Biomedical subjects

K Sakamoto

Publications and source records attributed to K Sakamoto.

At least 163 records · Page 9Linked to original sources

PubMed2000

Effects of eicosapentaenoic acid intake on plasma fibrinolytic and coagulation activity by using physical load in the young.

To assess the effect of eicosapentaenoic acid (EPA) intake on fibrinolysis and coagulation, 30 male subjects, approximately 19-23 y old, were examined for plasma fibrinolytic and coagulation activity by using a bicycle ergometer load (90 W, 20 min) before and after EPA intake of 1.125 g/d for 2 wk. Because of the EPA intake, the fibrinolytic activity was promoted, the plasmin-alpha 2 plasmininhibitor complex (PIC) level was decreased by 16.7%, and the thrombin-antithrombin III complex (TAT) level was increased by 75.4%; conversely, the D-dimer of the fibrin degradation peptide (D-dimer) level did not change from that before EPA intake. By the physical load, 1 h after ingesting the load, the PIC level was significantly decreased by 26.7%, the TAT level was significantly increased by 51.1%, and the D-dimer level was significantly decreased by 24% in comparison with levels before EPA intake. Thus, as determined by the load, a small amount of daily EPA intake clearly decreased fibrinolytic activity and increased coagulation activity. One hour after a physical load, the rate of change of the gamma-glutamyl transpeptidase (gamma-GTP) level correlated significantly and negatively to the rate of change in the PIC and TAT levels. Thus, EPA intake may affect liver and kidney function. EPA intake decreased systolic blood pressure by 5 mmHg and diastolic blood pressure by 10 mmHg.

Adult↗

PubMed2000

Membrane-type 1 matrix metalloproteinase enhances lymph node metastasis of gastric cancer.

The mechanisms of the lymph node metastasis remain unclear. We demonstrate the role of MT1-MMP on the lymph node metastasis using in vivo experimental model of lymph node metastasis by orthotopic implantation of MT1-MMP transfected gastric cancer cell line in the stomach of nude rats. TMK-1 cell line without expression of MT1-MMP was transfected with the pcDNA3 plasmid containing a 3.4-kb MT1-MMP cDNA fragment by calcium phosphate method, and the transfected cell line was designated as TMK-MT. Western blot and RT-PCR analyses showed the specific bands corresponding to MT1-MMP in the TMK-MT cells. By gelatin zymography, the activated form (62-kDa) of MMP-2 was identified in the medium of TMK-MT cell line, but was not detected in TMK-1 cells. Six weeks after orthotopic implantation of TMK-1 and TMK-MT xenografts of nude mouse-subcutaneus tumor into the stomach of nude rats, gastric tumors were found in all the animals. Histologically, the lymphatic invasion was found in the submucosa of the TMK-MT gastric tumors. Lymph node metastasis was not detected in nude rats bearing TMK-1 gastric tumor (0/8). In contrast, lymph node metastasis was detected in five out of 8 rats, bearing TMK-MT gastric tumor. MT1-MMP immunoreactivity was found on the cell membrane and cytoplasm of TMK-MT cells not only in the lymph node metastasis but also in the stomach tumor. These results suggest that MT1-MMP overexpression induced by transfection of its gene may promote lymph node metastasis of transformed cells.

Animals↗

PubMed2000

Site-specific accumulation of a LINE-like retrotransposon in a sex chromosome of the dioecious plant Cannabis sativa.

Male-associated DNA sequences were analysed in hemp (Cannabis sativa L.), a dioecious plant with heteromorphic sex chromosomes. A male-associated DNA sequence in C. sativa (MADC1) and its flanking sequence encoded a reverse transcriptase that was strongly homologous to those of LINE-like retrotransposons from various plants and other organisms, as well as another open reading frame (ORF). Fluorescence in situ hybridization (FISH) with MADC1 as probe, which yielded strong signals specific for male genomic DNA in gel blot analysis, generated a clear doublet signal at the end of the long arm of the Y chromosome. FISH using pachytene chromosomes of pollen mother cells at meiotic prophase I revealed that pairing of X and Y chromosomes occurred at the short arm of the Y chromosome where MADC1 was not present. Furthermore, FISH using extended DNA fibers, with MADC1 and its flanking DNA as probes, revealed that 100 to 200 copies of the retrotransposon were located in tandem on the Y chromosome. These results support the hypothesis that accumulation of a specific LINE-like retrotransposon at the terminal region of the long arm of the Y chromosome might be one cause of heteromorphism of sex chromosomes.

Amino Acid Sequence↗

PubMed2000

Immunohistochemical analysis of Ki-67, p53, p21, and p27 in benign and malignant apocrine lesions of the breast: its correlation to histologic findings in 43 cases.

We examined Ki-67, p53, p21, and p27 immunolocalization in 43 cases of apocrine lesions of the breast and correlated these findings with histologic parameters to understand their biologic significance. Twenty cases were benign, 1 case was borderline, and 22 cases were diagnosed as malignant, including 9 intraductal and 13 invasive apocrine carcinomas. Both the ratio of Ki-67-positive cases (17 of 21 [88.9%] versus 1 of 19 [5.3%]; P < .001) and the Ki-67 labeling index of positive cases examined (15.0% versus 2.7%; P < .005) were significantly higher in malignant than in benign apocrine lesions. None of the benign or borderline cases was immunohistochemically positive for p53, but 15 of 22 malignant cases (68.2%) demonstrated p53 (P < .001). In addition, the ratio of p53-positive cases was significantly higher in high nuclear grade cases (11 of 13 [84.6%]) than in intermediate nuclear grade cases (4 of 9 [44.4%]; P < .05). P53 immunoreactivity was also positively correlated with the nuclear grade of carcinoma cases examined in this study. Neither p21 nor p27 demonstrated any correlation with histologic parameters or findings of the apocrine lesions. Results of these studies suggest that Ki-67 and p53 may be good markers for differentiation between benign and malignant breast apocrine lesions.

Apocrine Glands↗

PubMed2000

Design syntheses and mitochondrial complex I inhibitory activity of novel acetogenin mimics.

Some natural acetogenins are the most potent inhibitors of mitochondrial complex I. These compounds are characterized by two functional units [i.e. hydroxylated tetrahydrofuran (THF) and alpha, beta-unsaturated gamma-lactone ring moieties] separated by a long alkyl spacer. To elucidate which structural factors of acetogenins, including their active conformation, are crucial for the potent inhibitory activity we synthesized a novel bis-acetogenin and its analogues possessing two gamma-lactone rings connected to bis-THF rings by flexible alkyl spacers. The inhibitory potency of the bis-acetogenin with bovine heart mitochondrial complex I was identical to that of bullatacin, one of the most potent natural acetogenins. This result indicated that one molecule of the bis-acetogenin does not work as two reactive inhibitors, suggesting that a gamma-lactone and the THF ring moieties act in a cooperative manner on the enzyme. In support of this, either of the two ring moieties synthesized individually showed no or very weak inhibitory effects. Moreover, combined use of the two ring moieties at various molar ratios exhibited no synergistic enhancement of the inhibitory potency. These observations indicate that both functional units work efficiently only when they are directly linked by a flexible alkyl spacer. Therefore, some specific conformation of the spacer must be important for optimal positioning of the two units in the enzyme. Furthermore, the alpha,beta-unsaturated gamma-lactone, the 4-OH group in the spacer region, the long alkyl tail attached to the THF unit and the stereochemistry surrounding the hydroxylated bis-THF rings were not crucial for the activity, although these are the most common structural features of natural acetogenins. The present study provided useful guiding principles not only for simplification of complicated acetogenin structure, but also for further wide structural modifications of these molecules.

Animals↗

PubMed2000

Embryonal sarcoma of adult and pediatric kidneys: report of a case with localized submucosal invasion of the renal pelvis and long-term survival.

A case of cystic embryonal sarcoma of the kidney (CESK) with a rapidly fatal outcome was recently reported.1 Here, we report another case of a 12-year-old boy with a localized but ill-defined submucosal lesion of CESK in the right renal pelvis. The tumor consisted principally of small mesenchymal cells with oval to spindle nuclei and scanty cytoplasm, infiltrating in dense arrangements. Two growth patterns were distinguished in the tumor cells: (i) a diffuse infiltrating pattern without an epithelial component; and (ii) a foliated pattern with an epithelial lining over the surface. Foci of the diffuse pattern predominated over those that were lobular, infiltrating superficial layers of renal sinuses and along pyramids, in both of which remarkable intravenous invasion was evident. Foci of the foliated pattern invaded deeper portions of a few sinuses and frequently penetrated into their veins, producing together with their epithelial lining a characteristic foliated structure. Lining epithelial cells around lobular foci often appeared hob-nailed or eosinophilic in the cytoplasm. Despite the remarkable intravenous encroachment, the patient has remained well without a recurrence for more than 26 years after a simple nephrectomy. The present case report expands our understanding of the biological nature of CESK.

Child↗

PubMed2000

Light-induced phase-shifts in the circadian expression rhythm of mammalian period genes in the mouse heart.

To investigate the molecular mechanism that regulates circadian rhythms in mammalian peripheral tissues, we examined the phase shifts evoked by light exposure in the circadian mRNA expression rhythms of mammalian Period genes (mPer1, mPer2 and mPer3) and a clock-controlled gene Dbp, in the mouse heart, by Northern blot analysis. The light pulse did not induce any acute mRNA expression of mPer in the heart, but the pulse gave rise to phase shifts in the circadian mRNA rhythms. On the first day after the exposure, only mPer1 mRNA showed a phase shift, whereas obvious phase shifts were not observed in the rhythms of mPer2, mPer3 and Dbp mRNAs. On the second day, phase shifts occurred to a similar extent in the mRNA rhythms of all four genes examined. The rhythm of mPer1 mRNA shifted fastest among those of the three mPers. Therefore mPer1 seems to play an important role in phase resetting of mammalian peripheral oscillators. Immediate responses to light pulses in mRNA expression of mPers may not be required for phase shifting of peripheral circadian oscillators. Our findings suggest that mammals require more than one day to have peripheral oscillators entrained to a new daily schedule.

Animals↗

PubMed2000

Possible effects of one week vitamin K (menaquinone-4) tablets intake on glucose tolerance in healthy young male volunteers with different descarboxy prothrombin levels.

To clarify the roles of vitamin K (VK) in the pancreas, twice oral, glucose tolerance tests were examined in 12 healthy young male volunteers before and after 1 week of VK tablet intake. Blood were collected by venipucture at 0, 30 and 120 min after 75 g oral glucose loading. They then took VK tablets (90 mg/d of menaquinone-4) for 1 week, and the second glucose tolerance test was examined. The subjects were divided into three groups by serum descarboxy prothrombin (DP) levels; four of lowest DP (L-DP), middle of DP (M-DP) and highest DP (H-DP) levels. They were compared by one-factor analysis of variance and Scheffè's F (group differences) and paired t -test (the effects of 1 week of VK intake). Age, body mass index and glucose status [plasma glucose (PG) and immunoreactive insulin (IRI), hemoglobin-Alc, fructosamine] of all groups were almost the same, but the IRI of the H-DP group was higher than that of the other groups at 120 min after the glucose loading (mean+/-SEM; L; 10.6+/-0.9, M-; 17.5+/-4.2, H-; 40.4+/-6.0 microU/ml). One week of VK intake tended to decrease the plasma DP levels of all groups and significantly reduced IRI of the H-DP at 120 min by half (before; 40.4+/-6.0 vs after: 18.4+/-4.6 microU/ml). The IRI/pG ratio in areas under the curve (AUC) of H-DP from 0 to 120 min after the loading was significantly decreased by 1 week of VK tablet intake (before: 31.0+/-7.4 vs after: 20/1+/-3.8 microU/g). These results suggested that there may be some relationship between pharmacological dose of vitamin K and insulin response.

Adult↗

PubMed2000

Translocation of Salmonella typhimurium in rats; effect of enteral and parenteral nutrition.

OBJECTIVE: To study translocation of Salmonella typhimurium from ileal loops in rats fed enterally or parenterally. DESIGN: Laboratory experiment. SETTING: University departments of surgery and microbiology, Japan. SUBJECTS: Male Wistar rats and female BALB/C CrSlc mice. INTERVENTIONS: First experiment: portal venous blood and mesenteric lymph nodes from normally fed rats were cultured under aerobic and anaerobic conditions. Second experiment: various concentrations of S. typhimurium (GIFU 12142) were injected intraperitoneally in mice and their survival was monitored. Third experiment: 7 rats were given total parenteral nutrition for 14 days and 6 were given standard chow and water for the same period. Cultures of S. typhimurium were injected into closed ileal loops and portal and vena caval blood and mesenteric lymph nodes were cultured. MAIN OUTCOME MEASURES: Presence and number of bacteria in all samples, and survival of mice. RESULTS: In the first experiment 3/17 blood samples and 9/17 node samples grew enteric bacteria. In the second experiment all the mice died within 5 days. In the third experiment no sample grew bacteria in the enterally fed group, whereas at least some samples from 5/7 rats in the parenterally fed group grew organisms; the difference was significant (p = 0.02). CONCLUSION: Total parenteral nutrition encourages the translocation of S. typhimurium from ileal loops.

Animals↗

PubMed2000

Solid-pseudopapillary tumor of the pancreas: immunohistochemical localization of neuroendocrine markers and CD10.

To clarify the neuroendocrine differentiation and CD10 expression in solid-pseudopapillary tumors (SPTs) of the pancreas, we performed immunohistochemical analysis in 19 such tumors, including one solid-pseudopapillary carcinoma (SPC), along with 20 pancreatic neuroendocrine tumors (PNTs), six acinar cell carcinomas (ACCs), and one pancreatoblastoma (PB). We used antisera directed against CD56, synaptophysin, protein gene product 9.5, the alpha-subunit of Go protein, chromogranin A, CD10, trypsin, chymotrypsin, various cytokeratins (CKs), CA19-9, vimentin, and alpha-1-antitrypsin (AAT). All SPTs exhibited immunoreactivity for CD56 and CD10, and 15 expressed other neuroendocrine markers focally with the exception of chromogranin A. Frequent clustering of synaptophysin-positive cells was noted. Two cases contained a peculiar nodule that cytomorphologically and immunohistochemically resembled PNT. CD10-positive cells were scarce in one SPC. PNTs were CD56-positive, but often with faint intensity, and staining for other neuroendocrine markers, including chromogranin A, was diffusely positive. CD10 was detected, mostly in a focal pattern, in five PNTs. Pan-CK, CK8, CK18, and CK19 were more frequently demonstrated in PNT than SPT. Vimentin and AAT were often identified in PNT as well and were not specific for SPT. ACCs were CD56-negative, with the exception of one case designated as a mixed acinar-endocrine carcinoma. PB was focally positive for CD56 at the periphery of the tumor nests. Four ACCs and one PB exhibited focal CD10 reactivity. This study demonstrated the unique immunohistochemical features of SPT. Our results also suggest that SPT exhibits, at least focally, neuroendocrine differentiation, and that these neuroendocrine markers and CD10 are diagnostically useful.

Adolescent↗

PubMed2000

Changes of HDL subfractions by eicosapentaenoic acid intake and physical load in 20- to 25-year-old men.

The effects of daily eicosapentaenoic acid (EPA) intake and physical activity on high-density lipoprotein (HDL) subfraction, which may be an index of health status, were examined. The HDL subfraction, triglyceride and T-chol levels in the serum of 10 male volunteers aged 20-25 were examined before, immediately after and 1 h after being subjected to a physical load by bicycle ergometer at 90 W for 20 min. Subjects were then given 1.25 g EPA/day for 2 weeks, and the above test was repeated. By EPA intake, the distribution of HDL3b and 3c decreased significantly by 16.8 and 15.3%, respectively, and that of 2b increased significantly by 17.9%. The rate of change of subfraction of the 29th part (2b) of 30 parts in the total range of HDL increased by 67%, and decreased by 47% in 7th part (3c). By physical load, the distribution of HDL2a increased significantly by 15.4%, while 3b tended to decrease. By physical load after EPA intake, the distribution of 2a decreased significantly by 9.7%, and those of 3b and 3c increased significantly by 20.5 and 5.4%, respectively, and that of the 7th part (3c) increased by 37%. Thus, the physical load after EPA intake is effective to prevent arteriosclerosis as increasing the rate of change of HDL3c and as showing the longevity pattern of the HDL subfraction. Concentration of TG in a modal HDL pattern group increased by 95% after EPA intake, but that of a bimodal group did not show any change. HDL-cholesterol level in the bimodal group was higher than that in the modal group, especially after EPA intake. Two type III subjects changed to type IV by the load and the EPA intake, respectively. Thus, it seemed that the transformation from a modal pattern to a bimodal pattern by a certain lifestyle, especially regular physical activity and proper food intake, is a very important trial for the prevention of cerebrovascular diseases.

Adult↗

PubMed2000

Highly potent and orally active non-peptide arginine vasopressin antagonists for both V1A and V2 receptors: synthesis and pharmacological properties of 4'-[(4,4-difluoro-5-methylidene-2,3,4,5-tetrahydro-1H-1-benzoazepin-1-y l)carbonyl]-2-phenylbenzanilide derivatives.

A series of compounds structurally related to 4'-[(4,4-difluoro-5-methylidene-2,3,4,5-tetrahydro-1H-1-benzoaz epin-1-yl) carbonyl]-2-phenylbenzanilide were synthesized and evaluated for arginine vasopressin (AVP) antagonistic activity. Compounds with a (Z)-olefin geometry at the 5-position of benzoazepine possessed potent affinity for both the V1A and V2 receptors. Further study has shown that one of these derivatives, (Z)-4'-(¿4,4-difluoro-5-[(4-dimethylaminopiperidino)carbonylmet hylene]-2,3,4,5-tetrahydro-1H-1-benzoazepin-1-yI¿carbonyl)2- phenylbenzanilide monohydrochloride (29, YM-35471), exhibits exceptionally potent affinity for both of V1A and V2 receptors, even when administered orally. The synthesis and pharmacological properties of this compound are detailed in this paper.

Anilides↗

PubMed2000

Hemodynamic and thermal responses to a 30-minute constant-workload aerobic exercise in middle- or old-aged patients with cardiovascular diseases.

The aim of the present investigation was to compare the hemodynamic and thermal responses to a 30-min aerobic exercise between middle- or old-aged patients with normal left ventricular function and those with left ventricular dysfunction. Constant-load sitting ergometer exercise of approximately 90% of the subject's oxygen uptake (VO2) at the anaerobic threshold for 30 min was conducted in 21 patients with left ventricular dysfunction (61+/-10 years, left ventricular ejection fraction (LVEF) 35+/-7%) and 24 patients with normal left ventricular function (59+/-9 years, LVEF 71+/-7%). Heart rate (HR), blood pressure, deep temperatures in the forehead and thigh, and forearm skin blood flow (SkBF) were measured every minute, and cardiac output (CO) and stroke volume (SV) were determined every 10 min with the dye-dilution technique during the exercise. Patients of both groups exhibited a progressive elevation in each temperature and an increase in SkBF during the exercise. Although the VO2 and CO remained stable, almost the same magnitude of decrease in SV as increase in HR was seen after the 10th min of exercise in both groups. The magnitude of the decrease in SV was greater in old-aged than middle-aged patients with left ventricular dysfunction. Thus, the downward drift in SV during a 30-min constant-load aerobic exercise might not be influenced by left ventricular function, but intensified by aging in patients with left ventricular dysfunction.

Adult↗

PubMed2000

Energy preserving effect of l-cis diltiazem in isolated ischemic and reperfused guinea pig hearts: a 31P-NMR study.

We determined the effect of 1-cis diltiazem, the enantiomer of diltiazem (d-cis isoform), on the energy metabolism of isolated guinea pig hearts during ischemia-reperfusion. We used 31P-NMR to measure the high-energy phosphate content and intracellular pH (pHi) during global ischemia for 30 min followed by reperfusion for 30 min. Before ischemia, the left ventricular developed pressure (LVDP) was reduced less by 10 microM l-cis diltiazem than by 3 microM diltiazem or 500 nM nifedipine. However, 10 microM l-cis diltiazem preserved the intracellular ATP content during ischemia and reperfusion, reduced the end-diastolic pressure increase during ischemia and reperfusion, and restored LVDP after reperfusion. Nifedipine at 50 nM, which reduced the LVDP more than 10 microM l-cis diltiazem, showed no cardioprotective effect. Ten micromolar l-cis diltiazem and 3 microM diltiazem, but neither 50 nor 500 nM nifedipine, reduced the pHi decrease that occurred 25 or 30 min after the onset of ischemia. Therefore, l-cis diltiazem has a cardioprotective effect on ischemic and reperfused myocardium and is less cardiodepressive than diltiazem and nifedipine. The effect of l-cis diltiazem during ischemia and reperfusion involves energy preservation, which is probably independent of its Ca2+-channel blocking action.

Adenosine Triphosphate↗

PubMed2000

Surgical approach to a giant fibrolipoma of the supraglottic larynx.

This paper describes the surgical procedures for a fibrolipoma that first appeared as a giant tumour in the hypopharynx and extended to the cardiac antrum of the oesophagus. At the initial surgery, a pedunculated tumour originating from the left arytenoid of the larynx was found to occupy the cervical as well as thoracic oesophagus and was thus removed through a lateral pharyngectomy. A histological examination revealed fibrolipoma. However there was a recurrence of the tumour in the arytenoid and the patient suffered from dysponea. In addition, a submucosal tumour was also found in the left false vocal fold. At the second surgery, the masses in the arytenoid and false vocal fold were subtotally removed without damaging the mucosa. The mucosa of the arytenoid was sutured to the thyropharyngeal muscle on the same side and the arytenoid swelling disappeared almost completely. The post-operative course has been uneventful for more than two years.

Humans↗

PubMed2000

Purification and characterization of a novel lactonohydrolase from Agrobacterium tumefaciens.

A novel lactonohydrolase, catalyzing the stereospecific hydrolysis of L-pantoyl lactone to L-pantoic acid, was purified 2,400-fold to apparent homogeneity with a 1.96% overall recovery from Agrobacterium tumefaciens AKU 316 through a purification procedure including ammonium sulfate fractionation, and column chromatographies on DEAE-Sephacel, phenyl-Sepharose CL-4B, Sephacryl S-200, Mono-Q and alkyl-Superose. The relative molecular mass of the native enzyme estimated on high-pressure gel permeation chromatography was 62,000 Da, and the subunit molecular mass was estimated to 26,500 Da on SDS-polyacrylamide gel electrophoresis. The enzyme hydrolyzes several aromatic lactones, such as 3,4-dihydrocoumarin and homogentisic acid lactone, other than L-pantoyl lactone. The Km and Vmax for L-pantoyl lactone were 3.59 mM and 13.7micromol/min/mg, respectively. The enzymatic activity was inhibited by several chelating reagents, Fe2+, Sn2+, Pb2+, and Fe3+.

Agrobacterium tumefaciens↗

PubMed2000

Carotid intima-media thickness in Japanese type 2 diabetic subjects: predictors of progression and relationship with incident coronary heart disease.

OBJECTIVE: To examine carotid intima-media thickness (IMT), predictors of its progression, and its relationship with incident coronary heart disease (CHD) in type 2 diabetic Japanese patients. RESEARCH DESIGN AND METHODS: Carotid IMT of 287 subjects with type 2 diabetes (mean age 61.6 years) without CHD or cerebrovascular disease was examined at baseline and after a mean follow-up of 3.1 years. RESULTS: The annual progression of IMT (means +/- SEM) was 0.04+/-0.004 mm/year. Stepwise multivariate analysis demonstrated that independent risk factors for progress of IMT were the initial IMT (P<0.001), the average HbA1c level (P<0.001), and age (P = 0.001). Both the initial IMT (odds ratio [OR] 4.9, 95% CI 1.7-14.1) and a low average HDL cholesterol (OR 0.2, 0.1-0.8) were identified as predictors of incident nonfatal CHD (angina pectoris or nonfatal myocardial infarction; 3-year incidence 10.1%) after adjusting for age, sex, average HbA1c, and other risk factors. CONCLUSIONS: The predictors of the progression of carotid IMT in Japanese type 2 diabetic subjects were its baseline thickness and the average HbA1c during the follow-up. Baseline carotid IMT and low HDL cholesterol predicted the incidence of nonfatal CHD.

Asian People↗

PubMed2000

[Laser debulking surgery prior to radiotherapy for T1T2 carcinoma of the hypopharynx].

The local control rate for T1-T2 carcinomas of the hypopharynx is rather high whereas the overall survival rate is unsatisfactory, irrespective of treatment modalities. Radical radiotherapy has yielded a local control rate of 40-70% and an overall 5-year survival of 30-50%, while surgical treatment with or without postoperative radiotherapy has yielded a local control rate of 60-90% and an overall 5-year survival rate of 30-60%. Based on these reasons, for the patients with minor hypopharyngeal lesions, such as T1-T2 carcinomas, in the Kurume University Hospital radiotherapy has often been selected as a first choice instead of partial pharyngectomy. If the primary lesion is exophytic and has a large volume, laser debulking surgery has been employed prior to radiotherapy to improve the local control rate. The purpose of the present study is to describe the details of laser debulking surgery prior to radiotherapy (LDSR) for the treatment of T1-T2 carcinomas of the hypopharynx. In addition, the preliminary results for this treatment procedure will also be compared with the results of partial pharyngectomies preserving the larynx (PPPL) that were performed in the Kurume University Hospital. In this study 20 patients (T1: 4, T2: 16) who had undergone PPPL and 16 patients (T1: 4, T2: 12) who had undergone LDSR were included. For patients undergoing PPPL, the 5-year local control rate, 5-year larynx conservation rate and disease specific 5-year survival rate were 83.6%, 70.4%, and 75.0%, respectively, whereas for patients undergoing LDSR these were 87.1%, 93.8%, 87.5% respectively. Although the treatment outcomes by LDSR did not show a significant drastic improvement compared with those by PPPL, the quality of life of the patients undergoing LDSR was not aggravated. LDSR may thus be preferable to PPPL for selected cases of T1-T2 carcinomas of the hypopharynx.

Adult↗