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Biomedical subjects

K Kumagai

Publications and source records attributed to K Kumagai.

At least 37 records · Page 2Linked to original sources
PubMed2001

Vascular endothelial growth factor C gene expression is closely related to invasion phenotype in gynecological tumor cells.

OBJECTIVE: The correlation between the gene expression of various angiogenic factors and in vitro invasive activity in 16 human gynecological cancer cell lines was investigated. METHODS: Semiquantitative reverse transcription polymerase chain reaction analysis was performed to investigate the mRNA expression levels of vascular endothelial growth factors (VEGF-A, -B, -C, and -D), basic fibroblast growth factor (bFGF), and matrix metalloproteinase (MMP)-2 with beta-actin coamplified as an internal standard. Tumor cell migration along a gradient of substratum-bound fibronectin and invasion into reconstituted basement membrane were evaluated by haptotactic migration and invasion assay. RESULTS: Expression of VEGF-A mRNA was detected in all 16 cell lines, whereas the relative expression levels of other VEGF family members and bFGF, differed markedly among the cell lines. There was a statistical correlation between VEGF-C gene expression and the number of cells that migrated and invaded (P < 0.01). However, expression of mRNAs of other angiogenic factors did not correlate with motility and invasive activity of the cells. Moreover, there was a close correlation between VEGF-C and MMP-2 gene expression levels (P < 0.05). CONCLUSION: Tumor cells that produce VEGF-C may have a higher invasive and metastatic potential because of their capacity to pass through tissue barriers.

DNA, Neoplasm↗
PubMed2001

[Perioperative management of a patient with purpura fulminans syndrome due to protein C deficiency].

PURPOSE: Protein C is a vitamin K-dependent anticoagulant and homozygous protein C deficiency is a rare fatal thrombotic disease. This report describes the perioperative management of homozygous protein C deficiency in a patient who underwent a total of three surgical procedures under general anesthesia and the successful use of activated protein C concentrate. CLINICAL FEATURES: A female baby, who developed disseminated intravascular coagulation and purpura fulminans shortly after birth, was diagnosed as purpura fulminans syndrome due to homozygous protein C deficiency. At one month of age, she suffered bilateral retinal detachment and glaucoma due to retinal hemorrhage. After marked improvement of her condition after administration of activated protein C concentrate, she underwent a left iridectomy and implantation of a Broviak catheter under general anesthesia. Her intraoperative course was uncomplicated but, on postoperative day four, she presented another episode of massive cutaneous necrosis and gangrene. Activated protein C concentrate was administered again, with good results. She underwent replacement of a Broviak catheter at four months of age, and right iridectomy for glaucoma at eight months. Both were uneventful. CONCLUSION: The perioperative management of homozygous protein C deficiency and purpura fulminans requires appropriate measures for thromboembolic prophylaxis. Sufficient iv fluid administration is necessary. Attention should be paid to decrease the risk of tissue compression such as that associated with positioning, blood pressure cuff, and endotracheal intubation, which may cause necrosis over pressure points. Replacement therapy with activated protein C concentrate appears safe and effective. The anesthetic management is reviewed and discussed.

Anesthesia, General↗
PubMed2001

Liver metastasis in gastric cancer with particular reference to lymphatic advancement.

BACKGROUND: We have previously reported that, in models of mesenteric lymph vessel obstruction in rats, we observed lymphaticovenous communication. This suggested that cancer cells metastasized to the liver by a lymphatic route. In the present study, we investigated the relationship between liver metastasis and lymphatic involvement in gastric carcinoma by examining resected specimens. METHODS: Twenty gastric cancer patients who had synchronous liver metastasis and 17 who developed metachronous liver metastasis after gastrectomy, performed between 1985 and 1997, were included in this study. They were compared with 44 advanced gastric cancer patients who had neither synchronous nor subsequent liver metastasis, and who survived with a disease-free course for more than 5 years. We compared the patients' clinicopathological features; in particular, we investigated extranodal invasion in the resected lymph nodes. This invasion was classified according to the pattern of extranodal cancer invasion, with or without rupture of the lymph node capsule. RESULTS: Liver metastasis was more frequent in patients with extranodal invasion than in those without extranodal invasion (P < 0.002). Multivariate analysis revealed that the correlation between extranodal invasion and liver metastasis was significant (P < 0.024); the odds ratio was 4.412. Metastasis to the lymph nodes was the next most significant risk for liver metastasis. CONCLUSION: We consider that the lymphatic system is closely related to the establishment of liver metastasis; in particular, extranodal invasion is a significant risk factor for liver metastasis in patients with gastric cancer.

Aged↗
PubMed2001

Variables That Influence Visual Acuity After Macular Hole Surgery.

Purpose: To evaluate the variables that influence visual acuity and visual improvement after macular hole surgery.Methods: Our study included 421 eyes in which macular holes were successfully closed after surgery and followed up at least 1 year after the last surgery. Surgical techniques were conventional methods (Group 1: 350 eyes) with retinal pigment scalping of the macular hole basis added in the refractory cases (Group 2: 71 eyes). The variables used for the multiple regression were gender, age, preoperative visual acuity, hole stage, duration of symptoms, hole size, and axial length.Results: The variables that most influenced postoperative visual acuity were as follows: Group 1: gender (r = -0.011, P =.016), age (r = -0.17, P =.005), preoperative visual acuity (r = 0.51, P <.0001), duration of symptoms (r = -0.015, P <.0001), and axial length (r = -0.090, P =.045). Group 2: age (r = -0.18, P =.047), and preoperative visual acuity (r = 0.47, P <.0001).Conclusions: The variables that influenced visual acuity and visual improvement after macular hole surgery were common. In Group 1: gender, age, preoperative visual acuity, duration of symptoms, and axial length; in Group 2: age and preoperative visual acuity.

Journal Article↗
PubMed2001

Refraction and Anterior Chamber Depth Change After Vitrectomy for Pseudophakia.

Purpose: To evaluate the association between the vitreous and the refractive error in pseudophakia.Methods: Vitrectomy was performed in 67 eyes of 61 patients who underwent cataract surgery. Vitrectomy was needed for epiretinal membrane in 30 eyes, macular edema in 22 eyes, macular hole in 3 eyes, lamelar macular hole in 2 eyes, macular hole in 3 eyes, lamelar macular hole in 2 eyes, vitreous opacity in 6 eyes, and vitreous hemorrhage in 4 eyes. Refraction was measured before the operation, and 1 month, 3 months, 6 months, and 12 months after operation. Anterior chamber depth was measured in 10 eyes before the operation, and 1 month, 3 months, and 6 months after operation. We evaluated the refractive error after vitrectomy in 49 eyes that had predicted refraction.Results: The mean value of refractive change was -0.3 D 1 month postoperatively, and then gradually became positive. The variation of refraction (6-month postoperative refraction minus preoperative refraction) was negatively correlated with preoperative refraction (P =.0052, R(2) = 0.146). If preoperative refraction was more myopic than -1.5 D, then refraction became positive. If preoperative refraction was not more myopic than -1.5 D, then refraction became negative.Conclusion: About 15% of postoperative refractive error may be associated with the vitreous, but further investigation is required.

Journal Article↗
PubMed2001

Alleviation of sleep disturbance and repetitive behavior by a selective serotonin re-uptake inhibitor in a boy with Asperger's syndrome.

An 8 year-old boy with Asperger's syndrome had difficulties in communicating with his teachers and classmates. He occasionally stole out of the classroom. He could not sleep at night recalling his awful experience and kept crying every night and refused to go to school. The treatment with fluvoxamine was started at the dose of 25 mg daily. Four weeks after the treatment, his repetitive behavior and hyperactivity decreased and night crying diminished. Although he still has difficulties in communicating with others, he is now able to attend extra-curricular classes in a private school. Fluvoxamine, a selective serotonin re-uptake inhibitor that has been mainly used for patients with depression and obsessive-compulsive disorder, might be effective for compulsive symptoms and sleep disturbance of patients with pervasive developmental disorders.

Asperger Syndrome↗
PubMed2001

Increased von Willebrand factor in the endocardium as a local predisposing factor for thrombogenesis in overloaded human atrial appendage.

OBJECTIVES: We investigated immunoreactive von Willebrand factor (vWF), a platelet adhesion molecule, in the endocardial endothelium and its relationship to thrombogenesis in the human atrial appendage. BACKGROUND: Intra-atrial thrombogenesis is generally thought to be induced by blood stasis in the atrial appendage involved with atrial fibrillation (AF). Little attention has been paid to alterations of the endocardial endothelium on which the thrombus develops. METHODS: Atrial appendage tissue was obtained at heart surgery or at autopsy from AF and non-AF cardiac patients and from noncardiac patients. Immunohistochemistry for endothelial cell markers including vWF, CD31, CD34 and endothelial nitric oxide synthase (eNOS) and platelet glycoprotein Ib/IX or IIb/IIIa was performed and semiquantitatively graded. RESULTS: In contrast to the apparent immunostaining for CD31, CD34 and eNOS, only focal or little immunoreactive vWF was seen in the endocardium of noncardiac patients. Immunoreactive vWF in the endocardial endothelium was increased in most cardiac patients, particularly in the left, but not in the right, atrial appendage of patients with mitral valvular disease, irrespective of whether AF was present. Platelet adhesion/thrombus formation in the endocardium was found in limited sites in which the overlying endothelium was deficient in eNOS and CD34. When warfarin-treated cases were excluded, there was a significant correlation between the immunohistochemical grade for vWF and the degree of platelet adhesion/thrombus formation in the endocardium. CONCLUSIONS: Immunoreactive vWF in the endocardial endothelium was increased in overloaded human atrial appendage, which may be a local predisposing factor for intraatrial thrombogenesis.

Adult↗
PubMed2001

Spontaneous right ventricular outflow tract tachycardia in a patient with Brugada syndrome.

We report the case of a 28-year-old man with no structural heart disease, who exhibited clearly augmented ST segment elevation in the right precordial leads, followed by induction of spontaneous right ventricular outflow tract tachycardia with intravenous administration of Class IA antiarrhythmic drugs. The electrophysiologic mechanism of this tachycardia was thought to be triggered activity due to delayed afterdepolarizations. Due to the existence of substrates that were similar to Brugada syndrome combined with right ventricular outflow tract tachycardia, this case may represent a subtype of Brugada syndrome.

Adult↗
PubMed2001

Lack of noninvasive markers of ventricular repolarization inhomogeneity in patients with idiopathic ventricular tachyarrhythmia.

Noninvasive markers reflecting repolarization inhomogeneity have been proposed to be useful indices for identifying patients at risk of ventricular arrhythmias based on organic heart disease. In this study, we clarify whether or not repolarization inhomogeneity markers are useful in patients with idiopathic ventricular tachycardia (VT). We investigated T-wave alternans (TWA) and corrected QT-interval dispersion (QTD) in 84 consecutive patients with idiopathic VT, 90 patients with VT associated with organic heart disease (organic VT), and 87 normal individuals. VT was defined as tachycardia lasting > or =5 consecutive ventricular ectopic beats at a rate of > or =120 beats/min. TWA was positive in 20 of 84 patients (24%) with idiopathic VT, 59 of 90 patients (66%) with organic VT, and 16 of 87 normal individuals (18%). The alternans voltage was 2.6 +/- 3.1 micro V in idiopathic VT patients, 5.6 +/- 6.4 micro V in organic VT patients, and 2.9 +/- 5.7 micro V in normal individuals. QTD were 53 +/- 20 ms in idiopathic VT patients, 92 +/- 20 ms in organic VT patients, 46 +/- 18 ms in normal individuals, respectively. A positive TWA test result was seen more (P <.01) frequently, and QTD was longer (P <.01) in organic VT patients compared to normal individuals, whereas there was no difference between idiopathic VT patients and normal individuals. In addition, in patients with idiopathic VT, neither did any of these measurements differ between patients with sustained VT (lasting for > or =30 s) and those with nonsustained VT. Noninvasive markers of repolarization inhomogeneity, such as TWA and QTD, are not useful for identifying patients with idiopathic VT. Repolarization inhomogeneity may not affect to the pathogenesis of idiopathic VT.

Adult↗
PubMed2001

Identification of sinus node dysfunction by use of P-wave signal-averaged electrocardiograms in paroxysmal atrial fibrillation: a prospective study.

BACKGROUND: In patients with paroxysmal atrial fibrillation (Paf), the identification of the coexistence of sinus node dysfunction (SND) has therapeutic implications. This study sought to prospectively determine whether SND in patients with Paf would be identified by use of atrial early potential (EP), low-amplitude potentials early in signal-averaged P wave. METHODS: The study population consisted of 149 patients with Paf. Signal-averaged electrocardiography was recorded with the P-wave-triggering technique. The root mean square voltage for the initial 30 MS and the duration of initial low-amplitude signals < 4 microV of signal-averaged P wave were measured in the vector magnitude. The criteria of EP were defined as "the root mean square voltage for the initial 30 MS < 3.0 microV and the duration of initial low-amplitude signals < 4 microV >22 MS." SND was diagnosed by use of the conventional 12-lead electrocardiography, 24-hour Holter monitoring, and bedside electrocardiographic monitoring. RESULTS: Thirty-eight of 149 patients with Paf had EP. Eighteen (47%) of 38 patients with Paf and EP had SND, whereas SND was found in only 5 (5%) of the other 111 patients with Paf without EP (P <.0001). EP gave a sensitivity of 78% and a specificity of 84% for the detection of SND in patients with Paf. CONCLUSION: EP would be useful for the identification of SND in patients with Paf.

Aged↗
PubMed2001

Advantage of combined procedure in vitreous surgery.

Lens preservation facilitates the progression of nuclear cataracts after vitreous surgery among patients over 45 years old, and postoperative nuclear cataracts frequently necessitate intraocular lens surgery. Once the lens is removed, the fundus from the posterior pole to the ciliary process becomes recognizable and surgically reachable, thus making total vitreous removal possible. The complete removal of the incarcerated vitreous to the scleral wound prevents postoperative vitreous base tears, and anterior hyaloidal fibrovascular proliferation. Simultaneous vitreous surgery plus intraocular lens surgery (triple surgery) will prevent these complications before they arise. Triple surgery for patients over 45 years of age is reasonable even if they have amplitude of accommodation, and is an effective surgical strategy in that it improves both the result of the vitreous surgery and the patient's quality of life.

Cataract↗
PubMed2001

Results of macular hole surgery combined with PEA and IOL.

We evaluated the factors affecting closure and postoperative visual acuity, as well as complications among idiopathic macular hole surgery cases comprising 631 eyes in 576 patients. Almost all the surgeries were combined with simultaneous intraocular lens surgery (triple surgery). In some cases, the standard method was accompanied by internal limiting membrane peeling around the macular hole or abrasion of retinal pigment epithelium at the base of the macular holes. We found that male gender and short eye axial length were associated with closure and postoperative visual acuity. Although the frequency of peripheral retinal tears during surgery was high, the frequency of postoperative retinal detachment was less than 2%. The reopening frequency was about 5% among all cases, and was highest among eyes that underwent the abrasion method. There were no other significant complications. Internal limiting membrane peeling is effective for treatment of cases with unfavorable preoperative conditions. However, the standard method is sufficiently effective for cases with favorable preoperative conditions. Further analysis is required to evaluate postoperative visual function by methods other than visual acuity. Further study of internal limiting membrane peeling, as a treatment alternative, is also required.

Adult↗
PubMed2001

Results of epiretinal membrane removal combined with PEA and IOL.

We examined 558 eyes from 538 surgical cases of idiopathic epiretinal membrane with respect to the effectiveness of the triple surgery that involves concomitant intraocular lens surgery, the most appropriate timing for the evaluation of postoperative visual acuity, and the relationship between the pre- and postoperative visual acuity. From the viewpoint of the timing of the intraocular lens surgery, we classified our patients into 4 groups: (1) a phakic eye group; (2) a two-step surgery group; (3) a triple surgery group; and (4) an intraocular lens group. The visual acuity evaluation was performed in 22 eyes from the phakic eye group based on the patient's age being 45 years or younger, in all 326 eyes from the triple surgery group, and in all 86 eyes from the two-step surgery group. We excluded the intraocular lens group from the visual acuity evaluation. The timing of the visual acuity evaluation was one year after the surgery for the phakic eye and triple surgery groups, and one year after the intraocular lens surgery for the two-step surgery group. The postoperative visual acuity was correlated with the patient's age. When a patient was less than 55 years of age, the postoperative visual acuity correlated positively with age. In contrast, when a patient was 55 years of age or older, it correlated inversely with age. The postoperative visual acuity was significantly correlated with the preoperative visual acuity, and it was possible to predict the postoperative visual acuity based on a regression equation. The preoperative visual acuity necessary for a postoperative visual acuity of 20/20 or more was 20/20 for patients under 40 years old, 20/40 for 40-59 years, 20/32 for 60-79 years, and 20/20 for 80 years and older.

Adolescent↗
PubMed2001

Apoptosis in the normal human amnion at term, independent of Bcl-2 regulation and onset of labour.

This study was designed to detect apoptosis in the human amnion and to elucidate the signalling pathway involved in its regulation. Samples of human amnion were obtained from 34 women (weeks 11-42 of gestation) and studied using the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling (TUNEL) method with light microscopy (LM) and transmission electron microscopy (TEM). Apoptotic regulators in the samples were studied by immunohistochemistry and caspase activity assay. The TUNEL method with LM demonstrated that the percentage of TUNEL-positive cells in the amniotic epithelium was the highest in weeks 40-41 of gestation (P < 0.05) independent of the onset of labour, and the cells were often detached from the epithelium into the amniotic cavity at term. The TUNEL method with TEM clearly showed the characteristic features of apoptosis such as the nuclear condensed chromatin with abundant free 3'-OH DNA ends, cell shrinkage and a decrease in the number of desmosomes, except for the presence of apoptotic bodies. Fas and Fas ligand (FasL) were constantly expressed on apical membranes of amniotic epithelial cells from weeks 16-27 through to 40-41 of gestation, while no Bcl-2 expression was observed throughout the gestational periods. Activities of caspase-3 and caspase-8, but not of caspase-9, were higher in weeks 40-41 than those from weeks 16-27 of gestation (P < 0.01). We conclude that apoptosis in term amniotic epithelium is independent of Bcl-2 regulation and onset of labour, and may play an important role in the fragility and rupture of human fetal membranes at term.

Amnion↗
PubMed2001

Allelotype frequency of the thiopurine methyltransferase (TPMT) gene in Japanese.

Polymorphisms at three loci in the thiopurine methyltransferase (TPMT) gene are known to be responsible for azathioprine and 6-mercaptopurine (6MP) toxicity. Among them, only TPMT*3C variant allele with A719G mutation was found in 15/522 (2.9%; 17/1044 alleles; 1.6%) Japanese individuals including two homozygotes. The allele frequency was different from that in Caucasians, and investigation of TPMT polymorphisms with consideration of ethnic differences before administration of azathioprine or 6MP may provide clinically useful information.

Alleles↗
PubMed2001

Predicting the recurrence of ventricular tachyarrhythmias from T-wave alternans assessed on antiarrhythmic pharmacotherapy: a prospective study in patients with dilated cardiomyopathy.

BACKGROUND: Microvolt T-wave alternans (TWA) has been proposed as a useful index to identify patients at risk of ventricular tachyarrhythmias. Recent studies have demonstrated that antiarrhythmic drugs, such as amiodarone and procainamide, decrease the prevalence of TWA. In this study, we tested whether TWA in patients on antiarrhythmic pharmacotherapy significantly predicts the recurrence of ventricular tachyarrhythmias in patients with dilated cardiomyopathy. METHODS: To evaluate the ability to predict the recurrence of ventricular tachyarrhythmias, determinate TWA and left ventricular ejection fraction (LVEF) were prospectively assessed in 49 patients with ischemic or nonischemic dilated cardiomyopathy on antiarrhythmic pharmacotherapy for sustained ventricular tachycardia (VT) or ventricular fibrillation (VF). The pharmacotherapy consisted of class I (17 patients), III (29 patients), and IV (3 patients) antiarrhythmic drugs. The study endpoint was the first recurrence of sustained VT or VF on treatment during the follow-up period. RESULTS: TWA was positive on antiarrhythmic pharmacotherapy in 30 patients (61%). During a follow-up of 13 +/- 11 months, the sustained VT or VF recurred in 21 of the 41 patients (51%) with available follow-up data. The sensitivity of TWA and LVEF for predicting recurrence of ventricular tachyarrhythmias was 76 and 38%, specificity was 60 and 70%, positive predictive value was 67 and 57%, and negative predictive value was 71 and 52%. Kaplan-Meier event-free analysis revealed that TWA was a significant risk stratifier (P = 0.02), whereas LVEF was not. CONCLUSIONS: This prospective study suggests that TWA significantly predicts the recurrence of ventricular tachyarrhythmias, even on antiarrhythmic pharmacotherapy, in patients with dilated cardiomyopathy. TWA may also be a useful marker for evaluating the efficacy of antiarrhythmic drugs for ventricular tachyarrhythmias.

Adult↗
PubMed2001

[Outbreak of methicillin-resistant Staphylococcus aureus (MRSA) infection or colonization among patients with neoplastic disease: a clinico-epidemiological study of 11 cases].

MRSA infection or colonization developed in eleven patients with neoplastic disease including malignant lymphoma (5 cases), soft tissue sarcoma (2 cases), acute myeloblastic leukemia (one), myelodysplastic syndrome (one), multiple myeloma (one), and mesothelioma (one) at our ward from October to December 1999. The infections were pneumonia (six cases), enteritis (three), bacteremia (one), and wound infection (one). Ten of 11 cases received antimicrobial agent (s) during one month before isolation of MRSA, suggesting selection of MRSA. Five cases improved and survived, but six cases died of infection. At the isolation of MRSA, the neutrophil count (NC) of the alive cases was 1, 500/microliter or more but the NC of five cases who died was less than 1,000/microliter, especially less than 100/microliter in three cases who had just received a cancer chemotherapy. Pulsed-field gel electrophoresis, performed in 9 cases, showed an identical DNA-pattern of MRSA in 7 cases, indicating a nosocomial infection. Our method to prevent spread of MRSA targeting solely the patients with MRSA infection was obviously unsatisfactory. We should target also the cases of MRSA colonization and make an effort to wash hands more vigorously. Furthermore, radical reformation such as increasing single sick-rooms drastically and increasing the number of nursing staff is also required.

Adult↗