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Biomedical subjects

S Katsuno

Publications and source records attributed to S Katsuno.

At least 19 recordsLinked to original sources
PubMed2001

Gait initiation in bilateral vestibular loss.

OBJECTIVE: Gait initiation is a transient procedure between orthostatic posture and steady-state locomotion and includes anticipatory anteroposterior (AP) and lateral movements. Commands for this task are located in some levels of brain stem, which modulates activity of central pattern generator in the spinal cord. The purpose of this work was to explore the role of the vestibular system in this voluntary stepping. METHODS: Six patients with chronic bilateral vestibular loss (BVL) were measured by means of a large force plate (70 cm x 120 cm ) and the displacement of the center of pressure (COP) during gait initiation was calculated. Measurement parameters comprised maximum distance (MD), velocity (MV) in the AP and lateral direction as well as for pre-, first- and second-step stages, and the angle of the COP trajectory. RESULTS: For all stages, BVL patients registered lower values for both MD and MV in the AP direction than did normal subjects. In the lateral direction, however, neither MD nor MV in BVL patients showed any difference from those of normals. The step angle of the COP trajectory was obviously reduced. CONCLUSION: These results suggest that in the AP direction, the vestibulospinal pathway can influence the locomotor related neural circuits, including the central pattern generator and supraspinal levels, by means of modifying the velocity and step length in order to stabilize the trunk. On the other hand, the control mechanism in the lateral direction may be different from that in the AP direction.

Adult↗
PubMed2001

Direct screening of the IMP-1 metallo-beta-lactamase gene (blaIMP) from urine samples by polymerase chain reaction.

BACKGROUND: As Gram-negative bacterial isolates producing plasmid-mediated IMP-1 metallo-beta-lactamase usually demonstrate resistance to various broad-spectrum beta-lactams, including cephamycins and carbapenems, transmission and proliferation of these microorganisms in clinical settings could become a clinical threat in the near future. According to previous studies by the same authors, IMP-1-producing strains are usually isolated from urine samples. Therefore, in this study, a polymerase chain reaction (PCR) was applied for direct screening of the IMP-1 metallo-beta-lactamase gene in urine samples. METHOD: Urine samples were collected from 273 inpatients to whom various broad-spectrum beta-lactams, including carbapenems, had been administered in 57 hospitals in 1997. DNA templates for PCR analyses were prepared directly from 19 urine samples from which Serratia marcescens strains demonstrating high-level resistance (minimal inhibitory concentration > 128 microg/mL) to both ceftazidime and cefoperazone-sulbactam were later isolated. RESULTS: The IMP-1 metallo-beta-lactamase gene (blaIMP)-specific 578 bp fragments were able to be amplified successfully in eight of the 19 samples. In the seven strains isolated from the eight samples, the presence of blaIMP was also detected by a DNA hybridization analysis. The lower limit of the PCR method was determined as 1 x 10(2) CFU of blaIMP-bearing bacterial cells per 1 mL of urine sample. No false positive result was found. CONCLUSION: The PCR-aided direct screening of blaIMP is applicable to early recognition of IMP-1-producing bacteria in urine samples. This method would help to prevent nosocomial and interhospital transmission of this kind of hazardous bacteria, as well as the advancement of rigorous infection control.

Bacterial Proteins↗
PubMed2001

Two-dimensional alterations of myenteric plexus in jejunoileal atresia.

PURPOSE: The purpose of this report is to investigate changes in the myenteric plexus associated with the dilated proximal segment of jejunoileal atresia (JA). Two-dimensional morphologic changes in the myenteric nerve plexuses were investigated using whole-mount preparation. METHODS: Proximal (P) and distal (D) intestinal segments from 7 cases with JA and control (C) segments from 5 postmortem neonates were investigated. The circumference of the jejunoileal segments was measured after fixation. Antibodies for protein gene product 9.5 and neurofilament protein were used in whole-mount preparation. The sizes of neural networks were calculated by measuring the longest circular distance in a neural network (x) and the longest longitudinal distance (y), and the width of the internodal strands (i) with a videomicrometer. RESULTS: Median circumference of the segments was 8.5 in P, 2.0 in D, and 2.0 cm in C. The neural networks in P were expanded longitudinally as well as circularly (x = 817.10 microm, y = 561.26, i = 31.04: median) while comparing them to those in D (x = 431.40 microm y = 288.07, i = 26.05) or C (x = 285.03 microm y = 372.20, c = 1113.57, i = 32.39). The nerve plexus was less expanded than the intestinal wall. CONCLUSIONS: Proximal intestinal segments showed a restructuring that resulted in mild hypoplasia of the enteric nerve plexuses in the proximal segments. The less expansion of the myenteric nerve plexus seen in the proximal bowel in infants with JA suggests a histologic basis for the efficacy of tapering or plication of the dilated bowel.

Case-Control Studies↗
PubMed2001

Is carotid reconstruction for advanced cancer in the neck a safe procedure?

Head and neck surgeons hesitate to resect the carotid artery because of the postoperative risk of neurologic sequelae. On the other hand, there is no curative therapeutic option for head and neck cancer involving the carotid artery, except for complete tumor removal. A retrospective review of all published articles in the English literature dealing with carotid reconstruction for head and neck cancer from 1987 to 1998 was performed. There were only 11 articles, including our series, that reported outcomes of this procedure. Among the 148 patients of this series, major neuromorbidity was 4.7%, and mortality occurred in 6.8% of the patients. Combined major neuromorbidity and mortality was 10.1%. Because total removal of the advanced cancer is the only therapy that can offer the patients a chance for cure, head and neck surgeons should aggressively perform carotid resection and reconstruction.

Carotid Arteries↗
PubMed2001

[Retropubic radical prostatectomy with the use of ultrasonic cutting and coagulating system (AutoSonix System)].

We report our experience of using the ultrasonic coagulating and cutting device, AutoSonix System, which began in January 2000 to reduce the amount of bleeding in radical retropubic prostatectomy. The mean age of the 24 prostate cancer patients operated on was 68.2 years old. The operation results were excellent; the mean operation time was 227 +/- 29 minutes (mean +/- standard deviation), and the mean amount of blood loss during the operation was 215 +/- 114 ml. There were no major complications. After three months or more of follow-up, no patients needed any pads for urinary incontinence. Only one case showed a stricture at cystourethral anastomosis. AutoSonix System was useful to reduce the blood loss from the venous plexus in the pelvic cavity. We believe that radical prostatectomy would be safer if this device would be used by the urologist.

Aged↗
PubMed2000

The effects of intense click sounds on velocity storage in optokinetic after-nystagmus.

Vestibular evoked myogenic potentials (VEMP) occurring after click stimulation in cervical muscles are thought to be a polysynaptic response of otolith-vestibular nerve origin. In optokinetic after-nystagmus (OKAN) the direction of after-nystagmus changes and slow-phase velocity decreases with head tilt. This phenomenon may be an otolith response to the direction of gravity. We assumed that intense clicks might have some influence on OKAN via the otolith-vestibular nerve. Twelve normal subjects who showed VEMP at 75 dB normal hearing level (nHL) clicks were examined. The OKAN was recorded under four conditions: right monaural, left monaural and binaural stimulation by 75 dB nHL clicks, and absence of click stimulation. Horizontal optokinetic stimulation was applied using stepwise increasing speeds from 30 deg/s to 90 deg/s. Two seconds before the stimulus ended, clicks were sounded. The slow-phase velocity of the recorded electro-nystagmography was manually measured. There was no effect on OKAN with unilateral stimulation but binaural stimulation suppressed it. These results suggest that a velocity storage integrator is influenced by intense clicks via the otolithic area.

Acoustic Stimulation↗
PubMed2000

Chemical constituents of Clausena excavata: isolation and structure elucidation of novel furanone-coumarins with inhibitory effects for tumor-promotion.

A study of the chemical constituents of the leaves of Clausena excavata cultivated in a greenhouse led to the isolation and identification of 10 new furanone-coumarins named clauslactones A (1), B (2), C (3), D (4), E (5), F (6), G (7), H (8), I (9), and J (10), together with a known carbazole, clauszoline M, and a coumarin, umbelliferone. The new coumarins contain a C(10) terpenoid side chain with a furanone (gamma-lactone) moiety. Further, in clauslactones A-D (1-4), the terpenoid side chain was shown to be linked to the 7,8-dioxygenated coumarin skeleton through a 1, 4-dioxane ring system. This is the first example of coumarins with these structural characteristics in nature. These furanone-coumarins were found to exhibit inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate-induced Epstein-Barr virus early antigen activation in Raji cells.

Anticarcinogenic Agents↗
PubMed2000

Microsurgical vasoepididymostomy with sperm cryopreservation for future assisted reproduction.

BACKGROUND: Although obstructive azoospermia is treatable with microscopic seminal reconstruction, the number of patients who choose to undergo vasoepididymostomy is limited because of recent advances in assisted reproductive technology (ART). We attempted to define the outcome of surgical reconstruction in patients with suspected epididymal obstruction and no previous history of vasectomy. METHODS: We described 40 eligible end-to-side vasoepididymostomy procedures performed on 24 azoospermic patients who had either bilateral or unilateral epididymal obstruction. RESULTS: The overall patency rate following surgery was 54% (13/24) and for four patients (17%), natural intercourse resulted in pregnancy. Two pregnancies were initiated with intracytoplasmic sperm injections using frozen sperm collected during vasoepididymostomy. CONCLUSIONS: In the era of modern ART, microsurgical vasoepididymostomy with cryopreservation of sperm collected during the operation is recommended for patients with epididymal obstructions.

Adult↗
PubMed2000

Chemical constituents of Avicennia alba. Isolation and structural elucidation of new naphthoquinones and their analogues.

Three new naphthoquinones and their analogues, named avicequinone-A (1), -B (2), -C (3), and avicenol-A (4), -B (5), -C (6), respectively, were isolated from the stem bark of Avicennia alba (Avicenniaceae) collected in Singapore, and their structures were elucidated by means of spectral methods. Gillan and co-workers have proposed that the structures of the new phytoalexins isolated from Avicennia marina are 1,2-naphthoquinones 8 and 9. Our synthetic and spectrometric studies showed that these structures should be revised respectively to 1,4-naphthoquinones 2 and 3, named avicequinone-B and -C by us.

Magnetic Resonance Spectroscopy↗
PubMed2000

Bilateral basal-cell adenomas in the parotid glands.

A rare case of bilateral basal-cell adenomas in the parotid glands of a 65-year-old woman is reported. There have been only four previous reported cases of bilateral parotid basal-cell adenomas, all of which occurred synchronously with dermal cylindromas. The present lesion is the first case reported in the English literature of bilateral parotid basal-cell adenoma without coexisting dermal cylindroma. Histological examination revealed that the left tumour had adenoid cystic change, which closely resembled adenoid cystic carcinoma. This case is of interest not only because of the raity of bilateral parotid basal-cell adenomas, but also because of the necessity for differentiation from adenoid cystic carcinoma in order to plan appropriate treatment.

Adenoma↗
PubMed1999

Excision of cervical cystic lymphangioma using injection of hydrocolloid dental impression material. A technical case report.

A lymphangioma, arising in an adult patient, was completely removed after injection of hydrocolloid dental impression material. The postoperative course was uneventful, with no sign of foreign-body reaction. The agar impression material, which had excellent tractability during operation, may be used as a filling material, as long as preoperative examinations show that the tumor does not involve major vessels or nerves.

Adult↗
PubMed1998

Possible factors affecting response to intravesical bacillus Calmette-Guérin (Tokyo 172 strain) therapy for carcinoma in situ of the bladder: a multivariate analysis.

To evaluate clinicopathological factors affecting response to intravesical instillation therapy with the bacillus Calmette-Guérin (BCG) Tokyo 172 strain for carcinoma in situ (CIS) of the bladder, we reviewed data for 84 patients treated between 1985 and 1996. Median follow-up was 56 months. The patients comprised three groups: primary (only the in situ lesion, 31 patients), subsequent (found after treatment of a gross neoplasm, 20), and concomitant (found together with a gross neoplasm, 33). A complete response was found in 62 (74%) of the 84 patients. Intravesical BCG therapy eradicated tumour cells in 74% of the primary group, 70% of the subsequent group, and 76% of the concomitant group. Multivariate logistic regression analysis revealed that the presence of gross haematuria and patient age were significantly associated with a complete response to the intravesical BCG therapy (p<0.05). On the other hand, gender, irritative bladder symptoms, type of extent of CIS, histological grade of CIS, BCG dose, and number of times BCG was given did not exert any significant influence. The 5-year recurrence rate was 33% for the 62 patients for whom a complete response was once achieved. Patients aged 60 or older had a higher probability of recurrence than those less than 60 years of age (p<0.05). Disease progression was found in 13% of the 84 patients and total cystectomy was performed in 19%. The present finding that patient age is related to the response to intravesical BCG therapy may point to a role for the reduced host immunocompetence in elderly individuals.

Administration, Intravesical↗
PubMed1998

Different concentrations of two small stress proteins, alphaB crystallin and HSP27 in human urological tumor tissues.

Concentrations of two small stress proteins, alphaB crystallin and the 27-kDa heat shock protein (HSP27) were quantitated in tissues of the human normal genitourinary system and their tumors. Levels of HSP27 in renal cell carcinomas (mean +/- SE: 1450+/-262 ng/mg protein, n = 15) were significantly higher than in normal kidney (the cortex: 540+/-99 ng/ mg protein, n = 13; the medulla: 600+/-106 ng/mg protein, n = 13) while those of alphaB crystallin tended to be increased without statistical significance. These findings were similar to those previously reported for renal cell tumors chemically induced in rats. Concentrations of alphaB crystallin in prostatic carcinoma tissues (410+/-129 ng/mg protein, n = 10) were also significantly higher than in benign prostatic hyperplasia (54+/-12 ng/mg protein, n = 14), whereas alphaB crystallin levels in testicular tumors including seminomas (2.1+/-0.8 ng/mg protein, n = 11) and non-seminomas (5.2+/-2.3 ng/mg protein, n = 9) were significantly lower than in normal testicular tissues (29.7+/-6.2 ng/mg protein, n = 5). Both alphaB crystallin and HSP27 could be immunohistochemically localized in the normal kidney and renal cell carcinoma tissues.

Animals↗
PubMed1997

Characterization and management of deep neck infections.

A retrospective review was conducted of 91 patients with deep neck infections to determine the pattern of clinical disease and formulate a management plan. The spaces involved, as determined by clinical, radiologic, and operative findings, were the peritonsillar space (72 patients), parapharyngeal space (eight patients) submandibular space (seven patients), retropharyngeal space (one patient) superficial space (one patient), anterior visceral space (one patient), and visceral vascular space (one patient). Of the 19 patients who did not have a peritonsillar space infection the origin of the infection was found in eight; four of these were odontogenic. Thirty-eight patients required surgical drainage of the abscess. Five patients underwent tracheotomy due to increasing dyspnea. One patient with diabetes mellitus and a past history of myocardial infarction died of unknown cause. All other patients had an uneventful recovery without major complications. The combination of early radiologic diagnosis, effective antimicrobial therapy, and intensive surgical management contributed to the good prognosis.

Abscess↗
PubMed1997

Carotid resection and reconstruction for advanced cervical cancer.

Patients with advanced cervical cancers often have direct invasion of their carotid arteries. The prognosis for these patients with nonsurgical therapy is extremely poor. Because complete tumor removal is the only therapy that can offer these patients a chance for cure, carotid resection should be performed. We performed carotid resection and reconstruction on nine patients with advanced cervical cancers. Of these patients, none suffered from severe neurologic postoperative complications such as permanent hemiplegia. Three of the nine patients have been disease free for more than 24 months. These three patients would not have survived without carotid resection. Further study will show the usefulness of carotid resection and reconstruction in decreasing the morbidity and mortality in patients with cervical cancer involving the carotid artery.

Adult↗
PubMed1997

Surgical outcome of microscopic vasectomy reversal: an analysis of 30 cases.

The results of 30 consecutive microscopic vasovasostomy procedures performed at a single institution over a five-year period between 1991 and 1995 were reviewed. When the surgical outcomes of patients who were operated on less than five years after their vasectomy were compared with the outcomes of those patients who received a vasovasostomy more than five years after their vasectomy, decreases in technical success rates were observed as measured by appearance of sperm in ejaculate (56% vs. 36%), biologic recovery as measured by mean sperm counts (56 million vs. 35 million) and mean progressive sperm motility (44% vs. 21%), along with a decrease in clinical success, as measured by overall pregnancy rates (50% vs. 7%, p < 0.05). Therefore, a microscopic vasovasostomy within 5 years of a vasectomy is a favorable procedure for vasectomy reversal.

Adult↗