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Biomedical subjects

K Minami

Publications and source records attributed to K Minami.

At least 73 records · Page 4Linked to original sources
PubMed2000

Single-center experience with the thoratec ventricular assist device.

OBJECTIVE: The Thoratec ventricular assist device (Thoratec Laboratories, Pleasanton, Calif) is widely accepted for univentricular and biventricular support in patients with various indications. The aim of this study is to describe our experience with implantation of the Thoratec ventricular assist device in more than 100 patients. METHODS: From March 1992 to June 1998, 114 patients (98 men and 16 women; mean age, 47.9 years) received the Thoratec ventricular assist device for a mean duration of 44.9 days. The patients were divided into 3 groups. Group 1 included 84 patients in whom the system was applied as a bridge-to-transplant procedure. Group 2 included 17 patients with postcardiotomy cardiogenic shock, and group 3 included 13 patients with cardiogenic shock of other causes. RESULTS: Sixty-eight percent of patients in group 1 survived to transplantation with a posttransplant survival of 88%. The only independent risk factor affecting survival was age more than 60 years. Survivals in groups 2 and 3 were 47% and 31%, respectively. Main complications in all groups were bleeding, multiple organ failure, liver failure, sepsis, and neurologic disorders. CONCLUSIONS: The Thoratec ventricular assist device has proved to be a reliable device for bridge to transplantation and postcardiotomy support. Further studies are required on patient selection and on patient and device management to reduce the incidence of complications in these patient populations.

Adolescent↗
PubMed2000

Predictors of survival in patients bridged to transplantation with the thoratec VAD device: a single-center retrospective study on more than 100 patients.

BACKGROUND: Careful patient selection markedly influences the outcome of patients who undergo mechanical circulatory support. Therefore, we tried to evaluate predictors of survival after implantation of the Thoratec ventricular assist device (VAD). METHODS: Between October 1992 and January 2000, 104 patients (86 men, 18 women, aged 11 to 69 years) received the Thoratec VAD as a bridge to transplant. A total of 51 patients required left ventricular support (LVAD), 50 patients required biventricular support (BVAD), and 3 patients required total artificial heart implantation. We performed univariate analysis of 25 parameters with regard to their effect on survival and then applied a multivariate analysis to evaluate those factors that turned out to be marginally significant. We performed all analysis for the total collective as well as for the LVAD and BVAD sub-group. RESULTS: The BVAD patients tended to have worse outcomes than did LVAD patients. We found no significant predictors of survival in either sub-group. In the total collective, however, we found the following pre-implant conditions were independent risk factors for survival after VAD implantation: patient age > 60 years (odds ratio [OR] 3.87, confidence interval [CI] 1.39 to 10.76), pre-implant ventilation (OR, 6.76; CI 2.42 to 18.84), and increased pre-implant total bilirubin (OR, 1.42; CL, 1.19 to 1.69). CONCLUSIONS: Transplant candidates on inotropic support should be considered for bridging to transplant as soon as bilirubin values start to increase or before respiratory function deteriorates and ventilation becomes necessary. In elderly patients, careful patient selection, particularly considering potential risk factors, might favorably affect their outcomes.

Adolescent↗
PubMed2000

INR self-management following mechanical heart valve replacement.

INR self-management can reduce severe thromboembolic and hemorrhagic complications following mechanical heart valve replacement. Beginning anticoagulation therapy immediately in the postoperative period further reduces anticoagulant-induced complications. Data were collected from the first 600 surviving patients (from a total study sample of 1200 patients) who completed follow-up of at least 2 years. Patients were randomly divided into a self-management group and a control group. INR self-management reduced severe hemorrhagic and thromboembolic complications (P=0.018). Nearly 80% of INR values recorded by patients themselves, regardless of educational level, were within the target therapeutic range of INR 2.5-4.5, compared with 62% of INR values monitored by family practitioners. Only 8.3% of patients trained in self-management immediately after surgery were unable to continue with INR self-management. The results differed slightly between patient groups with different levels of education. We conclude that all patients for whom anticoagulation is indicated are candidates for INR self-management regardless of education level.

Anticoagulants↗
PubMed2000

Clinical usefulness of urine-based enzyme-linked immunosorbent assay for detection of antibody to Helicobacter pylori: a collaborative study in nine medical institutions in Japan.

BACKGROUND: A urine-based enzyme-linked immunosorbent assay (ELISA) kit for detection of antibody to Helicobacter pylori has been developed in Japan. Urine samples can be obtained noninvasively and are easier and safer to handle than are serum samples. The aim of this study was to examine the clinical usefulness of this urine-based ELISA kit. MATERIALS AND METHODS: A pair of random, single-void urine and serum samples was collected from each of 1,061 subjects, including 238 patients with gastroduodenal disease. The sensitivity and specificity of the urine-based ELISA was compared with those of three commercially available serum-based ELISA kits. For those patients with gastroduodenal disease, the urine- and serum-based ELISA results were also compared with those for other diagnostic methods using endoscopic biopsy specimens, such as culture, histology, and rapid urease tests. RESULTS: Based on the three serum-based ELISA results, the sensitivity, specificity, and accuracy of the urine-based ELISA were 97.7%, 95.6%, and 96.8%, respectively. On the basis of the biopsy test results, the sensitivity (96.2%), specificity (78.9%), and accuracy (91.0%) of the urine-based ELISA were almost equivalent or superior to all three serum-based ELISAs tested. In addition, 10 of the 12 false-positive cases for urine-based ELISA were confirmed to be true positives for antibodies to H. pylori by Western blot analysis and inhibition ELISA. CONCLUSIONS: The urine-based ELISA (URINELISA H. pylori Antibody) is very accurate and should be useful as an alternative to serum-based ELISAs for screening of H. pylori infection.

Antibodies, Bacterial↗
PubMed2000

Morbidity and outcome after mechanical ventricular support using Thoratec, Novacor, and HeartMate for bridging to heart transplantation.

Between September 1989 and June 1999, 228 patients were supported with a ventricular assist device as a bridge to heart transplantation. In this study, the results of implantation were evaluated in patients supported with one type of device, including 85 supported with a Thoratec, 61 with a Novacor, and 37 with a HeartMate. The mean support time was 49, 148, and 124 days, respectively. Successful transplantation and weaning rates were 64. 7% with Thoratec, 59.0% with Novacor, and 62.0% with HeartMate. Cerebral embolism and drive-line and pocket infection were major causes of postoperative morbidity and mortality. We recommended that a Thoratec system be employed as a bridge to heart transplantation for patients with biventricular heart failure, and that a Novacor or HeartMate system be implanted in patients requiring a long-term circulatory support.

Adolescent↗
PubMed2000

Stability of simultaneous maxillary and mandibular osteotomy for treatment of class III malocclusion: an analysis of three-dimensional cephalograms.

PURPOSE: The current investigation was undertaken to study the three-dimensional (3-D) stability of simultaneous maxillary advancement and mandibular setback using rigid fixation. The study also aimed to analyse the factors involved in postsurgical relapse by evaluation of changes in various parameters. PATIENTS: Twenty-five cases were evaluated of simultaneous Le Fort I maxillary advancement and mandibular setback using rigid fixation. METHODS: Preoperative, immediate and 6-month postoperative skeletal and dental changes were analysed using 3-D cephalograms obtained from biplanar stereoradiography. Maxillary fixation screws were used as landmarks to evaluate postoperative stability. RESULTS: The mean maxillary advancement was 3.7 mm. Relapse in the sagittal, vertical, and transverse planes was not detectable in the maxilla (p > 0.05). However, for an average mandibular setback of 5.7 mm, mean mandibular relapse was 1.1 mm or 19.3% anteriorly (p < 0.05). Surgical or postsurgical skeletal changes in the maxilla had no detectable influence on mandibular relapse (p > 0.05). Vertical alterations of the facial skeleton achieved surgically predicted the mandibular relapse (R2 = 0.27, p < 0.05). CONCLUSION: Maxillary advancement and vertical changes of +/- 2 mm did not influence the postoperative stability of the mandible. Relapse of the mandible seems to be influenced mainly by the amount and direction of the surgical alteration of mandibular position.

Adult↗
PubMed2000

Inhibition by neuromuscular blocking drugs of norepinephrine transporter in cultured bovine adrenal medullary cells.

UNLABELLED: Pancuronium stimulates the cardiovascular system, whereas vecuronium, a derivative of pancuronium, has far fewer effects. The inhibition of norepinephrine transporter (NET) in the sympathetic nervous system may partly account for the stimulatory actions of pancuronium. To investigate the mechanism of action of pancuronium on NET, we examined the effects of pancuronium on NET activity by using cultured bovine adrenal medullary cells and compared pancuronium with other neuromuscular blocking drugs. Pancuronium (1-300 microM) inhibited desipramine-sensitive [(3)H]norepinephrine (NE) uptake in a concentration-dependent manner. Vecuronium (100-300 microM) and d-tubocurarine (300 microM) also decreased [(3)H]NE uptake but were less potent than pancuronium at clinical concentrations. Succinylcholine had little effect on [(3)H]NE uptake. Saturation analysis showed that pancuronium and vecuronium reduced an apparent maximum velocity (V(max)) of [(3)H]NE uptake without altering Michaelis-Menten constant, indicating noncompetitive inhibition. Pancuronium did not inhibit the specific binding of [(3)H]desipramine to plasma membranes isolated from bovine adrenal medulla. A protein kinase C inhibitor, GF109203X, did not affect the inhibition of [(3)H]NE uptake by pancuronium. Pancuronium enhanced the inhibition of NET induced by ketamine. These results suggest that pancuronium, with clinically relevant concentrations, inhibits NET activity by interacting with a site distinct from the recognition site for NE and the desipramine binding site on the transporter. IMPLICATIONS: In this study, pancuronium inhibited norepinephrine uptake and was the most potent of the neuromuscular blocking drugs we tested, including pancuronium, vecuronium, d-tubocurarine, and succinylcholine. Pancuronium may affect the sympathetic nervous system by inhibiting the activity of the presynaptic norepinephrine transporter at clinically relevant concentrations.

Adrenal Medulla↗
PubMed2000

Dual effects of intravenous anesthetics on the function of norepinephrine transporters.

BACKGROUND: Norepinephrine transporters (NETs) terminate the neuronal transmission of norepinephrine, which is released from noradrenergic neurons. To investigate the interaction with NET, the authors examined the effects of short- and long-term treatment with anesthetics on the activity and mRNA level of NET. METHODS: To assay [3H]norepinephrine uptake, bovine adrenal medullary cells in culture were incubated with [3H]norepinephrine in the presence of intravenous anesthetics, including propofol, thiamylal, and diazepam. To study the direct interaction between the anesthetics and NET, the effect of propofol on the binding of [3H]desipramine to the plasma membrane was examined. To study the long-term effect of anesthetics, [3H]norepinephrine uptake by cells pretreated with propofol for 6-24 h and [3H]desipramine binding after pretreatment for 12 h were measured. Simultaneously, we examined the effect of anesthetics on the expression of NET mRNA using the reverse transcriptase-polymerase chain reaction. RESULTS: All of the intravenous anesthetics inhibited [3H]norepinephrine uptake in a concentration-dependent manner. The active concentrations of propofol (1-3 microm) and thiamylal (< or = 30 microm) were similar to those encountered clinically. The kinetic analysis revealed that all the anesthetics noncompetitively inhibited [3H]norepinephrine uptake. Propofol inhibited [3H]desipramine binding with a potency similar to that observed in [3H]norepinephrine uptake. Scatchard analysis showed that propofol competitively inhibited [3H]desipramine binding. On the other hand, long-term treatment of cells with propofol (10 microm) enhanced the NET functional activity and [3H]desipramine binding, and also increased the level of NET mRNA. CONCLUSIONS: These results suggest that intravenous anesthetics have a dual effect on NET; short-term treatment causes inhibition, whereas long-term treatment leads to up-regulation. The interaction of intravenous anesthetics with NET may modulate the neuronal transmission of norepinephrine during anesthesia.

Adrenal Medulla↗
PubMed2000

Insulin secretion and differential gene expression in glucose-responsive and -unresponsive MIN6 sublines.

We have established two sublines derived from the insulin-secreting mouse pancreatic beta-cell line MIN6, designated m9 and m14. m9 Cells exhibit glucose-induced insulin secretion in a concentration-dependent manner, whereas m14 cells respond poorly to glucose. In m14 cells, glucose consumption and lactate production are enhanced, and ATP production is largely through nonoxidative pathways. Moreover, lactate dehydrogenase activity is increased, and hexokinase replaces glucokinase as a glucose-phosphorylating enzyme. The ATP-sensitive K(+) channel activity and voltage-dependent calcium channel activity in m14 cells are reduced, and the resting membrane potential is significantly higher than in m9 cells. Thus, in contrast to m9, a model for beta-cells with normal insulin response, m14 is a model for beta-cells with impaired glucose-induced insulin secretion. By mRNA differential display of these sublines, we found 10 genes to be expressed at markedly different levels. These newly established MIN6 cell sublines should be useful tools in the analysis of the genetic and molecular basis of impaired glucose-induced insulin secretion.

ATP-Binding Cassette Transporters↗
PubMed2000

Is suprapubic cystostomy an optimal urinary management in high quadriplegics?. A comparative study of suprapubic cystostomy and clean intermittent catheterization.

INTRODUCTION: Long-term outcome of spinal cord injury (SCI) patients was compared between those managed by suprapubic cystostomy (SPC) and clean intermittent catheterization (CIC) with particular emphasis on an incidence of urinary tract complications and patients perception for urinary management. MATERIALS AND METHODS: The study comprised 61 SCI patients; 34 patients managed with SPC (group A), while 27 with CIC (group B). After stabilization of their condition, all were followed annually on an outpatient basis with clinical history, urinalysis, urinary imaging and renal function studies. Mean follow-up periods were 8.6 and 9.9 years for groups A and B, respectively. Between groups, a comparative study was performed on the incidence of urinary complications such as renal dysfunction, hydronephrosis, vesicoureteral reflux, symptomatic genitourinary infection and urinary stone. Satisfaction with urinary management was also estimated using the questionnaires during follow-up. RESULTS: Renal dysfunction, hydronephrosis and vesicoureteral reflux were not found in either group. Symptomatic genitourinary infection was seen in 4 (12%) of group A and 7 (26%) of group B, respectively. The incidence of renal stone was 3 (9%) in group A and 1 (4%) in group B. A significant difference was not found between two groups in these urinary complications. On the contrary, bladder stone was seen more frequently in group A (65%) than in group B (30%) with a significant difference (p<0.001). The degrees of incontinence, bother score of daily activities, and overall satisfaction showed no significant difference between the two groups. CONCLUSION: Except for bladder stones, SPC is a valuable option of urinary management for quadriplegic patients, the results of which were comparable to paraplegic SCI patients managed with CIC.

Adolescent↗
PubMed2000

High molecular weight transglutaminase inhibitor produced by a microorganism (Streptomyces lavendulae Y-200).

Transglutaminases catalyze the cross-linking and amine incorporation of proteins, and are implicated in various biological phenomena such as blood clotting, wound healing, apoptosis, and cell differentiation. Streptomyces lavendulae Y-200, isolated from soil, produced a substance that inhibited transglutaminases. The inhibitory substance was purified from the cultured medium by procedures of acid precipitation, deoxyribonuclease treatment, and gel filtration chromatography. The partially purified sample was dark brown. The inhibitory activity was stable under acidic, alkaline, and high temperature conditions, and resistant to the treatment with proteinases such as trypsin and Pronase. The molecular weight of the inhibitory substance was estimated to be between 10(4) and 10(5) from its permeability through ultrafilter membranes. The acid hydrolysate of the inhibitory substance contained amino acids and sugars. The inhibitory substance inhibited both calcium-dependent and calcium-independent transglutaminases in a competitive manner with a glutamine substrate. The extent of inhibition caused by the calcium-dependent transglutaminase increased with increasing calcium concentration. The results obtained here may help identify a novel regulatory substance of transglutaminase in biological systems.

Animals↗
PubMed2000

Comparison between palatal configurations in UCLP infants with and without a Hotz plate until four years of age.

OBJECTIVE: To evaluate the efficacy of presurgical orthopedic treatment three dimensionally, we previously developed a novel measuring system and described the efficacy of the treatment until 18 months of age. The aim of this study was to compare palatal configuration in complete unilateral cleft lip and palate (UCLP) infants fitted with a Hotz plate to those without it until four years of age using the same measuring system. PATIENTS: Twenty complete UCLP infants were divided into two groups. A Hotz plate was used with 12 patients who first visited our clinic from January 1990 to March 1992 and was not used with an additional eight patients who first visited from April 1992 to July 1993. MAIN OUTCOME MEASURES: Palatal casts taken from birth until four years of age were measured three dimensionally and were compared between the two groups. RESULTS AND CONCLUSIONS: The width of the palate was larger in the group with a Hotz plate than in the group without it at four years of age. No difference was observed between the anteroposterior distance of the palate in the two groups at four years of age. Similarly, the alveolar arch form did not differ between the two groups. The degree of curvature of the palatal surface was smaller in the group with a Hotz plate than in the group without it. These data were similar to data obtained at 18 months of age.

Child, Preschool↗
PubMed2000

Mitroflow pericardial valve prosthesis in the aortic position: an analysis of long-term outcome and prognostic factors.

BACKGROUND AND AIM OF THE STUDY: Pericardial valves combine optimal hemodynamic properties with limited durability. To describe the long-term performance of Mitroflow pericardial valves in the aortic position, outcome and risk factors up to 12 years after implantation were analyzed. METHODS: A retrospective study, based on follow up of 1,029 patients who received 1,044 Mitroflow pericardial valves in the aortic position between February 1985 and December 1996, was performed. Follow up was 98.2% complete. Average follow up was 3.79 years. Mean patient age was 75.2+/-6.5 years (range: 27.9-90.9 years). At surgery, 86.3% of patients were aged over 70 years. Among patients, 482 (46.8%) had concomitant operations. RESULTS: Results (+/- SE) are given for evident and possible (in parentheses) valve-related events; the latter included all reported postoperative strokes and sudden deaths. Actuarial event-free rates after 5 and 10 years respectively were: structural valve deterioration: 99.2+/-0.5% and 77.6+/-4.4%; non-structural valve deterioration: 99.7+/-0.2% and 99.7+/-1.2%; valve-related complications: 95.7+/-0.9% and 73.5+/-4.0% (5 years 90.1+/-1.2%, 10 years 57.0+/-4.3%); endocarditis: 96.6+/-0.8% and 92.6+/-1.6%; explantation: 98.6+/-0.5% and 80.1+/-3.9%; cerebrovascular accident 95.2+/-0.9% and 82.5+/-3.5%; embolism 99.9+/-0.1% and 99.9+/-0.5%; bleeding 99.8+/-0.2% and 99.8+/-1.3%; overall mortality 69.9+/-1.8% and 35.3+/-3.0%; valve-related death 97.5 +/-1.1% and 95.1+/-4.2% (5 years 91.9+/-1.4%, 10 years 76.1+/-3.2%). The 30-day mortality rate was 4.1%. Patients aged 70 years or more with valve diameters of < or =23 mm showed 10-year freedom rates of 85.8+/-4.6% for structural valve degeneration and 95.1+/-1.2% for evident valve-related death. The detailed risk factor analysis showed results that were in accordance with clinical experience. CONCLUSION: Long-term results with Mitroflow pericardial valves in the aortic position compare well with those for other widely used bioprostheses, especially in patients aged > or =70 years and with small aortic root diameters (< or =23 mm).

Adult↗
PubMed2000

Co-transduction of herpes simplex virus thymidine kinase gene and human interleukin-2 gene into mouse ovarian cancer cell line, OVHM.

We studied the thymidine kinase (TK) gene and the interleukin (IL)-2 gene co-transduction into tumor cells for a possible strategy of cancer gene therapy. A murine ovarian cancer cell line, OVHM, was retrovirally transduced with the TK (OVHM/TK) or the IL-2 gene (OVHM/IL-2). The TK or IL-2 expression was permanent in OVHM/TK or OVHM/IL-2. OVHM/TK cells were susceptible to gancyclovir (GCV) in vitro, and their intraperitoneal growth was completely regulated with GCV administration. The bystander effect was not observed in vitro and in vivo in this model, and only the marginal emergence of immune involvement was observed in the OVHM/TK-cured mice with GCV. OVHM/IL-2 cells produced IL-2 biologically active to be immunogenic, but still tumorigenic to kill the mice when inoculated intraperitoneally. Then, OVHM/TK cells were co-transduced with the IL-2 gene to establish OVHM/TK/IL-2 cells. OVHM/TK/IL-2 cells were also susceptible to GCV and transiently produced active IL-2. A significant resistance against the challenge of parental tumor cells was observed in the mice that were inoculated with OVHM/TK/IL-2 cells and cured with GCV administration. It is suggested that tumor cells transduced with both TK and IL-2 genes could be regressed with GCV administration with subsequent generation of immune activation in the host. Since the bystander effect may not always be a common phenomenon in gene therapy using the TK gene, this type of combination may be advantageous in the clinical application of gene therapy for human cancers.

Animals↗
PubMed2000

Pre-existing elevated pulmonary vascular resistance: long-term hemodynamic follow-up and outcome of recipients after orthotopic heart transplantation.

BACKGROUND: Elevation of pulmonary vascular resistance (PVR) has been considered to predict a bad outcome after orthotopic heart transplantation (HTx). A transpulmonary gradient (TG) > or =15 mmHg and PVR > or =5 wood (w) are correlated with a three-fold increase in 2-days as well as 30-days and 6-, 12-month mortality. METHODS: We performed a retrospective analysis of 400 consecutive transplanted patients (pts) on hemodynamic data over a time period of 3.5 years. In 83 pts (23%) preoperative PVR was > or =5 w and TG >15 mmHg. Vasodilator studies were performed in this group of pts in order to evaluate pulmonary vasoreactivity or hemodynamic improvement. RESULTS: Hemodynamic follow-up post-transplantation showed a significant (p<0.001) decrease in mean TG to 8.8 mmHg within the first, 7.7 after the fifth year as well as decrease in PVR from 5.5 to 1.6, within the first and fifth year post-transplantation. Compared to the control group (n=286) (re-transplants n=6 and pediatric pts n=25 excluded) pts with TG <15 mmHg and/or PVR <5 w, transplanted within the same period, 30-day mortality and cumulative survival after 1 and 5 years do not show any significant difference with a mortality of 3%, 22% and 33% (p<0.05). Subgroup analysis for pts with endstage of ischemic versus dilatative cardiomyopathy has not shown any significant difference in mortality. CONCLUSIONS: In a retrospective analysis of 400 pts elevated PVR does not predict a bad outcome after orthotopic heart transplantation in early and late mortality.

Adolescent↗
PubMed2000

[Acute transient swelling of the submandibular glands after laryngeal mask airway insertion].

A 40-year-old woman was scheduled for abdominal hysterectomy. Moderate difficulty in tracheal intubation was expected on preoperative evaluation. A size 3 laryngeal mask airway (LMA) was inserted after the induction of general anesthesia. The LMA insertion was accomplished smoothly at the first attempt and there was no air leakage during manual ventilation. Soon after the insertion, acute swellings were noted in the bilateral submandibular triangle regions. Enlargement and deformity of the submandibular glands were diagnosed by ultrasonography. The enlargements increased with elevated pressure of the LMA cuff, but disappeared completely in five minutes after removal of the LMA. Such enlargement did not occur with subsequent tracheal intubation. The patient had an uneventful postoperative course without any residual sequelae. We should pay attention to possible submandibular gland swelling by LMA insertion.

Adult↗