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Biomedical subjects

M Kamata

Publications and source records attributed to M Kamata.

At least 19 recordsLinked to original sources

Cervical oesophageal stent placement via a retrograde transgastric route.

During attempted oesophageal stent placement in a patient with cervical oesophageal cancer in whom swallowing of even saliva was impossible, transoral access to the cervical oesophagus was unsuccessful. Under ultrasound and fluoroscopy guidance, percutaneous gastric puncture was performed, and using an angiographic catheter and guidewire, access to the oesophagus by a retrograde transgastric route was successfully achieved. The obstructed segment of the oesophagus was traversed. It was then possible to pull the guidewire through the mouth and place an oesophageal stent via an antegrade approach.

Esophageal Neoplasms↗

A variable number of tandem repeats in the serotonin transporter gene does not affect the antidepressant response to fluvoxamine.

A variable number of tandem repeats (VNTR) in the second intron of the serotonin transporter gene (STin2) has been studied in association with the susceptibility to affective disorders. Recently, it was reported that selective serotonin reuptake inhibitors were more effective in patients with major depressive disorder having the homozygous allele pair (12-copy/12-copy) of VNTR in the STin2 than in ones having other allele combinations. As the study had methodological problems, further studies are needed to confirm the above finding. Therefore, the authors investigated whether the allelic variation of VNTR in the STin2 was associated with the antidepressant response to fluvoxamine in 66 patients with major depressive disorder. Fluvoxamine was prescribed up to 200 mg/day in the dosing protocol for 6 weeks. The present study showed no significant association between the polymorphism of VNTR in the STin2 and the treatment response to fluvoxamine.

Adult↗

Continuous selective intraarterial chemotherapy in combination with irradiation for locally advanced cancer of the tongue and tongue base.

We retrospectively evaluated the results of the concurrent combination therapy of selective continuous intraarterial chemotherapy and radiotherapy in 39 patients with locally advanced cancer of the tongue and tongue base between September 1992 and January 2000. Thirty patients were fresh cases (stage II, 10 patients; stage III, 15; stage IV, five) and nine were recurrent cases. The primary lesion was present in the mobile tongue in 33 patients and the tongue base in six. External irradiation (median dose, 48.6 Gy) was performed in all patients, and interstitial brachytherapy using an Au grain or Cs needle (median dose, 50 Gy) in 21. In intraarterial chemotherapy, a catheter was selectively inserted into the lingual artery via the superficial temporal artery, and carboplatin (CBDCA) was continuously infused (median dose, 460 mg/m(2)) concurrently with radiotherapy. In 13 patients with cervical lymph node metastasis, two courses of systemic chemotherapy with 5-FU (700 mg/m(2) x 5 days) and cisplatin (40-50 mg/m(2)x2 days) or its analog was also performed. In 37 (94.9%) of the 39 patients in whom this combination therapy was completed, the response rate was 94.6%. The 3-year local control rate, progression-free survival rate, and overall survival rate by Kaplan-Meier's method were 79.2, 53.2, and 58.9%, respectively. This combination therapy was effective for locally advanced cancer of the tongue and tongue base without causing severe adverse side effects, and a local control rate comparable to that by surgery can be expected.

Adult↗

Angiotensin-converting enzyme degrades Alzheimer amyloid beta-peptide (A beta ); retards A beta aggregation, deposition, fibril formation; and inhibits cytotoxicity.

We have demonstrated that the angiotensin-converting enzyme (ACE) genotype is associated with Alzheimer's disease (AD) in the Japanese population (). To determine why ACE affects susceptibility to AD, we examined the effect of purified ACE on aggregation of the amyloid beta-peptide (A beta) in vitro. Surprisingly, ACE was found to significantly inhibit A beta aggregation in a dose response manner. The inhibition of aggregation was specifically blocked by preincubation of ACE with an ACE inhibitor, lisinopril. ACE was confirmed to retard A beta fibril formation with electron microscopy. ACE inhibited A beta deposits on a synthaloid plate, which was used to monitor A beta deposition on autopsied brain tissue. ACE also significantly inhibited A beta cytotoxicity on PC12 h. The most striking fact was that ACE degraded A beta by cleaving A beta-(1-40) at the site Asp(7)-Ser(8). This was proven with reverse-phase HPLC, amino acid sequence analysis, and MALDI-TOF/MS. Compared with A beta-(1-40), aggregation and cytotoxic effects of the degradation products A beta-(1-7) and A beta-(8-40) peptides were reduced or virtually absent. These findings led to the hypothesis that ACE may affect susceptibility to AD by degrading A beta and preventing the accumulation of amyloid plaques in vivo.

Alzheimer Disease↗

T cell apoptosis causes peripheral T cell depletion in mice transgenic for the HIV-1 vpr gene.

Vpr, an accessory protein of HIV, is known to affect viral replication as well as cell growth, differentiation, and apoptosis in vitro. To investigate its pathogenicity in vivo, we have produced mice transgenic for the HIV-1 vpr gene with the CD4 enhancer/promoter. Interestingly, apoptotic death of T lymphocytes was enhanced in those mice, causing marked reduction of T cells in lymphatic organs and peripheral blood. Involvement of Bcl-x, Bax, and Caspase-1, but not of the Fas-Fas ligand system, was suggested in the apoptotic processes. These observations suggest that Vpr is involved in the pathogenesis of T cell depletion in HIV-infected people.

Animals↗

Aichi Cancer Center 10-year experience with conservative breast treatment of early breast cancer: retrospective analysis regarding failure patterns and factors influencing local control.

PURPOSE: We analyzed the clinical results of conservative breast therapy in our institute to determine the risk factors influencing local and distant disease recurrence. METHODS AND MATERIALS: From 1989 to 1997, 301 breasts of 295 women with early breast cancer were treated with conservative surgery and adjuvant radiotherapy. There were 212 incidences of Stage I breast cancer, and 89 of Stage II. Patients were routinely treated with local resection, axillar dissection, and 46--50 Gy irradiation given in 23--25 fractions. Some also received a radiation boost to the tumor bed. RESULTS: The 5-/8-year overall survival, disease-free survival, and local control rates were 93.2/91.5%, 86.0/80.6%, and 95.1/92.5%, respectively. Using both univariate and multivariate analyses, tumor volume, estrogen receptor status, and age < 40 years were significant prognostic factors for disease-free survival. Both age < 40 years and surgical method had a strong effect on local control by uni- and multivariate analysis. Surgical margin status was a significant prognostic factor for local control at the univariate level (p < 0.0001), though it had only borderline significance at the multivariate level (p = 0.08). No patient experienced severe morbidity due to radiotherapy. CONCLUSION: The results obtained are comparable to previously reported data. Although the follow-up period was too short to draw definite conclusions about long-term outcomes, the outcome from conservative breast treatment was acceptable.

Adult↗

External irradiation and intraluminal irradiation using middle-dose-rate iridium in patients with roentgenographically occult lung cancer.

PURPOSE: Therapeutic results were analyzed in 39 patients with roentgenographically occult lung cancer (ROLC), and the significance and optimal dose of this therapy were evaluated. METHODS AND MATERIALS: The subjects were 39 patients who underwent intraluminal irradiation between May 1987 and August 1999. Radiotherapy was performed by combining external irradiation with intraluminal irradiation using middle-dose-rate iridium (four 370-MBq wires) through a catheter with a spacer, which held the source in the center of the bronchus. The doses of radiation were 22-66 Gy (median value 45 Gy) by external irradiation and 10-46 Gy (median value 28 Gy) by intraluminal irradiation. RESULTS: The therapeutic effect was CR in 38 patients and PR in 1, and local recurrence was observed in a PR case and 3 of the 38 patients who showed CR. The 3-year and 5-year relapse-free survival rates were both 87%. No severe radiation injury was observed. CONCLUSIONS: Considering that ROLC often occurs as multiple cancers and that many patients with ROLC have reduced lung function, radiation therapy by a combination of intraluminal irradiation and external irradiation is expected to replace surgery as the first choice for the treatment of this disease in the twenty-first century.

Aged↗

Alternating chemoradiotherapy for nasopharyngeal cancer using cisplatin and 5-fluorouracil: a preliminary report of phase II study.

Alternating chemoradiotherapy was performed in 35 patients with locally advanced nasopharyngeal cancer. The median duration of follow-up was 20 months, and the 2-year progression free and overall survival rates were 83% (95% confidence interval: 66~101%) and 94% (95% CI: 84~105%), respectively. This method may be useful in treating nasopharyngeal cancer.

Adenocarcinoma↗

Assay of testicular angiotensin-converting enzyme activity in human spermatozoa.

The testicular isozyme of angiotensin-converting enzyme (ACE) is associated with male fertility. Spermatozoa from mice lacking ACE showed defects in transport within the oviducts and in binding to zonae pellucidae although the animals had normal sperm count, morphology and motility. In fact, unexplained infertility is difficult to be predicted by conventional parameters such as sperm count. We measured membrane testicular ACE activity in a sperm suspension in PBS and total testis ACE activity in spermatozoa by solubilization with Triton X-100. Total testis ACE activity and membrane testis ACE activity of the same subject were compared in 12 control subjects. We demonstrated that testicular ACE is stable in spermatozoa and the assay of testicular ACE activity is possible. Total testicular ACE activity was approximately twice the membrane testicular ACE activity in all of the subjects tested. The assay of testicular ACE activity in human spermatozoa could be a new method for the assessment of sperm function.

Adult↗

Activity of testis angiotensin converting enzyme (ACE) in ejaculated human spermatozoa.

Testicular angiotensin converting enzyme (ACE) isozyme is likely to play important functional roles in male reproduction. Several studies have shown that ACE is released from human spermatozoa during capacitation and that ACE is associated with reduced sperm motility. Recently, we established an assay to detect testicular ACE activity in human spermatozoa. The purpose of this study was to determine if testicular ACE activity is related to sperm motility in human ejaculates. Semen samples were collected from 80 infertile patients. According to the semen characteristics, they were divided into four (WHO) categories. Enzyme activities of ACE in spermatozoa (testicular ACE) and seminal plasma (somatic ACE) were spectrophotometrically determined. Total testicular ACE activity in spermatozoa was measured by solubilization of spermatozoa with Triton X-100. Membrane testicular ACE activity was measured in a sperm : PBS suspension. Sperm concentration and sperm motility were 136.6 +/- 154.1 x 10(6)/mL and 58.6 +/- 23.4%, respectively (mean +/- SD). Enzyme activities of membrane testicular ACE, total testicular ACE and somatic ACE were 0.273 +/- 1.219 microU/10(6) spermatozoa, 0.35 +/- 1.34 microU/10(6) spermatozoa and 684.7 +/- 226.6 mU/mL, respectively. A negative correlation was observed between sperm motility and membrane testicular ACE activity (p < 0.05). Membrane testicular ACE activity in 44 normal semen samples was 0.04 +/- 0.02 microU/10(6) spermatozoa, whilst that in 36 abnormal semen samples was 0.24 +/- 0.42 microU/10(6) spermatozoa. There was a significant difference between these two groups (p < 0.01). Membrane testicular ACE in sperm samples from normozoospermic men was significantly lower than that from oligoasthenozoospermic men (p < 0.05). These findings suggest that testicular ACE is released from normal functional spermatozoa for them to have fertilizing ability.

Cell Membrane↗

Therapeutic results of alternating chemoradiotherapy for nasopharyngeal cancer using cisplatin and 5-fluorouracil: its usefulness and controversial points.

BACKGROUND: The present study was conducted to evaluate the therapeutic results of alternating chemoradiotherapy for locally advanced nasopharyngeal cancer (NPC). METHODS: The subjects consisted of six patients with stage III nasopharyngeal cancer and 26 patients with stage IV nasopharyngeal cancer. Using 6 MV photons, radiotherapy was performed at an exposure of 1.8-2.0 Gy five times per week. That is, a total absorbed dose of 36-40 Gy was irradiated between the base of the skull and supraclavicular fossa. After decreasing the irradiation field, an absorbed dose of 26-30 Gy was additionally given thereafter. One course of chemotherapy consisted of the administration of 5-fluorouracil (5-FU) at a dose of 700 mg/m2/24 h for 5 days (days 1-5) and cisplatin (CDDP) at a dose of 50 mg/m2/24 h for 2 days (days 6-7) and a total of 2-3 courses of chemotherapy were performed. During the alternating chemoradiotherapy, chemotherapy was performed initially and 3-5 days after completing the chemotherapy, radiotherapy was performed for 3-4 weeks. Thereafter, chemotherapy and radiotherapy were performed alternately. RESULTS: The scheduled courses of alternating chemoradiotherapy were completed in 30 (94%) of 32 patients. Although one patient developed shock induced by metal allergy to CDDP, no severe adverse effects were noted in any other patients. In these 32 patients, the overall 5-year survival rate was 75% (95% confidence interval: 60-90%) and the progression-free survival rate was 63% (95% CI: 46-89%). CONCLUSIONS: This method of alternating chemoradiotherapy yielded higher or at least similar survival rates and lower toxicities than concurrent chemoradiotherapy and is worth trying in a multi-institutional study.

Adult↗

Therapeutic effects of simultaneous intraluminal irradiation and intraluminal hyperthermia on oesophageal carcinoma.

An applicator enabling simultaneous intraluminal radiotherapy and intraluminal hyperthermia delivery was developed to improve the treatment results for locally advanced oesophageal carcinoma. Eight inoperable cases were treated by this method. Six cases received 40 Gy external irradiation followed by simultaneous intraluminal hyperthermia and radiotherapy (3 Gy and 4 Gy in three cases each) once weekly for 3 weeks; the remaining two cases received 50 Gy external irradiation followed by simultaneous intraluminal hyperthermia and radiotherapy (4 Gy) once weekly for 2 weeks. Hyperthermia was delivered by a radiofrequency current thermotherapy instrument for 30 min at an output that raised the oesophageal mucosal surface temperature to 42-43 degrees C. Intraluminal radiotherapy was delivered with a microSelectron to a submucosal depth of 5 mm after the first 15 min of hyperthermia. Four cases achieved complete response, with all demonstrating local control. Partial response was obtained in four cases, and three of these patients died of local recurrence. There were no significant adverse side effects apart from fistula in one case. In conclusion, simultaneous intraluminal radiotherapy and hyperthermia may improve the current treatment results for locally advanced oesophageal carcinoma.

Aged↗

[Two cases of squamous cell carcinoma of the anal canal treated with chemoradiotherapy].

We recently treated 2 patients with squamous cell carcinoma in the anal canal with bilateral inguinal nodal metastases using chemoradiotherapy. Chemotherapy (CT) consisted of 5-fluorouracil 700 mg/m2/day (continuous intravenously) on days 1-5 and cisplatin 50 mg/m2/day (continuous intravenously) on days 6-7. Chemotherapy was administered before the beginning of radiotherapy. In one patient, 2 cycles of CT were performed, and in the other patient 1 cycle only. The total radiation dose was 57.6 Gy to the primary lesion in each patient, and 53.6 Gy, 55.8 Gy to the nodal metastases, respectively. As a primary treatment response, CR was obtained in both patients. Acute grade 3-4 hematologic toxicities were observed in one patient. The patients have had 7 and 9 months survival without disease, and excellent function of the anal sphincter after treatment.

Aged↗

[A case of infected subdural hematoma due to Campyrobacter fetus].

A 20-year-old male presented fever, nausea and headache 1 week after eating uncooked liver. On admission, it was revealed he had suffered a closed head injury 3 months before without unconsciousness. On admission, computed tomography scan showed a left chronic subdural hematoma. Gd-DTPA magnetic resonance images revealed unusual enhancement of the capsule and linear enhancement of the subarachnoid space. The patient underwent burr hole irrigation and drainage. The culture of the hematoma content showed Campylobacter fetus. Therefore, the diagnose was infected subdural hematoma. A drainage operation and administration of antibiotics were effective. Our case suggests that enhanced magnetic resonance images are useful for diagnosis and follow-up of infected subdural hematoma.

Adult↗

[Necessity of co-operation of the community medical system based on the results from the survey by questionnaires-participation of the home healthcare and/or hospice systems in southern Tama community hospitals].

Home Care Division of Fujisawa Pharmaceutical Co. Ltd. has been providing the local public with the following services: 1) providing aseptic medicines prescribed in the clean room, 2) renting the infusion fluid pumps, and 3) supporting the community cooperation in healthcare services. Last year, we surveyed questionnaires to the public users (patients and caretakers) of these services, in order to understand the actual status of patients after changing from conventional hospitalization to the home infusion therapy (HIT). From the results of our present survey, it was found that the patients and their family members had positively accepted HIT, while 61% of the HIT users exhibited a strong anxiety in their skills and methods of HIT. Moreover, it was also shown that 61% had other means of nursing and treatment in addition to HIT, indicating a great financial burden on the families. Among them, 69% of the HIT users considered that visiting nurses and primary care physicians were the best co-operators, and changed their conventional healthcare system (hospitalization) to HIT. However, the home caretakers showed a high anxiety in their skill in the home healthcare system, specifically HIT, which was generally highly dependent on the medical care, Thus, a good relationship and co-operation with visiting nurses and primary care physicians was one of the major factors for the users to decide to choose HIT instead of their old medical hospitalization. Therefore, in order to make HIT more useful and widely prevail, it is concluded that establishment of the co-operative systems within our local community, where visiting nurses and primary care physicians can easily provide the patients and their family with professional suggestions, advice and actual care whenever the home caretakers need them.

Community Health Services↗

A combination therapy of continuous superselective intraarterial carboplatin infusion and radiation therapy for locally advanced head and neck carcinoma. Phase I study.

BACKGROUND: To improve the treatment result for locally advanced head and neck carcinoma, the authors used a combination of radiotherapy with superselective continuous intraarterial therapy using carboplatin. The dose limiting toxicity (DLT), maximum tolerated dose (MTD), and treatment effectiveness were tested in Phase I and II protocols. PATIENTS AND METHODS. Thirty-five patients were entered into the study from August 1992 to May 1997. The target arteries were the lingual artery in 18 cases, facial artery in 5 cases, maxillary artery in 11 cases, and external carotid artery initially changing to lingual artery in 1 case. Escalating daily carboplatin doses were tested, starting from 10 mg/m(2) (total dose, 360 or 400 mg/m(2)) to 15 mg/m(2) (total dose, 405 or 450 mg/m(2)) and then 20 mg/m(2) (total dose, 460 or 500 mg/m(2)). Radiotherapy was administered using a 6-megavolt linear accelerator to a total dose of 50-60 grays. Interstitial radiotherapy boost also was used for carcinoma of the tongue. RESULTS: Excluding 3 patients who discontinued treatment, the treatment results of 32 patients were complete response in 21 cases, partial response in 10 cases, and no change in 1 case. Neutropenia was the DLT, and the MTD was 500 mg/m(2). The local control rate was 64%. CONCLUSIONS: Superselective continuous intraarterial carboplatin and concurrent radiation therapy can be delivered safely with good efficacy for locally advanced carcinomas of the tongue and base of the tongue. Surgical treatment of these diseases usually incurs severe functional loss. This current approach may be a breakthrough in these cancers.

Adult↗

Induction of apoptosis by the Vpr protein of human immunodeficiency virus type 1 occurs independently of G(2) arrest of the cell cycle.

The HIV-1 accessory gene product Vpr can inhibit cell proliferation via cell cycle arrest at the G(2) phase, and it can induce apoptosis after G(2) arrest. We found recently that C81, a carboxy-terminally truncated form of Vpr, induced apoptosis via G(1) arrest but did not induce G(2) arrest of the cell cycle. Thus, it seemed possible that expression of Vpr in cells might cause apoptosis independently of the ability of Vpr to induce G(2) arrest. We demonstrate here that Vpr-induced apoptosis occurs by a mechanism that does not necessarily require induction of G(2) arrest. First, it was found that the extent of apoptosis reached a maximum even when few cells were arrested at the G(2) phase of the cell cycle and was reduced in inverse proportion to the increased induction of G(2) arrest. Thus, the extent of induction of G(2) arrest was not correlated with the extent of Vpr-induced apoptosis. Furthermore, we replaced the Ile/Leu residues in the leucine zipper-like domain of Vpr with Ala or Pro and used cells that expressed the mutant protein to demonstrate that Vpr caused apoptosis in a manner that was independent of G(2) arrest. Finally, replacement of Ile/Leu by Pro at positions 60, 67, 74, and 81 within the leucine zipper-like domain of wild-type Vpr and C81 revealed that the Ile/Leu residues at positions 60, 67, and 74 in the leucine zipper-like domain were indispensable for induction of apoptosis induced by Vpr and by C81 and confirmed, in addition, that both processes might be regulated by the same pathway. C81 appears to be a useful tool for elucidation of the mechanism of apoptosis induced by expression of Vpr protein.

Amino Acid Sequence↗

Dynamic distribution of an antigen involved in the differentiation of avian myoblasts: II. Possible association of beta1 integrin with myofibril organization.

Previous studies have shown that a monoclonal antibody, H-145, inhibits myotube formation of quail myoblasts transformed with a temperature-sensitive mutant of Rous sarcoma virus (QM-RSV cells) [Hyodo and Kim, 1994: Exp. Cell Res. 212:120-131]. The antigen recognized by H-145 (H-145 antigen), which is a glycoprotein with a molecular mass of about 116 kDa, is related to a step immediately before myoblast fusion. To determine the functional significance of H-145 antigen, we examined its dynamic state during myogenic differentiation of QM-RSV cells. H-145 antigen showed a unique and discrete distribution. In immature myotubes immediately after myoblast fusion, many ring-like structures of H-145 antigen appeared on the ventral surface of the cells, encircling the actin dots detected simultaneously by immunofluorescence and interference reflection microscopy. The core of the ring-like structures was filled with the termini of actin bundles, mainly formed by alpha-actin. Other cytoskeletal-associated proteins, such as vinculin and alpha-actinin, were also associated with these structures. The ring-like structures of H-145 antigen were observed only during a restricted period when myoblasts fused actively, suggesting their relationships to myotube formation and an early stage of myofibril formation. With maturation of the myotubes, most of the H-145 antigen became redistributed in linear arrays on the apical cell surface and was probably associated with the termini of actin bundles to organize myofibrils, suggesting that the antigen was also related to maturation of myotubes. Experiments using monoclonal antibodies against chick beta1 integrin showed that H-145 antigen is beta1 integrin or a very closely related derivation. Thus H-145 antigen (beta1 integrin) is possibly involved in both myoblast fusion and the myofibril organization in myotubes.

Actins↗