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Biomedical subjects

S R Baker

Publications and source records attributed to S R Baker.

At least 181 records · Page 10Linked to original sources
PubMed1982

Evidence for multiple leukotriene D4 receptors in smooth muscle.

Using pure leukotriene D4 (LTD4) as the agonist, we determined the dissociation constants, Kb and pA2 values, for the selective leukotriene antagonist FPL 55712 on guinea pig ileum, trachea, and parenchyma. Responses of the 3 tissues to LTD4 were competitively antagonized by FPL 55712. Kb and pA2 values were similar for trachea and parenchyma. However, these values differed from those obtained in ileum. We propose the existence of multiple LTD4 receptors, with those in lung differing from LTD4 receptors in ileum.

Animals↗
PubMed1982

Prognostic factors in nasopharyngeal malignancy.

Data collected from review of 99 patients with carcinoma of the nasopharynx was submitted for statistical analysis. The purpose of the analysis was to determine patient, tumor and treatment factors that influence survival. The only patient factor observed to influence survival was patient age (P = 0.05). Greatest survival was noted for patients in the age group 0 to 20 years (44%), while poorest survival rates were in patients over 60 years of age (14%). Tumor factors influencing survival included the location of regional metastases (P = 0.05). Homolateral cervical metastases was associated with survival rates approximating 30% compared with 10% when bilateral metastases were present. Survival decreased markedly as cervical metastases progressed from the upper third of the neck to involvement of the middle and lower thirds. Survival was 20% when nodal involvement was confined to the upper neck compared with 8% when metastases extended to lower cervical regions. The only treatment factor apparently influencing survival was duration of therapy (P = 0.08). Longer treatment periods offered better five-year control rates. Higher dosage levels of radiotherapy were associated with improved survival, but not significantly so.

Adolescent↗
PubMed1982

Treatment of the patient with extensive osteoradionecrosis of the mandible.

The management of osteoradionecrosis of the mandible remains controversial. Involvement of large areas of the mandible or the entire mandible with osteoradionecrosis may result in severe functional disability and cosmetic deformity. Pain, trismus, difficulty with speech and eating, and a malodorous wound are all problems that must be corrected. Local forms of therapy may be inadequate in the treatment of extensive osteoradionecrosis, and more aggressive surgical management is required. The extent of surgical intervention depends on the individual case. However, preservation of function and avoidance of disfigurement are important goals in the treatment plan. From both a functional and cosmetic standpoint, surgical management can be effective in achieving satisfactory rehabilitation goals.

Adult↗
PubMed1982

Innovative regional therapy for head and neck cancer.

A totally implantable infusion pump (infusaid) has been developed to achieve continuous drug delivery for long periods of time. The recent availability of a dual-catheter totally implantable infusion pump permits the infusion of both external carotid arteries simultaneously. This has obvious advantages for the treatment of extensive tumors of the head and neck that extend across the midline. Likewise, for the first time, unilateral local-regional disease that extends inferiorly beyond the nutrient field of the external carotid artery may be treated with intra-arterial infusion chemotherapy without the need to infuse the common carotid or innominate arteries. Unilateral infusion of the entire head and neck is accomplished by using the dual-catheter pump to infuse both the thyrocervical trunk and the external carotid artery.

Antineoplastic Agents↗
PubMed1982

Long-term intraarterial chemotherapy infusion of ambulatory head and neck cancer patients.

The complications of percutaneous intraarterial infusion chemotherapy of the head-and-neck-cancer patient has dampened enthusiasm for this approach. A totally implantable infusion pump system circumvents many of these complications and will in the long term enhance the opportunity to expand upon the advantages of infusion chemotherapy for the benefit of all cancer patients.

Adult↗
PubMed1982

A comparative study of the physical properties and enzymatic reactions of slow reacting substance of anaphylaxis and some leukotriene D4 isomers.

Eight synthetic isomers of 5-hydroxy-6-S-cysteinylglycine -7,9,11,14-eicosatetraenoic acid were compared with authentic guinea pig SRS-A using UV spectroscopy, high performance liquid chromatography and soybean lipoxygenase. It was found that only the 5S, 6R 7,9trans 11,14cis isomer was similar to SRS-A in all respects. The 5S,6R 7trans, 9,11,14 cis isomer shows similar UV and HPLC characteristics but differs in that it spontaneously undergoes a 1,7 hydride shift reaction and unexpectedly does not react with soybean lipoxygenase.

Animals↗
PubMed1981

Functional upper airway obstruction. A new syndrome.

Functional airway obstruction is an uncommon condition that must be considered in adults with apparent airway distress. The disorder is characterized by stridor without abnormal physical findings on laryngeal examination other than intense vocal cord adduction. Three patients had functional upper airway obstruction documented by objective criteria. In each case the respiratory embarrassment was severe enough to warrant tracheostomy. A thorough search for systemic causes did not reveal an organic etiologic factor. Psychiatric evaluation demonstrated psychological disorders in each case. Functional airway obstruction represents an important consideration in the differential diagnosis of airway obstruction in the adult.

Adult↗
PubMed1981

Free lateral thoracic flap in head and neck reconstruction.

Clinical reports of free skin flaps that are transferred by microvascular anastomosis have increased in frequency since the introduction of microvascular surgery. The groin flap with its large area of available skin, reliable donor vessels, and favorable donor scar is probably one of the most frequently used free flaps. However, it has a distinct disadvantage with its short vascular pedicle. The free lateral thoracic flap has a longer vascular pedicle and larger-caliber vessels compared with the groin flap. A vascular pedicle that contains vessels, approaching 2 mm in external diameter and up to 10 cm in length, allows greater versatility in head and neck reconstruction. Once the surgeon has become familiar with the vascular anatomy of the lateral thoracic area, free flap harvest requires less time and is simpler relative to the harvest of the free groin flap.

Aged↗
PubMed1981

Reconstruction of mandibular defects with the revascularized free tensor fascia lata osteomyocutaneous flap.

In recent years, experience with microvascular surgery has enabled the use of free vascularized bone grafts to bridge mandibular defects. Such grafts have several advantages over conventional nonvascularized bone grafts. Advantages include improved survival and more rapid healing in poorly vascularized recipient sites, less risk of absorption, and greater resistance of the graft to infection and subsequent extrusion. Several free osteocutaneous rib grafts have been reported for mandibular replacement; however, only a few reports have advocated the use of free compound flaps that use iliac crest bone. Two cases of immediate mandibular reconstruction used the revascularized free tensor fascia lata osteomyocutaneous flap. This flap uses revascularized iliac crest bone. Viability of one bone graft was confirmed by scintigraphy ten days after transfer of the compound flap.

Aged↗
PubMed1981

The Singer-Blom voice restoration procedure.

The Singer-Blom tracheoesophageal puncture (TEP) technique is an effective and safe surgical method for speech rehabilitation of the alaryngeal patient. The silicone prosthesis, which is fitted in the TEP tract, allows pulmonary air to be used for voice production but prevents aspiration. In a series of 63 patients, 56 (89%) were able to develop fluent speech, but only 45 patients (71%) currently use tracheoesophageal speech as their prime mode of communication. Of the 18 patients (29%) who no longer use tracheoesophageal speech, 11 experienced either inadvertent dislodgement of the prosthesis or were noncompliant, five patients failed to develop fluent speech after adequate trial, and two patients failed because of aspiration. Almost all of the successful patients have voice quality and fluency that are as good or better than accomplished esophageal speakers, despite the fact that most of these patients were unable to learn esophageal speech. Since the Singer-Blom technique has eliminated most of the problems associated with other forms of surgical speech rehabilitation, it is considered to be the best surgical technique presently available for restoring speech in the alaryngeal patient.

Esophagus↗
PubMed1981

Preoperative cisplatin and bleomycin therapy in head and neck squamous carcinoma. Prognostic factors for tumor response.

A multi-institutional National Cancer Institute trial of preoperative cisplatin (100 mg/sq m, day 1) and intravenous bleomycin sulfate (15-mg/sq m bolus, day 3, followed by 15 mg/sq m/day, 24-hour infusion, days 3 to 7) was carried out in patients with previously untreated, resectable stage III and IV squamous cell carcinoma of the oral cavity or larynx and hypopharynx. Of the first 113 patients who received a single course of induction chemotherapy, eight complete responses and 47 partial responses at the primary site were observed (49%). Of 76 patients who had clinically positive regional adenopathy, 11 complete responses and 31 partial responses of neck nodes were observed (55%). The response rates of the primary tumor and the regional nodes to induction chemotherapy were assessed with respect to several pretreatment patient and tumor characteristics and to reported toxic effects after chemotherapy. Of the factors examined, no prognostic indicators were highly useful to predict the response of the primary tumor. However, the response of regional adenopathy was associated with the initial N class, the site of primary tumor, and the response of the primary tumor to induction chemotherapy.

Bleomycin↗
PubMed1981

Malignant tumors of the nasopharynx.

One hundred and twenty patients with malignancy of the nasopharynx were reviewed. The most common presenting symptoms of this disease were cervical mass and hearing loss. Neoplasm occurred three times more frequently in males than in females. Cranial nerve dysfunction was present in 17.5% of patients at the time of initial evaluation. The overall 3- and 5-year determinate survival for the entire series of nasopharyngeal malignancies was 38.9, and 27.0%, respectively. Nonsquamous cell and undifferentiated neoplasms (24%). The presence of cervical metastases offered a poorer prognosis. A 39.6% 5-year survival was recorded for patients without nodal disease. Massive lymphadenopathy or bilateral cervical metastases forecasted an ominous 5-year survival of 13.6%. Control rate was greatest among patients with tumors restricted to one area of the nasopharynx and without regional metastases. The 5-year survival of such patients was 71.4% compared to 13.3% for patients having tumor extension beyond the nasopharynx producing cranial nerve impairment or bone erosion.

Adenocarcinoma↗
PubMed1980

Glycosaminoglycans and other carbohydrate groups bound to proteins of control and transformed cells.

The membrane glycoproteins from control (BHK21/C13) and Rous sarcoma virus-transformed (C13/B4) baby hamster kidney cells labeled with D-[14C]- or D-[3H]glucosamine, respectively, were purified by means of polyacrylamide electrophoresis and gel electrofocusing. The homogeneity of the isolated glycoproteins was demonstrated by analysis of the NH2-terminal peptides. Some purified glycoproteins were found to be hybrid molecules in terms of the type of oligosaccharides they bear. The majority of the oligosaccharides (approximately 90%) bound on thee glycoproteins are N-glycosidically linked (Mr approximately 3000 to 5000). Another 5% appears to be small groups linked O-glycosidically to several adjacent or closely spaced amino acid residues. The remainder (5%) of the carbohydrate groups appears to be small, covalently bound glycosaminoglycans. This is the first report of hybrid molecules bearing glycosaminoglycans in the cell surface. The ratio of the types of oligosaccharides varies among different glycoproteins. There is slightly more glycosaminoglycan present on glycoproteins from malignant cells. A remarkably complex but similar array of N-glyucosidically linked oligosccharides is bound to different individual membrane glycoproteins. Each individual polypeptide must contain only a small number of the total observed carbohydrate groups, i.e. the carbohydrate groups on individual polypeptides are grossly heterogeneous. This implies that purification is based largely on the characteristics of the polypeptide, and that overall charge and size of the carbohydrate groups are relatively constant in a single population of glycoproteins. Our results suggest that the differences between the carbohydrate groups derived from glycoproteins from control and transformed cells are mainly quantitative.

Animals↗
PubMed1980

Sleep apnea syndrome and supraglottic edema.

Obstructive sleep apnea is becoming more widely recognized. Otolaryngologists will be called upon to evaluate affected patients and offer consultation as to the appropriateness of surgical intervention. The extent to which this syndrome is attributable to edema of the larynx and hypopharynx is unknown. It may, on occasion, explain chronic fatigue, weight loss, and daytime somnolence seen in some patients following irradiation of the head and neck. Sleep apnea associated with upper airway obstruction can be confirmed by polysomnography during sleep. Monitoring the EEG, electro-oculogram, electromyogram, ECG, airflow, and respiratory effort allows differentiation of obstructive sleep apnea from central or mixed apnea. Once the diagnosis of obstructive sleep apnea is established, treatment consists of correcting the airway obstruction.

Adult↗
PubMed1980

Carcinoma of the lip.

Carcinoma of the lip is a common variety of head and neck malignancy frequently seen in the elderly Caucasian male. Three hundred and fifty consecutive cases of invasive squamous cell carcinoma of the lip are anlayzed and the treatment methods and their results are presented. Surgical management is recommended for most patients because of the advantage of tumor margin assessment, avoidance of radiotherapy complications, and rapid rehabilitation.

Adult↗