Biomedical subjects

Patrick J Byrne

Publications and source records attributed to Patrick J Byrne.

7 recordsLinked to original sources

PubMed2005

Scalp reconstruction.

The unique properties of the human scalp affect the surgeon's ability to reconstruct defects in this area. The scalp has a rich vascular supply, the ability to withstand wounds of greater tension than other regions, and often has hair that can camouflage resulting scars or asymmetries. Nevertheless, most of the scalp is relatively inelastic and is ideally reconstructed with hair-bearing skin. These properties compromise the ease of effective reconstruction. However, multiple reconstructive options exist. The selection depends on the size and thickness of the defect, its location on the scalp, limiting comorbidities of the patient, and the need for immediate or delayed reconstruction. These options are reviewed in a systematic manner, organized by the factors outlined previously.

Humans↗

PubMed2004

Long-term clinical and pathologic response of Barrett's esophagus after antireflux surgery.

BACKGROUND: The impact of antireflux surgery on outcome in Barrett's esophagus, in particular its effect on both the regression of metaplasia and the progression of metaplasia through dysplasia to adenocarcinoma, remains unclear. This long-term follow-up study evaluated clinical, endoscopic, histopathologic, and physiologic parameters in patients with Barrett's esophagus who underwent antireflux surgery in a specialist unit. METHODS: Between 1985 and 2001, 58 patients with Barrett's esophagus (49 long-segment and 9 short-segment) underwent a Rossetti-Nissen fundoplication, 32 via open procedure and 26 laparoscopically. Symptomatic follow-up with a detailed questionnaire was available in 58 (100%) and follow-up endoscopy and histology in 57 (98%) patients, and 41 patients (71%) underwent preoperative and postoperative 24-hour pH monitoring. RESULTS: At a median follow-up of 59 months, 52 patients (90%) had excellent symptom control, whereas 6 patients (10%) had significant recurrent symptoms and were on regular proton pump inhibitor medication. Seventeen of 41 patients having preoperative and postoperative pH monitoring (41%) had a persistent increase of acid reflux above normal. Thirty-five percent (20 of 57) of patients showed either partial or complete regression of Barrett's epithelium. Six of 8 patients with preoperative low-grade dysplasia showed evidence of regression. Dysplasia developed after surgery in 2 patients, and 2 patients developed adenocarcinoma at 4 and 7 years after surgery. All 4 of these patients had abnormal postoperative acid scores. CONCLUSIONS: Nissen fundoplication provides excellent long-lasting relief of symptoms in patients with Barrett's esophagus and may promote regression of metaplasia and dysplasia. Control of symptoms does not concord fully with abolition of acid reflux. Progression of Barrett's to dysplasia and tumor was only evident in patients with abnormal postoperative acid scores, suggesting that pH monitoring has an important role in the follow-up of surgically treated patients.

Adenocarcinoma↗

PubMed2004

Lip augmentation.

Lip augmentation has become increasingly popular in recent years as a reflection of cultural trends emphasizing youth and beauty. Techniques to enhance the appearance of the lips have evolved with advances in biotechnology. An understanding of lip anatomy and aesthetics forms the basis for successful results. We outline the pertinent anatomy and aesthetics of the preoperative evaluation. A summary of various filler materials available is provided. Augmentation options include both injectable and open surgical techniques. The procedures and materials currently favored by the authors are described in greater detail.

Adipose Tissue↗

PubMed2004

Importance of facial expression in facial nerve rehabilitation.

PURPOSE OF REVIEW: This review discusses contemporary evidence for the importance of facial expression to human beings. Strategies for management of patients with facial nerve dysfunction are discussed. RECENT FINDINGS: The purpose of facial expression from a cognitive neuroscience perspective has become clearer, including its role in emotional communication and identification. Facial retraining may have a role in rehabilitation. SUMMARY: Greater awareness of the biologic basis for facial expression may lead us to pay increased attention to evaluation and treatment of this component of facial nerve dysfunction. The timing of intervention remains important, and many effective techniques exist.

Adult↗

PubMed2004

Detection of BRAF mutation on fine needle aspiration biopsy specimens: a new diagnostic tool for papillary thyroid cancer.

Numerous biomolecular markers have been studied to improve the accuracy of fine needle aspiration biopsy (FNAB) in the diagnostic and prognostic evaluation of thyroid tumors, but none of them has yet become clinically useful. The recently discovered BRAF mutation, which occurs specifically in papillary thyroid cancers (PTC) with a high prevalence and is associated with poor clinicopathological outcomes, has the potential to be a useful diagnostic and prognostic marker for PTC. In the present study, we investigated whether detection of BRAF mutation on FNAB specimens was technically possible and could be used as an adjunct diagnostic tool with routine FNAB. Evaluation of a new colorimetric mutation detection method demonstrated 100% sensitivity and 100% specificity in comparison with conventional DNA sequencing as the "gold standard" in a large pool of DNA samples from various primary thyroid tumor specimens and cell lines. We found this novel technique even more sensitive in detecting BRAF mutation on FNAB specimens than conventional sequencing. In a series of 48 patients undergoing thyroidectomy, mostly for thyroid cancer or for suspicion of cancer, we performed preoperative FNAB and, using the colorimetric mutation detection method, identified BRAF mutation on the cytological specimens. Prospective analysis showed that 50% of the nodules that proved to be PTC on surgical histopathology were correctly diagnosed by BRAF mutation analysis on FNAB specimens; there were no false positive findings. Thus, we have demonstrated the usefulness of BRAF mutation detection on FNAB specimens that can help diagnose and identify those PTC patients who may need more aggressive surgical treatment and vigilant clinical monitoring.

Biomarkers, Tumor↗

PubMedDate not supplied

The use of "inside-out" lateral osteotomies to improve outcome in rhinoplasty.

OBJECTIVE: To evaluate the anatomic effects of the transnasal nasal "inside-out" lateral osteotomy in comparison to a continuous lateral osteotomy to widen the excessively narrow bony nasal pyramid. DESIGN: A series of 4 fresh cadavers were used. Lateral osteotomies were performed on each cadaver. On one side, a continuous lateral osteotomy was performed with a curved, guarded 4-mm osteotome. On the contralateral side, a straight 2-mm osteotome was used to perform the transnasal perforating inside-out lateral osteotomy. The soft tissue was then dissected off the nasal dorsum and the effects were noted. Specifically, the following factors were assessed: (1) the continuity of the internal and external periosteum; (2) any change, without manipulation, of the position of the lateral nasal walls; (3) the mobility of the fragments; and (4) the effect of any of the preceding factors on the nasal airway. RESULTS: All 4 cadavers showed identical results. The external and internal periostea were significantly disrupted on each of the sides with continuous osteotomies. The periosteum was completely preserved on the sides, which underwent inside-out lateral osteotomies, with the exception of the 3 or 4 holes created by the 2-mm osteotome. In each of the sides with continuous osteotomies, the lateral nasal wall was demonstrably unstable, as the segment was, to varying degrees, displaced inwardly. The inside-out lateral osteotomized segments were uniformly lateralized and stable to gentle palpation. Finally, these changes corresponded to a visible effect on the diameter of the nose in the region of the nasal valve. The inward displacement of the segments undergoing continuous osteotomies narrowed the airway. However, the contralateral inside-out osteotomized segments were lateralized, which widened the diameter of the valve. CONCLUSIONS: The inside-out lateral osteotomy is an effective technique for lateral repositioning of the bony lateral sidewall of the nose. It is reproducible and accurate and appears to provide greater preservation of the periosteal support of the bony segments than a continuous osteotomy. This technique provides a more predictable long-term result, with preservation and/or improvement of the nasal airway. The procedure is ideal for managing the bony nasal segment that needs lateralization, particularly in revision rhinoplasties or after trauma.

Cadaver↗

PubMedDate not supplied

An electrophysiologic model for functional assessment of effects of neurotrophic factors on facial nerve reinnervation.

OBJECTIVES: To establish a sound objective model for assessing the effects of neurotrophic factors on facial nerve function after injury and to compare the effects of brain-derived neurotrophic factor (BDNF) with its neutralizing antibody on facial nerve function after injury. DESIGN: Prospective electrophysiologic analysis of recovery of function 4 weeks after axotomy involving facial nerve transection and primary end-to-end reanastomosis in adult rats and blind comparison with randomized intramuscular injection of either BDNF, monoclonal antibody to BDNF in neutralizing concentration, or control solution. RESULTS: There were no statistically significant differences between groups in latencies, duration, amplitude, area, or conduction velocity before axotomy, and recorded conduction velocities were consistent with previously reported values, which suggests that the recordings were reliable and reproducible. After transection, there was a mean increase in latency 1 and decreases in latency 2, integrated average area, muscle action potential duration, amplitude, and conduction velocity for all 3 groups. When the groups were compared after transection, the anti-BDNF group showed a significant decrease in conduction velocity and muscle action potential duration (Kruskal-Wallis P = .01 and P = .008, respectively) compared with the other groups. There were no statistically significant differences in latencies, amplitude, or area among the groups. CONCLUSIONS: We have established an electrophysiologic model for objective assessment of facial nerve function in the rat. Future studies should combine functional electrophysiologic assessment and histologic examination to provide a more robust model for studying the effects of neurotrophic factors on facial nerve reinnervation and synkinesis.

Animals↗