Treating hummingbirds as feathered bees: a case of ethological cross-pollination.

Hummingbirds feed from hundreds of flowers every day. The properties of these flowers provide these birds with a wealth of information about colour, space and time to guide how they forage. To understand how hummingbirds might use this information, researchers have adapted established laboratory paradigms for use in the field. In recent years, however, experimental inspiration has come less from other birds, and more from looking at other nectar-feeders, particularly honeybees and bumblebees, which have been models for foraging behaviour and cognition for over a century. In a world in which the cognitive abilities of bees regularly make the news, research on the influence of ecology and sensory systems on bee behaviour is leading to novel insights in hummingbird cognition. As methods designed to study insects in the laboratory are being applied to hummingbirds in the field, converging methods can help us identify and understand convergence in cognition, behaviour and ecology.

Extremity soft-tissue sarcomas selectively treated with surgery alone.

PURPOSE: This study determined local control (LC), freedom from distant recurrence (FFDR), overall survival (OS), and potential prognostic factors in 34 adult patients with primary extremity or limb girdle soft-tissue sarcoma selectively managed with limb-conservation surgery alone. METHODS AND MATERIALS: The medical records of 34 patients who underwent surgery alone for localized soft-tissue sarcoma of the extremity were reviewed. Median duration of follow-up in survivors was 55 months (range, 24-143). There were 13 (38%) females. Eighteen (53%) of the tumors were low-grade, 15 (44%) were superficial, 15 (44%) were small (5 cm or less), and 16 (47%) involved the distal extremity. RESULTS: Actuarial 5-year LC was 80%, FFDR was 86%, and OS was 82%. All recurrences (local and distant) were in patients with high-grade tumors; their 5-year LC was 60%, FFDR was 71%, and OS was 69%. In 2 patients, metastatic disease developed either concurrent with or after their local recurrence. Univariate analysis revealed better OS, FFDR, and LC for patients with low-grade tumors (p < 0.05). Female patients had significantly better FFDR and OS (p < 0.05). CONCLUSION: It is appropriate to consider withholding irradiation for selected patients with low-grade tumors resected with negative margins if, in the event of a local failure, a function-preserving surgical salvage is anticipated. For patients with high-grade sarcomas, the control of local and distant disease was not acceptable with limb-conservation surgery alone.

Ewing sarcoma of the rib: results of an intergroup study with analysis of outcome by timing of resection.

OBJECTIVE: We sought to establish the outcome and optimal therapeutic sequence for patients with nonmetastatic Ewing sarcoma/primitive neuroectodermal tumor of the chest wall. METHODS: Patients 30 years of age or younger with nonmetastatic Ewing sarcoma/primitive neuroectodermal tumor of the bone were randomly assigned to receive vincristine, doxorubicin, cyclophosphamide, and dactinomycin or those drugs alternating with ifosfamide and etoposide. Local control was obtained with an operation, radiotherapy, or both. RESULTS: Fifty-three (13.4%) of 393 patients had primary tumors of the chest wall (all rib). Event-free survival at 5 years was 57% for the chest wall compared with 61% for other sites (P >.2). Ifosfamide and etoposide improved outcome in the overall group (5-year event-free survival, 68% vs 54%; P =.002), and a similar trend occurred in chest wall lesions (5-year event-free survival, 64% vs 51%). Patients with chest wall lesions had more attempts at initial surgical resection (30%) than those with other primary tumor sites (8%, P <.01). The attempt at initial resection for chest wall lesions did not correlate with size. Initial resections at other sites were restricted to smaller tumors. Initial resection resulted in negative pathologic margins in 6 of 16 patients, whereas the delayed resection resulted in negative margins in 17 of 24 patients (P =.05). Although there was no difference in survival by timing of the operation in rib lesions, a higher percentage of patients with initial surgical resection received radiation than those with resection after initial chemotherapy (P =. 13). CONCLUSIONS: Although rib primary tumors are significantly larger than tumors found in other sites, their outcome is similar. We favor delayed resection whenever possible to minimize the number of patients requiring radiation therapy.

Nonrhabdomyosarcoma soft tissue sarcomas in children. The Mayo Clinic experience.

Eighty-six children to 18 years of age were treated for nonrhabdomyosarcoma soft tissue sarcomas of the trunk and extremities. Synovial sarcoma (31), fibrosarcoma (13), malignant fibrous histiocytoma (11), epithelioid sarcoma (10), and clear cell sarcoma (7) were the most common diagnoses. Four patients presented with metastatic disease. A high percentage of patients presented after biopsy by the referring physician, although this could not be shown to affect outcome. Patients were treated with wide removal of the tumor when possible, with judicious use of adjuvant radiation, or with chemotherapy in selected cases. Mean followup was 11 years. Five- and 10-year survival was 92% and 84%, respectively. Tumors larger than 5 cm were associated with a worse prognosis. When compared with published data in adults, the prognosis of primary, localized nonrhabdomyosarcoma soft tissue sarcomas in children appears to be more favorable.

Surgical treatment of metastatic disease of the femur.

Nearly every malignant neoplasm has been described as having the capability to metastasize to bone. Of the estimated 1.2 million new cases of cancer diagnosed annually, more than 50% will eventually demonstrate skeletal metastasis. Advances in systemic and radiation therapy have led to a considerable improvement in the prognosis of patients with metastatic disease. As a result, orthopaedic surgeons are being asked with increasing frequency to evaluate and treat the manifestations of skeletal metastases. The femur is commonly the site of large impending lesions and complete pathologic fractures. Although the health status of some patients may preclude operative intervention, established pathologic fractures of the femur and metastatic lesions deemed likely to progress to imminent fracture generally should be treated surgically. A rational approach to selection of the proper treatment for these problems includes consideration of the patient's overall medical condition and the type, location, size, and extent of the tumor. Treatment principles are the same regardless of location. A construct should ideally provide enough stability to allow immediate full weight bearing with enough durability to last the patient's expected lifetime. All areas of weakened bone should be addressed at the time of surgery in anticipation of disease progression. To minimize disease progression and possible implant or internal fixation failure, postoperative external-beam irradiation should be considered.

Total elbow arthroplasty after resection of tumors at the elbow.

Between 1980 and 1993, 13 patients underwent total elbow arthroplasty at the authors' institution after resection of tumors around the elbow. Arc of elbow motion from extension to flexion improved from a preoperative mean of 29 degrees to a postoperative mean of 73 degrees. Pain scores decreased from a preoperative mean of 3.6 to a postoperative mean of 2.0. Three patients had an excellent, six had a good, two had a fair, and two had a poor result. All seven patients with primary tumors had good or excellent results, compared with only two of six patients with metastatic lesions to the elbow. The data from this study suggest total elbow arthroplasty after resection of tumors provides significant pain relief and improvement in function. Patients with metastatic lesions may be candidates for the procedure, especially if all other methods of palliation have been exhausted. However, the results for patients with metastatic lesions may not be satisfactory.

Malignant lesions arising in chronic osteomyelitis.

Neoplasia occurring in a sinus tract is a well known complication of chronic osteomyelitis. Previous series have been too small to permit survival analysis. Fifty-three consecutive patients (44 men and 9 women) from the authors' institution were reviewed, including 24 who previously were reported. There were 50 patients with squamous cell carcinomas, one with fibrosarcoma, one with myeloma, and one with lymphoma. Mean age was 59 years. One patient sought treatment elsewhere and was lost to followup. Forty-four patients underwent amputation, and eight underwent limb salvage. Followup averaged 9 years. Of 50 patients with squamous cell carcinoma, five died of disease. Overall survival in this group was not statistically different from that expected for age matched controls. Despite the low grade nature of most of these lesions, amputation often is chosen as the most reliable means of treating the tumor and the chronic infection.

Primary chondrosarcoma of long bones and limb girdles.

BACKGROUND: Chondrosarcomas are common solid malignant tumors of bone, second in incidence only to osteosarcomas. The biologic evolution of chondrosarcomas is slow, requiring long follow-up intervals for meaningful survival analysis. METHODS: This study describes the clinicopathologic profiles of 344 patients, 194 male and 150 female (M:F, 1.3:1.0), with primary chondrosarcoma of long bones and limb girdles seen at 1 institution over a period of 80 years. RESULTS: The average age at presentation was 46 years (range, 5-82 years). The pelvis was the most common location (1.7% of all patients). Local pain was the most frequently reported initial symptom (81.4%). Survival analysis was limited to 233 patients whose primary treatment was given at the Mayo Clinic. All 233 patients had potential follow-up of at least 5 years. The overall 5-year survival rate was 77% (the expected rate was 96%). Local recurrence developed in 19.7% of patients and metastatic lesions in 13.7%. The recurrence rate was higher for tumors of the shoulder and pelvis than for tumors of long bones. Radiographically, chondrosarcomas had a characteristic appearance, including a combination of bone expansion and cortical thickening. Entering the tumor at surgery increased the risk of local recurrence. Histologic tumor grade was an important predictor of local recurrence and metastasis. CONCLUSIONS: With adequate initial surgical intervention, chondrosarcoma is primarily a local disease with a low metastatic rate.

Epidemiology of osteosarcoma and Ewing's sarcoma in childhood: a study of 305 cases by the Children's Cancer Group.

BACKGROUND: The Children's Cancer Group conducted a case-control study to determine the role of a broad range of environmental and familial factors in the etiology of Ewing's sarcoma and osteosarcoma in children. These factors included radiation exposure and, for children with osteosarcoma, parental exposure to beryllium. METHODS: The parents of 152 children with osteosarcoma and 153 children with Ewing's sarcoma were interviewed by telephone. Controls were obtained by random digit dialing and were matched to cases by age and race. RESULTS: Female osteosarcoma patients had earlier onset of breast development (age 11.4 vs. 11.8 years, P=0.03) and menarche (age 12.1 vs. 12.5 years, P=0.002) but no significant differences in growth, whereas male osteosarcoma patients were similar in age at the onset of secondary sexual characteristics but reported significantly less weight gain during their growth spurt (6.6 vs. 11.7 kg, P=0.003). For children with Ewing's sarcoma, the growth spurt began earlier (age 12.1 vs. 12.7 years, P=0.12) and resulted in less weight and height gain (5.2 vs. 9.7 kg, P=0.002, and 10.2 vs. 12.7 cm, P=0.02, respectively) for males, but no differences were observed among females. For factors not related to growth and development (including a wide range of occupational, medical, and household exposures), there was little evidence of an etiologic role with respect to either tumor type. CONCLUSIONS: Differences between cases and controls with respect to growth and development showed no consistent pattern. This study did not identify any important risk factors for either type of childhood bone tumor.

Functional laboratory assessment after oncologic shoulder joint resections.

A laboratory evaluation was undertaken to assess the shoulder range of motion and distal strength after oncologic resection and reconstruction involving the shoulder joint and to compare these functional parameters based on potentially important variables. Inclusion in the study was limited to 32 patients with bone tumors of the proximal humerus or scapula treated surgically by resection of the shoulder joint including the proximal humerus from 1976 through 1992. Active shoulder range of motion and isometric elbow extension and forearm supination strength are significantly less after surgery in patients with greater amounts of bony resection and with resection of the deltoid. Patients who had a modified Tikhoff-Linberg resection were able to achieve 10 degrees to 15 degrees greater shoulder motion in each direction than were patients who had the classic procedure including complete scapulectomy. However, elbow flexion and extension strength and forearm pronation strength were greater for the patients with the classic resection. Osteoarticular allografts as a reconstructive alternative provide as a group the best shoulder motion and overall distal upper extremity strength, but these reconstructions were performed only when the rotator cuff muscles and deltoid were able to be reconstructed. Diminishing elbow strength was seen with longer followup in the patients with osteoarticular reconstructions, corresponding temporally to subchondral collapse observed on radiographs. Range of shoulder motion except rotation was just as good for allograft vascularized fibular arthrodeses as for the osteoarticular allografts, but strength was significantly less with the arthrodeses.

Ewing's sarcoma of the foot.

The results of treatment were reviewed in 16 patients (10 male and six female) who had Ewing's sarcoma of the foot from 1954 through 1992. Mean age was 17 years (range, 10-42 years). The tumor involved the metatarsals (six patients), phalanges (four), calcaneus (three), navicular (one), talus (one), and calcaneus and phalanx (one). Seven patients had metastatic disease at the time of diagnosis, and only one of these patients survived. None of the patients with pulmonary metastasis at presentation survived. Nine patients had localized disease at the time of diagnosis, and eight survived. In the overall series, nine of the 16 patients were alive at followup (eight survived at least 5 years). Diagnosis was established at an average of 14 months from the onset of symptoms: 7 months in forefoot tumors and 22 months in hindfoot tumors. None of the six patients who had a resection had local failure. Seven of the 10 patients with forefoot lesions survived, and two of the six patients with hindfoot lesions survived. Treatment of Ewing's sarcoma of the foot by local control with radiation or operation and systemic control with chemotherapy is recommended. Survival appears to be better in patients who present with localized disease and forefoot lesions. Survival is worse in patients who present with metastatic disease. Surgical treatment appears to have an important role in local control and survival.

Malignant melanoma: Mayo Clinic experience.

To present the Mayo Clinic experience with treatment of melanoma of the trunk and extremities, we reviewed previous Mayo Clinic studies on the management of malignant melanoma and summarized the survival data and treatment-related outcome. A prospective trial involving elective lymph node dissection in 171 patients with malignant melanoma showed no advantage in overall survival and disease-free survival in the group whose nodes were removed. In an assessment of the treatment variables, a Cox stepwise multiple regression analysis showed a strong correlation of lesion thickness and level of invasion with survival. Another study of 535 patients with melanomas that involved the trunk and extremities, who were treated at the Mayo Clinic between 1971 and 1980, showed an overall survival of 83%. Patients with thin lesions (less than 0.76 mm thick) had a 98% 5-year survival, whereas patients with lesions 4 mm thick or thicker had only a 45% 5-year survival. Because the Mayo Clinic prospective randomized study showed no benefit for patients with melanoma who undergo immediate or delayed lymphadenectomy in the trunk and extremities, we do not perform elective lymph node dissection; however, close follow-up of patients is instituted, and lymph node dissection is performed when nodal involvement is first suspected.

Distal upper extremity function following proximal humeral resection and reconstruction for tumors: contralateral comparison.

BACKGROUND: Most functional analyses after limb salvage operations about the shoulder have focused on proximal function with the assumption that distal function is largely unaffected. This analysis examines distal function objectively. METHODS: Objective laboratory data regarding distal upper extremity strength after reconstructive procedures for tumors near the shoulder joint was collected over a 16-year period. Thirty-two patients were able to participate fully in the data collection at an average most recent follow-up duration of > 3.5 years. RESULTS: Statistically significant reductions on the involved side compared with the uninvolved side in grip, forearm pronation, forearm supination, elbow flexion, and elbow extension strength were documented (p < 0.05). The magnitude of reduction in strength diminishes distally, with the greatest effect in this group of patients being observed in elbow extension, followed by elbow flexion, forearm supination, and forearm pronation. Grip strength consistently showed the least amount of strength reduction compared with the uninvolved side, even within resection and reconstruction groups. Subjective patient rating of dexterity was no less than 3 of 5. Ninety percent of patients rated their dexterity 4 of 5 (52%) or 5 of 5 (38%). CONCLUSIONS: Despite the insistence of "normal" function in the distal upper extremity after limb salvage procedures, complete normality is not maintained. However, the degree of maintenance of distal function appears to be high, especially for grip strength and forearm pronation strength, and patient satisfaction is acceptable.

Megaprostheses after resection of distal femoral tumors. A rotating hinge design in 30 patients followed for 2-7 years.

Between 1981-1993, we inserted 32 Kinematic Rotating-Hinge Knee tumor prostheses in 30 patients, of which 2 concerned revisions of the same type of prosthesis. The diagnoses were 21 osteosarcomas, 2 chondrosarcomas, 2 Ewing's sarcomas, 2 metastatic breast carcinomas, 1 multiple myeloma, 1 giant cell tumor and 1 Gorham's disease. The median age was 25 (12-60) years and the median follow-up for survivors was 3.5 (2-6.6) years. There were 7 metastases and 1 local recurrence. 20 knees had excellent (MSTS) scores for motion (median flexion 120 degrees), 8 had good (84 degrees) and 4 had fair (45 degrees). The overall function was excellent in 6 cases, good in 14, fair in 9 and poor in 3. The radiographic assessment (ISOLS) gave "excellent" or "good" scores in 27 knees for bone remodelling, 31 for the interface, 28 for the anchorage, 31 for the implant body and 30 for the articulation. Extracortical bone bridging greater than 25% was observed in 18 of 27 prostheses.

Epithelioid sarcoma: a clinicopathologic review of 55 cases.

OBJECTIVE: To identify any clinical and pathologic features of treatment modalities that are predictive of outcome in patients with epithelioid sarcoma, a rare slow-growing soft tissue tumor most commonly occurring in the distal extremities of young adults. DESIGN: We reviewed the institutional files for cases of epithelioid sarcoma for the period 1956 to 1991 and analyzed the effect of various factors on survival. MATERIAL AND METHODS: Fifty-five cases of epithelioid sarcoma were found, and the relevant clinical, pathologic, treatment, follow-up, and outcome features were assessed. RESULTS: All tumors were treated initially by operative resection. The recurrence rate progressively decreased with increasing aggressiveness of the initial operation; however, no difference was noted in metastatic rate. Overall, the recurrence rate was 38% and the metastatic rate was 47%. At the end of a mean follow-up of 102 months, 69% of patients had no evidence of disease, 27% had died of the disease, and 4% were alive with disease. Increasing tumor size, necrosis of more than 30%, and vascular invasion correlated significantly with a worse prognosis. CONCLUSION: Epithelioid sarcoma should be considered a malignant neoplasm with a significant potential for aggressive behavior, and close follow-up of affected patients should be maintained for many years. Initial treatment should be aggressive in an attempt to prevent recurrence.

Local control of extra-abdominal desmoid tumors.

We analyzed the records and histopathological specimens of fifty patients who had had a previously untreated desmoid tumor. The patients were followed for at least two years (average, forty-eight months). Three patients had a biopsy and were managed with observation only, and three patients had radiation therapy only. Of the remaining forty-four patients, thirty-four were managed with an operation and ten, with an operation and radiation therapy. In the group that was managed operatively without radiation therapy, the resection was wide in thirteen patients, marginal in nineteen, and intralesional in two. At the most recent follow-up examination, there had been no local recurrence in eleven of the patients who had had a wide resection, ten of the patients who had had a marginal resection, and one of the patients who had had an intralesional resection. Thus, twenty-two (65 per cent) of the thirty-four patients had no local recurrence at the time of the latest follow-up. In the group of ten patients who had been managed with an operation and radiation therapy, eight had no local recurrence: the two who had had a wide resection, three of the four who had had a marginal resection, and three of the four who had had an intralesional resection. None of the fifty patients died of the disease.

Genetic analysis of schizophrenia as an example of a putative multifactorial trait.

A new method for analysis of multifactorial traits is described which involves mathematical definition of MZ and DZ twin concordances in terms of penetrance and the number of contributory genes. This allows the number of major genes and their joint penetrance to be estimated. Application to familial schizophrenia indicates causation by a single dominant allele, a deduction supported by several treatments of observed risks in other family members. Lifetime empiric risks are analysed in the context of four conditions: genetic predisposition, prenatal trauma, psychological or other trauma in early adult life and possible exacerbation of symptoms associated with close contact with affected family members. Comparative empiric risks for twins and sibs are explained by consideration of coincident gestations, season of birth and the sharing of a chorionic sac and foetal blood supply. The data are consistent with penetrance being complete in homozygotes and generally around 0.33 in heterozygotes, but it increases in additive fashion depending on risk factors associated with the type of relationship with one or more affected family members and factors associated with twinning. The influence of an affected parent is nearly 3 times as great as that of an affected sibling. The population frequency of heterozygotes is deduced to be around 2.6%.

Intercalary spacers in the treatment of segmentally destructive diaphyseal humeral lesions in disseminated malignancies.

During a 10-year period, 17 patients with segmentally destructive bone lesions of the humeral diaphysis in disseminated malignancies resulting in impending fracture (8 patients), pathologic fracture (6 patients), or failure of attempted internal fixation techniques (3 patients) were treated with resection of the involved diaphyseal segment and reconstruction with a cemented modular intercalary humeral spacer. Fourteen patients had metastatic cancer, 2 had multiple myeloma, and 1 had lymphoma. Breast and renal carcinoma were the most common pathologic diagnoses. The involved site was within the middle 1/3 in 8 patients, in the proximal-middle junction in 5, in the middle-distal junction in 2, and within the proximal and distal 1/3 in 1 patient each. Early pain relief was successful in 88% of patients. Early in the postoperative hospital course, patients generally were able to use the ipsilateral hand to assist feeding. Radiographic analysis revealed that the limited selection of stem lengths led to 76% of the distal stems and 47% of the proximal stems being shorter than the ideal length. The complication rate independent of disease progression was 29%. The most common complication was temporary radial nerve injury (3 patients). There were 3 implant failures, most commonly due to disengagement of the male-female junction. Two periprosthetic fractures occurred, 1 proximally (due to tumor progression) and 1 distally. Suggestions are given for modification of the implants to improve the major problems of limited versatility in intramedullary stem length and inadequate mating at the junction.