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Biomedical subjects

S R Baker

Publications and source records attributed to S R Baker.

At least 37 records · Page 2Linked to original sources
PubMed1998

(2S,4S)-amino-4-(2,2-diphenylethyl)pentanedioic acid selective group 2 metabotropic glutamate receptor antagonist.

(2S,4S)-2-Amino-4-(4,4-diphenylbut-1-yl)-pentane-1,5-dioic acid 1m, is a novel metabotropic glutamate receptor (mGluR) antagonist with insignificant ionotropic affinity. It is selective antagonist of negatively-coupled cAMP-linked mGluRs with no effect on phosphoinositide coupled mGluRs. A series of 4-substituted glutamic acid analogues were prepared and it was found that compound 1k is tenfold more potent than 1m. Compound 1k has neither significant affinity for ionotropic glutamate receptors nor group 1 and 3 metabotropic receptors.

Animals↗
PubMed1998

The subcutaneous pedicle flap in melolabial reconstruction.

OBJECTIVE: To review and report our experience with the subcutaneous pedicle flap in the reconstruction of defects adjacent to the melolabial crease. DESIGN: Retrospective review. SETTING: Cutaneous surgery unit of an academic tertiary referral center. PATIENTS: One hundred nine patients with defects of the lateral aspect of the upper lip, the medial aspect of the cheek, and the melolabial crease after Moh excision of cutaneous lesions. CONCLUSIONS: In our experience, the subcutaneous pedicle advancement flap is often ideally suited to the reconstruction of cutaneous defects adjacent to the melolabial crease. We have been particularly satisfied with the results of this reconstructive technique when addressing deep defects adjoining the alar facial sulcus in patients with full cheeks.

Basal Cell Carcinoma↗
PubMed1998

Lengthening the short nose.

Correction of the aesthetically short nose is one of the most challenging problems in facial plastic surgery. We discuss several techniques aimed at the correction of this problem and propose an algorithm based on the desired effect of the lengthening procedure on tip rotation. Five principal techniques for nasal lengthening are discussed, with figures and cases to illustrate the concepts: (1) the flying buttress graft, which is made up of a single or paired spreader grafts secured to a columellar strut; (2) caudal septal grafts and (3) tip grafts of various shapes; (4) radix grafts placed to elevate the nasion; and (5) interposition grafts placed between the upper and lower lateral cartilages. When the tip is overrotated, small to moderate gains in nasal length may be achieved by a triangular-shaped caudal septal graft or a shield graft that is backed by wedge grafts near the tip. More substantial lengthening and derotation can be achieved by the flying buttress technique or by interposition cartilage or composite grafting between the upper and lower lateral cartilages. With a nasal tip that is adequately rotated or underrotated, nasal lengthening can be achieved by a rectangular-shaped caudal septal graft or by a full-length shield graft. An onlay graft to augment the radix and elevate the nasion to a higher point on the dorsum can be used alone or in combination with a tip or septal graft.

Algorithms↗
PubMed1998

Encephalocoele as a complication of intranasal sinus surgery: optimal evaluation with magnetic resonance imaging.

We report a case of post-operative frontal basal encephalocoele evaluated using a new magnetic resonance imaging (MRI) sequence, fast inversion recovery for myelin suppression (FIRMS). FIRMS was developed to enhance the differentiation between grey and white matter. In this case, the sequence was beneficial in distinguishing the encephalocoele from adjacent nasal mucosa and secretions.

Adult↗
PubMed1998

Nasal lining flaps in contemporary reconstructive rhinoplasty.

The advances that have taken place in the last decade in reconstructive rhinoplasty are based in strong major on the development of internal lining mucosal flaps used to resurface the interior of reconstructed full thickness nasal defects. This paper provides an in-depth analysis of these thin well vascularized flaps harvested from the remaining mucosa and vestibular skin of the nasal passage. They provide the foundation which is overlaid with cartilage grafts to replace skeletal support and covering flaps to resurface the grafts. This contemporary concept of layered reconstruction, replacing missing tissue with like tissue has revolutionized the approach to reconstructive rhinoplasty and has raised it to a higher level of sophistication resulting in enhancement in aesthetic and functional results.

Bone Transplantation↗
PubMed1997

Triplane rhytidectomy. Combining the best of all worlds.

OBJECTIVE: To combine certain aspects of the sub-superficial musculoaponeurotic system (sub-SMAS) and subperiosteal rhytidectomies to maximize the advantages while minimizing the disadvantages of each. DESIGN: The subperiosteal rhytidectomy is used to reposition the ptotic malar fat pad concomitantly with the elevation of the corner of the mouth by means of shifting upward the origin of the zygomatic major muscle. The sub-SMAS rhytidectomy is used to maximize elevation of the jowl. SETTING: Ambulatory surgical facility. METHOD: Preauricular and temporal dissection is subcutaneous to the malar eminence above and angle of mandible below. A subperiosteal dissection of the middle part of the face is then accomplished through a sublabial approach combined with an incision over the malar eminence. An incision is made through the SMAS from the malar eminence to the mandibular angle and sub-SMAS dissection is accomplished under the jowl. The subperiosteal dissection is suspended to the temporal fascia and the SMAS dissection is imbricated with 2 suspension suture lines. CONCLUSIONS: Follow-up in patients who are 1-year postoperative demonstrates a continued youthful elevation and flattening of the melolabial fold and complete correction of the jowl. No facial nerve injury or hematomas were observed.

Ambulatory Surgical Procedures↗
PubMed1997

Usefulness of the staged excision for lentigo maligna and lentigo maligna melanoma: the "square" procedure.

BACKGROUND: Management of lentigo maligna (LM) and lentigo maligna melanoma (LMM) may present problems because of the characteristic, yet unpredictable, subclinical peripheral and periadnexal extension of atypical junctional melanocytic hyperplasia beyond the visible margins. OBJECTIVE: We used paraffin-embedded (permanent) peripheral vertical section margin control in a staged fashion in the management of LM and LMM. METHODS: We used a modification of surgical excision in a staged fashion by means of a two-bladed knife with permanent peripheral vertical section margin control. RESULTS: This method is technically easy and results in complete histologic evaluation of the peripheral margins without compromising the measurement of tumor thickness of the primary melanoma. CONCLUSION: The use of the "square" procedure, a staged excision with permanent peripheral vertical section margin control, is useful in the management of LM and LMM.

Biopsy↗
PubMed1997

The staged cheek-to-nose interpolation flap for reconstruction of the nasal alar rim/lobule.

BACKGROUND: A deep defect of the nasal alar rim or lobule may represent a unique and difficult challenge because of the lax free margin and structural support supplied by the alar rim and lobule. Traditional closure strategies, including granulation, full thickness skin grafting, or nasolabial transposition flaps may result in unsatisfactory cosmetic and functional outcomes. OBJECTIVE: This article describes our experience with the staged cheek-to-nose interpolation flap for repairing deep skin cancer excision defects of the nasal alar rim and lobule. METHODS: The staged cheek-to-nose interpolation flap was used immediately after Mohs micrographic surgery to repair 18 deep nasal alar rim/lobule defects. In 13 patients, a free cartilage graft was used to restore structural support. RESULTS: The cosmetic and functional outcomes of each repair were judged from good to excellent by patient and surgeon. No cases of infection or flap necrosis occurred. To enhance the cosmetic outcome, three patients underwent spot dermabrasion within 2 months after flap detachment. CONCLUSION: The staged cheek-to-nose interpolation flap, with or without free cartilage grafts, consistently provides good to excellent cosmetic and functional outcomes when performed on properly selected deep nasal alar rim/lobule defects.

Cartilage↗
PubMed1997

Visualization of the extrahepatic segment of the ligamentum teres: a sign of free air on plain radiographs.

PURPOSE: To assess visualization of the extrahepatic segment of the ligamentum teres on plain radiographs, the ligamentum teres sign, which is an indicator of pneumoperitoneum. MATERIALS AND METHODS: The ligamentum teres was recognized in 12 patients with pneumoperitoneum. Findings from supine radiographs were correlated with those from oblique radiographs and computed tomograms. RESULTS: The extrahepatic segment of the ligamentum teres, which extended between the umbilicus and the ligamentum teres notch at the inferior border of the liver, was visualized on supine radiographs. The ligamentum teres appeared in the right upper quadrant as an obliquely oriented, straight, or slightly arcuate interface with a sharply demarcated inferolateral margin or as a similarly positioned, well-defined band of soft tissue of varying length. The falciform ligament was also seen in six of the 12 patients as a long, thin line that ran vertically to the right of the midline and joined the ligamentum teres caudally near or at the umbilicus. Even though there were other signs of pneumoperitoneum in all cases, the ligamentum teres sign was the most prominent in three cases. CONCLUSION: Visualization of the extrahepatic segment of the ligamentum teres on supine radiographs requires the anterior accumulation of extraluminal, intraperifoneal gas and is another sign of moderate to massive amounts of free air.

Adult↗
PubMed1997

Depiction of diaphragmatic muscle slips on supine plain radiographs: a sign of pneumoperitoneum.

PURPOSE: To describe the diaphragm muscle slip sign, a previously unreported finding of pneumoperitoneum on plain radiographs. MATERIALS AND METHODS: Diaphragmatic muscle slips were observed on supine plain abdominal (n = 6) or recumbent frontal chest (n = 3) radiographs in nine patients. Computed tomographic (CT) confirmation was available in six patients; free air was depicted on upright chest radiographs in the other three patients. RESULTS: Muscle slips of the costal portion of the diaphragm were depicted in the right upper quadrant as they indented the adjacent air-filled peritoneal cavity. On supine radiographs, these discrete muscle bundles appeared as two or three large, arcuate interfaces or as bands of increased opacity of similar dimensions, with their long axes directed vertically. These smoothly marginated bundles were parallel to the dome and converged superomedially. On the CT scans, the costal muscle slips were clearly defined as bands or small peripheral triangles impinging on the parietal peritoneum. CONCLUSION: Depiction of the undersurface of the long costal muscle slips of the diaphragm on supine plain radiographs is a sign of pneumoperitoneum.

Adult↗
PubMed1997

Conceptual considerations in head & neck reconstruction. Defect analysis and options for reconstruction.

This article reviews the authors' approach to the management of facial defects based on extensive experience in facial reconstruction. The article describes basic principles of wound healing with attention to healing by secondary intention and its role in facial reconstruction. Detailed consideration is provided for various options of repair of facial defects including primary closure, grafting, and local flap techniques.

Head and Neck Neoplasms↗
PubMed1996

Aerosolized LTB4 produces delayed onset increases in pulmonary gas trapping.

Airway obstruction, as measured by increases in postmortem pulmonary gas trapping, and lung inflammatory changes were examined in guinea pigs exposed for up to 4 h to aerosols of leukotriene B4 (LTB4) or its non-chemotactic isomer, 6-trans-12-epi-LTB4. Airway obstruction and cytological responses in isomer-exposed animals were similar to those of unexposed control animals. LTB4-exposed animals had minimal inflammatory changes at 0.5 h but became dyspneic by 2 h and had increased airway obstruction, bronchoalveolar lavage neutrophils and eosinophils, and pulmonary tissue granulocyte scores. The LTB4-induced effects at 4 h were similar to those 2 h, except for further increase in BAL neutrophils and eosinophils. LTB4-induced airway obstructive and inflammatory changes were prevented by pretreatment with the LTB4 receptor antagonist SC-41930, but were unaffected by indomethacin. Thus, prolonged LTB4 inhalation can produce delayed onset airway obstruction that is stereospecific, cyclooxygenase-independent, and temporally associated with the influx of granulocytes into lung airways.

Aerosols↗
PubMed1996

An automated film masking and illuminating system versus conventional radiographic viewing equipment: a comparison of observer performance.

RATIONALE AND OBJECTIVES: We compared observer performance in the interpretation of radiographs using an automated film masking and illuminating system (AFIS) with performance using standard radiographic viewing equipment. METHODS: Observer performance was compared in three ways. In the first method, a radiographic pattern of vertical bars of varying conspicuity was shown to 11 subjects with use of the two different viewing systems. Subjects were not allowed to use a brightlight or handle the film. We then performed a receiver operating characteristic (ROC) study to compare observer accuracy in detection of low-contrast targets. ROC methodology was also used in the third portion of our study to compare the accuracy of interpretation of cervical spine radiographs by six radiologists. In both the second and third portions of our study, film handling and use of a bright-light was permitted to simulate clinical circumstances. RESULTS: As a group, observers performed significantly better using the AFIS in the first (P < .001) and second (P < .05) portions of our study. There was no significant difference in performance in interpretation of cervical spine radiographs between the two viewing systems. CONCLUSION: The AFIS enhanced low-contrast perception, but further research is needed to determine its ideal clinical applications.

Automation↗