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Biomedical subjects

H Sakata

Publications and source records attributed to H Sakata.

At least 55 records · Page 3Linked to original sources
PubMed1999

Penetration by a huge abdominal aortic aneurysm into the lumbar vertebrae: report of a case.

We report herein the case of a 64-year-old man who underwent urgent surgery for a huge abdominal aortic aneurysm (AAA) with severe lumbago. At surgery, a defect in the posterior wall of the AAA, through which the adjacent lumbar vertebrae was seen after removal of intraluminal thrombi, was encountered with no evidence of blood leakage. This is a rare case of AAA that eroded the posterior wall and exposed the vertebrae.

Angiography↗
PubMed1999

Neural representation of three-dimensional features of manipulation objects with stereopsis.

In the first part of this article, we review our neurophysiological studies of the hand-manipulation-related neurons in the anterior part of the lateral bank of the intraparietal sulcus (area AIP). We describe the properties of visually responsive neurons in area AIP. Object-type visual-dominant neurons responded to the sight of objects and showed selectivity not only for simple geometrical shapes, but also for complex objects such as a knob-in-groove and a plate-in-groove. Some of the object-type visual-dominant neurons showed selectivity for the orientation of the longitudinal axis or the plane (surface) of a plate or a ring. In the second part of this article, we review our study of binocular visual neurons in the caudal part of the lateral bank of the intraparietal sulcus (c-IPS area), in particular, of axis-orientation-selective (AOS) neurons and surface-orientation-selective (SOS) neurons. AOS neurons preferred long and thin stimuli, were sensitive to binocular disparity, and tuned to the axis orientation in three-dimensional (3D) space. SOS neurons preferred broad and flat stimuli and were tuned to the surface orientation in depth. Some SOS neurons responded to a square in a random dot stereogram (RDS) with orientation tuning, suggesting that they encode surface orientation from a disparity gradient. Others responded to solid figure stereograms with orientation disparity and/or width disparity. It was concluded that the c-IPS area is a higher center for stereopsis, which integrates various binocular disparity signals received from the V3 complex and other prestriate areas to represent the neural code for 3D features. It may send projections to the AIP area and contribute to visual adjustment of the shape of the handgrip and/or hand orientation for manipulation and grasping. Neurons of the AIP area may also receive monocular cues of depth from the ventral visual pathway to discriminate the 3D shape of the object of manipulation.

Depth Perception↗
PubMed1999

Ileal varices associated with recurrent bleeding in a patient with liver cirrhosis.

We report a rare case of massive and recurrent bleeding from ileal varices in a patient with hepatitis C virus-positive liver cirrhosis. A 66-year old woman, who had undergone laparotomy and blood transfusion 36 years before (because of an extrauterine pregnancy) and endoscopic sclerotherapy for esophageal varices 1 year previously, was admitted to our hospital with loss of bright red blood per rectum. The bleeding was massive and recurrent, and frequent blood transfusions were required. Endoscopic studies failed to find the bleeding site. In the venous phase of selective superior mesenteric angiography, mesenteric varices in the lower part of the abdominal cavity were observed. Laparotomy was performed to control the repeated bleeding which had lasted for more than 1 month. Varices communicating with the right ovarian vein were found on the ileal wall and segmental resection of the ileum was performed. Histological examination demonstrated a massive varicose vein and several dilated veins in the submucosa. The patient's postoperative course was favorable, with no hemorrhagic events during a follow-up of more than 6 months after surgery. Ileal varices should be considered in the diagnosis of a patient who presents with lower gastrointestinal bleeding and portal hypertension.

Aged↗
PubMed1999

Proportion of reflux esophagitis in 6010 Japanese adults: prospective evaluation by endoscopy.

Compared with findings in Western countries, the prevalence of reflux esophagitis in Oriental countries is estimated to be low. In this prospective study, we aimed to examine the proportion of reflux esophagitis in Japanese adults, as evaluated by endoscopy. Endoscopists were prospectively directed to grade esophageal mucosal breaks with esophagitis according to the Los Angeles Classification of Esophagitis in all subjects that underwent endoscopic examination. In total, 6010 subjects underwent endoscopic examination for evaluation of esophagitis grading from December 1996 to February 1998. The subjects included 4394 outpatients who were not receiving medication for gastrointestinal disease and 1616 subjects who visited the hospital for routine physical examinations. The overall proportion of esophagitis was 16.3%. Most of the subjects with esophagitis were classified as having grade A or B (proportion of grades A and B, 9.6% and 4.6%, respectively). The age-related proportion of esophagitis and of severe esophagitis (i.e., grades C and D) increased in females aged over 70 and in males aged over 80. Increased body mass index (partly due to decreased height caused by osteoporosis), and/or hiatal herniation, were related to the proportion of esophagitis in females aged over 70. These data indicated that reflux esophagitis is a common disease in Japan. However, severe esophagitis (grades C and D) is not common.

Adult↗
PubMed1999

Evaluation of endoscopic variceal ligation in prophylactic therapy for bleeding of oesophageal varices: a prospective, controlled trial compared with endoscopic injection sclerotherapy.

BACKGROUND: To evaluate the efficacy of endoscopic variceal ligation (EVL) in prophylactic therapy for oesophageal varices, we performed a randomized prospective trial to compare the recurrence of oesophageal varices treated by EVL with those treated by endoscopic injection sclerotherapy. METHODS: Fifty patients with liver cirrhosis were divided into two groups at random, after informed consents were obtained, to receive prophylactic therapy for bleeding of oesophageal varices. Group 1 patients underwent sessions of sclerotherapy with 5% ethanolamine oleate used as the sclerosant. Group 2 patients underwent EVL followed by one or two sessions of sclerotherapy. RESULTS: During the 18 month follow-up period, both the recurrence rate in group 2 (56%) and the incidence of bleeding (20%) were significantly higher compared with group 1 (recurrence rate 16%, bleeding 0%). CONCLUSIONS: This result indicates that EVL is not effective for prophylactic therapy for oesophageal varices in liver cirrhosis.

Esophageal and Gastric Varices↗
PubMed1999

[Influence of dexamethasone on the clinical course of bacterial meningitis in children. Especially on secondary fever. Experiences in 27 institutions].

Of pediatric patients with purulent meningitis seen at the institutions listed in the title page of this paper between 1986 and 1994, 93 patients treated with antibiotics and dexamethasone (DXM) were compared with 91 patients treated with antibiotics alone. The patients receiving antibiotics with dexamethasone achieved overall improvement in inflammatory symptoms and signs and cerebrospinal fluid findings and became afebrile significantly earlier than those receiving antibiotics alone. However, some of the patients became febrile again. The secondary fever rate for the DXM group was much higher than that for the antibiotic alone group (p < 0.0001). In most of the rebounded cases, the body temperature rose above 38 degrees C and remained elevated for 2-4 days. Cerebrospinal fluid (CSF) was cultured daily in 54 and 32 patients receiving antibiotics with and without DXM, respectively. Although this study was not a controlled study in a strict sense, these patients compared. In both groups, the CSF became mostly culture-negative within 48 hours. In a few patients receiving DXM, however, it became culture-negative after 72 hours or longer. DXM caused an adverse effect in a patient with meningitis caused by Streptococcus pneumoniae. The adverse effect was mild gastrointestinal bleeding, which recovered spontaneously. From the findings described above, the use of DXM combined with antibiotic therapy was considered to accelerate the relief from fever and improvement of inflammatory symptoms and signs and CSF findings. The body temperature rose again in more than half of the patients receiving DXM, but fell to normal spontaneously without treatment. The elevation doubtlessly could not be distinguished from recurrence of the meningitis itself or complications. It seems to be likely that no treatment but careful observation is required even if the fever recurs as far as the CSF findings showed favorable progress with excelluent general conditions. When DXM is given, it is essential that CSF tests and culture are repeated during the early stages and the progress is monitored carefully.

Anti-Bacterial Agents↗
PubMed1999

Angiolipoma of the colon with right lower quadrant abdominal pain.

BACKGROUND/AIM: An angiolipoma is a common benign neoplasm with a characteristic vascular component that occurs in the subcutaneous tissue and rarely in the gastrointestinal tract. We report on a 69-year-old man with a submucosal angiolipoma in the cecum. METHODS: This patient was treated with a laparoscopy-assisted ileocecostomy, and a side-to-side anastomosis was performed extracorporeally. RESULTS: A light microscopic study supported the diagnosis of an angiolipoma of the colon. After 5 years of follow-up, the patient has no symptoms or signs of recurrence. CONCLUSION: The colonic angiolipoma was successfully removed using a minimally invasive laparoscopic technique.

Abdominal Pain↗
PubMed1999

Efficiency of donor screening for human parvovirus B19 by the receptor-mediated hemagglutination assay method.

BACKGROUND AND OBJECTIVES: Mass screening for parvovirus B19 (B19) by receptor-mediated hemagglutination assay (RHA) may be inadequate to eliminate the virus from plasma pools. We characterized B19 carriers detected in blood donor screening by RHA to explain why some carriers were not detected by RHA. MATERIALS AND METHODS: Donor plasma was screened for B19 by RHA, B19 DNA by nested polymerase chain reaction (PCR) assay, and anti-B19 by enzyme immunoassay. RESULTS: B19 DNA-positive specimens (n = 73) screened from 456,665 donors were divided into group A (n = 41) with high DNA and high RHA titers, group B (n = 16) with low DNA and low RHA titers, and group C (n = 16) RHA-negative. Most (37/41) of the group A samples were without anti-B19, while most (15/16) of the group B samples were positive for anti-B19. Group C specimens were screened by PCR from 3, 042 random RHA-negative specimens. Analysis of samples from early infections revealed that the viremic period, corresponding to group A, lasted only 8-10 days after infection. The RHA reactivity fell rapidly with the appearance of anti-B19 and disappeared 28-30 days after infection, thus corresponding to group B. The RHA reactions of group B specimens were often unstable, probably because of the formation of immune complexes. The B19 DNA-positive, RHA-negative state lasted for several months, which corresponded to group C. CONCLUSION: Only group A specimens are reliably eliminated in donor screening by RHA. Therefore, although donors with high B19 DNA could be screened out by testing for B19 by the RHA, most B19 carriers, with low B19 DNA and RHA-negative, will not be eliminated.

Antibodies, Viral↗
PubMed1998

Neural coding of 3D features of objects for hand action in the parietal cortex of the monkey.

In our previous studies of hand manipulation task-related neurons, we found many neurons of the parietal association cortex which responded to the sight of three-dimensional (3D) objects. Most of the task-related neurons in the AIP area (the lateral bank of the anterior intraparietal sulcus) were visually responsive and half of them responded to objects for manipulation. Most of these neurons were selective for the 3D features of the objects. More recently, we have found binocular visual neurons in the lateral bank of the caudal intraparietal sulcus (c-IPS area) that preferentially respond to a luminous bar or place at a particular orientation in space. We studied the responses of axis-orientation selective (AOS) neurons and surface-orientation selective (SOS) neurons in this area with stimuli presented on a 3D computer graphics display. The AOS neurons showed a stronger response to elongated stimuli and showed tuning to the orientation of the longitudinal axis. Many of them preferred a tilted stimulus in depth and appeared to be sensitive to orientation disparity and/or width disparity. The SOS neurons showed a stronger response to a flat than to an elongated stimulus and showed tuning to the 3D orientation of the surface. Their responses increased with the width or length of the stimulus. A considerable number of SOS neurons responded to a square in a random dot stereogram and were tuned to orientation in depth, suggesting their sensitivity to the gradient of disparity. We also found several SOS neurons that responded to a square with tilted or slanted contours, suggesting their sensitivity to orientation disparity and/or width disparity. Area c-IPS is likely to send visual signals of the 3D features of an object to area AIP for the visual guidance of hand actions.

Animals↗
PubMed1998

Fatty acid omega and (omega-1)-oxidation within intrasplenically transplanted fetal hepatocytes.

BACKGROUND: The expression and enzymatic activity of the cytochrome P450 LAomega within intrasplenically transplanted hepatocytes was investigated. METHODS: Fetal hepatocytes were harvested from spontaneously hypertensive rats and transplanted into recipient adult spontaneously hypertensive rat spleens. RESULTS: Microscopic examination revealed masses of hepatocytes in the red pulp. Immunochemical studies detected cytochrome P450 LAomega in transplanted hepatocytes by 6 and 10 weeks after transplantation. Cytochrome P450 LAomega mRNA accumulates at 6 weeks after transplantation. Cytochrome P450-arachidonic acid omega/omega-1 hydroxylase activity (formation of 20/19-hydroxyeicosatetraenoic acid) was detected at 10 weeks after transplantation. CONCLUSION: These results demonstrated that fetal hepatocytes grow in the spleen and function similarly to adult hepatocytes.

Animals↗
PubMed1998

Infected abdominal aortic aneurysm caused by Campylobacter fetus subspecies fetus: report of a case.

A 45-year old man with fever, abdominal pain, and a pulsating mass underwent an aneurysmectomy, with in situ reconstruction using a bifurcated knitted Dacron graft, for a saccular abdominal aortic aneurysm (AAA). A culture taken postoperatively grew Campylobacter fetus subspecies fetus. The administration of antibiotics sensitive to this organism was continued for 3 months, and no infection has been encountered in the 1 year since his operation. This is only the 13th documented case of AAA infected by C. fetus subspecies fetus.

Aneurysm, Infected↗
PubMed1998

Outbreak of severe infection due to adenovirus type 7 in a paediatric ward in Japan.

Between November 1996 and January 1997, 14 patients were diagnosed as having infection caused by adenovirus type 7 in a paediatric ward of Asahikawa Kosei Hospital. The age range of the patients was from two months to five years. Their diseases and abnormal laboratory findings were pneumonia in all 14, leukocytopenia in 10, myositis in nine, gastroenteritis in eight, encephalitis in five, liver dysfunction in three, pleuritis in two, inappropriate secretion of antidiuretic hormone syndrome in two, and thrombocytopenia in two. The infected patients, except for the first had been hospitalized in the paediatric ward for treatment of another disease and re-admitted because of high fever and coughing a few days after improvement or discharge. It is thought that the cause of the outbreak was hospital-acquired infection.

Adenovirus Infections, Human↗
PubMed1998

Fifteen-year experience in axillofemoral bypass with externally supported knitted Dacron prosthesis in a Japanese hospital.

BACKGROUND: Recently, several reports in the United States have demonstrated remarkable improvement in the patency of axillofemoral (AXF) bypass with an externally supported prosthesis. The purpose of this study was to review the prognoses regarding graft patency, limb salvage, and survival of patients who underwent AXF bypass grafting with an externally supported, knitted Dacron prosthesis (EXS) in a Japanese hospital and to analyze what factors affected the graft patency. METHODS: The clinical records of 81 patients with arteriosclerosis obliterans (ASO) who underwent 47 axillounifemoral bypasses and 34 axillobifemoral bypasses with EXS were retrospectively checked and, by uni- and multivariate analysis, perioperative factors were evaluated. RESULTS: The cumulative primary and secondary patency rates of AXF bypass grafts were 81% and 88%, 73% and 80%, and 70% and 77% at 3, 5, and 7 years, respectively, with no change thereafter. Limb salvage rate was 100%. The operative mortality was 3.7% and the survival rate was 63%, 41%, and 35% at 3, 5, and 7 years, respectively. The risk factors adversely affecting the patency were age (younger than 75 years), poor distal runoff, and preoperative leukocyte count (more than 8,000/microL) by univariate analysis, none of which were significant by stepwise multivariate analysis. CONCLUSIONS: AXF bypass using EXS was an acceptable procedure in ASO patients at high risk for conventional anatomic bypass or with limited life expectancy, and there was no significant risk factor that independently affected the patency.

Age Factors↗
PubMed1998

Changes in purine metabolism and production of oxygen free radicals by intermittent partial umbilical cord occlusion in chronically instrumented fetal lambs.

OBJECTIVE: Undetected umbilical-cord compression has been suggested to be implicated in unexplained fetal brain damage. We tested the hypothesis that the generation of oxygen-free radicals (OFRs) during intermittent partial umbilical cord occlusion might play a causal role in antenatal CNS injury. METHODS: Using 7 established chronically instrumented fetal lambs, intermittent partial occlusion of the umbilical circulation was produced according to the method of Clapp et al. for 1 of every 3 minutes for 2 hours. A microdialysis probe was implanted in the fetal brain white matter. Normal saline was infused, and the perfusate obtained at 2 micrograms/ min. Hypoxanthine (HX), xanthine (XA), and inosine-5-monophosphate (IMP) concentrations in the perfusate and blood samples obtained from fetal jugular veins were assayed by HPLC. Concurrently, the perfusate, which contained superoxide produced in the brain, when mixed with cypridina luciferin analogue extracorporally, caused chemiluminescence that in 4 cases was measured by a highly sensitive electronic fluorescence detector. RESULTS: (1) HX, XA, and IMP concentrations in the blood and perfusate were higher than in the control during the intermittent partial occlusion of the umbilical circulation period and returned to control levels during the recovery period. (2) The residual chemiluminescence of perfusate revealed that the intermittent partial occlusion of the umbilical circulation level was about 100% higher than the control level, and during the recovery period the level returned to the control level. (3) The chemiluminescence during the intermittent partial occlusion of the umbilical circulation period was inhibited by infusion through the fetal jugular vein of 1 micron polyethylene glycol conjugated superoxide dismutase. CONCLUSION: During the intermittent partial occlusion of the umbilical circulation period the fetal brain tissue releases a large amount of OFRs, and a portion of these might be synthesized by the increased conversion of HX to XA. This phenomenon might play an important role in the etiology of fetal brain injury.

Animals↗
PubMed1998

[Result of antibiotic therapy for children with Escherichia coli O26:H11 infection].

Between the end of November 1996 and the beginning of March 1997, there was an outbreak of Escherichia coli O26:H11 infection in Asahikawa. The strain produced only verotoxin type 1. The minimal inhibitory concentrations (microgram/ml) of the strain under aerobic condition and those of anaerobic were as follows: chloramphenicol (1.56, 0.78), minocycline (12.5, 3.13), kanamycin (3.13, 25), ampicillin (> 100, > 100), fosfomycin (12.5, 1.56), norfloxacin (0.1, 0.1), and cefaclor (6.25, 3.13). Forty-one episodes of antibiotic therapy to 32 children, who were treated in Asahikawa Kosei Hospital, Asahikawa Municipal Hospital, and Asahikawa Red Cross Hospital, were evaluated bacteriologically. In 26 episodes treated with fosfomycin, the pathogen from stools of 19 were eradicated, 4 were not eradicated, and 3 were isolated again within 2 weeks after the cessation of therapy. Eight episodes treated with norfloxacin and 5 episodes in kanamycin were all eradicated.

Anti-Bacterial Agents↗
PubMed1998

[Study on bacteremia due to community-acquired infection in infants and children without underlying diseases].

Between July 1988 and June 1998, 22 pediatric patients without underlying diseases were diagnosed as bacteremia caused by community-acquired infection in Asahikawa Kosei Hospital. The age range of the patients was from 7 days to 4 years. Their diseases were meningitis in 6, urinary tract infection in 6, respiratory tract infection in 4, skin infection in 2, and unknown origin in 4. The causative organisms were Escherichia coli in 7, Haemophilus influenzae in 4, Streptococcus pneumoniae in 4, Staphylococcus aureus in 2, Streptococcus pyogenes in 1, Streptococcus agalactiae in 1, Listeria monocytogenes in 1, Moraxella catarrhalis in 1, and Rahnella aquatilis in 1. Though 21 patients recovered with antimicrobial treatment, only one patient with H. influenzae meningitis had lateral deafness and paresis in the lower limbs as sequelae.

Bacteremia↗