Avirulence (AVR) Gene-Based Diagnosis Complements Existing Pathogen Surveillance Tools for Effective Deployment of Resistance (R) Genes Against Rice Blast Disease

Avirulence (AVR) genes in Magnaporthe oryzae, the fungal pathogen that causes the devastating rice blast disease, have been documented to be major targets subject to mutations to avoid recognition by resistance (R) genes. In this study, an AVR-gene-based diagnosis tool for determining the virulence spectrum of a rice blast pathogen population was developed and validated. A set of 77 single-spore field isolates was subjected to pathotype analysis using differential lines, each containing a single R gene, and classified into 20 virulent pathotypes, except for 4 isolates that lost pathogenicity. In all, 10 differential lines showed low frequency (<24%) of resistance whereas 8 lines showed a high frequency (>95%), inferring the effectiveness of R genes present in the respective differential lines. In addition, the haplotypes of seven AVR genes were determined by polymerase chain reaction amplification and sequencing, if applicable. The calculated frequency of different AVR genes displayed significant variations in the population. AVRPiz-t and AVR-Pii were detected in 100 and 84.9% of the isolates, respectively. Five AVR genes such as AVR-Pik-D (20.5%) and AVR-Pik-E (1.4%), AVRPiz-t (2.7%), AVR-Pita (0%), AVR-Pia (0%), and AVR1-CO39 (0%) displayed low or even zero frequency. The frequency of AVR genes correlated almost perfectly with the resistance frequency of the cognate R genes in differential lines, except for International Rice Research Institute-bred blast-resistant lines IRBLzt-T, IRBLta-K1, and IRBLkp-K60. Both genetic analysis and molecular marker validation revealed an additional R gene, most likely Pi19 or its allele, in these three differential lines. This can explain the spuriously higher resistance frequency of each target R gene based on conventional pathotyping. This study demonstrates that AVR-gene-based diagnosis provides a precise, R-gene-specific, and differential line-free assessment method that can be used for determining the virulence spectrum of a rice blast pathogen population and for predicting the effectiveness of target R genes in rice varieties.

[Achondroplasia and hypochondroplasia in paediatric orthopaedics]

Achondroplasia and hypochondroplasia are the most common forms of short stature. The leading sign is the diminished body height. Most cases of achondroplasia can be detected by clinical examination. Hypochondroplasia is more often not diagnosed until preschool age.In achondroplasia many different orthopaedic problems can arise, which influence the ADL. Mainly pathologic alterations of the occipitocervical region or a stenosis of the medullary cavity should be expected. In the limbs a bow-leg deformity and hyperlaxity of the ligaments often can be seen, which in some cases restrict walking capacity. Even if many people of short stature contemplate a lengthening procedure, the correction of deformities is much more important. The CORA method should be used in planning any osteotomy.

Pulsed low-intensity ultrasound: a new salvage procedure for delayed unions and nonunions after leg lengthening in children

From 1998 to 2001, 112 lengthening procedures with or without deformity correction were performed in 108 children by external fixation with the Ilizarov method. Of these cases, 16.9% did not lead to a solid bone consolidation. Two children were operated the second time, mainly because of the parent's decision. Seventeen delayed unions or nonunions in 13 children were treated with low-intensity pulsed ultrasound. All 17 cases healed within 3 to 12 months without any risk of surgical intervention.

Kindliche Fußfehlformen

During the skeletal development of the axis and foot of the child physiological specialties can occur. Those are thick fatty sole, increased valgus in the ankle joint, tibial varus as a toddler with first varus, later on valgus in the knee, increased laxity of the ligaments, increased anteversion of the femoral neck with "kneeing in" and "toeing in", and with knees first in flexion, later on hyperextension. The knowledge of those specialties is important to be able to diagnose and treat deformities of the foot during childhood. Included are club foot, flexible flatfoot, vertical talus, pes adductus, equinus, cavus foot and talipes calcaneovalgus. If treated at the right time, those disorders of the feet can resolve completely. If an operation can't be avoided, the indication has to be chosen with care.

[Limb lengthening in dwarfism]

Limb lengthening in dwarfism has become a standardised procedure with a good prognosis. In most cases external fixation is used. Gain of leg length up to 15 cm and more is possible in the lower leg and the femur and 8.5 cm in the humerus. Limb lengthening is useful in many cases of dwarfism due to skeletal dysplasia. There are a number of risks and possible complications involved and the procedure also requires considerable time. We report the results of 48 patients with dwarfism operated on in the Orthopädische Kinderklinik Aschau (Orthopaedic Hospital for Children). It must not be recommended as a normal tool in handling the problems of dwarfism, but it makes sense in some cases of dwarfism. We describe and discuss the prerequisites for the operative treatment.

The effect of soft tissue release of the hips on walking in myelomeningocele

Walking and standing capacity in myelomeningocele is highly dependent on the level of the neurological lesion. Deformities, mainly flexion deformities, of the hip can severely interfere with mobility. In a retrospective study, undertaken in our hospital, we evaluated the role of soft tissue release of the hip in patients with hip flexion contractures. A special surgical technique was performed in 55 hips. The results show a good effect on verticalization, even if the hip joints cannot be extended actively. A subluxated or dislocated hip did not influence the final outcome. During the mean follow-up of approximately 4 years, only a slight recurrence of the former deformity was observed. Most of the patients obtained great advantage from the operation.

Social, emotional, and behavioral functioning of children with cancer

OBJECTIVE

It was hypothesized that children with cancer would have more social problems and difficulties with emotional well-being than case control, same race/gender, similarly aged classmates.

STUDY DESIGN

Using a case controlled design, children with any type of cancer requiring chemotherapy except brain tumors (n = 76), currently receiving chemotherapy, ages 8 to 15, were compared with case control classroom peers (n = 76). Peer relationships, emotional well-being, and behavior were evaluated based on peer, teacher, parent, and self-report, and were compared using analysis of variance and structural equation modeling.

RESULTS

Relative to case controls, children with cancer were perceived by teachers as being more sociable; by teachers and peers as being less aggressive; and by peers as having greater social acceptance. Measures of depression, anxiety, loneliness, and self-concept showed no significant differences, except children with cancer reported significantly lower satisfaction with current athletic competence. There were also no significant differences in mother or father perceptions of behavioral problems, emotional well-being, or social functioning. Scores on all standardized measures were in the normal range for both groups. Comparisons of the correlation matrices of children with cancer and to the correlation matrix of the comparison children using structural equation modeling suggested they were not significantly different.

CONCLUSIONS

Children with cancer currently receiving chemotherapy were remarkably similar to case controls on measures of emotional well-being and better on several dimensions of social functioning. These findings are not supportive of disability/stress models of childhood chronic illness and suggest considerable psychologic hardiness.

Hemimelia in Brachmann-de Lange syndrome (BDLS): a patient with severe deficiency of the upper and lower limbs

We report on a male infant with Brachmann-de Lange syndrome (BDLS) and ulnar hemimelia and monodactyly but also absence of both tibiae, the right distal femur being bifurcated. One similar observation was published earlier. The question is raised whether these malformations are coincidental or a rare component of BDLS.

Surgical correction of short stature in skeletal dysplasias

Limb lengthening has been undertaken in patients with short stature, including achondroplasia, hypochondroplasia and other skeletal dysplasias. The procedure consists of osteotomy of the tibia and fibula, and fixation of the limb using an external unilateral or circular fixator. Distraction (elongation) begins 1 week postoperatively, and during distraction osseous autoregeneration occurs. Consolidation of the autoregenerate takes about twice the time needed for lengthening, and the fixator is gradually mobilized during this time to allow greater weight-bearing. In 26 patients with short stature, the mean length gain was 10.1 cm (range, 7.3-14.8 cm). Transient deviation of the limb axis was observed in 80% of the patients, but reoperation was necessary only in 15%. Other complications included transient pain (70%), infection (45%), torn wires (40%), drop foot (35%), and stiffness of the ankle (30%) or the knee (15%). Not only must the possible length gain be judged, but it must also be ensured that no loss of function occurs.

[Hip joint changes in meningomyelocele]

With an incidence of approx. 2% among newborns, meningomyelocele is a rarely encountered condition. Its clinical manifestations vary within very wide limits, ranging from minor disability to extremely severe limitation of physical function. The function of the trunk muscles and of the lower extremities, and especially that of the hip joints, is impaired to different degrees in the patients affected, depending on the severity of the paralysis. The changes associated with meningomyelocele are typical, and the therapeutic principles adopted will usually depend on individual findings. Taking the disability into account, the primary goal must be to achieve optimal function. The value of imaging procedures is secondary to this consideration. In recent years a number of conventional therapeutic principles have undergone substantial modifications.

The state of technical orthopaedics in spina bifida

The Aschau experiences with different types of functional orthosis in children with MMC are described. The new type of orthosis allows maximal function and especially in lower level lesions, independent walking and free standing. The majority of the patients walk without help so that they have free hands. This helps them to accept the orthosis. The choice of the patients who are fitted with the functional orthosis must be very skillful.

[Closed distraction epiphysiolysis for leg lengthening and axis correction of the leg in children]

The distraction-epiphyseolysis is a method of leg-lengthening and allows to correct leg-deformities. A daily lengthening of 1 mm enhances ossification and enables a maximum lengthening of 8-10 cm. The indications, contra-indications and the method are described.

Amputations and prostheses for the lower limb

Amputations in the lower limb are now carried out principally in the elderly because of vascular disease. The management and rehabilitation of the amputee is best achieved by a team approach with the close cooperation of the different disciplines. Attention should be paid to the psychological state of the patient who should be encouraged to mobilise as soon as possible. Prosthesis design and manufacture has changed greatly in recent years. Widespread use is now made of lightweight plastic materials. Modern technology is being applied to the design and manufacture of prostheses, with increasing use of modular systems of components.

[The post-traumatic frozen shoulder]

The post-traumatic frozen shoulder is a sickness which develops relatively frequently following even small injuries of the shoulder joint. The particular anatomic conditions of this joint are the cause of its frequent lesions. After an injury typical pathological changes in function are observed. Most common injuries are distorsions, contusions, luxations and especially in increasing age the subcapital fractures of the humerus. Other injuries as there are rupture of the acromio-clavicular joint, fractures of the clavicle or scapula may also cause a frozen shoulder. The clinical examination is most important as it is the basis of the therapy. The current procedure consists of intensive physical therapy. If this treatment is not successful other ways must be discussed, e.g. mobilisation under anaesthesia. Operative treatment has a very strict indication. Medico-legal points of view of the frozen shoulder are difficult but a connection between injury and degenerative changes ought not to be denied in clear cases.

Neuropathological changes in cerebellar biopsies of epileptic patients

In 5 patients with pharmacologically intractable epilepsy, biopsy of the cerebellar cortex at the time of surface electrode implantation for therapeutic stimulation demonstrated marked degeneration of the Purkinje cell layer in every case. Two of the patients had never experienced a generalized convulsion. Comparison of these biopsy findings with the autopsy findings in two other groups of patients with a seizure disorder of different duration and severity and with the findings in other reported series suggests that permanent neuronal damage in epilepsy is related to the cumulative effects of the frequency and chronicity of the disorder. The pathogenesis remains unclear. The histopathological changes are identical to those seen in generalized cerebral hypoxia, but the observations in our series support the view that in epilepsy the pathogenesis may not be hypoxic.