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Biomedical subjects

J T Johnson

Publications and source records attributed to J T Johnson.

At least 181 records · Page 10Linked to original sources
PubMed1990

Management of inverted papilloma.

This paper updates a 1981 report on the management of inverted papilloma. In that report, routine lateral rhinotomy with en bloc resection of the lateral nasal wall, including the entire schneiderian membrane, was recommended. This report emphasizes the use of computed tomography scanning in management planning. Of 33 patients with inverted papilloma treated between 1969 and 1987, 7 had associated squamous cell carcinoma. Twenty-two patients with IP alone were treated with medial maxillectomy; however, 3 patients have been successfully treated with either a Caldwell-Luc/ethmoidectomy or an external ethmoidectomy for localized disease. The use of computed tomography capable of higher resolution allowed preoperative determination of the extent of disease, enabling the surgeon to plan the surgery more precisely. Patients were followed for an average of 9.6 years. Recurrent disease occurred in one patient (4%) following a lateral rhinotomy/medial maxillectomy approach. The principles set forth in this series of patients remain the same as those previously described due to the unique characteristics of this tumor: its ability to destroy bone, its tendency to recur, and its association with malignancy. The technique of lateral rhinotomy and en bloc excision of the lateral nasal wall, followed by meticulous removal of all mucosa in the ipsilateral paranasal sinuses, remains the standard therapy.

Adult↗
PubMed1990

Management of tumors arising in the parapharyngeal space.

Tumors originating in the parapharyngeal space are rare. During the period of January 1977 to July 1989, 51 patients underwent surgery for parapharyngeal space tumors at the University of Pittsburgh's Eye and Ear Hospital. Eighty percent of the parapharyngeal space neoplasms were benign; 20% were malignant. Fifty-seven percent (31/54) were of neurogenic origin, 30% (16/54) were of salivary origin, and 13% (7/54) were of miscellaneous origin. The use of computed tomography scan and magnetic resonance imaging, and selective use of angiography, allowed us to ascertain the location, size, vascularity, and relation of parapharyngeal space tumors to surrounding anatomical structures. Imaging techniques established the site of origin of these tumors with 96% accuracy. This information was essential in planning surgical approaches and predicting prognoses. Details of the surgery, morbidity, and outcome of these patients are presented.

Adolescent↗
PubMed1990

Adjuvant methotrexate-5-fluorouracil for extracapsular squamous cell carcinoma in cervical metastasis.

A trial of surgery, irradiation, and adjuvant chemotherapy was offered to patients with extracapsular spread of squamous cell carcinoma in cervical metastases. Following surgery and irradiation, methotrexate, 5-fluorouracil, and leucovorin were administered 18 times over 6 months. Fifty patients undertook chemotherapy, while 47 patients declined further therapy. Comparison of the two groups according to stage, site, and Karnofsky performance status demonstrated no significant differences. The number of nodes encountered and the number and percentage of nodes with extracapsular spread were similar in the two groups. The minimum 5-year adjusted survival for patients undergoing adjuvant chemotherapy is 54% (20 of 37 patients), while survival of patients who failed to undertake adjuvant chemotherapy was 17% (5 of 30 patients). These data suggest the efficacy of methotrexate-5-fluorouracil adjuvant chemotherapy and support the need for a prospective randomized clinical trial.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Polysomnography early after uvulopalatopharyngoplasty as a predictor of late postoperative results.

We performed nocturnal diagnostic polysomnography (PSG 1), PSG early after UPPP on the second to the fifth postoperative night (PSG 2) and PSG late after UPPP (PSG 3) six or more weeks after surgery, on 15 male patients with obstructive sleep-disordered breathing. On PSG 1, the A + H/I for the group was 66.6 +/- 8.8 (mean +/- SE). During non-REM sleep the A + H/I on PSG 3 (29 +/- 10) was lower than it was on PSG 2 (54.3 +/- 11.3) (p = 0.004) and lower than that on PSG 1 (70.8 +/- 10.3) (p = 0.003). Similarly, during non-REM sleep, the AI on PSG 3 (16.1 +/- 7.4) was less than that on PSG 2 (39.1 +/- 10.4) (p = 0.003) and less than that on PSG 1 (41.7 +/- 9.6) (p = 0.015). In the eight patients in whom REM sleep was recorded on all three PSGs, there was no difference with respect to A + H/I or AI. The nadir of SaO2 during non-REM sleep was higher during PSG 3 than during PSG 1 (p = 0.002), but not different from that on PSG 2. There were no differences among the three studies with respect to REM-related nadirs of SaO2; however, there was a good deal of interindividual variability across the three PSGs. In general, individuals with satisfactory amelioration of sleep-disordered breathing on PSG 2 demonstrated similar improvement on PSG 3. Patients who did not have a substantial improvement in the early postoperative period often had improvement on PSG 3, but there was a good deal of interindividual variability in this regard. We conclude that PSG within a few days following UPPP is warranted in patients with obstructive sleep-disordered breathing to determine if there has been worsening of upper airway function or oxygenation (or both) during sleep in the early postoperative period. A satisfactory result early after UPPP suggests that a late postoperative PSG is unnecessary, with savings in cost and the convenience.

Adult↗
PubMed1990

Tumor markers of head and neck carcinoma.

Evaluation of the various tumor markers that have been studied in patients with SCC of the head and neck reveals no single marker or battery of markers that is sufficiently specific or sensitive to provide useful clinical data in the treatment of patients with these cancers. This finding reinforces previous investigative and clinical impressions that would suggest that carcinoma of the head and neck is a heterogeneous entity. These tumor marker studies provide additional support for the hypothesis that although various carcinomas of the head and neck may appear identical microscopically, their behavior both clinically and biochemically is nevertheless heterogeneous. Due to the wide variability of the behavior of these tumors, the search for the perfect tumor marker continues. The development of additional multiple-marker batteries may provide the closest approximation to a perfect marker that is feasible. Additional studies into the nature and function of oncogenes may provide additional clues to the variability of these tumors and the resultant heterogenicity of their marker expression.

Antibodies, Viral↗
PubMed1990

Wound infection in head and neck surgery: prophylaxis, etiology and management.

Antibiotic prophylaxis in clean-contaminated major head and neck surgery is mandatory. Many prospective, randomized and double blind studies have established the efficacy of antibiotics against a large spectrum of bacteria. Prophylaxis should be initiated prior to surgery, and prolonged administration of antibiotics beyond the first 24 hours following surgery is unnecessary. The experience of the Eye and Ear Hospital of Pittsburgh is presented along with other studies concerning the effect of different regimens on wound outcome. The pathophysiology, bacteriology, evaluation and treatment of a postoperative infection are discussed, emphasizing the importance of gentle tissue handling and meticulous surgical technique.

Anti-Bacterial Agents↗
PubMed1990

Hearing loss--risk factor for cisplatin ototoxicity? Observations.

Ototoxicity associated with cisplatin chemotherapy is well established, but opinion is split regarding the relative risk associated with preexisting hearing loss. The emerging consensus is that pretreatment loss does not increase the risk of cisplatin ototoxicity. Results from a preliminary study of a small sample from our patient population supports this consensus.

Audiometry↗
PubMed1990

Thyroglossal duct and second branchial cleft anomalies in adults.

Definitive treatment is surgical removal of the cyst and any tract, with care taken to preserve vital structures. TDCs and BCCs are congenital cervical lesions that are encountered in adults. Experiences at the Eye and Ear Hospital of Pittsburgh are reviewed. Forty-five patients with TDCs and 59 patients with BCCs were treated between 1983 and 1988. Clinical findings are discussed and principles for diagnosis are detailed.

Adolescent↗
PubMed1989

How to stop a nosebleed.

Epistaxis is a common emergency usually caused by local trauma to the nasal mucosa. Occasionally, it may result from systemic diseases such as atherosclerosis, hypertension, or coagulopathy. Anterior nosebleed often can be controlled with topical vasoconstriction and cautery. Intranasal packing may be necessary to tamponade bleeding vessels. Occlusion of the sinus ostia by anterior nasal packing may necessitate prophylactic use of antibiotics to prevent sinusitis. Posterior nosebleed requires nasopharyngeal packing. Patients must be closely monitored and given supplemental high-humidity oxygen. Persistent or recurrent nosebleed or failure of posterior nasopharyngeal packing to control bleeding indicates the need for otolaryngologic consultation and perhaps surgical intervention.

Cautery↗
PubMed1989

Biology, cytogenetics, and sensitivity to immunological effector cells of new head and neck squamous cell carcinoma lines.

Twenty-one head and neck squamous cell carcinoma (HNSCC) cell lines were established from 89 fresh tumor specimens in order to study the biology of HNSCC lines, establish tumors in nude mice, and evaluate the sensitivity to immunological effector cells of these tumors in vitro and in vivo in nude mice. The lines were established from explants using differential trypsinization and culture for 2 to 20 mo. The explants were derived from 11 different sites. Three pairs of lines were derived from both the primary tumor and metastatic lymph nodes in the same patients. All cultures grew as either compact or diffuse adherent monolayers, and they had a median doubling time of 86 h (range, 33 to 531 h). DNA fingerprinting confirmed that the HNSCC lines were individual isolates. Thirteen of 14 lines tested induced tumors in athymic mice. The histology of each line growing in nude mice was similar to that of the original tumor tissue. Immunocytochemistry showed keratin production in all lines tested. Aneuploidy (36 to 87 chromosomes) was present in all 16 lines studied; the median chromosome number for lines derived from primary tumors was 70, whereas for lines originating from metastatic or recurrent tumors, it was 54. Karyotypic analysis showed deletion of the short arm of chromosome 3 (3p-) in 12 of 16 cell lines and trisomy 6 in 12 of 16 lines. In addition, translocations between chromosomes 9 and 11 or 9 and 12 were each present in five of 16 lines tested. The HNSCC lines were resistant to lysis by natural killer cells, but were efficiently lysed by lymphokine-activated killer cells in 4-h 51Cr release assays. These new lines have allowed us to establish a model of local adoptive immunotherapy of HNSCC in tumor-bearing nude mice, and they provide a resource for future studies of the biology of HNSCC.

Adult↗
PubMed1989

Factors delaying the diagnosis of oral and oropharyngeal carcinomas.

Most squamous cell carcinomas of the oral cavity and oropharynx are not diagnosed until they have attained at least the T2 stage (greater than 2.0 cm). This study identifies factors which may contribute to the delayed diagnosis of these tumors, despite the fact that they frequently arise at sites readily accessible to examination. Personal interviews of 149 patients with oral and oropharyngeal squamous cell carcinoma revealed delays by patients of one day to more than one year (mean, 17 weeks) before seeking care. Furthermore, delay by doctors occurred in 45 instances (30%). Neither short nor long delays had a statistically significant relationship to tumor T stage at the time of diagnosis. The length of patient delay was also not related to age, gender, amount of education, or history of alcohol consumption. The authors concluded that the early carcinomas were probably asymptomatic and subsequent manifestations were commonly misinterpreted as benign or innocuous oral/dental problems. These inconspicuous or misleading perceptions may be primarily responsible for the advanced stages of these tumors at the time of discovery. Emphasis must, therefore, be placed upon gaining access to high-risk individuals for periodic oral and oropharyngeal examinations and upon educational efforts to increase the skill of primary health care providers in recognizing this problem.

Adult↗
PubMed1989

Posterior nasal packing. Are intravenous antibiotics really necessary?

The use of antimicrobial prophylaxis in the presence of posterior nasal packing for the treatment of posterior epistaxis remains controversial. Twenty patients were prospectively randomized into this placebo-controlled, double-masked pilot study to receive either placebo or cefazolin sodium. Antibiotic-impregnated posterior gauze packing was employed in all patients. No infectious complications were noted in either group. The packings from the patients in the placebo group were foul smelling and heavily colonized with gram-negative bacteria while the packings from the antibiotic group were odor-free and lightly colonized with gram-positive organisms. This preliminary study suggests the usefulness of antimicrobial prophylaxis for preventing complications from posterior nasal packing, although a larger sample size will be needed to decrease the type II (beta) error.

Adult↗
PubMed1989

The role of hemilaryngectomy in the management of T1 vocal cord cancer.

A retrospective study was undertaken to assess the outcome of 54 patients who have elected to undergo vertical hemilaryngectomy for T1, NO squamous cell carcinoma of the glottic larynx. Fifty-one (94%) of 54 patients were cured with surgery alone. The voice was preserved in 52 (96%) of 54 patients. In the subgroup of patients who had received no prior radiation therapy, voice preservation was achieved in 98% of patients and ultimate control of disease with cure was achieved in 95%. These data substantiate the contention that vertical hemilaryngectomy offers better cure rates than external beam radiation therapy alone. Our data support the efficacy of hemilaryngectomy in T1, NO glottic carcinoma. These data question the traditional belief that surgery effects its success at the expense of voice preservation, whereas external beam radiation therapy does not.

Carcinoma, Squamous Cell↗
PubMed1989

Retention and clearance of inhaled submicron carbon black particles.

Carbon black aerosols were used as a probe of the pulmonary retention and clearance of submicron particles. Male Fischer rats (COBS CD) were exposed for 20 h/d, 7 d/wk for 1, 3, or 6 wk to either 7 +/- 2 mg/m3 carbon black or filtered air. The submicron aerosol (mass median aerodynamic diameter, MMAD, 0.24 microns) was generated with a Wright dust feed-cyclone system. Lung and hilar lymph node particle burdens were determined immediately following the exposure and at preselected intervals up to 1 yr postexposure. After 1-, 3-, and 6-wk exposures, the lung burdens were 1.1 +/- 0.1, 3.5 +/- 0.2, and 5.9 +/- 0.1 mg, respectively. One year after a 1-, 3-, or 6-wk exposure, 8%, 46%, and 61% of the initial lung burden remained in the lungs. Initially, the hilar lymph nodes contained 0.2%, 0.9%, and 2.0% of the lung burdens in the 3 exposure groups, respectively. At 1 yr postexposure, particle translocation from the lungs led to a rise in lymph node burdens to 1%, 21%, and 27% of the initial lung burden. The retention of carbon black in both the lungs and lymph nodes combined was 9%, 67%, and 89% for the 1-, 3-, and 6-wk exposed animals. Lung clearance was modeled as a compartmental system consisting of four lung compartments and a regional lymph node compartment. The results from the model are similar for carbon black and diesel engine exhaust particles. However, the compartmental kinetics of carbon black differed in two ways: the deposition efficiency in the alveolar region was lower than that for diesel exhaust particles, and there was earlier transport of particles to the regional lymph nodes. These results showed that when lung burdens reached 0.8 mg, lung clearance was decreased by 50% and lymphatic transport of insoluble particles was increased.

Administration, Inhalation↗
PubMed1989

Inhibitory effect of benzene metabolites on nuclear DNA synthesis in bone marrow cells.

Effects of endogenously produced and exogenously added benzene metabolites on the nuclear DNA synthetic activity were investigated using a culture system of mouse bone marrow cells. Effects of the metabolites were evaluated by a 30-min incorporation of [3H]thymidine into DNA following a 30-min interaction with the cells in McCoy's 5a medium with 10% fetal calf serum. Phenol and muconic acid did not inhibit nuclear DNA synthesis. However, catechol, 1,2,4-benzenetriol, hydroquinone, and p-benzoquinone were able to inhibit 52, 64, 79, and 98% of the nuclear DNA synthetic activity, respectively, at 24 microM. In a cell-free DNA synthetic system, catechol and hydroquinone did not inhibit the incorporation of [3H]thymidine triphosphate into DNA up to 24 microM but 1,2,4-benzenetriol and p-benzoquinone did. The effect of the latter two benzene metabolites was completely blocked in the presence of 1,4-dithiothreitol (1 mM) in the cell-free assay system. Furthermore, when DNA polymerase alpha, which requires a sulfhydryl (SH) group as an active site, was replaced by DNA polymerase I, which does not require an SH group for its catalytic activity, p-benzoquinone and 1,2,4-benzenetriol were unable to inhibit DNA synthesis. Thus, the data imply that p-benzoquinone and 1,2,4-benzenetriol inhibited DNA polymerase alpha, consequently resulting in inhibition of DNA synthesis in both cellular and cell-free DNA synthetic systems. The present study identifies catechol, hydroquinone, p-benzoquinone, and 1,2,4-benzenetriol as toxic benzene metabolites in bone marrow cells and also suggests that their inhibitory action on DNA synthesis is mediated by mechanism(s) other than that involving DNA damage as a primary cause.

Animals↗
PubMed1989

SCC-RIA in the diagnosis of squamous cell carcinoma of the head and neck.

A reliable circulating tumor marker, appropriate for head and neck malignancy, is not yet available. This manuscript reports the efficacy of using circulating squamous cell carcinoma antigen in evaluating patients with squamous cell carcinoma of the head and neck. Serum samples from 89 patients with squamous cell carcinoma of the head and neck were obtained before treatment and at intervals following treatment. Squamous cell carcinoma antigen levels were determined by radioimmunoassay. Elevated pretreatment serum levels of squamous cell carcinoma antigen were identified in 39 of 89 patients (44%) who had head and neck squamous cell carcinoma. Of the 16 patients evaluated from this group with recurrent or persistent disease, 15 (93.5%) demonstrated elevated levels of squamous cell carcinoma antigen. However, of the 21 evaluable patients who remained disease free, only 10 (48%) had post-therapy levels within the normal range. The possible use of this marker in aiding the clinical follow-up of head and neck cancer patients is discussed.

Adult↗
PubMed1989

Hypopharyngeal reconstruction: a comparison of two alternatives.

Gastric pull-up or free jejunal interposition was used for reconstruction after total laryngopharyngectomy in 31 patients. Complications and functional outcomes of the two methods are compared. Primary swallowing was achieved in 86% of patients after gastric pull-up and in 82% of patients after jejunal interposition. Patients who underwent jejunal interposition were able to swallow sooner and had a shorter hospital stay than patients who underwent gastric pull-up. Esophageal tumor recurrence after jejunal interposition was not observed. Hepatic failure occurred in two gastric pull-up patients, leading to perioperative death in one. Flap necrosis occurred in two jejunal interposition patients and one gastric pull-up patient. Two additional fistulas occurred in jejunal interposition patients as a result of microvascular complications. Stricture developed in four jejunal interposition patients, requiring revision surgery in two. Minor complications were more common in the gastric pull-up group. Long-term speech and swallowing function are compared. Our current choice of jejunal interposition or gastric pull-up for reconstruction after total laryngopharyngectomy primarily depends on the location of the tumor.

Aged↗