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Nude Gene Transfer And Remutation
Published in Miroslav Holub, Immunology of Nude Mice, 2020
Also, the viability of the athymic-asplenic mouse (lasat) was surprisingly good in SPF conditions and using outbred mice of the N:NIH(s) background.2,3 Hereditary asplenic mice (Dh/ +) manifest a decrease in the numbers of B cells in all lymphatic tissues and a retardation of T-cell maturation4,5 caused by the absence of spleen. Also, major abnormality of the hind legs, hemimelia, is caused by the Dh gene. Athymic-asplenic mice survived up to 9 months without any increased risk for spontaneous tumors. IgA levels in sera were increased compared to nu/nu; also IgG1 and IgG2 levels were elevated whereas IgM was considerably lower than in nu/nu.5 Thy 1.2 + cells were reduced compared to nu/ + or Dh/ + littermates, however significantly higher than in nu/nu, especially in Peyer’s patches and lymph nodes. On the other hand, the bone marrow content of CFU-C, i.e., monocyte and granulocyte precursors, was elevated in athymic-asplenic mice compared to Dh/+ and equal to the nu/nu figures. Leukopenia was similar to the nu/nu counts. The antibody response to sheep red blood cells and the mitogenic action of PHA were reduced as in the nu/nu mouse.5
Microdeletion Syndromes
Published in Merlin G. Butler, F. John Meaney, Genetics of Developmental Disabilities, 2019
Gopalrao V. N. Velagaleti, Nancy J. Carpenter
Malocclusion and dental abnormalities are common. There is marked laxity of the skin in infancy and early childhood, which diminishes with age. Cone-shaped epiphyses, particularly in the hands, are noted in radiographs in early childhood (Fig. 10). Multiple cartilaginous exostoses (bony growths from the surfaces of various bones) first develop between 1 and 5 years of age. They can occur on the ribs, flat bones, tubular bones, and the vertebrae. Other frequent abnormalities include hyperextensible joints, winged scapulae, pes planus and/or other foot deformities, scoliosis, narrow posterior ribs, and abnormal or brittle nails. Heart defects and bilateral tibial hemimelia have been reported in a few patients (65). Birth weights and lengths are in the range of 15–20% of normal, and the head circumference at birth is also normal (64). Feeding difficulties occur in infancy. Slow postnatal growth results in short stature in all patients, and microcephaly is seen in 85% of the patients (64).
Fibular hemimelia
Published in Benjamin Joseph, Selvadurai Nayagam, Randall Loder, Ian Torode, Paediatric Orthopaedics, 2016
Fibular hemimelia is a relatively common deficiency of the lower extremity. The incidence rate is about one or two per 100 000 live births. Although fibular hemimelia can occur as an ‘isolated’ deficiency, it is the author’s belief that one should treat all children with fibular deficiency as having whole limb involvement to a greater or lesser extent (Figure 35.1a,b). As noted in Chapter 37, Congenital short femur and proximal focal femoral deficiency, fibular hemimelia is associated with femoral deficiency in 50 percent of cases (Figure 35.1c). Fibular hemimelia can be classified into types I and II: type I is mere fibular hypoplasia or partial absence of the fibula and type II is complete absence of the fibula.1 While it is traditional to name the deficiency by the major bone absence, in fibular hemimelia, the extent of involvement of the other bones of the limb often dictates management.
Current opinion in the molecular genetics of Adams-Oliver syndrome
Published in Expert Opinion on Orphan Drugs, 2019
First described by Forrest H. Adams and Clarence P. Oliver in 1945 as ‘arrested development’ of the extremities and skull, Adams–Oliver syndrome (AOS) is distinct from congenital amputations due to its Mendelian inheritance pattern and association with a characteristic focal absence of epidermis on the scalp vertex [1]. The family in this original case report epitomizes an important feature of the condition, namely variable expression of the phenotype within families. Terminal transverse limb defects (TTLD) is typically asymmetrical and can range in severity from mild digit shortening to complete absence of the hands or feet. Brachydactyly, syndactyly, and hemimelia have also been documented [1,2]. Similarly, aplasia cutis congenita (ACC) varies in diameter from <1 to >10 cm and can occur with or without an underlying skull defect. Both TTLD and ACC may manifest as isolated defects and a complete absence of clinical features in obligate gene carriers supports reduced penetrance of the disease allele, representing a diagnostic challenge. Given such variability in phenotypic expression, the following criteria are recommended as compatible with a diagnosis of AOS: (a) clinical findings of a combination of scalp ACC and TTLD; (b) ACC and/or TTLD and an affected first-degree relative; (c) ACC and/or TTLD in conjunction with identified mutation in a recognized AOS-related gene (Table 1) [2].
Femoral lengthening might impair physical function and lead to structural changes in adjacent joints: 10 patients with 27 to 34 years’ follow-up
Published in Acta Orthopaedica, 2021
Patrick A Bjørge, Anne-Therese Tveter, Harald Steen, Ragnhild Gunderson, Joachim Horn
We conducted a cross-sectional study of 10 patients treated with unilateral femoral lengthening between 1985 and 1992. Patients were enrolled into the study during the period March–October 2019. Inclusion criteria were isolated unilateral femoral lengthening by the callotasis technique and a minimum of 15 years’ follow-up after completed lengthening—the time considered necessary to detect radiographic secondary OA changes (Schouten et al. 1992). All 50 patients who had undergone isolated femoral lengthening by the callotasis technique between 1977 and 2003 at Oslo University Hospital were identified based on protocols from the surgical department. Patients with inserted knee or hip prosthesis or any condition besides shortening that could lead to alteration of function or joint cartilage were excluded from the study. These conditions included: all cases of congenital limb shortening with concurrent axis deviation, malrotation or affection of cruciate ligaments or hip, knee, or foot deformity (proximal focal femoral deficiency/congenital femoral deficiency, fibula hemimelia, tibia hemimelia, pes equino varus). Furthermore, cases of acquired shortening with any condition that could have altered function or joint cartilage in the long term were excluded. These conditions included: hip dysplasia, Perthes disease, epiphysiolysis capitis femoris, posttraumatic shortening with joint involvement, and post-infectious shortening after septic arthritis. Patients undergoing lengthening using the Wagner method (from 1977 to 1985) were also excluded, as this method is not based on the principles of the callotasis technique. The inclusion criteria left us with cases of pure shortening due to either idiopathic leg length discrepancy, posttraumatic shortening without joint involvement either at the time of injury or at follow-up, or congenital hypoplasia or hyperplasia without axis deviation, or any pathology at the hip, knee, or foot. Following our strict inclusion criteria, 16 patients out of 50 were found to be eligible for inclusion of whom 10 consented to participate in the study (Figure 1 and Table 1, see Supplementary data).
Systematic review of complications with externally controlled motorized intramedullary bone lengthening nails (FITBONE and PRECICE) in 983 segments
Published in Acta Orthopaedica, 2020
Markus W Frost, Ole Rahbek, Jens Traerup, Adriano A Ceccotti, Søren Kold
To our knowledge, this is the first systematic review on complications related to bone lengthening nails. The primary outcome was the risk of type IIIB complications resulting in a new pathology or permanent sequelae. This review found such IIIB complications in 3% of lengthened segments. Furthermore, a complication of any type was found in 34% of lengthened segments, and 5% of segments did not achieve the planned lengthening due to a complication (IIIA). In 15% of segments treated with intramedullary PRECICE and FITBONE lengthening nails, a complication (II) resulted in substantial change in treatment, such as unplanned re-surgery. 6% (11/177) of time-determined complications occurred intra- or perioperatively prior to start of distraction, and 94% of complications (166/177) occurred during or after the end of distraction. The high diversity of complications demonstrates that several means must be applied to reduce the high number of complications in intramedullary bone lengthening. Concerning the primary outcome, where the (type IIIB) complication resulted in a new pathology or permanent sequelae, the majority of complications were a result of joint-related complications such as contracture, subluxation, or dislocation. It is likely that a reduction in joint-related complications is accomplished by improved patient selection and attention to soft-tissue release as well as individualized protocols for lengthening, temporary extraarticular screw arthrodesis, splints/orthoses, or physiotherapy. The risk of joint subluxation and dislocation was 6 and 1 per 1,000 segments, respectively. Joint contracture was seen in 5% (53/983) of the segments, and primary soft-tissue release might be a key to address this complication; this was, however, only reported in 5 of the 41 studies (Shabtai et al. 2014, Paley et al. 2015, Laubscher et al. 2016, Rozbruch 2017, Calder et al. 2019). Calder et al. made a systematic division of the iliotibial band (ITB) if the planned lengthening was above 3 cm. They found that, in femoral lengthening, females lost joint movement in the hip and knee earlier than males. Moreover, it took substantially more time to regain range of motion in patients treated with retrograde compared with antegrade nails. However, we believe that higher rates of severe joint complications must be anticipated in high-risk patients such as congenital femoral deficiency and fibular hemimelia. We believe there is a need for systematic reporting of primary soft-tissue release as there is a lack of knowledge of benefits and challenges concerning this issue.