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Biomedical subjects

S Hayakawa

Publications and source records attributed to S Hayakawa.

At least 73 records · Page 4Linked to original sources
PubMed1998

Colour Doppler-guided spectral analysis of gall-bladder wall flow.

For the purpose of the present study to diagnose gall-bladder cancers, which cannot be detected or are only partly visible by conventional ultrasonography (US), we attempted differential diagnoses of 69 patients with gall-bladder diseases (12 with gall-bladder cancer, five with acute cholecystitis, 11 with chronic cholecystitis, 27 with cholesterol polyp and 14 with adenomyomatosis) using the evaluation of gall-bladder wall blood flow (GWBF). GWBF was evaluated by colour Doppler-guided spectral analysis (CDSA). Thirty-three healthy volunteers were selected as controls at random. Two parameters of GWBF, namely flow velocity and resistive index (RI), were compared between patients with gall-bladder diseases and healthy volunteers. GWBF could be ultrasonically evaluated in 92 (90%) of 102 subjects. All 12 patients with gall-bladder cancer had a significantly rapid blood flow value compared with other patients and healthy volunteers. There was no significant difference in RI among patients and healthy volunteers. When cut-off level of the flow velocity was set at 30 cm/s, gall-bladder cancer could be diagnosed by flow velocity with 100% sensitivity (12/12) and 96% specificity (50/52). Using the same cut-off level of the flow velocity, 17 patients were analysed prospectively. In four asymptomatic gall-bladder cancers and two acute cholecystitis cases with some symptoms, the flow velocity was over 30 cm/s. In two of four patients with gall-bladder cancer, only a part of the tumour was visualized on conventional abdominal US. In conclusion, CDSA was more useful for diagnosing gall-bladder lesions than the conventional abdominal US due to estimation of arterial flow velocity in the gall-bladder wall.

Blood Flow Velocity↗
PubMed1998

Using polymerase chain reaction for rapid sex-determination of a case of sirenomelia.

A rare case of sirenomelia with its autopsy findings is reported. The 1188 g infant was delivered by cesarean section at the 36th week of gestation, and died at 4 h of life. Physical and pathologic findings included sirenomelia (a single lower extremity mass), lung hypoplasia, bilateral renal agenesis, blind-ending colon, severe deformity of the bony pelvis, an imperforate anus, absence of the bladder, and a single umbilical artery. Because of the difficulty in determining the sex of the infant, PCR directed against the SRY gene was performed. The PCR-based sex determination is a rapid technique in patients with ambiguous genitalia.

Autopsy↗
PubMed1998

Contrast-enhanced endoscopic ultrasonography in pancreatic diseases: a preliminary study.

OBJECTIVE: The purpose of this study was to clarify the usefulness of contrast-enhanced endoscopic ultrasonography in pancreatic diseases. METHODS: The subjects comprised 37 patients with pancreatic diseases: 11 with ductal cell carcinoma, 10 with mucin-producing tumor, five with pseudo-cyst, four with islet cell tumor, four with chronic pancreatitis, and three with serous cystadenoma. After endoscopic ultrasonography, Albunex (0.22 ml/kg) was injected intravenously at a rate of 1 ml/s into the right median vein, and observation was continued for 10 min. The presence or absence of enhancement of the lesion was determined in each disease. Because all the patients with ductal cell carcinoma, islet cell tumor, chronic pancreatitis, and serous cystadenoma, as well as five with mucin-producing tumor and three with pseudo-cyst, underwent angiography, vascularity was compared between angiographic images and those of contrast-enhanced ultrasonography. RESULTS: Enhancement of the lesion was observed in all patients with islet cell tumor and serous cystadenoma, in eight with mucin-producing tumor, and in three with chronic pancreatitis. However, no enhancement effect was observed in the patients with ductal cell carcinoma and those with pseudo-cyst. Comparison between the images of contrast-enhanced endoscopic ultrasonography and angiographic images showed three patients in whom angiograms were hypovascular, but enhancement effect was observed on ultrasonographic images. CONCLUSION: The combined evaluation of plain and enhanced images of endoscopic ultrasonography may be useful for the diagnosis of pancreatic diseases.

Adenocarcinoma, Mucinous↗
PubMed1998

Usefulness of intraductal ultrasonography in gallbladder disease.

This study was designed to compare intraductal ultrasonography of the gallbladder wall with histopathologic findings and to assess the clinical usefulness of this imaging method in gallbladder disease. Thirty-one gallbladder specimens were examined by intraductal ultrasonography retrospectively. The gallbladder is composed of three layers: an innermost hyperechoic layer, a middle hypoechoic layer, and an outermost hyperechoic layer. The second layer on ultrasonograms corresponds to the muscle layer plus the fibrous tissue of the superficial perimuscular connective tissue layer. In cases in which the thickness of the second layer was 500 microns or less, little fibrous tissue was seen and the second layer was approximately identical to the muscle layer on sonograms. Clinical study was performed on 22 gallbladders. The use of a guidewire through the papilla facilitated intraductal ultrasonographic examination. The intraductal sonographic probe could be inserted into the gallbladder fundus in 13 of 22 cases. In nine unsuccessful cases, technical difficulties were as follows: sharply angulated gallbladder (four cases), stenosis of the gallbladder (two cases), difficulty in transmitting power in the correct direction (three cases). With regard to the area visualized in 13 successful cases, in three cases the area visualized was 100%, in seven cases it was 75%, and three cases it was 50%. Intraductal ultrasonographic images could be obtained in 83.3% (10 of 12) of elevated lesions of the gallbladder. The indications for intraductal ultrasonography will be cases in which an abnormality was detected by transabdominal ultrasonography or other modalities in which the physician does not know whether or not to operate. In conclusion, we defined the intraductal sonographic images of gallbladder wall and clarified the clinical indications for use of this imaging method.

Gallbladder↗
PubMed1997

BLM (the causative gene of Bloom syndrome) protein translocation into the nucleus by a nuclear localization signal.

Bloom syndrome (BS) is a rare genetic disorder characterized by small body size, sun sensitivity, immunodeficiency and a high predisposition to various types of cancer. BLM was identified as the causative gene for BS, and BLM protein is homologous to DNA helicase. There are two putative nuclear localization signals (NLSs) within amino acid residues 1334-1349 in the C-terminus of the BLM protein, which has the distinctive structure of two basic residue arms separated by a spacer. The entire coding or deleted BLM sequences of various sizes were ligated into an enhanced green fluorescent protein (EGFP) vector and transfected into HeLa cells. The EGFP vector harboring the entire BLM coding sequence was transported to the nucleus. The BLM protein truncated at 1341 amino acid, containing an intact helicase domain and only one proximal arm, was not transported to the nucleus. The BLM protein truncated at 1357 amino acid, containing an intact helicase domain and two arms, was transported to the nucleus. The EGFP vector harboring DNA fragments encoding a protein having only the distal arms of basic amino acids in the C-terminus was also transported to the nucleus. The truncated BLM proteins corresponding to previously reported mutated BLM proteins were retained in the cytoplasm or both the cytoplasm and the nucleus as was the EGFP vector with no insert. These results show that the BLM protein translocates into the nucleus and that the distal arm of the bipartite basic residues in the C-terminus of the BLM protein is essential for targeting the nucleus.

Adenosine Triphosphatases↗
PubMed1997

Cardiovascular screening and emergency procedures at health clubs and fitness centers.

A survey of 110 fitness centers in Massachusetts reveals that many do not follow generally accepted guidelines for administering preparticipation cardiovascular screening, obtain physician consent for individuals with known cardiovascular disease, and prepare for emergency situations should they occur. Thus, the promotion of physical activity to the general public now underway in the United States must also coincide with better screening at all fitness centers to maximize the potential for safe exercise participation at fitness centers.

Cardiovascular Diseases↗
PubMed1997

Bioactivity of titanium treated with hydrogen peroxide solutions containing metal chlorides.

Commercially available pure metallic titanium was chemically treated at 60 degrees C for 24 h with H2O2 solutions containing various metal chlorides to provide titanium with bioactivity, that is, to give it the ability to form a biologically active bone-like apatite layer on the surface. After the chemical treatment the titanium specimens were soaked in a simulated body fluid (the Kokubo solution). Apatite was found to deposit on the specimens treated with the H2O2/TaCl5 and H2O2/SnCl2 solutions. X-ray photoelectron spectroscopic (XPS) study of the specimens treated with those H2O2 solutions indicated that basic Ti-OH groups in titania hydrogel layers on their surfaces were responsible for apatite nucleation and growth.

Body Fluids↗
PubMed1997

Intraductal ultrasonography of the pancreas: development and clinical potential.

Intraductal ultrasound (IDUS) probes mounted with 30 MHz or 20 MHz transducers were evaluated in the diagnosis of 239 patients with pancreatic disease (including 48 cancers, 90 mucin-producing tumors, seven islet-cell tumors, two metastatic pancreatic tumors, seven serous cystadenomas, one pancreatic teratoma, three solid cystic tumors, 49 cases of chronic pancreatitis, 25 cases of focal pancreatitis, and seven cases of pancreatolithiasis). The probe was inserted via the papilla into the main pancreatic duct. In terms of resolution, IDUS at 20 MHz was able to image cystic lesions of less than 30 mm in diameter and solid lesions of less than 20 mm in diameter. With regard to vessels, IDUS was able to image the entire cross-section of the portal vein and other large veins. IDUS was useful in detecting carcinoma in situ and small tumors, in assessing the intraductal spread of the tumor and its pancreatic parenchymal invasion in mucin-producing tumors of the main duct, and in assessing the indications for surgery by revealing mural nodules in mucin-producing tumors of the ductal branches. IDUS was also useful in evaluating the feasibility of partial resection of the tumor in mucin-producing tumors of the ductal branches and pancreatic islet-cell tumors, in accurately locating multiple lesions in pancreatic islet-cell cancer, and in differentiating benign from malignant cases of localized stenosis of the main pancreatic duct related to pancreatic stenting. With IDUS, the site of pancreatic stones could be identified in order to assess the need for endoscopic treatments such as stenting of the pancreatic duct and the bile duct, and the use of pulsed-dye laser treatment under pancreatoscopy for pancreatic stones. Acute pancreatitis as a complication occurred in one of the 239 patients who underwent IDUS (0.4%). An awareness of the limitations and usefulness of IDUS in evaluating pancreatic diseases can contribute to the treatment of these conditions.

Aged↗
PubMed1997

Change of pancreatic enzymes, pancreatic stone protein (PSP), and plasma alpha(2)-macroglobulin-trypsin complex-like substance (MTLS) in the activation of pancreatic juice.

To characterize the activation of pancreatic zymogens (trypsinogen, chymotrypsinogen, and proelastase 1) in acute pancreatitis, we studied the activation of pancreatic juice with porcine enteropeptidase in vitro, and then enzymatic activities and the generation of pancreatic stone protein (PSP) S1 form in pancreatic juice were investigated. Further, we determined immunoreactive trypsin, immunoreactive elastase 1, PSP, and alpha(2)-macroglobulin-trypsin complex-like substance (MTLS) levels in plasma to which the activated juice was added. In the present report, we demonstrate that the plasma MTLS level reflected the activation of pancreatic trypsinogen in pancreatic juice. Further, the generation of PSP S1 form was found at an early stage of activation. Therefore, the plasma MTLS level and the generation of PSP S1 form may offer new diagnostic information on the amounts of activated proteases and subsequently on the severity of acute pancreatitis.

Animals↗
PubMed1997

Optimism, Type A behavior, and psychological well-being in Japanese women.

The relations of self-report scores for optimism, Type A behavior, and stress with those for depression and anxiety were examined in 144 Japanese female college students. A significant interaction of scores on optimism and Type A behavior indicated that subjects who reported higher optimism and higher Type A behavior had a lower mean for anxiety than those who reported lower optimism and higher Type A behavior.

Adaptation, Psychological↗
PubMed1997

[Molecular diagnosis of post-transfusion GVHD using Y-chromosome specific sequences].

Graft-versus-host disease (GVHD) is one of the most serious complications of blood transfusion. Thus, it is important to make a correct diagnosis of post-transfusion GVHD as soon as possible in its onset. Presence of Y-chromosome positive donor lymphocytes in the peripheral blood of female GVHD patients is one of the direct evidences of lymphocyte chimerism, as well as shown by HLA chimerism. We have reported a rapid diagnosis technique of post-transfusion GVHD by polymerase chain reactions directed against Y-chromosome specific SRY gene. (Hayakawa S, et al: Transfusion. 1993, 33, 413-417). We can detect single male cell in 10,000 female cells by SRY directed nested PCR. Though this method is applicable only for the female GVHD cases involved with Y-chromosome positive male lymphocytes, it is possible to detect not only chimeric peripheral lymphocytes but also skin infiltrating donor lymphocytes.

Aged↗
PubMed1996

Optimal conditions for collection of blood samples for assay of alpha 2-macroglobulin-trypsin complex-like substance (MTLS).

We have developed an enzyme-linked immunosorbent assay (ELISA) for the specific quantification of alpha 2-macroglobulin-trypsin complex-like substance (MTLS). To exclude artifacts in measured values of MTLS, the conditions for collection of blood samples are critical. In the present study, we have determined the optimal conditions for blood collection and investigated the role of MTLS as a clinical tool for diagnosis in pancreatitis. Results obtained are as follows: (1) MTLS levels of all sera were more than 10-fold higher than the corresponding plasma; (2) MTLS levels of heparinized plasma were the lowest among plasma with three anticoagulants (sodium citrate, sodium EDTA and heparin); (3) some kinds of blood collection tubes containing heparin were not suitable for the sampling; (4) MTLS values of plasma obtained by blood collection tubes containing Trasylol and sodium EDTA were demonstrated more stable and lower than those obtained by heparin tubes; and (5) under these conditions, we can exclude elevation of MTLS values caused by inappropriate blood sampling and find the time course of the elevation reflecting clinical course of a patient with acute pancreatitis and a patient after endoscopic retrograde cholangiopancreatography (ERCP). The optimal conditions for collection of blood samples were as follows. Blood sampling should be performed by blood collection tubes containing Trasylol (50 microliters/ml blood) and sodium EDTA (1.5 mg/ml blood). The samples were immediately stored at 4 degrees C and centrifuged at 3,000 rpm for 15 min. The plasma were stored in plastic tubes at 4 degrees C until assayed.

Anticoagulants↗
PubMed1996

Plasma alpha 2-macroglobulin-trypsin complexlike substance (MTLS) in pancreatic disease.

alpha 2-macroglobulin-trypsin complexlike substance (MTLS) was determined in plasma of pancreatic and nonpancreatic diseases using a two-step enzyme immunoassay to study the diagnostic and pathophysiological significance of MTLS. Plasma levels of MTLS in acute pancreatitis (mean +/- SD = 265.6 +/- 346.2 ng/ ml, n = 9), calcified chronic pancreatitis (128.6 +/- 257.4, n = 13), and noncalcified chronic pancreatitis (13.5 +/- 12.5, n = 10) were significantly higher than that in controls (3.6 +/- 1.8, n = 81). In other diseases such as gastric cancer, hepatoma, diabetes mellitus, and gallstones, MTLS values were not different from those of control. Plasma MTLS values showed low correlation with serum trypsin, elastase 1, pancreatic amylase, lipase, and pancreatic secretory trypsin inhibitor (PSTI). The elevation of plasma MTLS values in acute pancreatitis suggests that plasma MTLS levels reflect that protease is inappropriately activated in pancreatic acinar cell and released into the circulation and that the determination of MTLS can be useful for diagnosis and pathophysiology of acute pancreatitis and chronic pancreatitis.

Adult↗
PubMed1996

Myofibroblastoma of the breast: report of a case.

We report herein the case of a 36-year-old woman in whom a breast mass was diagnosed histologically and immunohistochemically as myofibroblastoma (MFB). The patient initially presented with a breast mass measuring 1.0 x 1.5 cm which was demonstrated by mammography as a well-circumscribed, round tumor with two coarse calcifications. On ultrasonography, the tumor showed slight shadowy internal echoes. Histological examination of an excisional biopsy specimen demonstrated a tumor consisting of spindle-shaped cells and broad bands of hyalinized collagen with cartilaginous and osseous components, but no epithelial components were observed. Immunohistochemically, the tumor cells were diffusely positive for alpha smooth muscle actin, and a diagnosis of MFB was made. A wide excision of the breast was performed as a secondary procedure, and the patient is well and free from recurrence 1 year after her operation. We present this case to stress the need for breast surgeons to be aware of the existence of MFB when considering the differential diagnosis of stromal lesions of the breast to avoid performing unnecessarily extensive procedures.

Adult↗
PubMed1996

Expression of the recombinase-activating gene (RAG-1) in murine early embryogenesis.

The recombinase activation genes, RAG-1 and RAG-2, are expressed together in immature T or B lymphocytes and possess activity to induce V(D)J rearrangement in T cell receptor (TCR) and Ig genes. In vertebrates, only Ig and TCR molecules are reported to have recombination in their development using multiple V, D, J component gene segments. Thus, expression of RAG genes are localized only in lymphoid organs and sites of extrathymic T cell differentiation. In this study, we have used RAG-1 and RAG-2 genes as markers of possible genetic recombination in developing murine preimplantation embryos, using the highly sensitive reverse transcriptase polymerase chain reaction (RT-PCR) technique and in situ hybridization. From 40 preimplantation embryos of various developmental stages we extracted RNA, reverse-transcribed it into cDNA and used it in RT-PCR studies. A PCR of 35 cycles disclosed expression of RAG-1 but not RAG-2 in morulae and blastocysts. Southern blot hybridization using a specific synthetic oligonucleotide probe for RAG-1 and RT-PCR with another primer pair identified RAG-1 expression in developing embryos. In situ hybridization using a cooled CCD camera also revealed localization of RAG-1 mRNA in blastocysts. We propose possible genetic recombination during late preimplantation murine embryogenesis which may contribute to the loss of totipotency and differentiation of inner cell mass and trophoectoderm.

Animals↗
PubMed1996

Decidua as a site of extrathymic V gamma I T-cell differentiation.

PROBLEM: Decidual tissue is an interface between the host and fetus, which is regarded as a natural allograft. We have reported the possible presence of extrathymic T cells in human decidua through the expression of recombinase-activating genes in the decidual CD16-CD56bright large granular lymphocytes. METHODS: In this study we analyzed expression of TCR V gamma delta gene segments in peripheral lymphocytes and decidual and nonpregnant endometrial samples using RT-PCR and oligonucleotide hybridization. RESULTS: Interestingly, a limited repertoire of V gamma gene segments were discovered in decidual lymphocytes of normal pregnancy when compared with peripheral lymphocytes, whereas usage of V delta gene segments were ubiquitous in peripheral and decidual lymphocytes. Strong expression of V gamma I gene segment, often exceeding 50% of total V gamma, were noted in all (13/13) pregnant decidual tissues obtained at different gestational stages. Interestingly, this predominance of V gamma I gene is also noted in nonpregnant endometrial samples and the decidua of patients with ectopic pregnancies. CONCLUSIONS: Our results suggest the nature of decidual V gamma I T cells as possible suppressors of rejective maternal cytotoxic T cells during the maintenance of normal pregnancies.

Adult↗
PubMed1996

Murine experimental abortion by IL-2 administration is caused by activation of cytotoxic T lymphocytes and placental apoptosis.

OBJECTIVE: Fetal loss caused by IL-2 administration to pregnant mice is regarded as a model of human habitual abortion due to allo-immune reactions. To estimate feto-placental damages in this model, we examined apoptosis histochemically in the placenta. METHODS: Four allogenic mated mice were administered intraperitoneally with 1000 IU of recombinant human IL-2 on days 3, 5 (7) after mating. We examined the presence of apoptosis in the placentae by TUNEL stain. We also examined expression of CTL specific granzyme B/perforin mRNA and usage of TCR V beta receptor segments by RT-PCR. RESULTS: 1. Allogenic pregnant mice given IL-2 revealed increased apoptotic scores in villous trophoblasts compared with control mice. Extracted DNA from IL-2 treated placentae revealed ladder formations. 2. Expression of granzyme B mRNA was increased while expression of perforin mRNA was not changed. 3. We observed increased numbers of TCR V beta gene segments in the decidua from IL-2 treated mice compared with untreated mice. CONCLUSION: We suggest that placental apoptosis caused by activation of maternal CTL may play important roles in the rejection of fetal allografts.

Abortion, Induced↗