Spontaneous Mutation in the Movement Protein of Citrus Leprosis Virus C2, in a Heterologous Virus Infection Context, Increases Cell-to-Cell Transport and Generates Fitness Advantage.

Previous results using a movement defective alfalfa mosaic virus (AMV) vector revealed that citrus leprosis virus C (CiLV-C) movement protein (MP) generates a more efficient local movement, but not more systemic transport, than citrus leprosis virus C2 (CiLV-C2) MP, MPs belonging to two important viruses for the citrus industry. Here, competition experiment assays in transgenic tobacco plants (P12) between transcripts of AMV constructs expressing the cilevirus MPs, followed by several biological passages, showed the prevalence of the AMV construct carrying the CiLV-C2 MP. The analysis of AMV RNA 3 progeny recovered from P12 plant at the second viral passage revealed the presence of a mix of progeny encompassing the CiLV-C2 MP wild type (MPWT) and two variants carrying serines instead phenylalanines at positions 72 (MPS72F) or 259 (MPS259F), respectively. We evaluated the effects of each modified residue in virus replication, and cell-to-cell and long-distance movements. Results indicated that phenylalanine at position 259 favors viral cell-to-cell transport with an improvement in viral fitness, but has no effect on viral replication, whereas mutation at position 72 (MPS72F) has a penalty in the viral fitness. Our findings indicate that the prevalence of a viral population may be correlated with its greater efficiency in cell-to-cell and systemic movements.

Modification of bacterial nanocellulose properties through mutation of motility related genes in Komagataeibacter hansenii ATCC 53582.

Bacterial nanocellulose (BNC) produced by Komagataeibacter hansenii has received significant attention due to its unique supernetwork structure and properties. It is nevertheless necessary to modify bacterial nanocellulose to achieve materials with desired properties and thus with broader areas of application. The aim here was to influence the 3D structure of BNC by genetic modification of the cellulose producing K. hansenii strain ATCC 53582. Two genes encoding proteins with homology to the MotA and MotB proteins, which participate in motility and energy transfer, were selected for our studies. A disruption mutant of one or both genes and their respective complementation mutants were created. The phenotype analysis of the disruption mutants showed a reduction in motility, which resulted in higher compaction of nanocellulose fibers and improvement in their mechanical properties. The data strongly suggest that these genes play an important role in the formation of BNC membrane by Komagataeibacter species.

Comparison of radiographic stress tests for syndesmotic instability of supination-external rotation ankle fractures: a cadaveric study.

OBJECTIVE: According to the classification of Lauge-Hansen, supination-external rotation IV (OTA 44-B) injuries should not have syndesmotic instability; yet, several studies have suggested disruption is present in up to 40% of these injuries based on stress tests. In this study, we examine various stress radiographic parameters in a cadaver model of supination-external rotation IV equivalent injury. We hypothesize that external rotation stress testing and widening of the medial clear space do not always represent syndesmotic instability. Rather, the better predictor of syndesmotic instability will be an increased tibia-fibula clear space with the lateral stress test. METHODS: Eleven fresh frozen human lower limbs were each secured into a custom frame. External rotation stress test was performed by applying an external moment of 7.5 Nm, and lateral stress test was performed by applying 100 N lateral pull at the distal fibula. True mortise radiographs were taken of intact ankles and while performing external rotation and lateral stress tests at each stage of sequentially sectioning the ankle ligaments. The deltoid ligament was sectioned first, then anterior-inferior tibiofibular ligament, posterior-inferior tibiofibular ligament, and interosseous membrane. Tibiofibular clear space and medial clear space were measured on each radiograph. RESULTS: External rotation stress test produced significant medial clear space widening when the deltoid ligaments were sectioned (P < 0.05). Lateral stress test produced no significant widening of the tibiofibular clear space until interosseous membranes were sectioned (P < 0.05). CONCLUSIONS: Lateral stress test with widening of the tibiofibular clear space is the preferred indicator of syndesmotic instability. The external rotation stress is a poor indicator of syndesmotic injury in the setting of deltoid ligament injury.

Retrospective analysis of malleolar fractures in an impact environment.

To protect against malleolar fractures in frontal crashes it is important to understand the mechanisms of injury. We have investigated the accuracy of Orthopaedic Specialists in deducing the injury mechanisms of experimentally generated malleolar fractures from radiographs; and the applicability of classic descriptors of injury mechanisms, such as the Lauge-Hansen classification system, in analysing impact induced trauma. Orthopaedic Specialists did not consistently deduce the mechanism of ankle injuries suggesting there may not be a unique fracture pattern for every injury mechanism and that the Lauge-Hansen classification system does not reliably describe ankle fractures created in the impact environment.

Quickly tapping targets that are flashed during smooth pursuit reveals perceptual mislocalisations.

In various studies subjects have been shown to misperceive the positions of targets that are flashed during pursuit eye movements. They mislocalise them in the direction of pursuit. Nevertheless, Hansen (1979) found that subjects accurately hit targets that are flashed during pursuit with a quick hammer blow. We examined whether this is because there is a fundamental difference between the information that determines our perceptual judgements of a target's position and the information that is used to guide our hand to a similar target. Subjects were asked to quickly tap targets that were flashed during pursuit with their index finger. They systematically tapped ahead of the position of the flash, in accordance with the above-mentioned perceptual mislocalisations. Thus the lack of systematic errors in Hansen's study is not a general property of fast motor responses.

A cirurgia de Smith na perda do movimento de aduçäo do polegar / Smith's surgery in the loss of the thumb adduction movement

Os autores analisam os resultados obtidos pela técnica cirúrgica descrita por Smith, que consiste na transferência do tendäo extensor radial curto do carpo para o tendäo do músculo adutor do polegar em sete pacientes com incapacidade da realizaçäo do movimento de aduçäo do polegar, devido à lesäo traumática do nervo ulnal (qatro casos) e neuropatia ulnal (três casos) causada pelo mal de Hansen.

[Correction of the Hansen claw hand using direct Zancolli lasso procedures and 2 of its variations]. / Correction des griffes cubitales hanséniennes par le procédé du "lasso de Zancolli" direct et par deux de ses variantes.

The procedure of the Zancolli "Lasso" or V direct Zancolli uses a flexor superficialis tendon which after a distal section is turned inside out and is fixed on itself after forming a loop around the proximal pulley of the sheath of the flexor. The mode of distal fixation being the same, the authors also study two different methods which resort either to one tendon for two, three or four fingers, or only to one strip of the flexor tendon for one finger. 45 cases of this kind of operation are reported. In the most important series in which the principle procedure has been used, the results are good in 80% of the mobile claws and average in 70% of the stiffened claws. The cases operated according to the two different methods, less numerous, give approximately the same results. The suggested indications are in favour of the changes in the procedure.

A new approach in muscle training to rehabilitate the hand in leprosy.

Rehabilitation of the hand in Leprosy with its deformities and anaesthesia no doubt poses a formidable challenge as far as rehabilitation is concerned. Here we have applied a combination of latest concepts in sports physiology and the exercise followed by the students of ancient Indian martial art known as Krishni Vidya. This exercise consists of crumpling a newspaper sheet with a single hand without any external support. We are unable to explain the type of exercise done by the people before existence of newspaper. They might be using naturally occurring materials for the same like woodbark. With this exercise we have been able to improve the function of the hand remarkably well and the rehabilitation time following surgery is drastically reduced, with function returning close to normalcy. The full function is achieved within four weeks from the date of removal of plaster as compared to eight to ten weeks or more with conventional physical therapy. This full function is not only in mobility but also in co-ordination, static and dynamic strength, speed of movement and flexibility required of a normal hand. 16 patients operated for lumbrical replacement (using sublimis as a motor from the long finger) at the Dr. Bandorawalla Leprosy Hospital were put under the paper crumpling exercise. It was observed that the average time for the achievement of fully close fist was two weeks. (All of them had thumb function intact, i.e. either normal or operated-out of sixteen, four patients were operated for opponens prior to lumbrical replacement).

Clawfinger correction: results of extensor-flexor many tailed operation.

The patient with paralytic clawfingers is greatly handicapped. This is especially true for the leprosy patient who needs his hands to earn a living. The inability to 'reach out' with the fingers is the most serious functional loss in an ulnar palsy. This study is a follow up of 155 hands whereby the extensor carpi radialis longus was employed to substitute for this lumbrical-interosseus function. The best results were obtained in hands with full assisted extension. Retropulsion of the metacarpal arch occurred in all hands with total loss of ulnar function.

Radiological and muscular status following injury to the lateral ligaments of the ankle. Follow-up of 144 patients treated conservatively.

An average of 4.2 years after conservative treatment of injury to the lateral ligaments of the ankle 144 patients attended a follow-up examination which included radiography and measurement of the strength of plantar flexion. Prior to treatment all of the patients had a difference in talar tilt of 6 or more degrees between the injured and uninjured side. At follow-up there was instability in 28 patients, or 19.4 per cent, but no correlation between instability and residual symptoms. Nine patients had an anterior "drawer sign" exceeding 2 mm, but this was also without relation to residual symptoms. Radiological evidence of osteoarthrosis was found in five patients, but four of them had a stable ankle joint and only one had residual symptoms. The mean age of the patients with osteoarthrosis was twice that for the entire material. Two patients had osteochondritis of the talus. The strength of plantar flexion was measured in 124 patients. There was significantly less strength in the injured than in the uninjured leg, but there was no statistically significant correlation between residual symptoms and reduced strength or between radiological instability and reduced strength. According to the results of the present study and a previous one (Hansen et al. 1979) and to the results reported in the literature, we find no reason to alter our present principles regarding the diagnosis and conservative treatment of injury to the lateral ligaments of the ankle.

Movement patterns of interosseus-minus fingers.

The patterns of isolated metacarpophalangeal-joint flexion and isolated interphalangeal-joint extension movements in eighty fingers with intact extrinsic and lumbrical muscles but no interossei (so-called interosseus-minus fingers) were studied. The pattern of metacarpophalangeal flexion resembled that seen in fingers with paralysis of all intrinsic muscles. From this it was inferred that in the interosseus-minus finger the lumbrical muscles are inactive during this movement. The pattern of isolated interphalangeal extension in the interosseus-minus fingers showed an improvement over that in totally intrinsic-minus fingers, suggesting that the lumbrical muscles reduce the extending forces at the metacarpophalangeal joint to some extent. Active participation of the interosseus muscles appears to be necessary for carrying out the movements of isolated metacarpophalangeal flexion and interphalangeal extension.

Movement patterns of intrinsic minus fingers. Role of intrinsic and extrinsic muscles in finger posture control.

A detailed study of the patterns of two movements (pure metacarpophalangeal flexion and pure interphalangeal extension) in intrinsic minus fingers shows that the long extensors and long flexors produce simultaneous movement at the metacarpophalangeal and interphalangeal joints. A comparison of the patterns of these movements in totally intrinsic minus and interosseous minus fingers shows that in the latter the lumbricals are probably largely inactive during attempted pure metacarpophalangeal flexion and contribute to restrain metacarpophalangeal extension considerably during attempted pure interphalangeal extension. Active participation by the interosseous muscles appears necessary for completing these movements.

Patterns of movement of totally intrinsic-minus fingers based on a study of one hundred and forty-one fingers.

A detailed study of metacarpophalangeal flexion and interphalangeal extension movements of 141 fingers with complete intrinsic-muscle paralysis due to leprosy showed that long flexors and long extensors produce movement at the metacarpophalangeal and proximal interphalangeal joints simultaneously, and not successively as is generally believed. The amounts of flexion resulting from long flexor activity are almost equal at the two joints and metacarpophalangeal flexion is achieved without excessive flexion of the proximal interphalangeal joint, but this is masked by the claw-finger deformity. The movement resulting from activity of the long extensor is complex and there are three or more qualitatively different patterns of extension. Although the long extensor produces simultaneous extension at the metacarpophalangeal and proximal interphalangeal joints, the latter consistently lags behind the former so that full extension is not achieved at the proximal interphalangeal joint even when the metacarpophalangeal joint is maximally extended. The diverse patterns of extension are not related to duration of degree of clawing or to any particular finger.

Opponensplasty in intrinsic-muscle paralysis of the thumb in leprosy.

For eighty-six cases of leprous paralysis of the intrinsic muscles of the hand, a modified Bunnell opponensplasty (transfer of a finger flexor) was done. Good results were seen in eighteen and fair results in sixty-three. The five poor results occurred because of infection, weakness, or deformity. Adjuvant procedures, as needed, were interphalangeal arthrodeis of the thumb, capsulorrhaphy of the wrist, and additional tendon transfers.