The extended latissimus dorsi flap in repair of anterior abdominal wall defects

Large abdominal wall defects (ventral hernias) can be difficult to repair. Some defects are not amenable to primary repair or the use of synthetic mesh because of repeated recurrence or wound infection. In complicated situations such as that mentioned above, the extended latissimus dorsi muscle flap has been used to repair upper and middle abdominal wall defects. This method has been utilized in six patients, and there has been no recurrence of the defect or evidence of a lumbar hernia. The follow-up has been from 7 to 66 months. The extended latissimus dorsi muscle flap has proven to be an excellent alternative in the repair of complicated abdominal wall defects.     

Evaluation of an automatic method for detection of defects in linear and curvilinear ultrasound transducers

PurposeThe high incidence of defective ultrasound transducers in clinical practice has been shown in several studies. Recently, a novel method using only stored images for automatic detection of defective transducers was presented. The method makes it possible to remotely monitor many transducers at the same time and send a notification when a defective transducer is found. The purpose of the present study was to evaluate the novel method and assess how well it performs when compared to an established method as reference.MethodsTo evaluate the novel method, in-air images were collected from 81 transducers in radiologic departments in nine hospitals. Two observers assessed the in-air images and marked the defects. Receiver operating characteristic (ROC)- and alternative free response receiver operating characteristic (AFROC)-curves and their figures of merit (FOM) were calculated for the novel method, using marked defects in the in-air images as reference truth.ResultsThe area under the ROC curve was 0.88 (SD 0.06), and the AFROC FOM was 0.71 (SE 0.07).ConclusionThe result shows that the novel method has a good agreement with the in-air method for detecting defects in ultrasound systems. This indicates that the novel method could be a complement to the normal quality control for early, and automatic detection of defects.     

孢粉壁准晶体结构研究进展

 论述了近十年来有关准晶体结构在生物组织中的研究和发现，对Kedves提出的生物聚合体准晶体结构和其三维构象进行了分析。介绍了其研究方法，指出其结构存在之不足。     

The fertility protein factor and congenital developmental defects

Protein factor of fertility (PFF) has been measured in seminal plasma by immunodiffusion method with sensitivity about 2 mg/L. It has been found that normal level of PFF was from 16 to 256 mg/L, on the average 45.9 mg/L. Family (husband and wife) has been studied in the genetic laboratory by traditional methods. It has been shown that there is the correlation between low PFF levels in seminal plasma (on the average 15.0 mg/L, i.e. from 2 to 64 mg/L) and several developmental defects of fetus. There were anencephalus, hydrocephalus, spina bifida and other morphological defects (coefficient correlation was P less than 0.01). The biological role of PFF in human developmental defects is discussed.     

Kinetic Monte Carlo simulation for the striation distribution of void defects in Czochralski silicon growth

Unique crystal-originated pit (COP) distribution, similar to a striation pattern, is well matched with the oxygen profile in experimental analysis. It shows the strong relationship between oxygen concentration and COP distribution. In this paper, we study the generation of void defects and the relationship between interstitial oxygen and vacancy using the kinetic lattice Monte Carlo (KLMC) method. The KLMC method has been applied extensively in various forms to the study of micro-defects in silicon wafers. It explained well the formation of void defects such as vacancy–oxygen complex and vacancy–vacancy complex. The formation of clusters is strongly affected by oxygen concentration, which showed the relationship between COP distribution and oxygen concentration. The unique COP distribution could be correctly explained with KLMC results, and this kind of meso-scale results has not yet been reported.     

Reconstruction of the upper portion of the ear by using an ascending helix free flap from the opposite ear

Reconstruction of partial, marginal defects of the ear has been a challenge. The ascending helix free flap based on superficial temporal vessels has been described and used solely to repair nose defects. We used reversed pedicle helical free flap for the repair of a major loss of the upper one-third of the opposite auricle. The method permits the transfer of tissue of the same quality with satisfactory cosmetic result. The equalization of the ears in dimension was accomplished with minimal donor-site deformity.     

Kinetic Monte Carlo simulation for the void defects formation in Czochralski silicon growth

The quality of silicon wafers used as substrates for microelectronic devices is measured in terms of the type, size and density of defects formed during crystal growth process. The native point defects such as vacancies and self-interstitials diffuse, react and aggregate to form intrinsic defects in the silicon wafers. We investigated the point defect behaviour using the kinetic lattice Monte Carlo (KLMC) model. The KLMC method has been applied extensively in various forms to the study of microdefects in silicon wafers. The purpose of this paper is to demonstrate the phenomena of void defect formation. The size and density of void defects are usually affected by system temperature, vacancy–vacancy reaction and vacancy–impurity reaction. In this paper, we study the temperature effect and the vacancy concentration effect. The simulation results with various temperatures are well matched with our experimental data, and the relationship between temperature and vacancy density describes well the phenomena of void defect formation. This is the first time such KLMC simulation results have been reported.     

Autosomal dominant inheritance of the DeMyer Sequence

Holoprosencephaly (HPC) may be an isolated trait or may be associated with other craniofacial defects. As an isolated trait, HPC has been reported to be inherited as an autosomal recessive, while autosomal dominant inheritance has been reported for sequences or syndromes in which HPC occurs. This paper presents a family in which several people have variable combinations of craniofacial defects. The most severely affected relatives have HPC, while others have only mild facial dysmorphia and decreased bitemporal diameters. One relative has a single central incisor in the maxilla. The pattern of defects in this family is inherited as an autosomal dominant. Other families with the reported pattern of defects, including single central incisors as minimal manifestations, are cited. Because HPC is found only occasionally in the pattern of defects, the term DeMyer Sequence is proposed as a more appropriate designator than the more commonly used Holoprosencephaly Sequence.     

Repair of major cranio-orbital defects with an elastomer-coated mesh and autogenous bone paste.

We present a method for repairing defects in the craniofacial region in which an elastomer-coated mesh is used as a template with bone paste. The method was developed by animal experimentation first, and then successfully used in the maxillofacial and mandibular regions. We have used this method to repair 16 craniofacial defects with satisfactory results, and complications have been kept to a minimum.     

Bone tissue engineering using marrow stromal cells

Bone tissue defects cause a significant socioeconomic problem, and bone is the most frequently transplanted tissue beside blood. Autografting is considered the gold standard treatment for bone defects, but its utility is limited due to donor site morbidity. Hence much research has focused on bone tissue engineering as a promising alternative method for repair of bone defects. Marrow stromal cells (MSCs) are considered to be potential cell sources for bone tissue engineering. In bone tissue engineering using MSCs, bone is formed through intramembranous and endochondral ossification in response to osteogenic inducers. Angiogenesis is a complex process mediated by multiple growth factors and is crucial for bone regeneration. Vascular endothelial growth factor plays important roles in bone tissue regeneration by promoting the migration and differentiation of osteoblasts, and by inducing angiogenesis. Scaffold materials used for bone tissue engineering include natural components of bone, such as calcium phosphate and collagen I, and biodegradable polymers such as poly(lactide-coglycolide) However, ideal scaffolds for bone tissue engineering have yet to be found. Bone tissue engineering has been successfully used to treat bone defects in several human clinical trials to regenerate bone defects. Through investigation of MSC biology and the development of novel scaffolds, we will be able to develop advanced bone tissue engineering techniques in the future.     

External oblique fasciocutaneous flap for elbow coverage

The external oblique fasciocutaneous pedicle flap can be used for reconstruction of soft-tissue defects of the elbow. This flap has been used in five patients, and results have been good. The technique is appropriate in patients with recurrent defects of the elbow in whom local tissue has been previously used and is no longer available. With the development of local fasciocutaneous units, this method may have limited application. However, because of the relationship of this flap to the elbow, the procedure can be done easily and rapidly with minimal immobilization. It is a clinical impression that blood supply to the skin is enhanced by elevation of its underlying fascia. Anatomic dissections have demonstrated that there is an axial-pattern blood supply to this flap arising from the lateral border of the external oblique muscle.     

Pullulan/dextran/nHA Macroporous Composite Beads for Bone Repair in a Femoral Condyle Defect in Rats

The repair of bone defects is of particular interest for orthopedic, oral, maxillofacial, and dental surgery. Bone loss requiring reconstruction is conventionally addressed through bone grafting. Depending on the size and the location of the defect, this method has limits and risks. Biomaterials can offer an alternative and have features supporting bone repair. Here, we propose to evaluate the cellular penetration and bone formation of new macroporous beads based on pullulan/dextran that has been supplemented with nanocrystalline hydroxyapatite in a rat model. Cross-linked beads of 300–500 µm diameters were used in a lateral femoral condyle defect and analyzed by magnetic resonance imaging, micro-computed tomography, and histology in comparison to the empty defects 15, 30, and 70 days after implantation. Inflammation was absent for both conditions. For empty defects, cellularisation and mineralization started from the periphery of the defect. For the defects containing beads, cellular structures filling out the spaces between the scaffolds with increasing interconnectivity and trabecular-like organization were observed over time. The analysis of calcified sections showed increased mineralization over time for both conditions, but was more pronounced for the samples containing beads. Bone Mineral Density and Bone Mineral Content were both significantly higher at day 70 for the beads in comparison to empty defects as well as compared with earlier time points. Analysis of newly formed tissue around the beads showed an increase of osteoid tissue, measured as percentage of the defect surface. This study suggests that the use of beads for the repair of small size defects in bone may be expanded on to meet the clinical need for a ready-to-use fill-up material that can favor bone formation and mineralization, as well as promote vessel ingrowth into the defect site.     

Effectiveness of a battery of tests to assess the potential mutagenic danger of chemical compounds

A new method for assessing the efficiency of batteries of arbitrary numbers of tests is proposed. The posterior probability of the mutagenicity of the substances studied has been estimated using discriminant analysis. The results of tests in each test system has been presented as the probability to obtain a positive result in the given test system. This has made it possible to decrease the sample size as the number of tests in the battery increased. As a result, prognostic power may be assessed even if the matrix of results is incomplete. This approach has been used to estimate the weights of evidence for mutagenic activities of 105 chemical compounds studied by means of a battery of four tests: Ames's test, the test for chromosome aberrations in vitro, the test for cytogenetic defects in vivo, and the test for dominant lethal mutations in rodents.     

Efficiency of Batteries of Tests for Estimating Potential Mutagenicity of Chemicals

A new method for assessing the efficiency of batteries of arbitrary numbers of tests is proposed. The posterior probability of the mutagenicity of the substances studied has been estimated using discriminant analysis. The results of tests in each test system has been presented as the probability to obtain a positive result in the given test system. This has made it possible to decrease the sample size as the number of tests in the battery increased. As a result, prognostic power may be assessed even if the matrix of results is incomplete. This approach has been used to estimate the weights of evidence for mutagenic activities of 105 chemical compounds studied by means of a battery of four tests: Ames's test, the test for chromosome aberrations in vitro, the test for cytogenetic defects in vivo, and the test for dominant lethal mutations in rodents.     

Neural tube defects: a review of human and animal studies on the etiology of neural tube defects

Although neural tube defects are a common congenital anomaly, their etiology is not known. Human studies have emphasized the pathology and epidemiology of the defects and suggest that in the majority of cases the etiology is multifactorial. Factors which appear possibly to be important are genetic predisposition, maternal illness, and fetal drug exposure. Animal studies have utilized naturally occurring neural tube defects and teratologically induced lesions. No animal model has been convincingly established as the equivalent of human neural tube defects. However, animal models have allowed investigation of the mechanisms of suggested human teratogens and determination of the pathogenesis of naturally occurring animal defects. Their most important contribution has been in furthering the understanding of the normal mechanisms of neural tube closure. It may be through this understanding that the etiology of human neural tube defects will be determined.     

Abdominal wall expansion in congenital defects

A method for expanding the skin, fascia, muscle, and peritoneal layers of the abdominal wall is described, and clinical application is demonstrated in two children with cloacal exstrophy and congenital absence of the lower half of the abdominal wall. This technique provides an innervated composite reconstruction of defects in excess of 50 percent of the abdominal surface and is recommended in large secondary defects where peritonealization has been achieved and in congenital defects that do not lend themselves to standard methods of closure. Cadaver dissection confirms that tissue expanders may be placed with preservation of innervation and blood supply to the abdominal wall.     

Molecular cloning and analysis of the CRY1 gene: a yeast ribosomal protein gene.

Using cloned DNA from the vicinity of the yeast mating type locus (MAT) as a probe, the wild type allele of the cryptopleurine resistance gene CRY1 has been isolated by the technique of chromosome walking and has been shown to be identical to the gene for ribosomal protein 59. A recessive cryR1 allele has also been cloned, using the integration excision method. The genetic distance from MAT to CRY1 is 2.2 cM, while the physical distance is 21 kb, giving a ratio of about 10 kb/cM for this interval. The phenotypic expression of both plasmid borne alleles of the gene can be detected in vivo. The use of this gene as a hybridization probe to examine RNA processing defects in the rna 2, rna 3, rna 4, rna 8, and rna 11 mutants is also discussed.     

The internal oblique muscle flap: an anatomic and clinical study

A new muscle flap based on the ascending branch of the deep circumflex iliac artery is described. Twenty internal oblique muscle flaps have been dissected and studied in 10 fresh cadavers. This muscle flap has been used successfully as a free-tissue transfer in seven lower extremity defects. There was one loss of flap due to venous thrombosis. Other complications included a local wound abscess (one case), partial loss of skin graft (two cases), and arterial thrombosis (one case). There has been no donor-site morbidity. The donor scars are well concealed and no hernias have been observed, the longest follow-up being 9 months. The additional advantages of this flap include its thin, flat shape, excellent vascularity, and ease of application to areas about the ankle, with good aesthetic results. The disadvantages are (1) bloody and tedious dissection and (2) potential for abdominal weakness or hernia in the long run. This muscle flap appears to be excellent as a free flap for coverage of small- to moderate-sized defects of the distal lower extremity and as a pedicle flap for coverage of soft-tissue defects of the groin and anterior perineum.     

Isolation of motile and non-motile insertional mutants of Campylobacter jejuni: the role of motility in adherence and invasion of eukaryotic cells

A method of insertional mutagenesis for naturally transformable organisms has been adapted from Haemophilus influenzae and applied to the study of the pathogenesis of Campylobacter jejuni. A series of kanamycin-resistant Insertional mutants of C. jejuni 81–176 has been generated and screened for loss of ability to invade INT407 cells. Eight noninvasive mutants were identified which showed 18-200-fold reductions in the level of invasion compared with the parent. Three of these eight show defects in motility, and five are fully motile. The three mutants with motility defects were further characterized to evaluate the method. One mutant, K2–32, which is non-adherent and non-invasive, has an insertion of the kanamycin-resistance cassette into the flaA flagellin gene and has greatly reduced motility and a truncated flagellar filament typical of flaA mutants. The adherent non-invasive mutants K2–37 and K2–55 are phenotypically paralysed, i.e. they have a full-length flagellar filament but are non-motile. All three mutants show an aberration in flagellar structure at the point at which the filament attaches to the cell. Mutants K2–37 and K2–55 represent overlapping deletions affecting the same gene, termed pflA (paralysed flagella). This gene encodes a predicted protein of 788 amino acid residues and a molecular weight of 90 977 with no significant homology to known proteins. Site-specific insertional mutants into this open reading frame result in the same paralysed flagellar phenotype and the same invasion defects as the original mutants.     

Detection of structural defects in phosphatidylcholine membranes by small-angle neutron scattering. The cluster model of a lipid bilayer

The oriented DPPC multilayers hydrated by D2O have been studied by a small-angle neutron scattering method in the Guinier range, and the gyration radius of the structural inhomogeneities has been estimated at about 29 A. They are interpreted as the annular defects between adjacent clusters uniting the all-trans chain 'segments' adjacent to the polar head group regions. The angle of the 'segment' tilt is determined by the hydrated polar group area (59.2 A2 for DPPC bilayers) and has been estimated to be about 44 degrees under the given experimental conditions. The hydrocarbon interior of a bilayer can be suggested as a 'sandwich' that is formed by two clustered layers (approx. 7 A of the thickness) and the central disordered (liquid) layer. The average cluster size along the bilayer surface is estimated to be approx. 24 A which correlates with the estimations of the short order region dimensions from the halfwidth of the X-ray 'packing' reflex (4.6 A)-1. The average interchain separation of approx. 5 A and the average cross-section area of a chain in a cluster (21.4 A2) were estimated from the reflex position and the chain cross-section geometry. The total volume of defects and the fraction of a bilayer surface occupied by them were estimated too.