Relationship between seasonal variation in isoprene emission and plant hormone profiles in the tropical plant Ficus septica.

In Ficus septica, the short-term control of isoprene production and, therefore, isoprene emission has been linked to the hormone balance between auxin (IAA) and jasmonic acid (JA). However, the relationship between long-term changes in isoprene emission and that of plant hormones remains unknown. This study tracked isoprene emissions from F. septica leaves, plant hormone concentrations and signalling gene expression, MEP pathway metabolite concentrations, and related enzyme gene expression for 1 year in the field to better understand the role of plant hormones and their long-term control. Seasonality of isoprenes was mainly driven by temperature- and light-dependent variations in substrate availability through the MEP route, as well as transcriptional and post-transcriptional control of isoprene synthase (IspS). Isoprene emissions are seasonally correlated with plant hormone levels. This was especially evident in the cytokinin profiles, which decreased in summer and increased in winter. Only 4-hydroxy-3-methylbut-2-butenyl-4-diphosphate (HMBDP) exhibited a positive connection with cytokinins among the MEP metabolites examined, suggesting that HMBDP and its biosynthetic enzyme, HMBDP synthase (HDS), play a role in channelling of MEP pathway metabolites to cytokinin production. Thus, it is probable that cytokinins have potential feed-forward regulation of isoprene production. Under long-term natural conditions, the hormonal balance of IAA/JA-Ile was not associated with IspS transcripts or isoprene emissions. This study builds on prior work by revealing differences between short- and long-term hormonal modulation of isoprene emissions in the tropical tree F. septica.

Plant hormone profile and control over isoprene biosynthesis in a tropical tree Ficus septica.

Plant hormone signalling and the circadian clock have been implicated in the transcriptional control of isoprene biosynthesis. To gain more insight into the hormonal control of isoprene biosynthesis, the present study measured plant hormone concentrations in jasmonic acid (JA)-treated leaves of our previous model study, examined their relationship with gene expression of isoprene synthase (IspS) and hormone signalling transcription factors. Of the plant hormones, IAA and JA-Ile and their related transcription factors (MYC2 and SAUR21) were significantly correlated with IspS gene expression. Concentrations of cytokinins, isopentenyladenine (iP), trans-zeatin riboside (tZR) and cis-zeatin riboside (cZR), were similarly significantly correlated with IspS expression. However, there was no significant correlation between their related transcription factor (ARR-B) and IspS expression. The circadian clock-related gene PRR7, but not the transcription factor LHY, was highly correlated with IspS expression. These results suggest that the hormonal balance between JA-Ile and IAA plays a central role in transcriptional regulation of IspS through the transcription factors MYC2 and SAUR21, the early auxin responsive genes. The putative cis-acting elements for SAUR on the IspS promoter (TGTCNN and CATATG), in addition to the G-box for MYC2, support the above proposal. These results provide insightful information on the core components of plant hormone-related regulation of IspS under coordination with the circadian clock genes.

Preoperative estimation of remnant hepatic function using fusion images obtained by (99m)Tc-labelled galactosyl-human serum albumin liver scintigraphy and computed tomography.

BACKGROUND: Assessment of hepatic functional reserve is important in hepatic resection. The aim of this study was to evaluate the role of hepatic asialoglycoprotein receptor (ASGP-R) analysis in the preoperative estimation of remnant liver function in liver surgery. METHODS: One hundred and one patients undergoing hepatic resection for liver tumours were studied. Seventeen patients had preoperative percutaneous transhepatic portal vein embolization (PTPE). Function of the hepatic remnant was estimated before surgery using radioactivity in fusion images of both liver single-photon emission computed tomography and computed tomography scans using (99m)Tc-labelled diethylene triamine penta-acetate-galactosyl-human serum albumin. RESULTS: All three patients with an ASGP-R concentration below 400 nmol/l and preoperative total amount of receptor in the future remnant liver (R0-remnant) of less than 53.0 nmol per liver died. Two patients with chronic hepatitis and R0-remnant values between 53.0 and 65.0 nmol per liver and a receptor concentration lower than 600 nmol/l developed liver dysfunction. The incidence of liver failure decreased inversely with increasing R0-remnant value. CONCLUSION: A combination of receptor concentration and the amount of hepatic receptor in the future liver remnant as detected on fusion images is useful in evaluating the risk of postoperative liver failure.

Helicobacter pylori eradication reduced the incidence of gastric cancer, especially of the intestinal type.

BACKGROUND: Although Helicobacter pylori infection is closely associated with gastric cancer development, follow-up studies after H. pylori eradication are still scarce. AIM: To clarify the cancer preventive effect of H. pylori eradication, with special attention to differences in effect according to histology. METHODS: Patients who underwent H. pylori eradication therapy and were followed-up endoscopically for at least 1 year were analysed. The incidence of gastric cancer and factors associated with cancer development were investigated. RESULTS: A total of 1807 patients were enrolled. Six of 1519 H. pylori eradicated and five of 288 persistent subjects developed gastric cancer. Four of the eradicated subjects developed the intestinal type and two the diffuse type, while four of the persistent subjects developed the intestinal type and one the diffuse type. Kaplan-Meier analysis indicated a significantly lower incidence in eradicated patients than in persistent patients. The incidence of intestinal type was significantly lower than in eradicated patients, while the diffuse type could not be evaluated because of the low incidence. CONCLUSIONS: Helicobacter pylori-eradicated patients had a reduced incidence of gastric cancer compared with H. pylori-persistent patients, particularly the intestinal type, suggesting that H. pylori is strongly associated with intestinal-type gastric cancer.

Genetic diagnosis of micrometastasis based on SCC antigen mRNA in cervical lymph nodes of head and neck cancer.

This study is designed to assess gene expression of squamous cell carcinoma antigen (SCCA) mRNA to detect micrometastases in cervical lymph nodes (LNs) of head and neck cancer. We examined the expression of SCCA mRNA in 12 primary tumors and 212 cervical LNs (101 LNs taken from 8 patients with tongue cancer, 71 from 7 patients with gingival cancer, 19 from 2 patients with laryngeal cancer, 9 from 2 patients with pharyngeal cancer, 7 from 1 patient with cancer of the buccal mucosa, and 5 from 1 patient with cancer of floor of the mouth). Detectability of metastatic LNs by nested and single reverse transcriptase-polymerase chain reaction (RT-PCR) was compared with semiserial sections (hematoxylin-eosin staining and keratin immunostaining). All primary tumors expressed SCCA mRNA. Of 198 histologically metastasis-negative nodes, SCCA mRNA was detected in 37 (18.7%) by nested PCR. Eleven micrometastatic foci in 9 LNs (4.6%) were discovered by semiserial sectioning. This suggests that SCCA mRNA is a promising tumor marker for detecting the micrometastases in cervical LNs of head and neck cancer.

Estimation of remnant liver function before hepatectomy by means of technetium-99m-diethylenetriamine-pentaacetic acid galactosyl human albumin.

To improve the results of hepatectomy in cirrhotic patients, the likely reserve function of the liver was evaluated before surgery. Asialoglycoprotein receptor (ASGP-R) is a hepatic cell surface receptor specific for galactose-terminated glycoproteins. Technetium-99m-diethylene triamine pentaacetic acid-galactosyl human serum albumin (99mTc-GSA) is a newly developed analog ligand to ASPG-R. The probable functional reserve of the remnant liver after hepatectomy was estimated preoperatively as the hepatic binding protein (HBP) concentration specific for ASGP-R on the hepatocellular membrane of the remnant liver. This estimate was based on the effective liver volume rate, obtained by the uptake of 99mTc-GSA. In all, 3 normal volunteers, 3 patients with chronic hepatitis (CH), 9 patients with liver cirrhosis (LC), 2 patients with hepatic cystadenoma, 3 patients with hepatocellular carcinoma (HCC) associated with CH, and 21 HCC patients with LC were studied. The mean value +/- SD obtained for HBP in normal volunteers (three cases) and in patients with mild (four cases), moderate (two cases), and severe liver damage (five cases) were 0.74 +/- 0.03 microM, 0.43 +/- 0.042 microM, 0.31 +/- 0.05 microM, and 0.20 +/- 0.05 microM, respectively. Most of the cases in which the preoperative HBP of the remnant liver was above 0.22 microM had a good postoperative course irrespective of the type of hepatectomy. On the other hand, in subjects with a remnant liver HBP of between 0.22 and 0.11 microM, postoperative severe liver dysfunction occurred in about 50% of cases. In all cases with a remnant liver HBP below 0.1 microM, the prognosis was very poor, indicating that hepatectomy should be avoided. The HBP concentration detected by the 99mTc-GSA study is a very sensitive indicator of changes in the hepatic functional reserve, and the HBP value for the functional reserve of the remnant liver is extremely useful for estimating the liver function before and after hepatectomy.

Treatment of hepatocellular carcinoma by transcatheter hepatic arterial injection of radioactive iodized oil solution.

After 12 days of culture, VX2 carcinoma cells were inoculated into the liver of 16 rabbits; 14 days later, 131I-labeled iodized oil ([131I]-Lp) suspended in lipiodol was injected into the hepatic artery. Selective accumulation of the contrast material in the tumor for an extended time was evident on X-rays and hepatic scintiphotographs. The antitumor effect was remarkable. [131I]-Lp agents warrant further examination for their clinical usefulness. Internal radiation therapy by transcatheter hepatic arterial injection of [131I]-Lp (group A) was evaluated in 9 patients with hepatocellular carcinoma (HCC, tumor stage III or IV) associated with liver cirrhosis (LC) and compared with combination therapy of Lp-TAE (group B) in 18 patients with HCC (tumor stage III or IV) associated with LC. In group A, serum AFP levels dropped rapidly in eight of the nine patients who had an elevated initial level of more than 500 ng/ml. The average reduction in tumor size was 50% in eight cases as determined by computed tomography. Histological examination of one resected liver specimen at 3 months after the third injection of [131I]-Lp revealed microscopic features highly suggestive of a radiation effect in the [131I]-Lp-containing area. The 1-year survival value for patients with HCC was estimated at 49.0% using the Kaplan-Meier method. The survival of patients treated with internal radiation therapy tended to be better than that of those treated with Lp-TAE (P = 0.119).

Effects of PAF on histamine H1 receptor mRNA expression in rat trigeminal ganglia.

The application of platelet-activating factor (PAF) to the nasal mucosa of humans has been shown to increase histamine-induced hyper-reactivity. To test the hypothesis that PAF acts by increasing the reactivity of sensory nerve endings in the nasal mucosa to histamine, we examined PAF-stimulated rat trigeminal nerve ganglion cells. We found that relatively low concentrations of PAF (10(-12)-10(-9) M) induced increased histamine H1 receptor mRNA expression. This increase appeared as early as 1 h after PAF stimulation, peaked at 4 h, and disappeared after 24 h. The PAF receptor antagonist WEB2086 inhibited the increased expression of histamine H1 receptor mRNA induced by PAF, suggesting that the effects of PAF are mediated by specific receptors. This PAF effect was abolished by actinomycin D, suggesting that PAF induces de novo transcription of histamine H1 and/or PAF receptor mRNA. PAF may be important in the hyper-responsiveness of nasal mucosa exposed to histamine.

Quantitative evaluation of the effects of thyroarytenoid muscle activity upon pliability of vocal fold mucosa in an in vivo canine model.

Stiffness of the vocal fold is a significant factor in determining mucosal wave propagation and in the control of the fundamental frequency of phonation. We measured pliability of the vocal fold mucosa in an in vivo canine model as an index of stiffness while the histological layer-by-layer structure of the vocal fold was not disrupted. The point 1 mm below the free edge showed a maximal pliability that gradually diminished toward the tracheal side and reached a minimum. When the thyroarytenoid (TA) muscle contracted, pliability of the mucosa was significantly increased (P < 0.001). Mucosal pliability of the excised larynx was significantly increased compared with that in vivo (P < 0.001). The point of minimal pliability in the absence of TA muscle contraction did not shift after excision of the larynx, while TA muscle contraction caused a downward shift of the point of minimal pliability. Mucosal pliability can thus be used to quantitatively assess the effects of TA muscle contraction on stiffness of the vocal fold mucosa.

Expression of fibroblast growth factor-2 in the nucleus ambiguus following recurrent laryngeal nerve injury in the rat.

OBJECTIVES: To examine fibroblast growth factor-2 (FGF-2) immunoreactivity in the nucleus ambiguus (NA) after three different recurrent laryngeal nerve (RLN) injuries. STUDY DESIGN: Immunohistochemical analysis of FGF-2. METHODS: Thirty adult rats underwent left-sided RLN crush (group A). The left RLN was transected in groups B (n = 30) and C (n = 30); in group C, both nerve stumps were covered with silicone caps. FGF-2 in the NA was assessed as the ratio of the positive areas on the left (operated [O]) and right (unoperated [U]) sides. The ratio (O/U) was measured 1, 3, 7, 14, and 28 days after the procedure. Three rats underwent left-sided RLN exposure and were killed 7 days later (control). RESULTS: Left-sided RLN paralysis occurred until day 28 in group A. In the control group, O/U was approximately 1. In group A, O/U was significantly elevated on day 7; in group B, on days 3, 7, and 14; and in group C, on day 3. O/U in group B was significantly greater than that in group A on days 14 and 28. Maximal FGF-2 immunoreactivity was significantly lower in group C than in groups A and B. CONCLUSIONS: We demonstrated elevated production of FGF-2 in the NA after RLN injury. This endogenous FGF-2 might contribute to preventing lesion-induced neuronal death. Blockage of axonal regeneration might suppress FGF-2 production in the NA. Further understanding of the roles of FGF-2 after RLN injury may contribute to the prevention of neuronal death and facilitation of axonal regeneration.

Sino-orbital aspergillosis associated with total ophthalmoplegia.

Invasive aspergillosis of the paranasal sinuses involving the orbit is termed sino-orbital aspergillosis. Prognosis of sino-orbital aspergillosis, complicated by impaired visual acuity and neurological signs, is disastrous and usually fatal. We herein report two patients with sino-orbital aspergillosis associated with total ophthalmoplegia. One patient was successfully treated with surgical eradication including orbital exenteration. In contrast, the other died of cerebral infarction, probably due to fungal thrombosis of the middle cerebral artery, despite repeated local debridement followed by orbital exenteration and administration of antifungal agents. Experience with these cases strongly indicates the necessity of prompt surgical eradication, including orbital exenteration if necessary, in the treatment of sino-orbital aspergillosis.

Two-dimensional analysis of vocal fold vibration in unilaterally atrophied larynges.

OBJECTIVE: Considerable inconsistencies regarding the vibratory pattern of the vocal fold among patients with unilateral vocal fold paralysis (UVFP) have been reported. These differences are derived from differences in the position, stiffness, and atrophy of the paralyzed vocal fold and other factors among patients. The purpose of this study was to assess the effects of unilateral atrophy of the vocal fold on vocal fold vibration. METHODS: Seven excised canine larynges were studied. The unilateral recurrent laryngeal nerve was severed to cause vocal fold atrophy in four of the seven. The lateral and vertical displacements were monitored simultaneously with photoglottography and a laser Doppler vibrometer, respectively. Videostroboscopy of each larynx was also performed before and after the experiment to translate photoglottographic output into absolute lengths. Atrophy of the unilateral vocal fold was confirmed histologically. RESULTS: The lateral amplitude was significantly greater than the vertical amplitude in all larynges. The Lissajous trajectories in the normal larynges were shaped like a reverse crescent. Vibration in the unilaterally atrophied larynges was periodical and symmetrical in phase when the thyroid ala on the atrophied side was pressed medially. The lateral and vertical amplitudes on the atrophied side were significantly greater than those on the normal side. The Lissajous trajectories differed from those of the normal larynges. CONCLUSIONS: In the absence of a prephonatory glottal gap, periodical vibration occurs in unilaterally atrophied larynges and the amplitude of vibrations of the atrophied vocal fold is greater in the lateral and vertical directions than that of the normal fold. This implies that phonosurgical procedures aiming at closure of the prephonatory glottal gap may have a beneficial effect on hoarseness in UVFP patients, although displacements of the vocal folds during vibration are not symmetrical.

Motor innervation of the guinea pig interarytenoid muscle: reinnervation process following unilateral denervation.

The authors investigated the process of denervation and reinnervation of the interarytenoid (IA) muscle in the guinea pig using transmission electron microscopy and glycogen depletion technique after unilateral transection of the recurrent laryngeal nerve (RLN) and superior laryngeal nerve to clarify the innervation pattern of the unpaired IA muscle. Anastomosis between the bilateral arytenoid branches was confirmed in the belly of the IA muscle. Five weeks after transection, all of the IA muscle fibers appeared to have been reinnervated by the contralateral RLN. As the arytenoid branch of the RLN runs together with that of the contralateral RLN in a single intramuscular nerve funiculus, it is possible that collateral sprouting branches grow and extend into the adjacent denervated Schwann's sheaths. The authors conclude that the unpaired IA muscle, as a whole, receives specific motor nerve supply from the bilateral RLNs, although each muscle fiber is innervated unilaterally.

Three-dimensional endoscopic mode for observation of laryngeal structures by helical computed tomography.

We produced high-quality three-dimensional (3D) endoscopic images of the larynx using helical scanning computed tomography. Subjects included two normal volunteers and 10 patients: five with laryngeal cancer, four with unilateral recurrent laryngeal nerve (RLN) palsy, and one with atrophied vocal folds. Two vertically split hemilaryngeal images were displayed together with the oral and tracheal views. Although motion artifacts were seen in four patients, laryngeal structures including the vocal fold, ventricular fold, and ventricle were clearly identified in all subjects. In the patients with cancer, axial images showing the extent of the tumor in each patient provided more information than 3D endoscopic images. In the patients with RLN palsy and atrophied vocal fold, combination of 3D endoscopic and cross-sectional images offered more diagnostic information than axial images alone.

Pliability of the vocal fold mucosa in relation to the mucosal upheaval during phonation.

OBJECTIVES: To quantitatively evaluate the effect of vocal fold lengthening on pliability of the mucosa measured along the superior-inferior axis and to examine the relation of the location of mucosal upheaval (MU) during phonation to the changes in pliability pattern of the mucosa when the vocal fold was lengthened. DESIGN: Investigation of mechanical characteristics of the vocal fold in relation to the MU during phonation. MATERIALS: Five excised canine larynges. INTERVENTIONS: Vibrations with and without vocal fold lengthening were recorded from the tracheal side via high-speed photography or video recording combined with stroboscopic illumination. Tattooed marks on the lower surface of the vocal fold were used to locate the MU. Pliability was defined as the maximal distance elevated in response to a constant focal negative pressure. RESULTS: Pliability decreased significantly (P=.05) when the vocal fold was lengthened. The point of minimal pliability and MU without vocal fold lengthening were located slightly above the area where the muscular layer approached the epithelial layer. They were located closer to the free edge of the vocal fold when it was lengthened than when it was not. Discrepancy of their locations when the vocal fold was lengthened was suggested. CONCLUSIONS: The MU occurs around the point of minimal pliability when the vocal fold is not lengthened, whereas the MU occurs slightly more laterally than the point of minimal pliability when the vocal fold is lengthened. Although further study is necessary to explain this discrepancy, the presence of the sparse deep layer of the lamina propria seems to be essential in the generation of the mucosal wave.

Tracheal view of vocal fold vibration in excised canine larynxes.

The mucosal upheaval where the mucosal wave starts and propagates upward appears on the lower surface of the vocal fold during vibration. We investigated the location of the mucosal upheaval in response to variations in vocal fold tension and mean air flow rate. Twelve excised canine larynxes were used in the experiment. The lower surfaces of the vocal folds were marked with india ink. After cinematography was performed, a small cut wound was made at the mark. This wound served to relate cinematographic findings with the histologically observed position of the mark. The larynx was then fixed, sectioned in the frontal plane, and stained for histologic examination. Horizontal movements of the free edge, mucosal wave, mucosal upheaval, and marks were analyzed. Under a fixed vocal fold tension, the mucosal upheaval appeared more laterally to a limited extent as mean air flow rate increased, but its location on the vocal fold mucosa did not change from its position before the increase of mean air flow rate. The mucosal upheaval appeared more medially when vocal fold tension increased. The position of the mucosal upheaval actually changed medially compared with its original position before the tension increase. Histologic examination indicated that the mucosal upheaval arose on the lower surface of the vocal fold between the free edge and the area where the muscular layer comes in close proximity to the epithelial layer.

Thyroarytenoid muscle activity and infraglottic aspect of canine vocal fold vibration.

OBJECTIVES: To investigate the effect of contraction of the thyroarytenoid (TA) muscle on the location of the mucosal upheaval (MU) and to estimate the location of the MU in relation to the histologic structure of the vocal fold. BACKGROUND: The MU is a small mucosal ridge arising on the lower surface of the vocal fold during phonation and is thought to be the lower border of the vibrating structure. METHODS: Vibrations were elicited under three conditions: during bilateral TA muscle contraction, without TA muscle stimulation, and during vocal fold lengthening. The vibrations were recorded from the tracheal side by high-speed cinematography or videotape recording combined with stroboscopic illumination. The larynx was prepared for histologic observation in the frontal plane. Tattooed marks on the lower surface of the vocal fold were used to locate macroscopically observed landmarks with reference to microscopic structures. RESULTS: The MU shifted laterally toward the tracheal side during TA muscle contraction. When the vocal fold was lengthened, the MU shifted medially toward the free edge. Histologic examination showed that the MU in the absence of TA muscle contraction arose slightly above the area where the muscular layer approached the epithelial layer. CONCLUSION: When the TA muscle contracts, the vibrating area expands toward the tracheal side, and a more dynamic mucosal wave occurs in the vertical direction. We believe that a part of the body and the cover are probably involved in the vibratory movement of the vocal fold.

Three-dimensional endoscopic images of vocal fold paralysis by computed tomography.

OBJECTIVE: To describe characteristics of 3-dimensional (3-D) computed tomographic (CT) endoscopic images of the larynx in unilateral vocal fold paralysis and the changes of the paralyzed vocal fold after phonosurgery as indicated by 3-D CT endoscopy. SETTING: A university medical center. PATIENTS: Twelve consecutive patients with unilateral vocal fold paralysis who underwent helical CT examination. Five of them underwent the CT examination before and after phonosurgical treatment. INTERVENTIONS: Three patients underwent arytenoid adduction, and 2 underwent type 1 thyroplasty. MAIN OUTCOME MEASURES: "Sagging," defined as caudal displacement of the vocal fold; and "thinning," defined as a decrease in the vertical thickness of the vocal fold and expansion of the ventricle on the affected side, were evaluated. RESULTS: Excessive motion artifacts in one patient prevented detailed description of his 3-D images. Sagging and thinning of the vocal fold and expansion of the ventricle on the affected side were noted on 6, 11, and 8 occasions, respectively. Adduction or augmentation of the paralyzed vocal fold after phonosurgery was observed in 3-D CT endoscopic images when displayed with bony densities. CONCLUSIONS: The use of 3-D CT endoscopy enables description of 3-D characteristics of unilateral vocal fold paralysis and supplements stroboscopic findings. Furthermore, CT endoscopic images, when simultaneously displayed with bony densities, may help in evaluating the effects of phonosurgical treatment of the paralyzed vocal fold.

Vocal fold vibration viewed from the tracheal side in living human beings.

The mucosal upheaval where the mucosal wave starts and propagates upward appears on the lower surface of the canine vocal fold during vibration. We investigated the vibratory behavior of the in vivo human vocal fold viewed from the tracheal side. Subjects consisted of 14 men and 6 women who had undergone tracheostomy for various head and neck diseases; their ages ranged from 22 to 70 years, with a mean of 53.9 years. The inferior aspect of the vocal fold during phonation was observed with the aid of a rigid oblique-view endoscope inserted through a tracheostoma (inferior glottoscopy). Each subject was asked to sustain the vowel /a/ at a comfortable pitch and loudness (easy phonation) and then at a higher pitch. Inferior glottoscopy could be performed during easy phonation in 19 subjects and during high-pitched phonation in 10 subjects. During easy phonation, the mucosal upheaval appeared on the lower surface of the vocal fold between the anterior commissure and the vocal process in all 19 subjects. During high-pitched phonation, the vocal fold became longer, and the subglottic vault surrounded by the bilateral mucosal upheavals became narrower compared with those during easy phonation. Use of a dilated blood vessel as a landmark in one subject showed the location of the mucosal upheaval on the vocal fold mucosa to actually shift medially toward the oral side during high-pitched phonation. Despite structural differences between the human and canine vocal folds, the infraglottic aspect of the vocal fold vibration observed in the living human larynx was quite similar to that observed in the excised canine larynx.

Transmandibular transpterygoid approach to the nasopharynx, parapharyngeal space, and skull base.

The nasopharynx, upper part of the parapharyngeal space, and skull base are relatively inaccessible to the surgeon without major postoperative complications. Operative fields reached by conventional approaches through the palate and maxillary sinus are too limited and narrow to remove extensive tumors. The authors applied a transmandibular transpterygoid approach for the removal of five residual nasopharyngeal carcinomas (NPCs) after full doses of irradiation, one pleomorphic adenoma of the nasopharynx, and one large parapharyngeal schwannoma extending into the jugular foramen. This approach offers a wide operative field so that large blood vessels and cranial nerves can be managed easily. All tumors were successfully resected. Two patients with benign neoplasma had uneventful recoveries after treatment. Of five patients with NPC, two are alive with no evidence of disease for 68 months and 50 months, respectively, while two died of metastases to the liver and bones. The other patient is alive with metastases in the lungs. No tumor recurred in the local primary site, however. Since the number of NPC cases is small, the usefulness of surgical removal of the postirradiation residual NPC is not clear. Our experience proved that the transmandibular transpterygoid approach is a practical method in the treatment of neoplastic lesions in the nasopharynx, parapharyngeal space, and skull base.