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Biomedical subjects

Y Kikuchi

Publications and source records attributed to Y Kikuchi.

At least 379 records · Page 21Linked to original sources

Improvement of coronary vasomotion with eicosapentaenoic acid does not inhibit acetylcholine-induced coronary vasospasm in patients with variant angina.

Impaired function of the endothelium may be a mechanism of the coronary vasospasm induced by acetylcholine. We examined whether purified eicosapentaenoic acid (EPA), a major component of fish oil, improves the coronary vasomotion in response to acetylcholine, and the effect of purified EPA on acetylcholine (ACh)-induced coronary vasospasm in 22 patients with variant angina. ACh was infused into the coronary artery both before and after 4 months of EPA treatment (EPA 1.8 g/day, n = 12). In the control group (n = 10) that did not receive EPA, the response of the coronary diameter to ACh did not change over time. In the EPA-treated group, the cholinergic response in non-spastic sites changed from vasoconstriction to vasodilation, while ACh-induced coronary vasospasm persisted at the spastic sites. Therefore, EPA treatment improved the coronary vasomotor responsiveness to ACh, but did not inhibit ACh-induced coronary vasospasm.

Acetylcholine↗

Pseudomonas fluorescens KKL101, a benzoic acid degrader in a mixed culture that degrades biphenyl and polychlorinated biphenyls.

A mixed culture we had isolated, which degrades biphenyl/polychlorinated biphenyls, is composed of two strains, Pseudomonas fluorescens KKL101 and Pseudomonas sp. strain KKS102. KKS102 produces benzoic acid as a dead-end metabolite in the degradation of biphenyl. In this study we showed that KKL101 grew on benzoic acid as a sole source of carbon. This indicated a role of KKS102 in the growth of KKL101 and KKL101 for the growth of KKS102 in the mixed culture.

Bacteriological Techniques↗

Hairpin ribozyme-mediated cleavage of the full-length beta-glucuronidase (GUS) mRNA.

We designed three hairpin ribozymes to cleave Escherichia coli beta-glucuronidase (GUS) mRNA and tested those activities in vitro. One of the ribozymes was designed to form 9 base pairs in total with the target GUS mRNA, and the other two ribozymes had longer substrate binding sites. All ribozymes cleaved the model substrate (100 bases long) at the predicted target site. Two ribozymes containing longer substrate binding sites cleaved the substrate much more efficiently than the other ribozyme containing shorter substrate binding site. Also, the ribozymes with long substrate binding sites had high activity against the full-length GUS mRNA (1.9 kilobases) and maintained the activity even at a low temperature, 26 degrees C, a general growth condition of plant cells. Effects of the substrate binding site length of the ribozyme on cleavage activity are discussed.

Base Composition↗

Relation between the stromal volume and liver metastasis in ductal cell carcinoma of the pancreas.

In 23 patients with ductal cell carcinoma of the pancreas, the volume density of the stromal area was estimated by morphometry on photomicrographs of cancer tissue taken at surgery. The patients were divided into three groups: those with metachronous liver metastasis (Group A, n = 8), with simultaneous liver metastasis (Group B, n = 4) and those without liver metastasis (Group C, n = 11). The analysis illustrated a significantly lower fraction of stromal element in Groups A and B as compared to Group C at a statistical level of 0.01 (Ryan test). The scirrhous pancreatic carcinoma tended to resist liver metastasis after various therapeutic modalities including pancreatic resection.

Carcinoma, Ductal, Breast↗

Different behavior of forearm blood flow during intermittent isometric handgrip in a thermo-neutral and a hot environment.

The purpose of the present study was to evaluate the different behavior of forearm blood flow (FBF) during intermittent isometric handgrip (IIHG, 6 seconds contraction +6 seconds relaxation) in a thermoneutral versus a hot environment. Six healthy men performed three times of 5-minute period IIHG at three different work loads (10%, 20% and 30% MVC). The IIHG was performed with the right hand. The experiments of IIHG were performed at two different air temperatures (25 degrees C and 40 degrees C, RH: 50%), and an experiment without work was also carried out at 40 degrees C (RH: 50%). The physiological responses measured involved heart rate (HR), cardiac output (CO), mean arterial blood pressure (MBP), FBF, and skin blood flow (SBF). HR, CO and SBF showed higher values during IIHG at 40 degrees C than at 25 degrees C. MBP had a tendency to increase with the intensity of work load at both 25 degrees C and 40 degrees C. Since intramuscular pressure might increase during contraction periods at 20% MVC and 30% MVC at 25 degrees C, FBF was significantly higher during relaxation periods than during contraction periods. FBF showed similar values between contraction and relaxation periods at 10% MVC at both temperatures. The present study suggested that FBF was sufficient for active muscles during IIHG at 10% MVC. FBF of contraction periods was close to that of relaxation periods at 40 degrees C due to the modulation of the sympathetic outflow to the muscles and/or the decreased efficiency of the muscle pump. It was suggested that FBF showed different behaviors during HHG at 25 degrees C versus at 40 degrees C.

Adult↗

Circulatory regulation during supine and sitting intermittent isometric handgrip in a hot environment.

We studied the circulatory regulation during intermittent isometric handgrip (IIHG, six seconds contraction + six seconds relaxation) in supine and sitting postures in a hot environment (40 degrees C, RH: 50%). Eight healthy male subjects performed thrice 5-minute period IIHG at three different work loads (10%, 20% and 30% MVC). The IIHG was performed with the right hand in the two postures. Heart rate (HR), cardiac output (CO), mean arterial blood pressure (MBP), forearm blood flow (FBF), skin blood flow (SBF), foot swelling (FSW) and tympanic temperature (Tty) were measured during IIHG, resting and recovery periods. During IIHG in a hot environment, HR, MBP, FSW and Tty showed higher values in the sitting than in the supine posture. FBF during relaxation showed higher values at high work load than at low work load in the two postures. FBF showed higher values in the sitting than in the supine posture, except during relaxation at 30% MVC. It was concluded that the decrements of blood volume of splanchnic organs might be greater in the sitting than in the supine posture due to sympathetic vasoconstrictor activity, and were responsible for the redistribution of blood flow. Posture had an effect on FBF because of hydrostatic pressure.

Adult↗

Changes in body shape of young individuals from the aspect of adult physique model by factor analysis.

The purpose of this study was to clarify characteristics of age-related changes in body shape in adolescence, in 11- to 19-year-old boys and girls, by using previously reported physique models of adult men and women as the scale. The scale consisted of four factors obtained by factor analysis using 30 items as variables, such as the values measured for the physique, skinfold thickness and body composition. The four factors were Factor 1: body fat, Factor 2: mass, Factor 3: leg length to height ratio, and Factor 4: length, and were interpreted in the men and women in a similar manner. The subjects were 307 boys and 368 girls; all were healthy. Thirty items were measured and included the values measured for the physique, skinfold thickness and body composition, as in the men and women. Factor scores in the subjects were standardized by mean and standard deviation for each item in the adult subjects, and calculated for individuals by using the coefficient of factor score in the adult subjects. The body shapes of the boys and girls were investigated from the factor score by age calculated for each factor. The following results were obtained: 1. Factor 1 tended to gradually decrease and reached the adult level at 15 years of age in the boys.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Effects of time stress on psychophysiological responses during data entry tasks.

Six male and six female students (19-23 yrs) volunteered as subjects in the present experiment. Subjects performed the data entry tasks. A hundred and twenty single digit numbers 12 by 10 lines matrix were displayed in a random sequence on the left side of monitor. Subjects input the same numeral as these numbers one by one with clicking of the mouse on the ten keys displayed on the right side of the monitor. Each task consists of the following conditions: 1) system response time is fast or slow; 2) delete the input numerals from 120 numbers or not; 3) button flashes after input or not; and 4) the remaining time is displayed or not during performing the tasks. These tasks are programmed to be finished automatically after 200 seconds independent of the rate of completing all inputs. We measured heart rate (HR), systolic and diastolic blood pressure (SBP and DBP), skin blood flow (SBF), skin potential level (SPL), number of errors (Es), total number of input and subjective ratings concerning the degree of irritation (SR1), difficulty of input (SR2) and unpleasantness in operation (SR3). It was shown that when system response time was slow, even the average of heart rate and blood pressure were lower than fast system response time, however, the subjects felt greater emotional irritation, difficulty of input and unpleasantness in operation hence making more errors.

Adult↗

Characteristics of body shape of female athletes based on factor analysis.

We examined the body shape of female athletes in comparison with female adult non-athletes by factor analysis. The subjects were 433 adult non-athletes and 464 athletes participating in 11 different sporting events. The physique, skinfold thickness and body composition of each subject were measured. The values obtained from non-athletes were analyzed by factor analysis, and the body shape of the athletes was then analyzed according to these factors. Four main factors with which 80 percent of total variance could be explained were body fat (Factor 1), mass (Factor 2), leg length to height ratio (Factor 3) and length (Factor 4), and were extracted from the values from non-athletes. The body shape of the athletes could be classified into 4 categories by cluster analysis for factor score of sporting events: less body fat and slim type, average type like non-athletes, muscular and well-balanced type, and tall and well-developed mass. Compared with non-athletes, female athletes for all sporting events had less body fat. Moreover, the athletes had a body shape suitable for their sporting events; i.e., their mass, length of leg and height.

Adult↗

[Eighteen cases of tortuosity of the internal carotid--usefulness of MR-angiography in diagnosis].

There have been few reports on tortuosity of the internal carotid exhibiting pulsation or swelling in the pharyngeal wall. Because this disease carries the risk of causing massive hemorrhage at the time of incision of a peritonsillar abscess, surgical treatment of the adenoids, or tonsillectomy, otolaryngologists should be aware of the existence of this disorder as a risk factor. We encountered tortuosity of the internal carotid in the pharynx in 18 cases over an approximately two year period. Females (15 cases) outnumbered males (3 cases), and the mean age was 68 years at the time of diagnosis. There was no right-to-left difference in terms of the incidence of the disease. The complication of hypertension was noted in 10 cases. MR-Angiography (MRA) was performed in 13 cases, and very clear images were obtained; this technique was useful for diagnosing this disorder. For the most part, contrast angiography has been employed for the diagnosis of this disorder, but various complications, including deaths, have been reported. As the incidence of tortuosity of the internal carotid is high in the elderly, it is thought that any complication which may occur has the potential to become serious. Non-invasive diagnostic techniques are thus recommended. MRA is absolutely non-invasive, and we therefore believe that this technique should be the modality of first choice for diagnosing tortuosity of the internal carotid.

Aged↗

[Participation of atrial natriuretic peptide (hANP) levels and arginine vasopressin (AVP) in aged persons with nocturia].

BACKGROUND: The associations of human atrial natriuretic peptide (hANP) and arginine vasopressin (AVP) with nocturia in two groups of elderly individuals were investigated. METHODS: Plasma hANP and AVP levels were determined at 8:00, 14:00, 20:00, 2:00 and 8:00 (2nd day) in 15 healthy younger elderly individuals and 30 elderly individuals who showed no abnormal physical findings. Urine volume, urinary Na and K levels, and urinary osomotic pressure were also determined every 6 hours at the above-mentioned times. The maximum diameter of the inferior vena cava (IVC) in the inferior portion of the confluence of the hepatic veins was determined at 14:00, 20:00 and 2:00 in 11 younger elderly individuals and 17 elderly individuals. RESULTS: The mean hANP level was significantly higher in the elderly group than in the younger elderly group, and the mean AVP level was significantly higher in the younger elderly group than in the elderly group. There were no significant differences in diurnal variation in hANP between daytime and night among the younger elderly individuals, but the hANP level was significantly increased during the night in the elderly individuals. The AVP level was significantly higher at night than during the daytime in the younger elderly individuals, while it was significantly decreased at night in the elderly individuals. Although there was no marked diurnal variation in the IVC in any of the younger elderly individuals, IVC diameter was significantly increased at night in the elderly individuals. Urine volume was high during the daytime in the younger elderly group, and increased during the night in the elderly group. CONCLUSIONS: The increase in body fluid and elevation of hANP over the time between evening and night, and the decrease in AVP accompanying these increases were considered to lead to the increase in urine volume during the night, and this increase is considered to be a factor in nocturia.

Adult↗

[A case of surgical retrieve of migrated microcatheter].

This is a report of an accidental breakaway of a microcatheter during endovascular embolization for cerebral arteriovenous malformation occurring in a 48-year-old female. She had a sudden onset of cerebral herniated signs caused by a large hemorrhage in the region of the right parietal lobe. An angiogram showed a large arteriovenous malformation in the same region. 48 days after emergency evacuation of the hematoma and clipping of a feeding artery, we performed endovascular embolization using a microcatheter as assistant therapy for total removal of the nidus. However, accidentally, the microcatheter broke and migrated to the distal middle cerebral artery. Although we tried to retrieve the catheter using a loop snare, we had no success. We eventually retrieved it by open surgery next day. Fortunately the migrated catheter could be seen through a cortical artery, so after trapping it by using elastic thread and cutting off the artery we were able to extract the migrated catheter. Finally we were able to remove the nidus totally without other complications. Since breaking and migration of a microcatheter is a rare but possible accident, we should be prepared to cope with it appropriately.

Catheterization↗

Dysgerminoma of the ovary with hypercalcemia associated with elevated parathyroid hormone-related protein.

The purpose of the present paper is to present a rare case of dysgerminoma of the ovary with hypercalcemia showing elevation of multiple serum tumor markers including parathyroid hormone-related protein (PTH-rP). An 18-year-old unmarried woman, with ovarian dysgerminoma showing hypercalcemia and elevated serum PTH-rP, received six courses of a combination chemotherapy consisting of bleomycin, etoposide and cisplatin after her first surgery, and had no evidence of recurrence approximately 30 months after completing the chemotherapy.

Adolescent↗

[Non-Hodgkin's lymphoma of stage I and II in elderly patients: a retrospective study in comparison with younger patients].

Forty-one patients with non-hodgkin's lymphoma at stages I and II who had received radiation therapy were reviewed to analyze the prognosis and prognostic factors, with the main focus on a comparison of elderly (age > 65 years) and younger patients. In terms of clinical and histological characteristics, there were no differences between the elderly and younger patients. The 5-year-survival rate (5YS) in elderly patients was 52.8%, compared with 68.6% for younger patients. In patients treated with irradiation alone, the 5YS was 49.5% in elderly patients and 22.1% in younger patients. Combination treatment consisting of irradiation and chemotherapy improved 5YS markedly to 84.9% in the younger patients, while no apparent improvement was seen in the elderly patients, in whom 5YS was 54.1%. Using Cox's multiregression life table, two prognostic factors, the presence of symptoms and LDH, were extracted and found to have a significant influence upon the survival of the elderly patients. Complete response was 90.2% in the elderly patients, although relapse was seen in 54.1% of the complete responders. Relapse occurred overwhelmingly outside the irradiated regions. Since the prognosis of elderly patients could not be improved with the current chemotherapy regimen, some different regimen must be established to lower the high relapse rate in the area outside the irradiated field.

Adolescent↗

A monoclonal antibody against a murine CD38 homologue delivers a signal to B cells for prolongation of survival and protection against apoptosis in vitro: unresponsiveness of X-linked immunodeficient B cells.

A novel monoclonal antibody (mAb) was established in an attempt to look for a cell-surface molecule that delivered a signal regulating apoptotic cell death of B cells. Because spleen cells in resting culture die from apoptosis, mAb were looked for that were able to prolong spleen cell survival in vitro. This screening selected mAb CS/2. CS/2 not only prolonged spleen cell survival in vitro, but also protected spleen cells from apoptotic cell death brought about by irradiation or dexamethasone. Moreover, stimulation of spleen cells with CS/2 mAb induced changes of cells to blastoid morphology, and a significant uptake of [3H]thymidine ([3H]TdR). The antigen recognized by CS/2 mAb (CS/2 Ag) was expressed on preB cells, B cells, and Mac-1+ cells. The cells surviving in vitro culture or irradiation in response to ligation with CS/2 mAb were mostly B cells expressing the CS/2 Ag. In addition, B cells from X-linked immunodeficient (XID) mice did not respond to CS/2 mAb. These results indicate that CS/2 mAb is agonistic to B cells, and that XID mice are deficient in this CS/2 mAb-mediated activation pathway. Determination of the amino-terminal 24 amino acid residues revealed that the CS/2 Ag appears to be identical to the CS/2 mAb is directed against a murine CD38 homologue, and suggest a possible role of the murine CD38 homologue in controlling apoptotic cell death of B cells.

ADP-ribosyl Cyclase↗

[Two surgical cases of tectal glioma].

Tectal glioma is rare and difficult to diagnose, and the tumor has been known as the tumor that gives no indication of the need for direct surgery because of its anatomical location. At present, MR imaging is available to detect the tumor and its location. We present two patients who underwent direct surgery. Case 1: A 18-year-old female was admitted with headache and nausea. MRI showed signs of stenosis of the aqueduct and a tumor of the tectal region. The tumor was removed partially. Histological examination of this tumor demonstrated a low grade astrocytoma. After surgery, hydrocephalus improved. Case 2: A 12-year-old boy was admitted with hydrocephalus detected by CT. MRI demonstrated a tumor of the midbrain without confirmation. He underwent a V-P shunt for hydrocephalus, and was discharged without any complaints. After 2 years, he was admitted again with shunt malfunction. After shunt revision, his consciousness recovered. However, Parinaud's sign appeared and patency of the shunt was unstable. MRI revealed a tumor of the tectal region and signs of stenosis of the aqueduct of Sylvius. The tumor was removed directly by the occipital transtentorial approach. The aqueduct was opened and a catheter was inserted from the 3rd to the 4th ventricle. Histological examination revealed a low grade astrocytoma. The patient followed a satisfactory postoperative course except for slight Parinaud's sign, and the V-P shunt was no longer necessary.

Adolescent↗

[Acute lymphoblastic leukemia accompanied by severe hypercalcemia; successful treatment with bisphosphonate].

A 62-year-old woman was admitted to the hospital because of bone pain. Laboratory data showed blasts in the peripheral blood, hypercalcemia (corrected calcium 15.1 mg/dl) and an increased level of parathyroid hormone related-protein (PTHrP). Bone marrow aspiration revealed increased lymphoblasts (96.5%), indicating acute lymphoblastic leukemia (ALL, L1). Subsequent radiological examination disclosed bone infiltration of ALL. Although the hypercalcemia was successfully treated with bisphosphonate, the PTHrP level remained high. After chemotherapy, the blasts in the peripheral blood disappeared and the PTHrP level normalized. We hypothesize that in the present case the production of PTHrP by lymphoblasts resulted in the hypercalcemic state. Although ALL is rarely accompanied by hypercalcemia, this case might help us to understand the relationship between ALL and hypercalcemia.

Diphosphonates↗