Ten ways remote sensing can contribute to conservation

In an effort to increase conservation effectiveness through the use of Earth observation technologies, a group of remote sensing scientists affiliated with government and academic institutions and conservation organizations identified 10 questions in conservation for which the potential to be answered would be greatly increased by use of remotely sensed data and analyses of those data. Our goals were to increase conservation practitioners' use of remote sensing to support their work, increase collaboration between the conservation science and remote sensing communities, identify and develop new and innovative uses of remote sensing for advancing conservation science, provide guidance to space agencies on how future satellite missions can support conservation science, and generate support from the public and private sector in the use of remote sensing data to address the 10 conservation questions. We identified a broad initial list of questions on the basis of an email chain-referral survey. We then used a workshop-based iterative and collaborative approach to whittle the list down to these final questions (which represent 10 major themes in conservation): How can global Earth observation data be used to model species distributions and abundances? How can remote sensing improve the understanding of animal movements? How can remotely sensed ecosystem variables be used to understand, monitor, and predict ecosystem response and resilience to multiple stressors? How can remote sensing be used to monitor the effects of climate on ecosystems? How can near real-time ecosystem monitoring catalyze threat reduction, governance and regulation compliance, and resource management decisions? How can remote sensing inform configuration of protected area networks at spatial extents relevant to populations of target species and ecosystem services? How can remote sensing-derived products be used to value and monitor changes in ecosystem services? How can remote sensing be used to monitor and evaluate the effectiveness of conservation efforts? How does the expansion and intensification of agriculture and aquaculture alter ecosystems and the services they provide? How can remote sensing be used to determine the degree to which ecosystems are being disturbed or degraded and the effects of these changes on species and ecosystem functions?

[Total ankle arthroplasty for rheumatoid arthritis]

Modern second generation total ankle arthroplasty is now a serious alternative to ankle fusion in patients with rheumatoid arthritis after careful assessment of the indications. The midterm results with 10-year survival rates between 70% and 90% and the possible revision for implant exchange or arthrodesis are the reasons for the increasing importance of ankle arthroplasty. Patients with rheumatoid arthritis in particular with generally lower physical requirements can expect a pain-free function of the operated ankle for 8-10 years. In comparison to fusion ankle arthroplasty allows a significantly faster remobilization and reserves the correction capabilities of the ankle. Arthrodesis remains a valuable therapeutic alternative for severe bony destruction and instability as well as a possible fallback for failure of arthroplasty.

The Miethke dual switch valve: experience in 169 adult patients with different kinds of hydrocephalus: an open field study

OBJECT

In spite of the development of approximately 200 different shunt systems within the last 50 years, overdrainage and valve obstructions are still major problems in the current treatment of hydrocephalus. In 1994, a new gravitational valve with different opening pressures (depending upon the patient's posture) and a big contact area to CSF was introduced by Miethke and co-workers (DSV). We report about a single institution's experience in the treatment of 169 adult patients with different kinds of hydrocephalus with this valve.

METHODS

We retrospectively reviewed the clinical and radiological data of all patients who were treated with a DSV between 1998 and 2005 at our institution. A telephone interview was perfomed at the end of the study, to determine the overall shunt survival. We analysed the outcome and the shunt-related complications.

RESULTS

Among 169 patients with DSV, we had 70 patients with normal pressure hydrocephalus (NPH), 40 patients with communicating hydrocephalus due to SAH, 31 patients with communicating hydrocephalus not due to SAH and 28 patients with occlusive hydrocephalus. We had a rate of shunt responders of 93.2%, an overdrainage rate of 3.2% and no valve obstruction in the whole series. The overall shunt survival was 81% after 82 months (mean follow-up: 47.6 months). All implantations were performed by the whole staff, as well as by residents of the neurosurgical department.

DISCUSSION

Among the currently available shunt systems, this series is one with the lowest complication rates due to overdrainage and valve obstructions. In patients with NPH, where low opening pressures are essential, the DSV seems to bear an advantage because of a high drainage rate and, in spite of this, a low rate of overdrainage. Even in patients with relatively high CSF protein content, we did not observe any valve obstruction. This study was an open field analysis providing data about the current complication rates of hydrocephalus treatment with this shunt system, outside of a specialized hydrocephalus team or a prospective study trial. However, this study is a retrospective analysis and a prospective randomized controlled trial is required for the comparison of these valves with other shunt systems, such as programmable and flow-controlled ones is required for the future.

[Long-term results of synovectomy in the rheumatoid ankle joint]

Inflammatory rheumatic ankle joint destruction endangers the mobility of the rheumatic patient by pain and loss of function. In the presented patient population, 29 patients with a mean preoperative history of 14.3 years of rheumatoid arthritis and 7.6 years manifestation of ankle arthritis underwent open synovectomy of the ankle joint optionally combined with accompanying tenosynovectomy. Disease duration and the prevalence of radiological alterations (81% LDE 2-3) characterize the procedures as late synovectomies. The rate of 93% of additional tenosynovectomies and the prevalence of radiological alteration in the adjacent rear foot joints indicate a panarticular pathology of the rheumatic disease. A progression of the Larsen, Dale and Eek (LDE) grade was found in 62% of the ankle joints. The significant gain in the Kofoed ankle score (42.4 versus 55.9 points, p=0.042) was mainly caused by pain reduction and gain of mobility, whereas a decline of function was detected. Both genders showed comparable outcomes. The mean pain level on a visual analogue scale decreased from 7.6 to 3.3 (p<0.001) and 81.5% of the patients assessed the results of the synovectomy as good or very good.

[Operative differential therapy of rheumatic wrists]

The wrists are affected in the long-term in 90% of people with rheumatism and are often (42%) the first manifestation of a destructive disease. The functionality of the wrist and the whole hand is of great importance because in many cases loss of function of the wrists leads to severe limitations. Local and operative treatment of the wrist in rheumatoid arthritis (RA) is one of the main duties in rheuma-orthopaedics. For operative treatment there is a finely tuned differential therapeutic spectrum available. The diagnostic indications take the local and total pattern of affection, the current systemic therapy as well as patient wishes and patient compliance into consideration. In the early stages according to LDE (Larsen, Dale, Eek), soft tissues operations such as articulo-tenosynovectomy (ATS) are most commonly carried out. In further advanced stages osseus stabilisation must often be performed. At this point a smooth transition from partial arthrodesis to complete fixation is possible. After initial euphoria, arthroplasty of the wrist is being increasingly less used for operative treatment due to the unconvincing long-term results and high complication rate. With reference to the good long-term results of all operative procedures, in particular early ATS with respect to pain, function and protection of tendons, after failure of medicinal treatment and persistence of inflammatory activity in the wrist, patients should be transferred to an experienced rheuma-orthopaedic surgeon.

[Update on rheuma-orthopedics - role and therapeutic options]

Orthopaedic treatment options for rheumatological patients have been further developed over recent years. For orthopaedic treatment, a range of different interventions are offered: orthoses and special technical aids as well as injections for joints and tendons, or surgery. Surgical interventions cover joint preservation, restitution and arthrodeses. Improvements in equipment and surgical procedures also make minimally invasive interactions possible for rheumatoid diseases. Thus, postoperative morbidity has been reduced significantly. Improvement in function, reduction of pain and prevention of recurrent local inflammation are primary. Considering these aims, arthrodeses are restricted to special indications. Joint preservation and restitution are the predominant measures used. The various procedures are discussed.

[Differential therapy for the rheumatoid thumb]

The thumb frequently is involved in rheumatoid arthritis and often is a source of significant functional loss, pain, and deformity. Surgical intervention in patients with rheumatoid arthritis of the thumb should be based on the degree of radiological destruction according to Larsen, the natural course of the rheumatoid hand, the nature and stage of deformity as well as the status of tendons, ligaments, and adjacent joints. The goals of surgery are to relieve pain, increase motion, and restore thumb function. The timing for shoulder surgery should be early in the course of the disease, since it determines the long-term prognosis and the remaining surgical options. Treatment options, alone or in combination, include synovectomy, arthrodesis, arthroplasty, and tendon repair or transfer. Joint-preserving surgery is indicated in the early stages of radiological destruction according to Larsen classification O-III, whereas the late stages of destruction (Larsen IV-V) require reconstructive surgery. Especially in hand and finger arthritis, the "wait and see" strategy should no longer be followed. Close interdisciplinary cooperation between surgeon and rheumatologist is necessary for early therapeutic strategy, taking into account the functional unit of the whole upper extremity. The ultimate aim is to provide pain relief, improve function, enhance appearance, and slow the progression of disease. When the pathogenesis and pathoanatomy of the impaired rheumatoid thumb are appreciated, and appropriate treatment is selected, surgical intervention is likely to provide a favorable outcome for the patient.

Modularphysiologische Handgelenkprothese

Silicone wrist arthroplasty has dominated reconstructive surgery of the rheumatoid wrist for a long time. The declining success rates of Swanson wrist arthroplasty has encouraged the development of new wrist devices. Modular physiological total wrist arthroplasty represents a new wrist prosthesis generation with anatomical reconstruction of carpal height and wrist pivot. This increases the efficiency of wrist and finger tendons. Modular physiological total wrist arthroplasty was developed in 1992 and has been in clinical application since 1993. A total of 46 total wrist arthroplasties in 39 patients were carried out between 1993 and 1999. All patients suffered from rheumatoid arthritis. The mean follow-up period was 4.6 years. The postoperative total wrist score averaged 77.3 points, representing 78% good and excellent scores. Patient satisfaction and pain relief were achieved in 86% of cases. The range of motion at last follow-up averaged 56 degrees of the combined extension and flexion and 27 degrees for combined ulnar and radial deviation were maintained. The radiographic analysis of MPH total wrist arthroplasty demonstrated a secure reconstruction of carpal height and restoration of joint pivot. Failures occurred in seven wrist arthroplasties. Malalignement of the carpal and radial component and soft-tissue dysbalance were the reasons for recurrent dislocation in four cases. Three wrists were fused and one exchange arthroplasty using a constrained revision prosthesis was performed. The remaining three revision cases were caused by one deep infection and two failures of the carpal implant.

[Synovectomy of the rheumatoid elbow]

We present a comparative study of 120 elbow synovectomies with and without radial head resection performed between 1985 and 1993. Minimal radiological destruction according to Larsen stage 1-2 was present in 38 joints; 28 patients were followed postoperatively for an average period of 8.2 years. Synovectomy was combined with radial head resection in 70 patients (82 joints) where rheumatoid arthritis had radiologically proceeded to Larsen stage 3-4. Fifty patients were available for clinical and radiological follow-up. The follow-up period ranged from 6 to 15 years (average: 9.3 years). All patients in both groups were suffering from rheumatoid arthritis, and the proportion of females dominated. The mean age at the time of operation was 50 and 56 years, respectively. The results according to Inglis and Pellicci (16) were graded as good and excellent in 63.3% (19 joints) after elbow synovectomy. An average postoperative score result of 80.7 points (range: 43-96 points) was obtained. Synovectomy and radial head resection achieved comparable score results (75.7 points), representing 59.4% (35 joints) good and excellent ratings. Complete pain relief was obtained in 51.5%, and 27.1% complained of slight pain after elbow synovectomy. Of the patients who underwent radial head excision, 45.8% were pain free and 27.1% experienced slight pain. The range of motion of combined extension and flexion averaged 113 degrees and 110 degrees, respectively. A comparable improvement concerning pro/supination was maintained at final follow-up with an average gain of 20.4 degrees after synovectomy and 25.3 degrees for the latter group. We routinely noticed a moderate radiographic progression in both groups according to the criteria of the Larsen classification. The radiographic deterioration did not correlate with the clinical outcome. Synovectomy of the rheumatoid elbow is a valuable procedure in early as well as late stages of the disease. Our long-term results after synovectomy of the elbow prove significant pain relief and restoration of elbow function. The radiographic assessment revealed a moderate radiological deterioration. From the clinical viewpoint, the elbow function is maintained for a long time and valuable time is gained before reconstructive surgery may become necessary.

[Differential therapy for the rheumatoid shoulder]

Despite frequent involvement, the rheumatoid shoulder is neglected in operative treatment of the upper extremities. The slow course of omarthritis, the compensation mechanism of scapulothoracic motion and neighbouring joints as well as dominating disabilities of the lower extremities and the rheumatoid hand are possible explanations. The pattern of destruction of the rheumatoid shoulder is characterized by progressive joint and soft tissue deterioration. Soft tissue involvement determines the course of the shoulder joint. The subacromial space is a common and early site for rheumatoid involvement, often leading to bursitis, tenosynovitis of the biceps tendon and rotator cuff rupture. Sonography and MRI enable the early detection of subacromial and glenohumeral pathology before deterioration is visible radiologically. Surgical intervention in patients with rheumatoid arthritis of the shoulder is based on the degree of radiological destruction according to Larsen, the natural course of the shoulder joint and the soft-tissue condition. The goals of surgery are to relieve pain, increase motion and restore shoulder function. Surgery should be carried out early in the course of the disease, thus determining the long-term prognosis and the remaining surgical options. Depending on the pattern of destruction of the rheumatoid shoulder, the options for treatment can be divided into early and late procedures.Joint-preserving surgery is indicated in the early stages of radiological destruction according to Larsen classification O-III, whereas the late stages of destruction (Larsen IV-V) require reconstructive surgery. The introduction of arthroscopic and semiarthroscopic techniques has improved the acceptance of early synovectomy for the rheumatoid shoulder, but there is still a place for open synovectomy in patients with extensive soft-tissue repair and bone-remodelling procedures. Arthroscopic and open synovectomy are supplementary and noncompetitive surgical procedures for the rheumatoid shoulder. With proceeding bone and soft-tissue destruction corresponding to Larsen stage IV and V, synovectomy is not successful and reconstructive surgery is necessary. Resection-interposition-arthroplasty (RAIP) remains a controversial alternative to arthroplasty in young patients with sufficient bone stock and a reconstructable rotator cuff. The success of cup-replacement will additionally restrict the indications for RAIP. RIAP remains a possible salvage procedure after aseptic and septic loosening of shoulder arthroplasty. Glenohumeral replacement arthroplasty has become the procedure of choice in reconstructive surgery of the shoulder. The severity of soft-tissue and bone destruction determines the choice of shoulder prosthesis. Current modular shoulder systems with increased numbers of humeral-head stem combinations are calculated to achieve a better adjustment of the soft-tissue tension and to optimize the adaptation between head geometry and the natural shape of the glenoid.The surrounding soft-tissue structure, especially the condition of the rotator cuff, is very important for the functional recovery after shoulder arthroplasty. We prefer a hemiarthroplasty of the rheumatoid shoulder joint to avoid critical glenoid fixation. Patients with irreparable rotator cuff tears and severe glenohumeral arthritis remain a difficult challenge in shoulder surgery and the ideal procedure has not yet been found.Pain relief and a modest increase in active motion are the main goals in operative treatment. Bipolar shoulder arthroplasty represents an adequate alternative to currently favoured hemiarthroplasty in patients with cuff-deficient shoulders.

[Radiolunate arthrodesis of the rheumatoid wrist - mid- and long-term results]

Late Synovectomy of the rheumatoid wrist combined with ulna head resection and dorsal wrist stabilization will not prevent carpal instability and dislocation. Depending on the radiological destruction pattern and the natural course of the wrist according to Simmen, dorsal wrist synovectomy is combined with soft-tissue or osseus stabilization procedures.This article describes the mid- and long-term results of radio-lunate arthrodesis in patients with rheumatoid arthritis. We present a retrospective study of 69 radiolunate arthrodesis performed from 1988 to 1994. Fifty patients with 57 wrists were available for clinical and radiological follow-up. All patients were suffering from rheumatoid arthritis (dominating female). The average length of R.A. illness was 9.6 years. The mean age at operation was 54.4 years. Postoperative results were reviewed with the Clayton score. The radiographic analysis included measurement of the carpal height index and ulnar translation of the carpus. The follow-up period ranged from 4 to 10.8 years (average: 7 years). The postoperative Clayton score averaged 74.2 points, representing 70% good or excellent results. Twelve wrists achieved satisfactory results and five were judged poor. The most benefit was achieved in pain relief and restoration of wrist function and extensor strength. Complete pain relief was achieved in 36 wrists, while 16 reported slight pain from loads. Five patients still complained about pain with daily wrist activity. We noticed a moderate decrease for extension-flexion (-39 degrees ) and for combined ulnar-radial deviation (-10 degrees ). The radiographic analysis proved stabilization of ulnar translocation in most cases. We routinely noticed a moderate radiographic progression according to the Larsen classification (+0.7) with reduction of the carpal height ratio. In conclusion radioulnate arthrodesis proved satisfactory pain relief and maintenance of functional wrist motion. Despite radiographic deterioration, partial wrist arthrodesis restrains ulnar translocation, while stabilization of the rheumatoid wrist is achieved.

[Long-term outcome of Swanson prosthesis management of the rheumatic wrist joint]

Silicone-wrist arthroplasty has dominated reconstructive surgery of the rheumatoid wrist for a long time. Silicone interposition wrist arthroplasty yielded good clinical results in short and midterm studies. The durability and longevity of the prosthesis however is limited and progressive X-ray deterioration and silicone synovialitis are the main shortcomings. We present the ten-year follow-up results of 102 rheumatoid wrists operated between 1984 and 1992. 72 patients with 82 wrist arthroplasties were clinically and radiologically examined. The mean age at operation was 56.9 years. The average onset of R.A. was 16.1 years. Each wrist was rated on a 100-point scale, with points based on wrist balance, range of motion, pain relief and extensor strength. The postoperative Clayton score averaged 69.4 points. Including revision cases, 51% of the Swanson implants were rated good or excellent, 16% fair, and 33% were judged poor because of pain or prosthesis breakage. Patient satisfaction and pain relief were achieved in 68.2%. Active motion with unrevised implants was 21 degrees extension and 31 degrees flexion. We noticed a moderate increase (7 degrees) for ulnar-radial deviation. There was a progressive deterioration in the radiographic appearance. Implant fracture occurred in 31% of the patients. Subsidence of the implant and significant reduction of carpal height was noticed in 82.5% of the prosthesis. Revision procedures were performed in eleven cases. We conclude that the clinical and radiological results of Swanson silicone interposition arthroplasty will deteriorate with the passage of time. Beyond the potential deleterious effects of silicone, long-term radiological complications such as implant fracture, subsidence and carpal collapse are the main disadvantages of Swanson arthroplasty of the wrist. We therefore currently recommend the MPH-total wrist design in patients with rheumatoid arthritis.

[Ankle prostheses. Mid-term results after Thompson-Richards and STAR prostheses]

Thirty-seven patients with 20 cemented Thompson-Richards prostheses and 19 cementless S.T.A.R. prostheses (2 bilateral cases) were followed up after 1-12 years. Rheumatoid arthritis was the main diagnosis in both populations, with females dominating. The investigation was based on the Kofoed ankle score. At follow-up the total scoring improved to 86.9 pts. in S.T.A.R. and to 77.7 pts. in T.R.P. replacement. The radiological examination showed a high rate of radiolucency for the tibial component (53.3%) in cemented T.R.P.; subsidence of talar component was seen in 3 cases with T.R.P. In cementless S.T.A.R. prothesis only 3 cases showed small radiolucent lines of the flat tibial component. Talar subsidence was not seen at all. In T.R.P. we had two revisions due to prothesis loosening and one maleollar fracture, giving a cumulative estimated survival rate of 87% at 12 years. In the S.T.A.R. prosthesis group two revisions had to be performed because of one meniscal breakage and correction of meniscal height. The estimated survival rate at 6 years was 94.3%.

Cytoplasmic transport in Drosophila ovarian follicles: the migration of microinjected fluorescent probes through intercellular bridges depends neither on electrical charge nor on external osmolarity

Using video-intensified fluorescence microscopy and a pseudocolor display of fluorescence intensity, we analyzed the distribution of microinjected molecules within the nurse-cell/oocyte syncytium of Drosophila ovarian follicles. We varied the composition and the osmolarity of the culture solution as well as the electrical charge and the molecular mass of the microinjected fluorescent probe. As culture solutions, we used four simple salines (IMADS) and a complex tissue-culture medium (R-14) that matched the osmolarity of adult hemolymph. Small amounts of two anionic dyes (Lucifer Yellow CH and Lucifer Yellow dextran) as well as of two cationic dyes (rhodamine 6G and tetramethylrhodamine dextran-lysine) were iontophoretically microinjected either into a nurse cell or into the oocyte of stage-10 follicles. In the tissue-culture medium, within a few seconds following microinjection, all tested dyes passed through the intercellular bridges in both the anterior direction (to the nurse cells) and the posterior direction (to the oocyte), independent of their electrical charge or molecular mass. In all simple salines, irrespective of their osmolarity, Lucifer Yellow CH was found to preferentially migrate in the posterior direction and to accumulate in the oocyte due to progressive binding to yolk spheres. Thus, with this sensitive method, no correlation was detectable between the external osmolarity, the electrical charge and the preferential direction of migration of a microinjected probe. Our results indicate that the electrical gradient described by other authors does not exert significant influence on the migration of charged molecules through intercellular bridges in situ.

[Medium-term results using the cement-free link endoprosthesis. Ribbed shaft V socket]

Since 3/84 340 primary implantations with the uncemented "Link" hip system (Rib-Type V socket) were done. The results with an average follow up of 3.2 years are published. Only 2.17% revision had to be suffered in the rib stem, while 0.77% socket revision had to be done. According to the score of Merle d'Aubigné the values of pain increased from 2.87% to 5.38%, walking ability from 3.68% to 5.27% and the range of motion from 133 degrees to 199 degrees. A high rate of good and satisfying results proved this anatomical implant system to be a good alternative in total hip replacement in younger patients.