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Biomedical subjects

M Murayama

Publications and source records attributed to M Murayama.

At least 37 records · Page 2Linked to original sources

[A case of gastrointestinal stromal tumor of rectum, difficult to differentiate from leiomyosarcoma of prostate].

A 70 year-old male was seen at the hospital with the chief complaints of frequent miction and incomplete urinary retention. A hen's egg-sized firm mass was palpable in anterior wall of rectum by digital rectal examination. Intravenous urography showed severe bilateral hydronephroureter. Transrectal ultrasound, CT scan and MRI revealed a mass with 5 cm in diameter between prostate and rectum, and the margin of them were unclear. On needle biopsy of the tumor, leiomyosarcoma of the prostate was suspected. We performed radical cytectomy and created continent urinary reserver. Because the tumor and rectum could not be lysed, part of the rectum was resected. Histological examination showed gastrointestinal stromal tumor (GIST) of rectum. GIST of rectum is a rare entity, and in case of contact with the prostate, it is difficult to differentiate from leiomyosarcoma of prostate.

Aged↗

Reconstruction of urinary tract utilizing transverse colon conduit for a cystectomized patient with post-ureterocutaneostomy complications and sigmoid colon cancer.

A seventy-four years old man had been suffering from symptomatic and infectious complications associated with conjoined cutaneoureterostomy following the radical cystectomy for advanced transitional cell carcinoma of the bladder 3 years ago. He underwent urinary reconstruction using transverse colon conduit after diagnostic exclusion of recurrent urothelial tumor in the upper urinary tract, evaluation of performance status and endoscopic examination of the colon. Enteroscopy incidentally revealed he had an early stage adenocarcinoma in his sigmoid colon to be resected, and the resection was followed by the urinary diversion. Postoperatively he is satisfied to be free from urinary complications and frequently visits the outpatient clinic for painful and troublesome ureteral catheter exchange.

Adenocarcinoma↗

Influence of angiotensin-converting enzyme gene polymorphism on development of athlete's heart.

BACKGROUND AND HYPOTHESIS: Genetic influence on development of athlete's heart is uncertain. This study investigated whether angiotensin-converting enzyme (ACE) gene polymorphism influenced development of athlete's heart. METHODS: Forty-three participants in a 100-km ultramarathon were classified on the basis of ACE gene polymorphism into a deletion group (n = 26) and an insertion group (n = 17). Echocardiograms were recorded to determine left ventricular end-diastolic and end-systolic diameters, interventricular septal thickness, left ventricular posterior wall thickness, left ventricular mass, and ejection fraction. RESULTS: Left ventricular end-diastolic diameter (65.5 +/- 4.0 mm) and left ventricular mass (369.5 +/- 73.9 g) were significantly larger in the subjects with deletion than in those with insertion (57.4 +/- 4.2 mm, 306.5 +/- 93.7 g). However, no significant differences in the other parameters were noted. CONCLUSIONS: In long-distance runners, ACE gene polymorphism of the D/D and D/I genotypes has a stronger influence on left ventricular hypertrophy than polymorphism of the I/I genotype.

Adult↗

Changes in hardness of the human elbow flexor muscles after eccentric exercise.

The purpose of this study was to investigate changes in muscle hardness after eccentric exercise of the elbow flexors muscles that produce muscle shortening and swelling. To assess muscle hardness, a pressure method was used in which the force required to deform the tissue (skin, subcutaneous tissue, muscle) was recorded. Eleven healthy male students performed 24 maximal eccentric actions of the elbow flexor muscles with their non-dominant arms. Muscle hardness, maximal isometric force (MIF), muscle soreness, plasma creatine kinase (CK) activity, relaxed elbow joint angle (RANG), upper-arm circumference (CIR) and B-mode ultrasound transverse images were measured before, immediately after, and 1-5 days after exercise. A long-lasting decrease in MIF, muscle swelling shown by increases in CIR and muscle thickness, large increases in plasma CK activity, and development of muscle soreness indicated that damage occurred to the elbow flexor muscles. The RANG had decreased by approximately 20 degrees at 1-3 days after exercise and showed a gradual recovery thereafter. The CIR increased gradually after exercise and peaked on day 5 post-exercise, the mean amount of increase in CIR being 18 mm. Muscle hardness measured at the relaxed elbow position did not change until 3 days after exercise, but increased significantly (P < 0.01) on days 4 and 5 post-exercise. On the other hand, muscle hardness measured when forcibly extending the shortened elbow joint increased significantly (P < 0.01) with time and peaked at 3 days after exercise. Muscle hardness assessed by the pressure method seems to reflect changes in muscle stiffness and swelling.

Adolescent↗

Effectiveness of a CD-ROM multimedia tutorial in transferring cognitive knowledge essential for laparoscopic skill training.

BACKGROUND: Computer-assisted instruction (CAI) can benefit surgical education by improving efficiency, effectiveness, standardization, and access. This study compares knowledge gains for laparoscopic skill acquisition following a standardized tutorial delivered via CD-ROM versus live instructor. METHODS: A standardized tutorial was written and subsequently converted to multimedia CD-ROM format by its author (JR). During a laparoscopic development course, experienced US-trained surgeons (n = 52) participated in the tutorial delivered live by the author. The CD-ROM tutorial replaced the instructor for the following groups: (1) experienced US-trained surgeons (n = 27); (2) US-trained surgical residents (n = 59); and (3) Greek surgeons (n = 63). A 51-item knowledge test was administered before and after tutorial instruction. RESULTS: The mean increase in scores between pretest and posttest was significant (P <0.01) and of similar magnitude in each group, with nonsignificant posttest mean differences among US-trained groups. CONCLUSIONS: The CD-ROM tutorial effectively transfers cognitive information necessary for skill development. Distance learning modes of this tutorial program may be feasible.

CD-ROM↗

Minimally invasive surgical training solutions for the twenty-first century.

Despite the tremendous impact of laparoscopic cholecystectomy on the practice of surgery over the past 9 years, minimally invasive surgery faces many challenges that must be addressed. SAGES and the American College of Surgeons already have defined guidelines that, if properly implemented, could eliminate most of these challenges. Medical educators must formulate a detailed program as to how these guidelines can be widely deployed with acceptable effectiveness. The current educational philosophies and techniques will not ensure widespread access to a standardized program that would support the achievement of the goals set forth by major surgical governing bodies. Therefore, new educational strategies and techniques that are assisted with the integration of cost-effective technology are needed. Suggested solutions include the deployment of a standardized, objective-based skill-development program that has a large database to evaluate the progress of participants. Next, the Internet, with its ability to transfer content with the click of a mouse, will play an increasing role in distant education. Video and audio streaming techniques will allow the deployment of content previously shackled to a CD-ROM platform. CD-ROM interactive technology also can help in developing clinical judgment with innovative strategies, such as Objective-Based Clinical Competency Evaluation Scenarios. Telecommunications will fuse the components of a coordinated distant learning strategy. Also, telecommunications will allow the availability of new training capabilities in the form of teleproctoring and telementoring to hospitals, no matter what their size or location. All of these components combined enable the realization of a continuing education program in minimally invasive surgery that is readily available to hospitals worldwide. Last, institutions, resident training programs, and individual surgeons must commit the time to partake in these cutting-edge programs for challenges facing us to be completely eliminated. A high priority must be placed on the resolution of these issues.

Education, Medical↗

Familial Alzheimer's disease-associated mutations block translocation of full-length presenilin 1 to the nuclear envelope.

A polyclonal antibody, M5, to the hydrophilic loop domain of human presenilin 1 (PS1) was prepared. Western blot and immunoprecipitation analyses showed that M5 specifically recognized the processed C-terminal fragment, but not the full-length PS1. Epitope mapping analysis revealed that the essential sequence for recognition of the C-terminal fragment by M5 is DPEAQRR (302-308). The recognition of the C-terminal fragment by M5 in a processing-dependent manner was further confirmed by competitive enzyme-linked immunosorbent assay using the synthetic peptide L281 (281-311), which contains the putative processing site and the preceding amino acids to the site. Although L281 contains the epitope sequence for M5, the maximum inhibition was only 14%. Immunocytochemistry using M5 combined with hL312, which recognizes both full-length PS1 and the C-terminal fragment, allowed us to distinguish the localization of the processed C-terminal fragment from that of full-length PS1. Confocal microscopy demonstrated that the full-length form of wild-type PS1 is preferentially located in the nuclear envelope, while the processed C-terminal fragment is mainly present in the endoplasmic reticulum (ER). However, PS1 with familial Alzheimer's disease-associated mutations could not translocate to the nuclear envelope, and both the full-length and processed mutants were co-localized in the ER.

Alzheimer Disease↗

Evaluation of the effectiveness of portable low-bandwidth telemedical applications for postoperative followup: initial results.

BACKGROUND: The idea of using telemedical applications to evaluate patients remotely is several decades old. It has already been established that x-ray images (and magnetic resonance images) can be transferred using a personal computer and a modem, and many other such applications have been implemented. Over the past 50 years the expense and technical demands of the equipment involved in telemedicine have hindered its widespread deployment. The purpose of this study is to evaluate the ability of a mobile, low-bandwidth telemedicine platform to achieve real-time postoperative visits in the home. STUDY DESIGN: This evaluation was designed to evaluate the feasibility of performing a real-time clinical visit with computer and telecommunications hardware and software. A nurse and medical student (for information gathering only) made postoperative visits at patients' homes while the physician stayed at the office. Clinical evaluations were performed by using low-resolution and frame-rate video, high-resolution still images, and simultaneous telephony over a standard telephone line. These remote visits were followed by a standard visit in the office. Eleven patients were included, all of whom had undergone various laparoscopic procedures. They lived 5 to 240 miles from their surgeon. Efficiency was measured by recording the time required to capture and send data required by the physician to make a clinical decision. The time expense was measured at both the patients' and physician's locations. Technical issues were evaluated and patient satisfaction was assessed by standardized objective questionnaires. The accuracy of the evaluation at the remote visit was determined with a standard office visit. RESULTS: No technical problems were observed. The mean total time of the housecall at the remote site was 86 minutes (range 60 to 160 minutes) and at the base station site was 41 minutes (range 21 to 71 minutes). After personnel became familiar with the system, the last three visits averaged 61 and 25 minutes at the two sites, respectively. This corresponds favorablywith current time requirements for visiting nurses and office visits. The patients were highly satisfied with the home visit and, on average, rated the experience as 4.8 out of a maximum of 5. CONCLUSIONS: Followup visits in patients' homes after laparoscopic procedures can be accomplished by transmitting simultaneous voice, low-resolution video, and high-resolution still images to accurately perform postoperative evaluations over standard telephone lines, with time requirements and clinical accuracy similar to those of standard visits.

Adult↗

Suppression of cellular immunity by surgical stress.

BACKGROUND: Suppression of cellular immunity is one of the host responses to surgical stress. In cancer patients this immunosuppression may accelerate the growth and metastasis of residual cancer cells, so it is desirable to restrict immunosuppression by surgical stress to a minimum. However, the extent and duration of immunosuppression caused by operations on gastrointestinal cancer, as well as the mechanisms involved, have not been determined. METHODS: To clarify these points, we investigated immunocyte function and measured the blood levels of hormones, cytokines, and acute phase reactants from before to after operation in 20 patients with stage I gastrointestinal cancer. RESULTS: In patients exposed to surgical stress, peripheral blood lymphocyte numbers and function were suppressed until at least 2 weeks postoperatively. This immunosuppression was mainly due to a decrease of helper-inducer T cells, cytotoxic T cells, natural killer cells, and interleukin-2 receptor-positive cells, as well as an increase of suppressor T cells. In addition, hypersecretion of cortisol and overproduction of immunosuppressive acidic protein were observed. CONCLUSIONS: Cellular immunosuppression by surgical stress was mainly due to an increase of lymphocyte subsets that depress cellular immunity coupled with a decrease of the subsets that promote it. Overproduction of cortisol and immunosuppressive acidic protein in response to surgical stress may play an important role in the development of immunosuppression.

Acute-Phase Proteins↗

Physiological role of endothelin-1 in nonworking muscles during exercise in healthy subjects.

Endothelin-1 (ET-1) is a potent vasoconstrictor peptide produced by vascular endothelial cells. However, the role of ET-1 in exercise-induced physiological responses is still to be investigated. The purpose of the present study was to investigate in healthy volunteers whether the ET-1 plasma concentration in nonworking muscles is changed by exercise and to investigate the physiological role of ET-1 during exercise. Bicycle ergometer cardiopulmonary exercise tests were performed in 36 healthy men (mean age, 22.5 years). Blood samples for measuring ET-1 were drawn from the cubital vein during rest and immediately after the exercise test. The ET-1 change ratio was calculated as ET-1 immediately following exercise/ET-1 during the resting state. Cardiac output (CO) was measured during the exercise test by the impedance method. Arterial venous oxygen difference (AVO2D) when CO reached 10L/min or 15L/min was calculated as AVO2D = VO2/CO. Results were as follows: (1) the ET-1 change ratio correlated inversely with exercise time at the anaerobic threshold (r = -0.37, p = 0.03) and peak exercise time (r = -0.35, p = 0.04); (2) the ET-1 change ratio tended toward an inverse correlation with deltaVO2/deltawork rate (r = -0.29, p = 0.09); (3) the ET-1 change ratio correlated positively with AVO2D when CO reached 10L/min (r = 0.42, p = 0.02) and tended toward a positive correlation with AVO2D when CO reached 15 L/min (r = 0.32, p = 0.08). These results indicate that an increase in ET-1 in nonworking muscles may participate in the exercise-induced redistribution of blood flow and in increasing the blood flow to working muscles.

Adult↗

Magnesium dynamics and relation to left ventricular function in acute myocardial infarction.

The present study investigated the serial changes in serum magnesium (Mg) and erythrocyte concentration of Mg in patients with acute myocardial infarction (AMI) and the relationship between these changes and left ventricular ejection fraction (LVEF) at 1 month after the onset of infarction. The study group comprised 26 patients with AMI (mean age, 57.9+/-8.9 years). Serum Mg and erythrocyte Mg were measured on hospital days 1, 2, 4, 7 and 21. The change in erythrocyte Mg during the acute phase was calculated as a ratio: [(erythrocyte Mg at day 2)-(erythrocyte Mg at day 1)]/(erythrocyte Mg at day 1). The change in serum Mg was calculated similarly. The following results were obtained. (1) Serum Mg tended to increase from the onset of myocardial infarction (day 1: 1.86+/-0.19, day 2: 1.93+/-0.22, day 4: 2.17+/-0.23; day 7: 2.25+/-0.20; day 21: 2.12+/-0.15 mg/dl). (2) Erythrocyte Mg on day 2 and day 4 showed a significant decrease compared with day 1 (day 1: 2.45+/-0.40, day 2: 2.09+/-0.41, day 4: 2.07+/-0.37, day 7: 2.22+/-0.33, day 7: 2.34+/-0.28 mg/dl per 400x10(4)/mm3 cells). (3) A significant positive correlation was observed between the change in serum Mg and LVEF (r=0.55, p<0.05), and a significant negative correlation was observed between the change in erythrocyte Mg and LVEF (r=-0.57, p<0.05). Thus, it was concluded that an extracellular shift in intracellular Mg occurred during the first 2 days after the onset of myocardial infarction. This responsive increase in the extracellular Mg level may be an important factor for maintaining left ventricular function in patients 1 month after the onset of AMI.

Aged↗

Clinical assessment of a new method for pacing pulse detection using a hybrid circuit in digital Holter monitoring.

Holter monitoring is widely used for the detection of arrhythmia and ischemic episodes. Traditionally, analog amplitude-modulated Holter devices have been used for detecting arrhythmia, but they produce signal distortion due to contour effects and phase distortion caused by the tape recorders. A digital Holter device without these disadvantages has been developed and can reproduce clinically accurate electrocardiographic waveforms useful for assessment of arrhythmia and ST segments. However, their reliability is questionable when detecting pacing pulses in pacemaker patients. Because electrocardiographic signals are digitized based on sampling rate, pacing pulses are occasionally missed. Therefore, the FM-300 was developed, a new device for detecting pacing pulses on digital recordings that has both digital and analog circuits in one system and indicates pacing pulse timing with arrows. This device can automatically detect and recognize pacing pulses from various artifacts and pacing modalities, making it easy to identify pacing pulses on digitally recorded electrocardiograms. The FM-300 is useful in the diagnosis and assessment of pacemaker function and has improved the reliability of pulse detection in digital Holter monitoring.

Artifacts↗

Purulent pericarditis due to group B streptococcus and mycotic aneurysm of the ascending aorta: case report.

A 61-year-old female, with a history of uterine and cervical cancer treated with radical hysterectomy and 2 years of postoperative chemotherapy, presented to the emergency department with dyspnea on exertion. Computed tomography of the chest revealed a large pericardial effusion and a sacciform aneurysm of the ascending aorta. The patient subsequently underwent emergency pericardiocentesis with drainage of approximately 330 ml of a bloody and turbid effusion. Cultures from the effusion yielded group B streptococcus. Multiple organ failure and disseminated intravascular coagulation syndrome occurred in the acute phase, but gradually improved with continuous antibiotic therapy. On the 194th hospital day, in situ reconstruction of the ascending aorta was successfully performed using a synthetic graft. Although rarely reported, both purulent bacterial pericarditis and mycotic aneurysm can be life-threatening.

Aneurysm, Infected↗

Impaired heart rate response during incremental exercise in patients with acute myocardial infarction and after coronary artery bypass grafting: evaluation of coefficients with Karvonen's formula.

Heart rate (HR) response during exercise in patients with ischemic heart disease was evaluated, and the appropriateness of Karvonen's method for determining rehabilitation exercise target HR was investigated. The study group comprised 24 patients with acute myocardial infarction (AMI) and 37 patients who had undergone coronary artery bypass grafting (CABG). Cardiopulmonary exercise testing (CPX) was performed with a cycle ergometer and changes in HR (deltaHR)/changes in work rate (deltaWR) and interval changes of the coefficient of Karvonen's formula were evaluated. In the AMI group and the CABG group, deltaHR/deltaWR were significantly lower than those of age-matched control subjects (p<0.01). Karvonen's coefficients ranged from 0.37 to 0.54 when calculated from actual peak HR and 0.21 to 0.32 calculated from the predicted peak HR. An impaired HR response was found in patients with AMI and those who had had CABG up to 6 months previously. Because the Karvonen's coefficient values, which ranged from 0.6 to 0.8, were elevated for these patients, and considering the data from the CPX, increased exercise is recommended for such cases.

Adrenergic beta-Antagonists↗

[A case of an advanced aged Eisenmenger's syndrome].

We report a 70-year-old women with Eisenmenger's syndrome. Eisenmenger's syndrome with ventricular septal defect was diagnosed at another hospital when she was 32 years old. Then, she was referred to our hospital at age 60 old and she now is according to the out patient in over clinic. She have mild cardiac function, NYHA classification, was II-M, polycythemia cell blood count 535 x 10(4) and 17.2 g/dl in hemoglobin. Echocardiography suggested serious Eisenmenger's syndrome. The left ventricle was compressed, the blood pressure of the right ventricle exceeded 105 mmHg, and the onset of the right to left shunt flow was thought to be 250 msec bored on the electrocardiogram Q wave. The reason why the progression of complicated obstructive pulmonary artery disease was slow may have been become of the mildness of her polycythemia, and this is presumed to be the reason for her long survival to age 70.

Aged↗

Efficacy of primary percutaneous transluminal coronary angioplasty for acute myocardial infarction in patients aged > or = 80 years.

The therapeutic result of primary percutaneous transluminal coronary angioplasty (PTCA) in the elderly was assessed in 20 of 44 patients > or = 80 years old (range 81-92 years, mean age 84 +/- 3 years) with acute myocardial infarction who underwent primary PTCA and the results compared with 194 younger patients (< 80 years) who underwent primary PTCA during the same period. In-hospital prognosis, and long-term outcomes were investigated. Emergency coronary angiography was performed in 47.7% of the patients with acute myocardial infarction in the elderly group with 45.5% receiving primary PTCA. Primary PTCA was successful in 95.0% of the elderly group, showing no significant difference from the younger group. In-hospital mortality showed no significant difference between the elderly group and the younger group (5.0% vs 4.1%). However, the incidences of pump failure of the heart and bleeding complication requiring blood transfusion were higher in the elderly group during hospitalization. The 2-year survival rate for the elderly group was 82.5 +/- 9.3%, which was better than previous studies. These results suggest that primary PTCA has a good success rate in the elderly patients with acute myocardial infarction, and decreases the in-hospital mortality and improves the long-term outcome. However, this study was conducted retrospectively in a small group of patients. The efficacy of primary PTCA for the elderly remains to be clarified in a larger prospective trial.

Age Factors↗

[Small adenocarcinoma of the lung under long-term observation].

A 68-year-old man presented with symptoms of common cold at our hospital on March 8, 1995. Ground glass opacity (GGO) was detected in the right S 4 a by high resolution computed tomography (HRCT) during a routine examination. Except for mild traction of the nearest pleura, the lesion itself demonstrated little change on HRCT images for 2 years. HRCT images disclosed slight enlargement of the lesion over a long-term period of follow-up observation. Exactly 25 months after the first examination, HRCT scans demonstrated an area of centralized dense concentration. Right middle lobectomy was performed 30 months after the lesion was first detected. Pathologic findings from the resected specimen revealed Noguchi's small adenocarcinoma of the lung (type B classification: localized bronchioloalveolar carcinoma with collapse of alveolar structure). The lesion was scanned 8 times with HRCT during the follow-up period. The change to GGO with centralized density and spicula was observed in detail, and thought to be evidence of a progression from type A to type B. We concluded that a set of fixed settings should be utilized for repeated HRCT examinations of small peripheral lesions exhibiting GGO.

Adenocarcinoma↗