PubMed Health⌕ Search

Biomedical subjects

K H Calhoun

Publications and source records attributed to K H Calhoun.

At least 19 recordsLinked to original sources
PubMed1998

Teaching paradigm for decision making in facial skin defect reconstructions.

OBJECTIVE: To present a decision paradigm for facial defect reconstruction, and test the ability of this paradigm to improve resident performance. DESIGN: A decision paradigm for reconstruction of facial skin defects is proposed and explained, with patient examples. The paradigm's usefulness is then tested with residents. SETTING: Otolaryngology residency training program at a tertiary hospital. STUDY PARTICIPANTS: Otolaryngology residents. INTERVENTIONS: Twelve residents took a pretest wherein they were presented with drawings of skin defects and asked to choose the "best" (most aesthetically pleasing) type of reconstruction from a closed set. This paradigm was presented to these residents, and their posttest consisted of choosing again with the same defects and closed set of choices. MAIN OUTCOME MEASURES: Cosmetic outcomes of reconstructive decisions on the pretest and posttest were rated on a scale of 0 to 5 (with 0 indicating poor; 5, excellent). RESULTS: There was a significant improvement in reconstructive choices between the pretest and posttest (P<.001, Student t test). CONCLUSION: This paradigm can be easily modified to accommodate different surgical approaches preferred by individual surgeons and is thus useful in almost any reconstructive teaching situation.

Algorithms↗
PubMed1998

Combined Epstein-Barr virus and human papillomavirus infection in nasopharyngeal carcinoma.

Epstein-Barr virus (EBV) has been shown to be a likely etiologic agent in nasopharyngeal carcinogenesis. Human papillomaviruses (HPVs) have previously been identified in numerous upper aerodigestive tract carcinomas. This pilot study was undertaken to investigate the prevalence of combined EBV and HPV infection in 17 patients with nasopharyngeal carcinoma (NPCA) using polymerase chain reaction (PCR). The primary goal was to determine if the presence of HPV could be correlated with molecular, histologic, or clinical parameters. There were seven patients with undifferentiated NPCA (World Health Organization [WHO] type III) and 10 patients with squamous cell carcinoma (WHO type I). All 17 patients had stage IV disease at presentation. EBV was identified in 15 patients (88.2%), and HPV subtypes were identified in samples from nine patients (52.9%). All HPV-positive cases were also EBV positive. Western blot analysis of six samples showed a high level of expression of c-myc and cdc2 kinase and a low level of p53 protein in NPCAs that contained both HPV and EBV (n = 3). Increased expression of c-myc and cdc2 kinase was seen in the cases that contained EBV only, but to a lesser extent (n = 2). These findings indicate an effect of the virus on cellular proliferation and differentiation. Similarly, an elevated level of Rb protein was found only in the HPV-containing NPCAs. Moderate differentiation (keratinization) occurred in four of eight HPV-negative and none of the nine HPV-positive NPCAs. (All HPV-positive cases were poorly differentiated or undifferentiated.) This difference is statistically significant for this sample size (P < 0.03). There was a trend for the group that was HPV positive to have WHO III histology and for the HPV-negative group to have WHO I. The presence of HPV could not be correlated with any clinical parameters in this small group of patients with advanced disease; however, these data suggest that coexistence of EBV and HPV infection may be a factor in the pathogenesis of NPCA and may have an effect on regulation of cellular proliferation and differentiation.

Adolescent↗
PubMed1997

Communication after laryngectomy. An assessment of patient satisfaction.

OBJECTIVES: To determine the satisfaction of patients with their current method of alaryngeal communication. To focus primarily on the patients' perception of their own speech. DESIGN: A retrospective review of patients who underwent total laryngectomy for malignancy identified 4 groups of patients. A survey using a mailed questionnaire was used to compare groups. SETTING: Tertiary care university hospital, University of Texas Medical Branch at Galveston. PATIENTS: Forty-seven patients underwent total laryngectomy for cancer and survived. Thirty-one of the 47 patients responded to the survey. Patients were divided into 4 groups by their current method of communication: (1) tablet writers; (2) esophageal speech; (3) electrolarynx; and (4) tracheoesophageal speech. MAIN OUTCOME MEASURES: Satisfaction with communication, satisfaction with speech quality, ability to communicate over telephone, limitation of interaction with others, and satisfaction with quality of life. RESULTS: Patients in group 4 were significantly more satisfied with their speech (P < .001), perceived their speech to be of better quality (P < .001), had improved ability to communicate over the telephone (P < .001), and had less limitation of their interactions with others (P < .004). Patients in group 4 also rated their overall quality of life higher (P = .23). CONCLUSION: Although many studies in the past have demonstrated the objective superiority of tracheoesophageal speech compared with other methods of alaryngeal communication, most studies have focused on the intelligibility of speech judged by listeners. This study demonstrates that patients who use tracheoesophageal speech rate their own speech significantly higher than patients who use other methods and most likely have an overall superior quality of life.

Adult↗
PubMed1997

Predictors of residency performance: a follow-up study.

In a 1990 study we investigated resident applicant characteristics associated with successful matching into otolaryngology. Of the 175 applicants studied, 87 matched, for a 49.7% success rate. Successful matching was much more likely for applicants with a history of excellent academic achievement in medical school. Of the 88 applicants who did not match during the year that was originally studied, 30 matched to otolaryngology in subsequent years. Of the 58 who never matched in otolaryngology, there is no evidence of board certification for 30. Of the other 28, 12 are board certified in anesthesia; 3 in radiology; 2 each in family medicine, internal medicine, general surgery, psychiatry, and physical medicine, and rehabilitation; and 1 each in pathology, emergency medicine, and dermatology. Of the total of 117 who matched in otolaryngology, 109 began residency training, and 107 finished otolaryngology training. Program directors answered questionnaires about 100 of 107 of these residents, detailing aspects of residency performance. The only correlation found between a highly satisfactory residency performance and characteristics that could be evaluated at the time of interviewing for residency positions was with excellent academic performance in medical school.

Certification↗
PubMed1997

Extended use of topical nasal decongestants.

Use of sympathomimetic topical nasal decongestants to treat nasal obstruction is usually restricted to 3 to 5 days to avoid potential rebound swelling (rhinitis medicamentosa). In this study, 10 healthy volunteers used oxymetazoline (long-acting topical nasal decongestant) nightly for 4 weeks. Subjects who used antihistamines, oral or topical decongestants, or systemic steroids or who had active sinusitis were excluded from the study. Weekly history, physical examination, and anterior rhinomanometry revealed no adverse effects. Eight (80%) subjects developed nightly nasal obstruction a few hours before the evening dose; the obstruction resolved within 48 hours if no more decongestant was used. All subjects remained responsive to oxymetazoline 4 weeks and 8 weeks after the study began. This finding suggests that long-acting decongestants may be safely used for longer than the recommended 3 to 5 days without adverse effects if used once nightly.

Humans↗
PubMed1996

Biomechanics of the helical rim advancement flap.

OBJECTIVES: To determine how helical rim closure with advancement flaps affects ear length and cupping, to compare the tension of closure with wedge excision and helical rim advancement and the effects of 3 tension-decreasing surgical techniques, and to review clinical experience with this flap. DESIGN: The laboratory study was performed on 6 fresh cadaver ears, by means of sequential excision of tissue, and closure tension was measured with a strain gauge. Results obtained in 10 patients were reviewed. SETTING: University referral hospital. PATIENTS: Ten patients with helical rim defects treated with helical rim advancement flaps. INTERVENTION: In cadaver ears, a helical rim defect of 5 mm was enlarged sequentially to 10 mm, 15 mm, and finally 20 mm. In the patients, defects of the helical rim caused by trauma or tumor were closed by this helical rim advancement flap method. MAIN OUTCOME MEASURES: For the laboratory study, the outcome measures were tension of closure of the defect, ear length, and ear cupping. For the review of cases, outcome was determination of perioperative complications and the patient's and surgeon's judgment of cosmetic appearance. RESULTS: Closure of a helical rim defect with advancement flaps caused minor shortening and moderate cupping of the ear. The tension of closure was decreased by extending the inferior incision into the earlobe, creating a Burow triangle, and shaving cartilage from the scapha. Both the Burow triangle and the scaphal shave caused mild increases in ear cupping. CONCLUSION: Helical rim advancement flaps provide satisfactory closure of helical rim defects up to at least 20 mm (longer in some ears) with excellent preservation of normal anatomic landmarks and a near-normal appearance of the reconstructed ear.

Adolescent↗
PubMed1996

Allergic fungal sinusitis.

Allergic fungal sinusitis is a non-invasive disease, first described in the early 1980s. We review our experience with 25 patients treated at the University of Texas Medical Branch, Galveston. All patients were treated surgically, using endoscopic techniques in 17, and combined endoscopic and external procedures in eight. Histological evidence of tissue invasion was absent in all 25 patients, in spite of extensive destruction of the skull base in four. Dematiaceous fungi were the most common cultural isolate. Fifteen patients were available for more than 6 months post-operative follow-up. None of the eight patients who developed recurrent disease had been treated with post-operative systemic steroids. Four of the seven patients who remained disease-free had received steroids. Clinical trials to test the efficacy of systemic steroids in the prevention of disease recurrence are clearly warranted.

Administration, Topical↗
PubMed1996

Effect of hyperbaric oxygenation on existing oral mucosal carcinoma.

Hyperbaric oxygen therapy (HBO) is used to treat some complications of head and neck carcinoma treatment. Several patients treated with HBO have had rapid growth of a clinically cured squamous cell carcinoma. Prior studies have produced conflicting evidence about the effect of HBO on tumor growth. This study was undertaken to determine the effects of HBO on established squamous cell carcinoma. Forty Golden Syrian hamster cheek-pouch carcinomas were induced with the established chemical carcinogen 9,10-dimethyl-1,2-benzanthracene. Twenty hamsters underwent 30 HBO dives for 60 minutes each to 2.81 atm, while 20 served as controls. At necropsy, animals receiving HBO therapy had significantly smaller tumors (P < .05) and showed a trend toward fewer cervical metastases (P < .06). HBO therapy with coexistent carcinoma inhibited the established tumor's growth.

Animals↗
PubMed1995

Gene expression of markers associated with proliferation and differentiation in human keratinocytes cultured from epidermis and from buccal mucosa.

Normal keratinocytes from epidermis and from buccal mucosa underwent dissimilar stages of differentiation in the same culture medium and responded differently to changes in the composition of the medium. Manifestations of these variations were examined in terms of the expression at the mRNA level (as measured by reverse transcriptase-polymerase chain reaction) of three regulatory genes (cdc2, c-myc, and p53) and five that encode structural proteins (keratins K5, K10 and K13, involucrin, and filaggrin), in three growth-medium formulations. The culture conditions enhanced or retarded maturation; the observed alterations in gene expression correlated with these changes. Except for the proliferation genes, the non-keratinizing buccal mucosa generally responded more weakly than the orthokeratotic epidermis to culture-medium supplementation favouring differentiation. Gene expression in cultured keratinocytes reflected their ability to differentiate in vivo; genes were expressed even when the corresponding protein was not seen in vitro. Although keratin K10 is not prevalent in the buccal mucosa nor keratin K13 in the epidermis, the genes for both were found to be expressed in both tissues.

Calcium↗
PubMed1995

Pseudoepitheliomatous hyperplasia mistaken for cancer after delayed reconstruction.

Pseudoepitheliomatous hyperplasia (PEH) arises in areas of chronic inflammation and can be mistaken for squamous cell carcinoma, leading to unnecessary removal of more tissue. We present a study of 21 patients having delayed reconstruction of defects left by Mohs micrographic surgery (MMS) to remove facial skin cancers. Reconstruction was done at an average of 6 days after MMS. Four of these 21 patients (19%) had PEH in the wound margins. Presence of PEH did not correlate with age, sex delay in reconstruction, frequency of wound care, size or location of the defect, type of tumor, or smoking status. During an average 24-month follow-up, none of these four patients had tumor recurrence, suggesting that the benign diagnosis of PEH was correct. We detail the histologic features of PEH, and describe techniques for minimizing confusion with squamous cell carcinoma.

Carcinoma, Squamous Cell↗
PubMed1995

Complications of endoscopic sinus surgery in a residency training program.

Endoscopic sinus surgery (ESS) is now taught in most otolaryngology residency programs in the United States. However, this is technically challenging surgery and concerns exist regarding patient safety early in the surgeon's learning curve. The authors reviewed 193 cases of ESS performed by residents, under faculty supervision at our program, between 1987 and 1992. Sixty-seven percent of patients underwent bilateral anterior ethmoidectomy, 40% had bilateral total ethmoidectomy, and 44% had bilateral middle turbinate reduction. The overall complication rate was 22% and included one major complication. Synechiae accounted for 50% of minor complications. There was no correlation between middle or inferior turbinate reduction and the formation of synechiae. Posterior ethmoidectomy was not associated with a significant increase in complications. We conclude that ESS can be safely performed by otolaryngology residents in carefully structured and supervised training programs.

Adolescent↗