Biomedical subjects

A Uchiyama

Publications and source records attributed to A Uchiyama.

At least 19 recordsLinked to original sources

PubMed2006

Fixation-sensitive myoclonus in Lafora disease.

The authors report a patient with Lafora disease, whose myoclonus was suppressed by passive eye closure. Neurophysiologic studies disclosed that fixation was the most important enhancer of myoclonus. Magnetoencephalographic studies of visual evoked fields revealed abnormal activation of the visual corticocortical pathway via the insular cortex not seen in controls. The authors hypothesize that abnormal activation of the insular cortex may be involved in triggering the mechanism of fixation-sensitive myoclonus.

Adolescent↗

PubMed2005

Laparoscopically assisted distal gastrectomy with standard radical lymph node dissection for gastric cancer.

BACKGROUND: Laparoscopically assisted distal gastrectomy (LADG) with limited lymph node dissection (D1+alpha) has been used to treat a subset of patients with early gastric cancer. Technical advances have expanded indications for LADG to more advanced gastric cancers. However, little data are available on the feasibility or advantages of LADG with standard radical D2 lymph node dissection for patients with gastric cancer. METHODS: This study reviewed the clinical features of 37 patients who underwent LADG with D2 lymph node dissection for preoperatively diagnosed gastric carcinoma, then compared the results with the features of 31 patients who underwent conventional open distal gastrectomy (ODG) with D2 lymph node dissection. RESULTS: The laparoscopic procedure was not converted to laparotomy in any patient. There was no operative mortality and no serious morbidity among the patients who underwent LADG with D2 lymph node dissection. As compared with the ODG group, the LADG group had less operative blood loss (p < 0.001), earlier recovery of bowel activity (p = 0.012), and a shorter duration of fever after surgery (p = 0.015), despite the longer operation time (p = 0.007). CONCLUSIONS: According to this study, LADG with D2 lymph node dissection is feasible and provides several advantages similar to those of limited lymph node dissection (D1+alpha). Depending on surgeons' technical proficiency, LADG can be used with standard radical lymph node dissection for patients with gastric cancers.

Carcinoma↗

PubMed2004

Infrasternal mediastinoscopic surgery for anterior mediastinal masses.

BACKGROUND: Infrasternal mediastinoscopic surgery is a new alternative to the thoracoscopic approach for patients with anterior mediastinal masses. METHODS: We applied this technique to 18 thymectomies, one thymomectomy, and one cystectomy in a total of 20 patients with anterior mediastinal masses and then assessed the surgical results. RESULTS: Infrasternal mediastinoscopic surgery was accomplished in 18 of the 20 patients (90%). The pathological diagnoses included 13 Masaoka stage I thymomas, one stage II thymoma, two stage III thymomas, one thymic cyst, one pericardial cyst, one thymic granuloma, and one mature teratoma. Two patients with stage III thymoma required conversion to sternotomy, one for invasion into the innominate vein and the other for invasion into the pericardium. There was no surgically related mortality or complications in any patients. CONCLUSION: Infrasternal mediastinoscopic surgery is safe and feasible for stage I thymoma and other benign tumors in the anterior mediastinum.

Adult↗

PubMed2004

[Partial anomalous pulmonary venous drainage to the high superior vena cava; repair by direct anastomosis between the superior vena cava and the right atrial appendage; report of a case].

A 10-year-old boy with partial anomalous pulmonary venous connection to the high superior vena cava (SVC) underwent surgical repair by Williams method. The SVC was divided above the orifice of the anomalous pulmonary vein. The proximal end of the SVC was closed and the distal end of the SVC was anastomosed to the right atrial appendage (RAA). The anomalous pulmonary vein was rerouted to the left atrium via the SVC and the surgically enlarged central type atrial septal defect (ASD). The postoperative course was uneventful except transient sinus bradycardia and catheter study showed no stenosis of the SVC and the RAA.

Anastomosis, Surgical↗

PubMed2003

Detection of Reovirus type 3 by use of fluorogenic nuclease reverse transcriptase polymerase chain reaction.

Reovirus type 3 (Reo-3) can infect numerous rodent species and induces the clinical syndrome 'oily skin disease' in neonatal mice, and is a common contaminant of biological materials. The reverse transcriptase polymerase chain reaction (RT-PCR) assay has proven useful for the detection of Reo-3 in rodents and contaminated biological materials. Fluorogenic nuclease reverse transcriptase polymerase chain reaction assays (fnRT-PCR) combine RT-PCR with an internal fluorogenic hybridization probe, thereby potentially enhancing specificity and eliminating post-PCR processing. Therefore, an fnRT-PCR assay specific for Reo-3 was developed by targeting primer and probe sequences to a unique region of the Reo-3 M3 gene. The fnRT-PCR detected both strains of Reo-3 (Dearing and Abney), but did not detect Reovirus types 1 or 2, other viruses in the family Reoviridae, or other RNA viruses that naturally infect rodents. The fnRT-PCR detected less than 1 fg of target template and detected viral RNA in tissues obtained from mice experimentally infected with Reo-3. The assay also displayed comparable sensitivity when compared to the mouse antibody production test commonly used to detect viral contamination of biological materials. In conclusion, this fnRT-PCR assay offers a potentially high-throughput diagnostic assay for detecting Reo-3 RNA in infected mice and contaminated biological materials.

Animals↗

PubMed2002

Laparoscopic wedge resection of gastric submucosal tumors.

BACKGROUND/AIMS: The purpose of this study was to evaluate the clinical utility of laparoscopic surgery for gastric submucosal tumor. METHODS: The records of 11 patients who underwent laparoscopic wedge resection (LR group) for gastric submucosal tumors were reviewed and compared with those of 8 patients who underwent open surgery (OS group). RESULTS: Mean operation time was 145 +/- 43 min in the LR group and 127 +/- 33 min in the OS group (p = 0.301). Mean blood loss was 97 +/- 107 and 107 +/- 47 g, respectively (p = 0.387). Patients in the LR group began walking 1.4 +/- 0.7 days after surgery, which was significantly earlier than those in the OS group (2.7 +/- 1.3 days, p = 0.021). The first flatus (1.5 +/- 0.5 vs. 3.1 +/- 0.6 days, respectively, p = 0.0004) and resumption of oral food intake (3.0 +/- 1.7 vs. 4.3 +/- 0.9 days, respectively, p = 0.020) were also earlier in the LR group. White blood cell count on the first postoperative day was lower (7,000 +/- 2,100 vs. 11,900 +/- 3,580/mm(3), respectively, p = 0.004) in the LR group than in the OS group, and the duration of fever (>38.0 degrees C; 0.1 +/- 0.3 vs. 0.9 +/- 0.8 days, respectively, p = 0.014) and the period of postoperative hospitalization (13.2 +/- 3.7 vs. 20.8 +/- 6.1 days, respectively, p = 0.014) were significantly shorter in the LR group than in the OS group. No complications occurred in either group. CONCLUSION: Laparoscopic surgery was superior to open surgery in terms of postoperative recovery time with comparable operation time and blood loss. Laparoscopic wedge resection is a promising surgical alternative for the treatment of gastric submucosal tumors.

Aged↗

PubMed2001

Production of biologically active recombinant bovine interferon-gamma by two different baculovirus gene expression systems using insect cells and silkworm larvae.

The full-length bovine interferon-gamma (bIFN-gamma) cDNA, including the secretion signal peptide coding region was recloned into baculovirus transfer vectors pAcYM1 and pBm050. These vectors were co-transfected with Autographa californica nuclear polyhedrosis virus (AcNPV) or Bombyx mori nuclear polyhedrosis virus (BmNPV) DNA into Spodoptera frugiperda cells (SF21AE) and Bombyx mori cells (BmN), respectively. The recombinant viruses, named AcBIFN-gamma and BmBIFN-gamma, were then recovered. Recombinant bIFN-gamma (rbIFN-gamma) was accumulated in the culture fluid of AcBIFN-gamma-infected Trichoplusia ni cells and BmBIFN-gamma-infected silkworm larvae. These rbIFN-gamma forms were shown to be glycosylated 20 and 22 kDa proteins as confirmed by SDS-PAGE and tunicamycin treatment. These products were sensitive to cystein proteinase. Both rbIFN-gamma proteins, showed high-level biological activities by plaque reduction assay using vesicular stomatitis virus, and MHC class II antigen induction on bovine macrophage cells.

Animals↗

PubMed2001

Mutation screening for Japanese Lafora's disease patients: identification of novel sequence variants in the coding and upstream regulatory regions of EPM2A gene.

The progressive myoclonus epilepsy of Lafora type (LD) is an autosomal recessive disorder caused by mutations in the EPM2A gene. We demonstrated recently that EPM2A encodes a dual-specificity phosphatase that is primarily associated with polyribosomes. In the present study, we screened for mutations in the EPM2A gene in 4 Japanese LD families and identified a novel mis-sense mutation, Ala46Pro (136G-->C), in heterozygous condition in one patient. In addition, sequence analyses in the patient and control DNA samples identified 4 single nucleotide polymorphisms (SNPs) (75G/A, 120G/T, 159C/G, 171C/T) in the coding region and a novel insertion/deletion polymorphic site (-483[T](11/10)[A](2/3)) and a SNP (-547A/G) in the putative regulatory region of the EPM2A gene. None of the sequence variants, however, co-segregated with the LD phenotype. Haplotype analysis for the 6q24 region in the affected families revealed lack of homozygosity at the EPM2A locus. Our studies suggest that EPM2A is not involved in the disease phenotype of the 4 families studied and that locus heterogeneity for LD may exist in Japanese population also. A simple test described for the detection of Ala46Pro mutation present heterozygously in Japanese population (allele frequency 0.026) can be used for screening this novel allele in a larger sample size.

Adolescent↗

PubMed2001

Video-assisted parathyroidectomy for primary hyperparathyroidism: a new approach involving a skin-lifting method.

BACKGROUND: Recent advances have allowed the performance of parathyroidectomy as an endoscopic procedure. Carbon dioxide (CO2) insufflation can be used to create a working space in the anterior neck, but it has been associated with a number of complications. We have devised a skin-lifting method to overcome these problems. METHODS: Eleven consecutive patients underwent video-assisted parathyroidectomy. Preoperative imaging revealed a solitary adenoma in all 11 cases. A 3-cm oblique incision was made below the clavicle, and a 5-mm incision was made on the lateral neck. After the skin was lifted, video-assisted parathyroidectomy was performed. RESULTS: Surgery required 186 +/- 50 min. No conversions to conventional cervicotomy were needed. Levels of serum calcium and intact parathormone decreased significantly in all patients on postoperative day 1. Laryngeal recurrent nerve paresis and seroma were noted in one patient each. CONCLUSIONS: Our procedure eliminates any potential CO2 problems and offers the advantages of direct manipulation and improved cosmesis. Endoscopic parathyroidectomy should be considered a viable option for the surgical treatment of a solitary adenoma.

Aged↗

PubMed2001

Comparison of laparoscopic versus open cholecystectomy in patients with cardiac valve replacement.

To evaluate the benefits and safety of laparoscopic cholecystectomy (LC) in patients with cardiac valve replacement (which frequently leads to cholelithiasis), 12 patients with cholelithiasis associated with cardiac valve replacement were studied. The patients were divided into two groups, of 6 patients each, according to the type of operation performed, open cholecystectomy (OC) or LC. The postoperative course was monitored with respect to laboratory data on postoperative days (POD) 1, 3, and 7. The mean duration of operation, blood loss, days to food resumption, length of hospital stay, and morbidity were compared between the two groups. Significant differences (P < 0.05) were found between the OC and LC groups in white blood cell counts on POD 1 (12 980 +/- 3040/mm3 vs 8300 +/- 1590/mm3), days to food resumption (2.7 +/- 0.4 days vs 1.0 +/- 0.7 days), and length of postoperative stay (15.8 +/- 1.0 days vs 10.8 +/- 1.6 days). There were no complications in the LC group, but 1 patient in the OC group had heart failure postoperatively. Our findings indicate the efficacy and safety of LC in patients with cardiac valve replacement.

Adult↗

PubMed2001

Association of enhanced cyclooxygenase-2 expression with possible local immunosuppression in human colorectal carcinomas.

BACKGROUND: Prostaglandin (PG) E2 has an influence on antitumor lymphocyte reactions and causes local immunosuppression at tumor sites. The contribution of cyclooxygenase (COX), a key enzyme in PGE2 synthesis, to this effect is still unclear. We examined if cyclooxygenase (COX)-2 is involved in local immunosuppression in human colon carcinoma cell lines and in clinical tumor specimens. METHODS: PGE2 concentrations were measured in culture media from a highly COX-2-expressing human colon carcinoma cell line (CE-1) and other cell lines. Lymphocyte proliferation in response to a mitogen was used to evaluate immunosuppression in tumor cell-lymphocyte cocultures with and without selective COX-2 inhibitor NS-398. We also evaluated expression of COX-2 mRNA in surgical specimens of colorectal carcinoma by reverse transcription polymerase chain reaction (RT-PCR) and COX-2 protein by immunohistochemistry, correlating COX-2 expression with clinicopathologic features. RESULTS: CE-1 cells produced large amounts of PGE2, which was significantly inhibited by NS-398. The proliferation index of lymphocytes cocultured with CE-1 cells was significantly less than that of control lymphocytes; again, this effect was inhibited by NS-398. While human colorectal carcinoma tissue expressed more COX-2 mRNA and protein than nonneoplastic tissue, no significant correlation was found between COX-2 levels and clinicopathologic features. CONCLUSIONS: Overexpression of COX-2 in colon cancer may cause local immunosuppression, and COX-2 inhibitors might be therapeutically useful against these tumors.

Adenocarcinoma↗

PubMed2001

Infrasternal mediastinoscopic thymectomy in myasthenia gravis: surgical results in 23 patients.

BACKGROUND: Infrasternal mediastinoscopic surgery is a new approach to resection of the anterior mediastinal mass. METHODS: We evaluated this new approach in 23 patients with myasthenia gravis who underwent total thymectomy assisted by infrasternal mediastinoscopy between 1998 and 2000. The results were analyzed with special reference to morbidity and short-term improvement of the disease severity determined according to quantitative myasthenia gravis (QMG) scores. RESULTS: Complete removal of the thymic gland with the pericardial adipose tissue was accomplished through an infrasternal mediastinoscopic approach in 21 of the 23 (91.3%) patients. The remaining 2 patients required conversion to sternotomy, the one for insufficient sternal lifting with vascular tape and the other for invasion of a thymoma to the innominate vein. There was no related mortality and only one complication, a phrenic nerve injury in 1 patient (4.3%). Significant clinical improvement of disease was achieved in the short term and several advantages were apparent. CONCLUSIONS: Infrasternal mediastinoscopic thymectomy is safe and feasible for patients with myasthenia gravis.

Adult↗

PubMed2001

Serological diagnosis of equine influenza using the hemagglutinin protein produced in a baculovirus expression system.

The hemagglutinin (HA) protein of an equine influenza strain, A/equine/La Plata/1/93 (LP/93), was produced using a baculovirus expression system. Silkworm larvae inoculated with recombinant baculovirus expressed high quantities of the HA protein which was then purified to greater than 95% purity by fetuin-affinity chromatography. Purified HA protein was used subsequently in an ELISA for detection of antibodies in horse sera. Two hundred serum samples from vaccinated racehorses were reacted on ELISA plates coated with 40.0 ng/ml of purified HA protein. Subsequent optical density (OD) levels revealed titers which correlated highly with respective hemagglutinin inhibition (HI) antibody titers which ranged from <1:8 to 1:256 (correlation coefficient among them was 0.850). ELISA OD levels and HI titers increased at 5 and 7 days post-inoculation, respectively, in a horse inoculated intranasally with LP/93. Respective antibody levels were observed to change in an essentially parallel manner during a period of 1 month. Similarly, ELISA OD levels correlated with HI titers in horses during a period of 6 weeks following intramuscular inoculation with inactivated single-strain vaccines containing LP/93, A/equine/Kentucky/1/81 (H3N8) or A/equine/Rome/5/91 (H3N8). A similar pattern was also observed in eight horses throughout a 10-week period following inoculation with a commercially available inactivated trivalent vaccine containing A/equine/Newmarket/1/77(H7N7), A/equine/Kentucky/81 and LP/93. From these results, it is suggested that this ELISA system could be used for disease diagnosis and surveillance of HI antibody titers among vaccinated horses.

Animals↗

PubMed2001

iNOS expression by activated neutrophils from patients with sepsis.

BACKGROUND: Enhanced production of nitric oxide (NO) is associated with various inflammatory diseases such as sepsis. Although activated neutrophils are presumably involved in septic organ injury, the expression of inducible nitric oxide synthase (iNOS) by these cells has not been elucidated. The authors investigated whether activated neutrophils in sepsis could induce mRNA for iNOS and produce NO. METHODS: Peripheral blood neutrophils were obtained from healthy volunteers, and septic patients underwent a surgical operation. The neutrophils of the healthy volunteers were stimulated with lipopolysaccharide (LPS) and/or tumour necrosis factor-alpha (TNF-alpha). The iNOS expression and NO production were examined by the reverse transcription-polymerase chain reaction and Griess method, respectively. RESULTS: Circulating neutrophils obtained from patients with sepsis expressed higher levels of iNOS mRNA than those from patients with systemic inflammatory response syndrome (SIRS). Resting neutrophils from normal controls did not express iNOS mRNA and thus did not produce NO. After in vitro stimulation with LPS and TNF-alpha, the neutrophils did express iNOS mRNA and thus produce NO. CONCLUSION: Activated neutrophils may be one source of NO production in sepsis.

Adult↗

PubMed2001

Physiologic effects of transtracheal open ventilation in postextubation patients with high upper airway resistance.

OBJECTIVE: To investigate whether transtracheal open ventilation (TOV), pressure control ventilation (PCV) through a minitracheotomy tube (internal diameter 4 mm), is an effective method of inspiratory assistance under high upper airway resistance in postextubation patients; to compare, in a lung model study, TOV with other methods. DESIGN: Clinical study: A prospective, controlled, crossover study. Lung model study: A prospective laboratory trial. SETTING: Clinical study: A six-bed general intensive care unit in a teaching hospital. Lung model study: Animal research laboratory. PATIENTS: Clinical study: Eleven postextubation patients, who had undergone minitracheotomy for sputum retention between January 1997 and December 1997. SUBJECT: Lung model study: Two-bellows-in-a-box lung model, which included ordinary and high levels of upper airway resistance. INTERVENTIONS: Clinical study: Ventilatory settings were: assist/control (A/C) mode, 2 breaths/min of A/C back-up rate, 35-40 cm H2O of PCV, 0.6-0.8 secs of inspiratory time, and 0 cm H2O of positive end-expiratory pressure. The ventilatory parameters of TOV were compared with those of spontaneous breathing (SB). Lung model study: Effect of TOV on inspiratory assistance was compared with those of SB, open minitracheotomy, 5 L/min of transtracheal gas insufflation, and 5 and 10 cm H2O of pressure support ventilation (PSV), which simulated noninvasive positive ventilation. TOV ventilatory settings were: A/C mode; 30, 40, and 50 cm H2O of PCV, 0.9 secs of inspiratory time, and 0 cm H2O of positive end-expiratory pressure. At each ventilatory setting, we adjusted the inspiratory effort of the model to give a tidal volume of 0.5 L. MEASUREMENTS AND MAIN RESULTS: Clinical study: TOV was performed for 76.6 +/- 38.6 hrs (mean +/- sd) over 5.6 +/- 2.6 days without major complication. Peak tracheal pressure, which was measured distal to the minitracheotomy tube in six patients by a catheter pressure transducer, was 4.33 +/- 0.59 cm H2O. Inspiratory tidal volume delivered by the ventilator was 0.51 +/- 0.06 L. Respiratory rate during TOV was lower than during SB. According to esophageal pressure and respiratory inductive plethysmography, TOV reduced the patient's inspiratory work and improved the breathing pattern. Lung model study: Mean tracheal pressure during TOV and 10 cm H2O of PSV were positive values and they had larger inspiratory assistance according to the pressure-time product of pleural pressure. Although high upper airway resistance reduced the inspiratory assistance of PSV, it did not change the effects of TOV. CONCLUSIONS: TOV effectively reduced patient's inspiratory work and was more useful than open minitracheotomy and transtracheal gas insufflation. TOV also improved the breathing pattern. TOV may be useful for resolving some postextubation respiratory problems and avoiding the need for reintubation.

Aged↗

PubMed2001

Impedance computed tomography using an adaptive smoothing coefficient algorithm.

In impedance computed tomography, a fixed coefficient regularization algorithm has been frequently used to improve the ill-conditioning problem of the Newton-Raphson algorithm. However, a lot of experimental data and a long period of computation time are needed to determine a good smoothing coefficient because a good smoothing coefficient has to be manually chosen from a number of coefficients and is a constant for each iteration calculation. Thus, sometimes the fixed coefficient regularization algorithm distorts the information or fails to obtain any effect. In this paper, a new adaptive smoothing coefficient algorithm is proposed. This algorithm automatically calculates the smoothing coefficient from the eigenvalue of the ill-conditioned matrix. Therefore, the effective images can be obtained within a short computation time. Also the smoothing coefficient is automatically adjusted by the information related to the real resistivity distribution and the data collection method. In our impedance system, we have reconstructed the resistivity distributions of two phantoms using this algorithm. As a result, this algorithm only needs one-fifth the computation time compared to the fixed coefficient regularization algorithm. When compared to the fixed coefficient regularization algorithm, it shows that the image is obtained more rapidly and applicable in real-time monitoring of the blood vessel.

Algorithms↗

PubMed2001

ECG data reduction method for medical telemetry systems.

In current medical practice, all transmitters used for monitoring an ECG send data continuously. If transmission could be limited to only the ECG data that requires the attention of a technician, the likelihood of interference and power consumption would be reduced considerably. In this paper, we propose a new ECG telemetry system. The transmitter has a simple ECG analyzer and it only transmits data when abnormal waveforms are detected. As part of this system, we propose a simple algorithm to detect an abnormal ECG. The algorithm is composed of a baseline drift canceller (utilizing a moving average calculation), a waveform detector (using a modified second order derivative) and an ECG analyzer. In order to test the effectiveness and feasibility of the algorithm, computer simulations (with a MIT-BIH ECG database) and experiments (with microprocessor-based hardware) were performed. The results of the simulations show that the detection performance and data compression performance of the algorithm are adequate. The results of the experiment show that the algorithm even performs adequately when used with microprocessor-based hardware that is of limited size or limited power consumption.

Algorithms↗

PubMed2001

Relationship between work of breathing provided by a ventilator and patients' inspiratory drive during pressure support ventilation; effects of inspiratory rise time.

Inspiratory drive and work of breathing provided by a ventilator (WOBv) during pressure support ventilation (PSV) were examined in 15 patients. At PSV 10 and 15 cm H2O during CPAP 5 cm H2O, patients with low P0.1 (<4.2 cm H2O, n=9) showed WOBv 0.57 and 0.92 J/l, those with high P0.1 (>4.2 cm H2O, n=6) showed 0.31 and 0.62 J/l respectively. WOBv was smaller and pressure-time product of oesophageal pressure (PTP) was significantly larger in high P0.1 patients. Peak inspiratory flow for low P0.1 patients increased as PSV level increased but high P0.1 patients showed no significant change. In a lung model, effects of inspiratory rise time (IRT) and PSV were studied at high and low inspiratory drives by using ventilators with (Servo 300) and without (Mallinckrodt 7200a) adjustable IRT. With 7200a, PSV 10 cm H2O during low drive was compared with PSV 10 and 15 cm H20 during high drive. In Servo 300, PSV 10 cm H2O (IRT 0.6 and 0.0 sec) during low drive was compared with PSV 10 cm H20 (IRT 0.6 and 0.0 sec) and PSV 15 cm H2O (IRT 0.6 sec) during high drive. Raising PSV and shortening IRT both increased peak inspiratory flow. Initial inspiratory flow increased in inverse proportion to IRT, but higher PSV had a little effect. WOBv with high drive was less than with low drive. Higher PSV preserved WOBv by increasing tidal volume. Shortening IRT recruited WOBv by increasing initial inspiratory flow without changing airway pressure and tidal volume. Compared with higher PSV, shorter IRT reduced PTP more. In conclusion, WOBv decreased as inspiratory drive increased due to inability to increase inspiratory flow. Increasing initial inspiratory flow was more effective than raising PSV to preserve inspiratory assistance of PSV at high inspiratory drive.

Adult↗