Clinical and psychosocial consequences of renal transplantation in children.
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Adolescent↗
Biomedical subjects
H C Kim
Publications and source records attributed to H C Kim.
A new automatic cardiac output control algorithm for moving actuator total artificial heart by motor current waveform analysis.
A new automatic cardiac output control algorithm for an implantable electromechanical total artificial heart (TAH) was developed based on the analysis of motor current waveform without using any transducer. The basic control requirements of an artificial heart can be described in terms of three features: preload sensitivity, afterload insensitivity, and balanced ventricular output. In previous studies, transducers were used to acquire information on the hemodynamic states for automatic cardiac output control. However, such a control system has reliability problems with the sensors. We proposed a novel sensorless automatic cardiac output control algorithm (ACOCA) providing adequate cardiac output to the time-varying physiological demand without causing right atrial collapse, which is one of the critical problems in an active filling device. In vitro tests were performed on a mock circulatory system to assess the performance of the developed algorithm and the results show that the new algorithm satisfied the basic control requirements of the cardiac output response.
Algorithms↗
Prototype continuous flow ventricular assist device supported on magnetic bearings.
This article describes a prototype continuous flow pump (CFVAD2) fully supported in magnetic bearings. The pump performance was measured in a simulated adult human circulation system. The pump delivered 6 L/min of flow at 100 mm Hg of differential pressure head operating at 2,400 rpm in water. The pump is totally supported in 4 magnetic bearings: 2 radial and 2 thrust. Magnetic bearings offer the advantages of no required lubrication and large operating clearances. The geometry and other properties of the bearings are described. Bearing parameters such as load capacity and current gains are discussed. Bearing coil currents were measured during operation in air and water. The rotor was operated in various orientations to determine the actuator current gains. These values were then used to estimate the radial and thrust forces acting on the rotor in both air and water. Much lower levels of force were found than were expected, allowing for a very significant reduction in the size of the next prototype. Hemolysis levels were measured in the prototype pump and found not to indicate damage to the blood cells.
Animals↗
The effects of dextromethorphan on kainic acid-induced seizures in the rat.
Several studies have shown that dextromethorphan (DM) has both anticonvulsant and proconvulsant effects depending on the animal model. In this study, we examined the effects of DM on three parameters associated with kainic acid (KA)-induced seizures: cell loss in the hippocampus, increased AP-1 DNA binding activity and increased c-Jun and fos-related antigen (FRA) expression. KA administration (8 mg/kg, ip) produced robust behavioral convulsions lasting 4-6 hr. Pretreatment with DM (12.5-75 mg/kg, po) 15 min before KA injections reduced the seizures as well as mortality in a dose-dependent manner. Histological studies revealed a severe loss of cells in the CA1 and CA3 fields of the hippocampus in KA-treated rats. DM pretreatment also reduced this cell loss in a dose-dependent fashion. Biochemical studies showed that DM pretreatment also attenuated the KA-induced increase of AP-1 binding activity and c-Jun/FRA expression in the hippocampus. These results indicate that DM is an effective antagonist of KA.
Animals↗
Role of cyclosporin A in bacterial translocation.
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Animals↗
A new polymer valve for mechanical circulatory support systems.
A new low-cost artificial heart valve with easily modified dimensions according to its application was developed using segmented polyurethane (SPU). It consists of a convex frame and a concave membrane which floats in the center of the frame while working. The hydrodynamic performance of the polymer valve was compared with that of the Björk-Shiley mechanical valve using a mock circulatory testing system. The hydrodynamic performance of this valve was superior to the Björk-Shiley mechanical valve. The valve was applied to a ventricular assist device (VAD) developed in our institute. In vivo performances of these systems were tested using mongrel dogs. During the experiments, there were no complications related to malfunction of the valve. At postmortem examinations, no thrombus formation was found on the valve surface, and no embolus was detected in the kidneys. We believe this valve could prove a very useful alternative for valves of mechanical circulatory support systems (MCSS) such as VAD and TAH.
Animals↗
[A 13-week subchronic toxicity study of gardenia blue in F344 rats].
A 13-week oral toxicity study of gardenia blue was performed in male and female F344 rats at the dose levels of 5.0, 2.5, 1.25, 0.6 and 0% in the diet, to determine the maximum tolerable dose (MTD) for subsequent investigation of carcinogenicity. Rats were randomly allocated to 5 groups, each consisting of 10 males and 10 females. No groups showed decreases in body weight gain and food intake, and all animals survived until the end of the experiment. A dose-dependent decrease in number of platelets was observed in females treated with gardenia blue in hematological examination, but not in males. No histopathological change, relating to the treatment, in megakaryocyte which is the progenitor cell of platelets was observed in the treated-females. Serum biochemistry revealed increases in GOT and GPT in both sexes treated with the 5.0% and 2.5% gardenia blue, as compared to the control value. However, these were not considered to be specific changes because of lack of any clear dose response. In addition, no histopathological changes indicating obvious toxicity of gardenia blue were observed in the liver of both sexes treated with gardenia blue. Based on these data, the MTD of gardenia blue for both sexes in F344 rats was considered to be 5.0% or more in the diet.
Alanine Transaminase↗
Enhancement of GST-P positive liver cell foci development by a medium-term carcinogenicity bioassay using repeated administration of D-galactosamine.
This study was performed for developing a new medium-term carcinogenicity bioassay treated with D-galactosamine (DGA) as a non-surgical method without partial hepatectomy (PH). In male F344 rats initiated with diethylnitrosamine (DEN, 200 mg/kg i.p.), enhancing effects of DGA (300 mg/kg i.p.) given twice 3 weeks apart during the promotion procedure with 2-acetylaminofluorene (2-AAF, 0.01% in diet) were compared along with those of PH by analyzing preneoplastic glutathione S-transferase placental form positive (GST-P+) hepatocyte foci as endpoint marker lesions. The DGA treatment did not affect the body weight gain whereas the PH treatment caused a transient body weight loss. Although both bioassay protocols were effective to detect the potential hepatocarcinogenicity of 2-AAF, the number and area of GST-P positive foci per cm2 were larger in the bioassay using DGA than in that using PH, the number being statistically significant (P < 0.05). Our results thus suggest that the present bioassay protocol with repeated administration of DGA instead of PH may offer a new and sensitive method to screen large numbers of environmental carcinogens.
2-Acetylaminofluorene↗
Factor VNew Brunswick: Ala221-to-Val substitution results in reduced cofactor activity.
We have characterized the factor V protein and cDNA of a patient displaying factor V deficiency (parahemophilia) and correlated the reduced activity with a missense mutation of Ala221-to-Val. Plasma from the subject individual (C1) presented reduced factor V antigen (39% of normal) that displayed reduced activity (approximately 26% of normal). Factor V purified from this individual by standard techniques shows normal migration on sodium dodecyl sulfate gels and a normal pattern of activation by thrombin. Purified antigen from sibling C2 gives a much reduced specific activity of 263 U/mg (17% of normal). Sibling C3, the mother, and the father have antigen within the normal range (57% to 200%) that has approximately normal specific activity. The cDNA encoding the factor Va heavy and light chains of the subject individual was polymerase chain reaction-amplified and sequenced and revealed an A-to-G substitution at position 3 of codon 51 (silent mutation), a C-to-T substitution in position 2 of codon 221 (Ala221-Val), a T-to-C substitution at position 3 of codon 708 (silent mutation), and a G-to-A substitution at position 1 of codon 2185 (Thr2185-Ala). The latter mutation was also observed in control individuals and is proposed to be a possible polymorphism. Restriction analyses demonstrated the presence of one mutant and one normal allele in the father. The subject individual (C1) and sibling C2 carry only the mutant allele. The mother and sibling C3 carry only the normal allele. The inheritance pattern suggests the presence of a missing or nonexpressed allele in the mother that is passed on to all the siblings. Expression of only the mutant allele by the subject individual (C1) and sibling C2 is consistent with reduced factor V antigen and activity in these patients. We have designated this mutant as Factor VNew Brunswick.
Adolescent↗
Use of laparoscopy in the diagnosis and treatment of patients with surgical abdominal sepsis.
Patients often present to the surgeon with abdominal pain, tenderness, and fever. Many exhibit progressive sepsis due to abdominal pathology. Delay in diagnosis and treatment often occurs due to the use of multiple, time-consuming, expensive diagnostic studies. We delineate the use of diagnostic laparoscopy in subsets of patients in whom confusion exists as to the cause of abdominal sepsis--i.e., females in child-bearing years, elderly patients, obese patients, immunosuppressed patients, and patients with suppression of physical findings. The methodical assessment of the entire abdominal cavity is performed utilizing manipulation of the patient's position (Trendelenburg, supine, reverse Trendelenburg, left side up, right side up) and meticulous inspection of the entire small bowel. Diagnoses included acute appendicitis, gangrenous appendicitis, perforated appendicitis with peritonitis or abscess, gangrenous cholecystitis, ischemic bowel disease, perforating carcinoma of the colon, perforating diverticulitis with abscess or peritonitis, tubo-ovarian abscess, closed-loop small-bowel obstruction, megacolon, and perforation of the colon. Laparoscopic treatment of 96% of the patients was performed successfully and a laparoscopic-assisted approach was used in the remainder. There was one mortality (cardiac) and no major morbidity. The development of a Formal Diagnostic Exploratory Laparoscopic (FDEL) approach has aided in the assessment of each of the diagnoses of sepsis in the abdominal cavity. The diagnostic and therapeutic approach laparoscopically avoids extensive preoperative studies, avoids delay in operative intervention, and appears to minimize morbidity and shorten the postoperative recovery interval.
Abdomen, Acute↗
Patency of a small vessel prosthesis bonded to tissue plasminogen activator and iloprost.
To test the thrombosis resistance of a vascular prosthesis coated with antithrombogenic agents, we evaluated a small vessel prosthesis of expanded polytetrafluoroethylene (ePTFE) implanted in the rat aorta and removed 1 week following surgery. Control grafts consisted of 1 mm internal diameter ePTFE. Experimental grafts consisted of 1 mm internal diameter ePTFE noncovalently bonded to tissue plasminogen activator (tPA) and iloprost using the surfactant tridodecylmethylammonium chloride. After 1 week the grafts were harvested, patency was determined, and histologic specimens were prepared for electron microscopy. Six of 10 control grafts were thrombosed, whereas 9 of 10 tPA-iloprost-bonded grafts were patent (p < 0.03). Of concern, there was an unexpectedly high mortality rate in the tPA-iloprost group compared to the control group among animals that died before completion of the study. Evaluation of the safety of these drugs must, therefore, be an early component of future experiments. Nevertheless, these studies indicate that a small vessel prosthesis bonded to tPA and iloprost may ameliorate some of the complications associated with early graft failure.
Animals↗
Comparison of screw placement patterns on the rigidity of the sagittal split ramus osteotomy: technical note.
Various screw placement patterns have been described for fixation of the sagittal split ramus osteotomy. This study is a comparative evaluation of 3 different screw placement patterns on the rigidity of the sagittal split ramus osteotomy. Twenty cadaver mandibles were used to compare the load strength of triangular pattern, oblique linear pattern versus linear pattern. Internal fixation with screws placed in a triangular pattern were significantly more rigid than those fixed with screws placed in the other patterns. Also, internal fixation with an oblique linear pattern was more rigid than that with a linear pattern.
Bone Screws↗
Changes in mRNA levels of a pituitary-specific trans-acting factor, Pit-1, and prolactin during the rat estrous cycle.
The present study examined the changes in mRNA levels of a pituitary-specific trans-acting factor, Pit-1, and prolactin during the rat estrous cycle. Total cytoplasmic RNA was analyzed by Northern blot and slot-blot hybridization to examine the prolactin mRNA level. Reverse transcription-polymerase chain reaction (RT-PCR) was performed to examine the Pit-1 mRNA level. Proestrous and estrous prolactin mRNA levels were significantly higher than the metestrous and diestrous levels, whereas Pit-1 mRNA levels of the estrous and metestrous stages were about two- to threefold higher than those of the proestrous and diestrous stages. Proestrous Pit-1 mRNA levels increased gradually from 10.00 h to 20.00 h, while prolactin mRNA levels slightly decreased until 14.00 h but increased later until 20.00 h. During the rat estrous cycle, especially in the afternoon of the proestrous day, changes of prolactin mRNA levels seem to follow a prior increase of Pit-1 mRNA. Therefore, Pit-1 may be partly involved in the regulation of prolactin gene expression according to the rat estrous cycle. Estradiol administration to ovariectomized rats significantly increased both the mRNA levels of prolactin and Pit-1, which suggests that the gene expression of Pit-1 is regulated by estrogen through indirect extracellular pathways.
Animals↗
Recovery of Pseudoterranova decipiens (Anisakidae) larvae from codfish of the Antarctic Ocean.
Anisakid larvae were found from the liver and stomach of the codfish (Notothenia neglecta) caught from the Antarctic Ocean, South Pole, where the Polar Research Center of The Korea Ocean Research and Development Institute is operating. Through observations by scanning electron (SEM) and light microscopy (LM), they were identified as the third stage larvae of Pseudoterranova decipiens, a potential agent of human codworm anisakiasis. They measured 25.0-28.5 mm in length, and 0.6-0.8 mm in width. The SEM revealed a prominent boring tooth, three lips, and excretory pore at the anterior end, and a small but prominent mucron at the posterior end. From whole mounts and cross sections of the larvae the ventriculus, intestinal cecum and a Renette cell were found characteristically at the same plane. Raw eating of the codfish caught from the Antarctic Ocean near the South Pole should be avoided so as to prevent human codworm anisakiasis in this area.
Animals↗
Effects of endoscopic variceal ligation in lower esophageal motor function: a prospective study.
OBJECTIVES: Endoscopic variceal ligation (EVL), a recently developed method for controlling active variceal bleeding and eradicating esophageal varices, has similar efficacy to endoscopic injection sclerotherapy (EIS) and is known to have a minimal risk of complications and fewer complications in the lower esophagus. However, since the site of EVL is chiefly done in the lower esophagus, we prospectively evaluated to investigate the effect of EVL on the lower esophageal motor function. METHODS: We evaluated the severity of esophageal varix with the endoscopy and the lower esophageal manometry in 27 patients who had no history of interventional therapy, for varices before EVL, 3 weeks and 6 months after the last EVL session. RESULTS: The EVL caused considerable diminution in the size of esophageal varix by a mean 8.2 (range 3-21) ligations in mean 1.7 (range 1-3) sessions. In most of the cases, the varices reappeared and enlarged when the procedure of EVL was stopped. There were two different types of changes (intermediate and late) in the lower esophageal motility. The intermediate post-EVL effects were the increase of peristaltic contraction amplitude and duration in the lower esophageal body after EVL. The late post-EVL effects were the prolongation of lower esophageal sphinctor (LES) relaxation duration and speedier peristaltic velocity in the lower esophageal body. CONCLUSIONS: We conclude from these findings that the intermediate post-EVL effect may be transient and the increase of peristaltic wave was due to diminution of esophageal varix.
Adult↗
Variability of in vivo recovery of factor IX after infusion of monoclonal antibody purified factor IX concentrates in patients with hemophilia B. The Mononine Study Group.
Monoclonal antibody purified factor IX concentrate, Mononine (Armour Pharmaceutical Company, Kankakee, Illinois, USA), is a recently developed replacement factor concentrate for the treatment of patients with hemophilia B. The pharmacokinetic properties of monoclonal antibody purified factor IX concentrate (MAb Factor IX concentrate) have been evaluated in only small samples of patients, and little is known about those factors that might influenced in vivo recovery of factor IX after infusion is a larger patient population. In vivo recovery of factor IX was therefore evaluated for 80 different indications in 72 patients who received MAb Factor IX concentrate for the management of spontaneous or trauma-induced bleeding, or as prophylaxis with surgery. The average recovery after infusions for presurgical pharmacokinetic analysis (mean +/- standard deviation) was 1.28 +/- 0.56 U/dl rise per U/kg infused (range 0.41-2.80), and the average recovery after all infusions for treatment was 1.23 +/- 0.49 U/dl rise per U/kg infused (range - 0.35-2.92). Recovery values for multiple MAb Factor IX doses in a given patient were also variable; the average recovery was 1.22 +/- 0.53 U/dl rise per U/kg given, and standard deviations ranged from 0.03 to 1.26. Patient age, weight, and MAb Factor IX concentrate dose minimally but significantly influenced factor IX recovery. There was no significant effect of either race, history of previous thrombotic complications during treatment with other replacement factor concentrates, or bleeding state on recovery. All of the patients treated with this preparation experienced excellent hemostasis, and no thrombotic complications were observed.
Adolescent↗
Erythrocytapheresis therapy to reduce iron overload in chronically transfused patients with sickle cell disease.
Chelation therapy with deferoxamine is effective in preventing the risk of transfusional iron overload, but treatment failure is common because of noncompliance. To reduce the transfusional iron load, we have evaluated longterm erythrocytapheresis in 14 subjects with sickle cell disease and stroke (11) or other complications (3) as an alternative to simple transfusion. Subjects were treated with erythrocytapheresis using the Haemonetics V50 (Haemonetics Corp, Braintree, MA) to maintain the target pretransfusion hemoglobin S (Hb S) level less than 50% for 6 to 71 months. The transfusional iron load and the donor blood usage were analyzed for a 6- to 36-month study period and were compared with similar data from a subset of 7 subjects previously treated with conventional (target Hb S < 30%) and modified (target Hb S < 50%) simple transfusion protocols. The effect of erythrocytapheresis on iron accumulation was determined by assessment of serum ferritin levels in the absence of iron chelation. The mean transfusional iron load and donor blood usage with erythrocytapheresis were 19 +/- 14 mg iron/kg/yr (range, 6 to 50) and 188.4 +/- 55.2 mL packed-red blood cells (RBC)/kg/yr (range, 107 to 281), respectively. Of 6 subjects receiving no iron chelation therapy, 5 maintained normal or nearly normal serum ferritin levels during 11 to 36 months of erythrocytapheresis. In comparison with conventional simple transfusion and modified simple transfusion, erythrocytapheresis reduced iron loading by 87% (P < .01) and 82% (P < .01), respectively, but increased donor blood usage by 23% and 73%, respectively. Subjects with pre-erythrocytapheresis Hb levels > or = 8.0 g/dL had lower iron accumulation (P < .001) and less donor blood usage (P < .005) than subjects with Hb levels < or = 8.0 g/dL. Although donor blood usage is increased in comparison with simple transfusion, long-term erythrocytapheresis markedly reduces or prevents iron accumulation. This form of transfusion therapy allows the cessation of iron chelation in well-chelated subjects and, if used as the initial form of transfusion therapy, may prevent long-term complications of sickle cell disease without risk of iron overload and the need for chelation therapy.
Adolescent↗
Autoimmune hemolytic anemia in chronic mucocutaneous candidiasis.
Chronic mucocutaneous candidiasis is an immunodeficiency disease characterized by T-cell dysregulation and chronic superficial candidal infections. We report on three patients with chronic mucocutaneous candidiasis who developed autoantibodies to erythrocytes. Our first patient, a 19-year-old female, developed autoimmune hemolytic anemia (AIHA) that required multiple courses of treatment, including corticosteroids, intravenous immunoglobulin, and danazol. During the last exacerbation of AIHA, intensive treatment with corticosteroids and intravenous immunoglobulin failed and yet the patient responded to plasmapheresis. Our second patient, a 21-year-old male, developed AIHA which responded to oral corticosteroid therapy. Our third patient, a 6-year-old female without evidence of hemolysis, was found to have erythrocyte autoantibodies on routine screening. These three patients had positive direct antiglobulin tests, and the first patient had both immunoglobulin G (IgG) and IgM erythrocyte autoantibodies, while the remaining two patients had only IgG autoantibody. This is the first report of the association of AIHA with chronic mucocutaneous candidiasis. We suggest that all patients with chronic mucocutaneous candidiasis be screened periodically for erythrocyte autoantibodies. Plasmapheresis, a safe ancillary procedure in the management of AIHA, may be life-saving in some cases. The occurrence of erythrocyte autoantibodies in mucocutaneous candidiasis may be related to immunoregulatory disorders in this disease.
Adolescent↗