenous iliac-crest physeal grafts into defects created in the lateral aspect of the distal femoral physis of rabbits. Excision of a portion of the lateral part of the physis led consistently to formation of a bone bridge, growth arrest, and valgus deformity. There was no evidence of increased activity by the persisting physis to fill the defect or of differentiation of mesenchymal cells into a functioning physeal layer. We carried out preliminary studies to define the optimum conditions for obtaining and transplanting a free autogenous iliac-crest physeal graft into the femoral physeal defect. The iliac apophysis is composed of a fibrocartilaginous layer, cartilage similar to epiphyseal cartilage, and a physis. The graft included the physis and some overlying epiphyseal cartilage but the outermost fibrocartilaginous layer and the surrounding perichondrium were removed, as these two tissues were believed to inhibit diffusion. The graft was separated gently from the metaphysis. Histological studies showed that the separation occurred at the lower hypertrophic-chondrocyte zone. After optimum techniques had been developed for transplantation and the feasibility of the procedure had been established in twenty-one rabbits, the capacity of the physeal transplants to prevent bone-bridge formation, growth arrest, and valgus deformity was evaluated in thirty-nine rabbits, three to four months old, using the standardized transplantation procedure. The results were assessed in terms of the gross and radiographic appearance of the femur, measurements of length, and histological characteristics. The transplanted physis retained its normal morphology, united with the residual part of the original femoral physis, and participated in endochondral bone formation. Bone-bridge formation between the femoral epiphysis and metaphysis, growth arrest, and valgus deformity were prevented or minimized in most animals, and the physeal transplants yielded good or excellent results in 60 per cent of the procedures using stringent criteria. The results of this study show that free physeal transplants into focal defects can remain viable and function satisfactorily if they are fashioned properly and inserted gently. CLINICAL RELEVANCE: This study demonstrated that transplantation of an iliac-crest physis into a defect of the lateral aspect of the distal femoral physis can prevent bone-bridge formation, growth arrest, and the development of valgus deformity.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Persistent left superior vena cava with coronary sinus and left atrial connections.

A 65-yr-old woman presented with severe congestive cardiac failure and physical signs of an atrial septal defect. Investigation by cardiac catheterisation and cross-sectional echocardiography showed a persistent left superior vena cava draining through an enlarged coronary sinus into the right atrium. In addition, the left atrium was connected to the coronary sinus by two defects in its lateral wall. The atrial septum was intact. The physiological result of this rare anatomical abnormality was a large left-to-right shunt with a small right-to-left component. The defects were closed surgically.

Coronary Vessel Anomalies↗

The glycinamide ribonucleotide transformylase (GART) gene is not responsible for familial amyotrophic lateral sclerosis.

Though the nature of the underlying metabolic defect which leads to amyotrophic lateral sclerosis (ALS) remains obscure, certain biochemical anomalies have been found, such as, reduced RNA content in ALS motor neurons. Recently, a gene causing the familial form of ALS (FALS) has been assigned to an interval of approximately 10 cM including the locus D21S58 on chromosome 21q22.1. This region includes the GART gene which encodes an enzyme catalyzing three steps in the de novo biosynthesis of purine nucleotides which are precursors for RNA. A defect of this gene might result in reduced RNA production and predispose to premature death of motor neurons. In order to test GART as a candidate we developed two highly informative DNA markers in this region and carried out linkage analyses for FALS. GART is excluded as a candidate for FALS.

Acyltransferases↗

Two-dimensional photonic band-Gap defect mode laser

A laser cavity formed from a single defect in a two-dimensional photonic crystal is demonstrated. The optical microcavity consists of a half wavelength-thick waveguide for vertical confinement and a two-dimensional photonic crystal mirror for lateral localization. A defect in the photonic crystal is introduced to trap photons inside a volume of 2.5 cubic half-wavelengths, approximately 0.03 cubic micrometers. The laser is fabricated in the indium gallium arsenic phosphide material system, and optical gain is provided by strained quantum wells designed for a peak emission wavelength of 1.55 micrometers at room temperature. Pulsed lasing action has been observed at a wavelength of 1.5 micrometers from optically pumped devices with a substrate temperature of 143 kelvin.

Journal Article↗

Susceptible periods during embryogenesis of the heart and endocrine glands.

One of the original principles of teratology states that, "Susceptibility to teratogenesis varies with the developmental stage at the time of exposure to an adverse influence" [Wilson JG. Environment and Birth Defects. New York:Academic Press, 1973]. The time of greatest sensitivity encompasses the period of organ formation during weeks 3-8 following fertilization in human gestation. At this time, stem cell populations for each organ's morphogenesis are established and inductive events for the initiation of differentiation occur. Structural defects of the heart and endocrine system are no exception to this axiom and have their origins during this time frame. Although the function and maturation of these organs may be affected at later stages, structural defects and loss of cell types usually occur during these early phases of development. Thus, to determine critical windows for studying mechanisms of teratogenesis, it is essential to understand the developmental processes that establish these organs.

Cell Differentiation↗

The bridging lateral mandibular reconstruction plate revisited.

BACKGROUND: Lateral oromandibular reconstruction using a soft tissue free flap with a first-generation locking mandibular reconstruction plate (MRP) was rejected in a previous series by the senior author (K.E.B.) owing to a high incidence of delayed plate extrusion through the cheek skin. OBJECTIVE: To reexamine this method of reconstruction using a second-generation, low-profile MRP. PATIENTS AND DESIGN: A prospective case series of 27 patients with segmental defects of the lateral mandible after treatment of head and neck cancer. SETTING: An academic tertiary care referral center. INTERVENTION: All patients had mandibular continuity restored using the Leibinger Locking System (Stryker Leibinger Inc, Kalamazoo, Mich) MRP. Associated soft tissue defects were repaired using radial forearm (n = 22) or rectus abdominis (n= 5) free flaps. MAIN OUTCOME MEASURE: Incidence of hardware-related complications. RESULTS: All microvascular flap transfers were successful. One patient experienced a plate fracture 9 months after reconstruction. Only 1 patient experienced external plate exposure, 6 months after undergoing reconstruction of a through-and-through defect. Reconstruction was successful in 25 (93%) of the cases after a median follow-up period of 19.5 months. CONCLUSIONS: The high incidence of external plate exposure in patients undergoing lateral oromandibular reconstruction using soft tissue free flaps and first-generation locking MRPs may have resulted from a plate geometry that was prone to result in extrusion. After a similar length of follow-up, the incidence of reconstructive failure was reduced by using a low-profile, rounded-contour MRP. Final assessment of the durability of this technique will require long-term follow-up.

Adult↗

Interaction between two auxin-resistant mutants and their effects on lateral root formation in rice (Oryza sativa L.).

Since root elongation is very sensitive to auxin, screening for reduced inhibition in root elongation has been an important method for the detection of auxin-resistant mutants. Two recessive auxin-resistant lines of rice (Oryza sativa L. ssp. indica cv. IR8), arm1 and arm2, have been isolated by screening for resistance to 2,4-dichlorophenoxyacetic acid (2,4-D). arm1 displays a variety of morphological defects including reduced lateral root formation, increased seminal root elongation, reduced root diameter, and impaired xylem development in roots, while the arm2 phenotype is almost similar to wild-type IR8 except for a slightly reduced lateral root formation, impaired xylem development in roots and an enhanced plant height. Although the growth of arm2 roots exhibited a resistance to 2,4-D, it was sensitive to 1-naphthaleneacetic acid (NAA) as the wild type. At the same time, the arm2 roots showed a reduced [14C]2,4-D uptake while uptake of [3H]NAA was normal, suggesting that the resistance to 2,4-D of arm2 roots is due to a defect in 2,4-D uptake. To investigate the possible interaction between arm1 and arm2 genes, a double mutant has been constructed. The roots of arm1 arm2 double mutant were more resistant to 2,4-D and formed fewer lateral roots than those of either single mutant, suggesting that the two genes show synergistic effects with respect to both auxin response and lateral root formation. By contrast, all these mutants displayed the normal gravitropic response in roots, as did the wild-type plants. Taken together, Arm1 and Arm2 genes seem to function in different processes in the auxin-response pathways leading to lateral root formation.

2,4-Dichlorophenoxyacetic Acid↗

[Effects of gene therapy with replication-defective adenovirus ericlosing Egr-1 promoter and Smad7 cDNA on irradiation-induced pulmonary fibrosis: experiment with mice].

OBJECTIVE: To investigate the effects of gene therapy with replication-defective adenovirus enclosing Egr-1 promoter and Smad7 cDNA on irradiation-induced pulmonary fibrosis. METHODS: The recombinant replication-defective adenovirus AD. Egr-Smad7 enclosing Egr-1 promoter and Smad7 cDNA was constructed. 288 C57BL mice were randomly divided into 6 groups: AD. Egr-Smad7 group (Group RA, receiving intratracheal instillation of AD. Egr-Smad7 of the dose of 10(9) pfu/0.1 ml), AD. Egr-Smad7 + radiation group (Group RAR, receiving intratracheal instillation of AD. Egr-Smad7 of the dose of 10(9) pfu/0.1 ml and then radiation to the chest 14 h later), replication-defective adenovirus group (Group AV, receiving intratracheal instillation of replication-defective adenovirus of the dose of 10(9) pfu/0.1 ml), replication-defective adenovirus + irradiation group (Group AVR, receiving intratracheal instillation of replication-defective adenovirus of the dose of 10(9) pfu/0.1 ml and then radiation to the chest 14 h later), blank control group (Group C), and pure irradiation group (Group R), each group was re-divided into 6 subgroups of 8 mice to be observed 0, 1, 2, 4, 8, and 12 weeks after the treatment. The mice were killed at different time points and their lungs were taken out. The levels of type I collagen, type III collagen, connective tissue growth factor (CTGF), and transforming growth factor-beta1 (TGF-beta1) were detected by ELISA. The level of hydroxyproline was examined by alkaline hydrolysis method. The lung tissues were stained with HE to undergo pathological examination. RESULTS: The TGF-beta1 levels of the irradiation groups all increased, peaking in the second week (all P < 0.05), all significantly higher than those of Group C. However, the TGF-beta1 levels at different time points of Group RAR were all significantly lower then those of the other irradiation groups. The CTGF levels of different groups at different time points were all significantly higher than those of Group C (P < 0.05 or P < 0.01), and the CTGF levels of Groups RA and AV were decreased to almost normal 12 weeks after the irradiation. The levels of type I collagen and type III collagen of the 1 and 2-week subgroups of Group RAR were significantly lower than those of Group C (all P < 0.01), then gradually increased, and were slightly higher than those Group C 12 weeks later. The levels of type I collagen and type III collagen at different time points of the other groups were all significantly higher than those of Group C (P < 0.05 or P < 0.01). However, The levels of type I collagen at different time points of Group RAR were all lower than those of the other groups except Group C, and the levels of type III collagen in the first to eighth weeks after irradiation of Group RAR were all lower than those of the other groups except Group C. The hydroxyproline level of the 1 and 2 week subgroups of Group RAR were significantly lower than those of Group C (all P < 0.01), and then gradually increased. The hydroxyproline levels of the other irradiation groups all gradually increased significantly, peaking at the 12 th week (all P < 0.01). 1 approximately 2 weeks after irradiation Groups RAR, RA, and AV showed remarkable pulmonary congestion changes, even more remarkable then those in Group R, 8 approximately 12 week later, fibrosis changes were found in Group R and AVR, and 12 weeks later the histological structure of lung of Group AV, RAR, and RA returned almost normal. CONCLUSION: Radioactive rays induce Egr-1 promoter to regulated the expression of exogenous Smad7 gene that blocks the signal transduction of TGF-beta. Thus use of AD. Egr-Smad7 may become a novel strategy of gene therapy in prevention and treatment of pulmonary fibrosis.

Adenoviridae↗

Growth defects in unrepaired unilateral cleft lip and palate.

The positional relationships of the dentoalveolar segments in ten subjects with unrepaired unilateral complete clefts of lip and palate were studied in order to assess the effects of the cleft malformation on dentoalveolar growth. The findings suggest that there are localized growth defects, particularly in lateral and vertical growth at the region of the alveolar cleft, which cannot be accounted for by operative trauma. The position and shape of the central incisor nearest the cleft was also found to be defective in some subjects.

Adolescent↗

Intracellular role of adenylyl cyclase in regulation of lateral pseudopod formation during Dictyostelium chemotaxis.

Cyclic AMP (cAMP) functions as the extracellular chemoattractant in the aggregation phase of Dictyostelium development. There is some question, however, concerning what role, if any, it plays intracellularly in motility and chemotaxis. To test for such a role, the behavior of null mutants of acaA, the adenylyl cyclase gene that encodes the enzyme responsible for cAMP synthesis during aggregation, was analyzed in buffer and in response to experimentally generated spatial and temporal gradients of extracellular cAMP. acaA- cells were defective in suppressing lateral pseudopods in response to a spatial gradient of cAMP and to an increasing temporal gradient of cAMP. acaA- cells were incapable of chemotaxis in natural waves of cAMP generated by majority control cells in mixed cultures. These results indicate that intracellular cAMP and, hence, adenylyl cyclase play an intracellular role in the chemotactic response. The behavioral defects of acaA- cells were surprisingly similar to those of cells of null mutants of regA, which encodes the intracellular phosphodiesterase that hydrolyzes cAMP and, hence, functions opposite adenylyl cyclase A (ACA). This result is consistent with the hypothesis that ACA and RegA are components of a receptor-regulated intracellular circuit that controls protein kinase A activity. In this model, the suppression of lateral pseudopods in the front of a natural wave depends on a complete circuit. Hence, deletion of any component of the circuit (i.e., RegA or ACA) would result in the same chemotactic defect.

3',5'-Cyclic-AMP Phosphodiesterases↗

Drosophila ATR in double-strand break repair.

The ability of a cell to sense and respond to DNA damage is essential for genome stability. An important aspect of the response is arrest of the cell cycle, presumably to allow time for repair. Ataxia telangiectasia mutated (ATM) and ATR are essential for such cell-cycle control, but some observations suggest that they also play a direct role in DNA repair. The Drosophila ortholog of ATR, MEI-41, mediates the DNA damage-dependent G2-M checkpoint. We examined the role of MEI-41 in repair of double-strand breaks (DSBs) induced by P-element excision. We found that mei-41 mutants are defective in completing the later steps of homologous recombination repair, but have no defects in end-joining repair. We hypothesized that these repair defects are the result of loss of checkpoint control. To test this, we genetically reduced mitotic cyclin levels and also examined repair in grp (DmChk1) and lok (DmChk2) mutants. Our results suggest that a significant component of the repair defects is due to loss of MEI-41-dependent cell cycle regulation. However, this does not account for all of the defects we observed. We propose a novel role for MEI-41 in DSB repair, independent of the Chk1/Chk2-mediated checkpoint response.

Animals↗

Localized vertical maxillary ridge augmentation using symphyseal bone cores: a technique and case report.

Vertical augmentation of the alveolar ridge is intended to restore resorbed alveolar ridges. This procedure is important for the placement of dental implants in a favorable position and also to enhance restoration esthetics. This article presents an approach for vertical ridge augmentation in the anterior maxilla utilizing symphyseal bone cores. A patient presented with 2 localized bony defects around the maxillary lateral incisors. Following extraction of these teeth, vertical bone defects of 7 mm on the right and 6 mm on the left were observed in relation to the cementoenamel junction of the adjacent teeth. Two bone cores were harvested from the mandibular symphysis using a trephine. These bone cores were tapped into 2 predrilled osteotomy sites with corresponding diameters until stabilization was achieved. The 2 sites were grafted with demineralized freeze-dried bone allograft and a titanium-reinforced expanded polytetrafluoroethylene membrane. After 5 months, the membranes were removed and vertical ridge augmentation of 5 mm on the right and 4 mm on the left was observed. The width of the ridge was increased as well. Two implants were placed in favorable positions, restored after 6 months, and followed successfully for 1 year after loading. This technique represents a viable approach for augmentation of deficient alveolar ridges prior to the placement of dental implants.

Adult↗

[Surgical treatment of anal insufficiency].

Organic defects in the lateral walls of the rectal obturative apparatus involving no more than one fourth of its circumference are repaired by end-to-end or side-to-side sphincteroplasty. Sphincterolevatoroplasty is indicated in anterior or posterior defects and sphincterogluteoplasty with short or long grafts of the greatest gluteus muscles in larger defects. For cases in which the gluteal muscles cannot be used, an operation has been developed for repair of the defects with the medial part of the great adductor muscle. A damaged internal sphincter muscle of the anus is reconstructed by means of a muscular cuff formed from the wall of a pulled down rectum.

Anus, Imperforate↗