Sympatric divergence and clinal variation in multiple coloration traits of Ficedula flycatchers.

Geographic variation in phenotypes plays a key role in fundamental evolutionary processes such as local adaptation, population differentiation and speciation, but the selective forces behind it are rarely known. We found support for the hypothesis that geographic variation in plumage traits of the pied flycatcher Ficedula hypoleuca is explained by character displacement with the collared flycatcher Ficedula albicollis in the contact zone. The plumage traits of the pied flycatcher differed strongly from the more conspicuous collared flycatcher in a sympatric area but increased in conspicuousness with increasing distance to there. Phenotypic differentiation (PST ) was higher than that in neutral genetic markers (FST ), and the effect of geographic distance remained when statistically controlling for neutral genetic differentiation. This suggests that a cline created by character displacement and gene flow explains phenotypic variation across the distribution of this species. The different plumage traits of the pied flycatcher are strongly to moderately correlated, indicating that they evolve non-independently from each other. The flycatchers provide an example of plumage patterns diverging in two species that differ in several aspects of appearance. The divergence in sympatry and convergence in allopatry in these birds provide a possibility to study the evolutionary mechanisms behind the highly divergent avian plumage patterns.

Natal dispersal based on past and present environmental phenology in the pied flycatcher (Ficedula hypoleuca).

Natal dispersal allows individuals to reach suitable breeding sites. The effect of present plant phenology as a cue for dispersal into areas with favourable stages of development has been well established across avian and mammalian taxa. However, the effect of past experience is less understood. We studied the effect of past and present phenology of the environment on the direction and distance of natal dispersal in a passerine bird, the pied flycatcher (Ficedula hypoleuca). We monitored spring settlement of local recruits in six nest box plots along a 10-km stretch of a south-north gradient of plant and caterpillar food development. We found that males used both past experience of caterpillar phenology from early life and actual plant phenology during the recruitment season as independent cues for breeding settlement. Males that had experienced a mismatch with the caterpillar food peak as a nestling, and/or those that arrived late in the spring in the recruitment year, moved north of their natal site, whereas males that had experienced a better match with the caterpillars as a nestling, and/or those that migrated earlier in the spring, settled at a similar site or more to the south. In females, no such effects were found, suggesting that the usage of phenological cues is sex specific. In summary, tracking environmental phenology by natal dispersal may represent an effective mechanism for settling in new favourable areas, and may thus potentially cause rapid change of a species' geographical breeding range in response to climate change.

Flycatcher song in allopatry and sympatry--convergence, divergence and reinforcement.

The theory of reinforcement predicts that natural selection against the production of unfit hybrids favours traits that increase assortative mating. Whether culturally inherited traits, such as bird song, can increase assortative mating by reinforcement is largely unknown. We compared songs of pied (Ficedula hypoleuca) and collared flycatchers (F. albicollis) from two hybrid zones of different ages with songs from allopatric populations. Previously, a character divergence in male plumage traits has been shown to reinforce premating isolation in sympatric flycatchers. In contrast, we find that the song of the pied flycatcher has converged towards that of the collared flycatcher (mixed singing). However, a corresponding divergence in the collared flycatcher shows that the species differences in song characters are maintained in sympatry. Genetic analyses suggest that mixed song is not caused by introgression from the collared flycatcher, but rather due to heterospecific copying. Circumstantial evidence suggests that mixed song may increase the rate of maladaptive hybridization. In the oldest hybrid zone where reinforcement on plumage traits is most pronounced, the frequency of mixed singing and hybridization is also lowest. Thus, we suggest that reinforcement has reduced the frequency of mixed singing in the pied flycatcher and caused a divergence in the song of the collared flycatcher. Whether a culturally inherited trait promotes or opposes speciation in sympatry may depend on its plasticity. The degree of plasticity may be genetically determined and accordingly under selection by reinforcement.

Laryngectomy clinical pathway: development and review.

OBJECTIVE: The goal of the study is to determine if the implementation of a protocol for the preoperative and postoperative care of patients receiving a laryngectomy for cancer of the larynx or hypopharynx (i.e., laryngectomy clinical pathway) reduced length and cost of hospital stay without increasing complication rates. DESIGN: This study is a comparison of the perioperative course of two groups of laryngectomy patients. Data were collected retrospectively from the records of patients operated on before the implementation of the clinical pathway as the institutional historical control. Comparison was made with data collected prospectively on patients operated on after the implementation of the clinical pathway. SETTING: The study was performed at a mid-sized teaching hospital associated with two regional cancer centres. All surgeries were performed by one of two otolaryngology-head and neck surgeons and residents under their supervision. METHODS: The demographic, patient, tumour, treatment, dietary, and complication data were analyzed. Fisher's exact (two-tailed) statistical test was used for parametric data and Wilcoxon scores for nonparametric data. MAIN OUTCOME MEASURE: The principal outcome measure was the length of postoperative inpatient stay. Secondary outcome measures were readmissions and postoperative complications. RESULTS: There was a statistically significant decrease of 6.7 days in the mean length of hospitalization in the clinical pathway group even when taking postoperative readmissions into account. There was no concomitant increase in surgical complications. The mean reduction in hospital cost per case was calculated to be $3,420 (Can). CONCLUSIONS: Application of a clinical pathway for patients receiving laryngectomy is both feasible and effective.

Predictability of hypocalcemia using early postoperative serum calcium levels.

OBJECTIVE: In operations involving the thyroid or parathyroid glands, postoperative serum calcium levels are one contributing factor to patients' length of hospital stay. In this study, we wanted to determine whether early postoperative serum calcium levels could be used to predict hypocalcemia following operations of the thyroid or parathyroid glands. METHODS: A retrospective chart review was performed on 203 patients who had undergone operations involving risk to the parathyroid glands. This included patients who had bilateral thyroid operations or those who had one or more parathyroid glands removed for various disease processes. Postoperative calcium levels were plotted as a function of time, and the slope between the first two levels was examined. Both serum calcium levels were drawn within 12 hours after the operation. RESULTS: A positive slope predicted normocalcemia in 100% of patients undergoing thyroid or parathyroid procedures. A negative slope was predictive in magnitude. Patients who developed hypocalcemia had an average slope two to three times more negative than those remaining normocalcemic. CONCLUSIONS: It appears that early serum calcium levels may be predictive for postoperative hypocalcemia in operations that put the parathyroid glands at risk.

[Possibilities and limits of ambulatory surgery: demands and reality in plastic surgery]. / Möglichkeiten und Grenzen ambulanten Operierens: Anspruch und Realität in der Plastischen Chirurgie.

With the development of office-based operating rooms and improved office anesthesia, the ability to perform more extensive surgery outside the hospital is now given. Experience with the tumescent technique for liposuction and abdominoplasty has demonstrated that extensive plastic surgery can performed with minimal postoperative discomfort. An emergency phone after surgery is necessary, and a call on the operating day evening and the initial postoperative day is a safe strategy with high patient acceptance for most types of plastic surgery. Additionally, the cost savings of office-based plastic surgery makes this surgery much cheaper for the patients and the health insurance organizations.

Maxillary giant cell granuloma, pheochromocytoma, and hyperparathyroidism without medullary thyroid carcinoma.

We examined a young man who had a benign giant cell granuloma of the maxilla, which we subsequently diagnosed as a brown tumor associated with hyperparathyroidism. During surgery for the granuloma, the patient developed severe hypertension and was discovered to have an extra-adrenal pheochromocytoma. Oncogene and calcitonin testing for medullary carcinoma of the thyroid was negative. Therefore, despite the presence of both pheochromocytoma and hyperparathyroidism, we concluded that this patient did not have multiple endocrine neoplasia type 2a.

Frey's syndrome and parotidectomy flaps: A retrospective cohort study.

Gustatory sweating, also known as Frey's syndrome, is a recognized phenomenon after parotidectomy. The incidence of clinically significant gustatory sweating may be dependent on the thickness of the skin flap that is elevated at the time of surgery. Dissection in the subcutaneous level or the deeper sub-superficial musculoaponeurotic system level are 2 commonly used techniques in the operation. Twenty-eight patients were prospectively evaluated for Frey's syndrome after superficial parotidectomy. Thirteen patients underwent subcutaneous and 15 patients sub-superficial musculoaponeurotic system flap elevation. The overall incidence of gustatory sweating was determined, and a comparison of the two surgical techniques was assessed subjectively by patient interview-questionnaire and objectively evaluated with starch-iodine testing.

Comparative study of the acute nephrotoxicity from standard dose cisplatin +/- ifosfamide and high-dose chemotherapy with carboplatin and ifosfamide.

The nephrotoxic effects of different platinum compounds based combination chemotherapies were compared. Chemotherapy consisted of either cisplatin fractionated over 5 days (5 x 20 mg/m2) or given as a single-day infusion (1 x 50 mg/m2) plus ifosfamide (4 g/m2) or high-dose chemotherapy was applied including carboplatin (3 x 500 mg/m2) and ifosfamide (3 x 4 g/m2) fractionated over three consecutive days. Conventional parameters such as serum creatinine and glomerular filtration rate (GFR), as well as urinary protein excretion of N-acetyl-beta-D-glucosaminidase (NAG)) and alpha 1-micro-globulin were assessed in 52 patients. Fractionation over 5 days without adding other nephrotoxic agents, i.e. ifosfamide, prevented decreases in GFR following cisplatin, whereas the combination of conventional dose cisplatin and ifosfamide, given as a single-day infusion, and high-dose carboplatin/ifosfamide yielded a pronounced fall of GFR. All groups showed increases in the urinary excretion levels of serum derived proteins and NAG, but with significant differences; about 2 to 3-fold for 5-days cisplatin, 3 to 5-fold for single-day cisplatin/ifosfamide, and 20 to 35-fold for high-dose chemotherapy. Thus, conventional approaches can reduce but not prevent the nephrotoxicity of cisplatin-based chemotherapy. In particular, high-dose chemotherapy regimens including carboplatin and ifosfamide are associated with comparable or even higher nephrotoxicity to single-day cisplatin/ifosfamide. In the light of the long-term consequences of persistent renal damage prevention of nephrotoxicity should be further improved.

Role of percutaneous gastrostomy tubes in the postoperative care of patients with cancer of the oral cavity and oropharynx.

OBJECTIVE: The purpose of this study was to document the use and complications of gastrostomy tubes placed following surgery for oral cancer at our institution and to determine preoperative predictors of the procedure. METHOD: A retrospective chart review of 105 patients treated surgically for oral cancer between March 1990 and June 1995 at St. Joseph's Health Care Centre, London, Ontario was conducted. Twenty patients were studied with regard to timing, indication, and morbidity (n = 24) of the procedure. Regression analysis was performed regarding preoperative predictors of postoperative gastrostomy including tumour site and stage, and the percentage of tongue resected. Outcome measures included time from surgery to gastrostomy, length of postoperative hospital stay, time gastrostomy tube in situ, complications of gastrostomy, and the predicted risk of postoperative gastrostomy tube. RESULTS: The mean time to gastrostomy tube placement was 17.4 days, and the mean length of hospital stay in gastrostomy patients was 26.8 days. Gastrostomy was temporary in 55% of patients. No significant complications of percutaneous gastrostomy were encountered. Oropharyngeal tumour site and advanced T stage were predictive of the need for postoperative gastrostomy. CONCLUSIONS: In oral cavity and oropharyngeal cancer patients treated surgically, early postoperative percutaneous gastrostomy tube placement is indicated in those at high risk for significant postoperative dysphagia.

Nonlinear, three-dimensional finite-element model of skin biomechanics.

OBJECTIVE: The aim of this study was to expand the rigour and scope of soft-tissue finite-element modelling through the introduction of nonlinear biomechanics. The capability to simulate "tissue" movement in three-dimensional space was a priority. METHOD: A computer-based finite-element technique was used to approximate the exact solution to the governing differential equations. Common fusiform defects were "closed" in two- and three-dimensional space. Strains of approximately 17% were introduced. Skin was modelled as a nonlinear elastic anisotropic material in a laminated-composite structure undergoing large deformations and large strain. The finite-element software package for nonlinear biomechanical analysis was run on a university-based, multi-user workstation. Repeated simulations were performed. The key independent variables were the magnitude of the subcutaneous adhesion and the degree of undermining. The two dependent variables were the "closure" force and the distortion field. RESULTS: The absolute values computed for "closure" force, ranging from 4.4 N to 5.2 N, were consistent with previous animal studies. The periphery of the distortion field varied from 4.7 to 5.9 cm from the defect midline. The force of subcutaneous adhesion was varied from 2 to 20 kN/m (+900%) and led to a -19% and +16% change in the distortion field width and "closure" force, respectively. Undermining was progressively increased from 1 to 5 cm (+400%) and produced a +5% and -12% change in the width of the distortion field and the "closure" force, respectively. CONCLUSIONS: The application of nonlinear biomechanics to soft-tissue finite-element modelling has been rewarding. The results correlate well with surgical experience. With specific regard to undermining, additional insight has been gained. Undermining broad-based soft-tissue flaps has progressively limited benefits. The computational demonstration of this result, consistent with prior animal studies, has not been previously published. Future application of this technology may permit the development of more complex flaps. Animal experimentation may be reduced and/or deferred until postulated flap designs have been simulated and refined.

The straight line graph in limb length inequality. A new design based on 182 Dutch children.

Moseley's Straight Line Graph (M-SLG), which is based on growth data obtained in the 1940s and 1950s, is helpful for the timing of physiodesis. We investigated whether current growth data could improve this graph. We estimated growth curves based on recent data on 182 Dutch children, collected between 1979 and 1994, using repeated measure analysis of variance. In both boys and girls, the mean femur and tibia length had increased, when compared to the data collected by Anderson et al. (1964). Based on our growth data, a new straight line graph (Rotterdam Straight Line Graph; R-SLG) was created. Its value was assessed by comparing the difference between the predicted length of the short (i.e., not operated) limb at maturity with the final limb length. In a group of 34 children who underwent physiodesis up to 10 years ago, the R-SLG gave better prediction of limb length at maturity than the M-SLG did in 22 of 34 cases and equal results were obtained in 5 cases. We conclude that our updated SLG can improve the prediction of final limb length and thus also the timing of physiodesis.

Fertility after chemotherapy for testicular germ cell cancers.

PURPOSE: To analyze the probability of recovery of spermatogenesis after orchidectomy and cisplatin-based chemotherapy (CT) for testicular germ cell cancer. PATIENTS AND METHODS: One hundred seventy-eight patients treated between 1979 and 1991 were selected by the requirement of sperm count both pre-CT and post-CT. Counts were classified as normospermic (NS) if more than 10 x 10(6)/mL, oligospermic (OS) if 1 to 9 x 10(6)/mL, and azoospermic (AS) if less than 1 x 10(6)/mL. The median follow-up time after CT before sperm analysis was 30 months. RESULTS: Analysis of 170 patients whose spermatogenesis was reassessed at least 1 year after CT showed that of 89 patients whose pre-CT counts were NS, the post-CT count was NS in 64%, OS in 16%, and AS in 20%. There was clear evidence for continued recovery beyond 1 year; the probability of spermatogenesis increased to 48% by 2 years and 80% by 5 years. There was a significantly higher probability of recovery to OS and NS count levels in the 54 patients treated with carboplatin-rather than cisplatin-based therapy. There was an independent and similar effect of normal pre-CT count. There was a reduced probability to recover to OS in the 26 patients treated with more than four cycles of CT. A prognostic model identified three groups with 25%, 45%, and 82% probabilities of recovering spermatogenesis by 2 years after CT. CONCLUSION: Analysis of pre-CT sperm count together with details of planned treatment can be used to predict recovery of spermatogenesis following germ cell CT.

Same-day admission thyroidectomy programme: quality assurance study.

OBJECTIVE: This study was conducted to evaluate the effectiveness of a same-day admission thyroidectomy programme. DESIGN: Prospective patient surveys and a retrospective quality assurance study were conducted. METHOD: Management of the initial 58 patients having a thyroidectomy at St. Joseph's Hospital, London, Ontario, after May 1992 when a same-day admission thyroidectomy programme was initiated, was evaluated. Early in the process, staff evaluation of the programme was also surveyed. RESULTS: The average length of stay for these patients was reduced from 4.5 to 3.2 days. No operative delays, cancellations, readmissions, or increased complications resulted from the new protocol. Also, patient and staff acceptance of the new programme was high. CONCLUSION: Our success with this programme has encouraged us to apply these concepts to more complex surgical patients.

Fine-needle aspiration cytology of lymphoid lesions of the salivary gland: a review of 35 cases.

OBJECTIVE: The aim of this study was to evaluate the effectiveness of fine-needle aspiration (FNA) in the diagnosis of primary lymphoid processes of the salivary gland. DESIGN: A retrospective study. METHOD: Between 1987 and 1994, 35 patients who underwent fine-needle aspiration (FNA) of the salivary gland had a diagnosis of a primary lymphoid process. Most presented with palpable parotid (28 patients) or submandibular (4 patients) gland masses which prompted a clinical diagnosis of pleomorphic adenoma. FNA was performed with immediate on-site evaluation. Flow cytometric cell-surface-marker analysis was performed in 28 of the 35 cases to determine the clonality of the B-cell proliferations. RESULTS: Sixteen cases of reactive hyperplasia and nine cases of malignant lymphoma diagnosed by FNA were confirmed by subsequent histopathologic examination. Lymphoma was confirmed in six of eight cases diagnosed as suspicious for lymphoma by FNA. Hodgkin's disease was suspected but not confirmed in one case and was diagnosed as a probable Warthin's tumour in another case. In all cases, the FNA diagnosis of either a reactive or malignant lymphoid process was unexpected and influenced the patient's further management. For patients diagnosed with an intraparotid lymph node, surgery could be deferred for a short period with the hope that the lymphadenopathy would spontaneously regress. For patients with a preoperative FNA diagnosis of lymphoma, a more limited biopsy could be performed, thereby reducing the operative risk to the patient and plans to process the tissue according to the institution's lymphoma protocol could be made. CONCLUSION: Clinically, reactive intraparotid lymph nodes and lymphomas present as parotid enlargements that are indistinguishable from pleomorphic adenomas. FNA is the only method of accurately establishing a preoperative diagnosis in these patients.

Comparison of maxillectomy patients with immediate versus delayed obturator prosthesis placement.

OBJECTIVE: To compare maxillectomy patients with immediate versus delayed placement of an obturator prosthesis in terms of patient outcomes. DESIGN: Retrospective review. OUTCOME MEASURES: The outcomes of 23 maxillectomy patients seen between 1975 and 1993 at St. Joseph's Health Centre in London, Ontario, were analyzed. METHODS: For 17 patients, a prosthesis was placed immediately as part of the operative procedure, and for 6 patients, an occlusive dressing only was placed. RESULTS: In all parameters studied (length of stay, i.v. requirements, swallowing, clear fluid diet and ambulation), the prosthesis group progressed more quickly and had a more rapid return to normal function. CONCLUSION: This study demonstrates the benefits of immediate prostheses for maxillectomy patients and justifies their continued use.

Measurement of limb length inequality. Comparison of clinical methods with orthoradiography in 190 children.

We studied the agreement in measuring limb length inequality with orthoradiograms and clinical methods. In 190 children attending our Limb Length Clinic for the first time, 95% of the measurements with wooden boards was within -1.4 and +1.6 cm of the results of the orthoradiograms. A tape measure had significantly less agreement. The predictive value of a localization of the main limb length inequality above the knee, as found with a tape measure, was 64% and for a localization of the main limb length inequality below the knee 75%. A Wooden Board Reliability Graph is presented, which can be helpful in the decision to perform orthoradiographic measurements of limb length inequality in, e.g., evaluation of impairment.

Imaging and surgery in hyperparathyroidism: a 10-year review.

A 10-year review (1984-1994) of patients undergoing surgical treatment for hyperparathyroidism at St. Joseph's Health Centre in London, Ontario, is presented. The role of preoperative localization is discussed. We review our experience with the various imaging modalities and their usefulness in the surgical decision-making process. Our experiences with the surgical management of both primary and secondary hyperparathyroidism are evaluated. Controversies in parathyroid surgery, unilateral versus bilateral neck exploration for parathyroid adenomas, and autotransplantation versus total parathyroidectomy for secondary hyperparathyroidism are discussed and our approach is explained.