Biomedical subjects

C Kim

Publications and source records attributed to C Kim.

At least 37 records · Page 2Linked to original sources

PubMed2005

Efficacy of electrolyzed water in the prevention and removal of fecal material attachment and its microbicidal effectiveness during simulated industrial poultry processing.

This study was undertaken to investigate the efficacy of alkaline and acidic electrolyzed (EO) water in preventing and removing fecal contaminants and killing Campylobacter jejuni on poultry carcasses under simulated industrial processing conditions. New York dressed and defeathered chicken carcasses spot-inoculated with cecal material or C. jejuni were subjected to spraying treatment with alkaline EO or 10% trisodium phosphate (TSP) water or combinations of spraying and immersion treatments with acidic EO and chlorinated water, respectively. Prespraying chicken carcasses with alkaline EO water significantly lowered cecal material attachment scores (3.77) than tap water (4.07) and 10% TSP (4.08) upon treatment of the dorsal area. Combinations of pre- and postspraying were significantly more effective than postspraying only, especially when using alkaline EO water in removing fecal materials on the surface of chicken carcasses. Although treatment by immersion only in EO and chlorinated water significantly reduced the initial population (4.92 log10 cfu/g) of C. jejuni by 2.33 and 2.05 log10 cfu/g, respectively, combinations of spraying and immersion treatment did not improve the bactericidal effect of sanitizers. The results indicated that alkaline EO water might provide an alternative to TSP in preventing attachment and removal of feces on the surface of chicken carcasses. The results also suggested that chicken carcasses containing pathogenic microorganisms may contribute to the cross-contamination of whole batches of chickens during processing in the chiller tank and afterward.

Animals↗

PubMed2005

Molecular screening for microdeletions at 9p22-p24 and 11q23-q24 in a large cohort of patients with trigonocephaly.

Trigonocephaly is a rare form of craniosynostosis characterized by the premature closure of the metopic suture. To contribute to a better understanding of the genetic basis of metopic synostosis and in an attempt to restrict the candidate regions related to metopic suture fusion, we studied 76 unrelated patients with syndromic and non-syndromic trigonocephaly. We found a larger proportion of syndromic cases in our population and the ratio of affected male to female was 1.8 : 1 and 5 : 1 in the non-syndromic and syndromic groups, respectively. A microdeletion screening at 9p22-p24 and 11q23-q24 was carried out for all patients and deletions in seven of them were detected, corresponding to 19.4% of all syndromic cases. Deletions were not found in non-syndromic patients. We suggest that a molecular screening for microdeletions at 9p22-p24 and 11q23-q24 should be offered to all syndromic cases with an apparently normal karyotype because it can potentially elucidate the cause of trigonocephaly in this subset of patients. We also suggest that genes on the X-chromosome play a major role in syndromic trigonocephaly.

Child↗

PubMed2004

Effects of an intracellular Ca(2+) chelator on insulin resistance and hypertension in high-fat-fed rats and spontaneously hypertensive rats.

We explored the possibility that a sustained elevation of intracellular Ca(2+) concentration ([Ca(2+)](i)) may be a cellular abnormality common to both insulin resistance and hypertension. In high-fat diet (HFD) fed rats, the steady-state glucose infusion rate (GIR) during the euglycemic hyperinsulinemic clamp was reduced by 40% (P <.05) and mean arterial pressure (MAP) was elevated by 20 mm Hg (P <.01) in comparison to the normal chow-fed rats. Intravenous injection of 5,5'-dimethyl derivative of bis(o-aminophenoxy)ethane-N,N,N',N' tetraacetic acetoxymethyl ester (dimethyl-BAPTA/AM), an effective intracellular Ca(2+) chelator, 90 minutes before the clamp not only restored about 50% of the reduced GIR, but also normalized MAP in the HFD rats. The chelator injection also significantly increased GIR by 25% (P <.01) and reduced MAP about 30 mm Hg (P <.01) in the spontaneously hypertensive rats (SHR). In addition, we have recently shown in the HFD rats that an injection of dimethyl-BAPTA/AM normalizes elevated [Ca(2+)](i) in adipocytes. These results together demonstrate that lowering [Ca(2+)](i) simultaneously ameliorates both insulin resistance and hypertension and provide presumptive evidence that sustained high levels of [Ca(2+)](i) may play a common pathophysiologic role in these 2 diseases.

Animals↗

PubMed2004

Induction of growth hormone release by Pueraria thunbergiana BENTH.

Puerariae Radix (PR), Puerariae Flos (PF), and Puerariae Surculus (PS) as well as their constituents were tested for induction of rat growth hormone (rGH) release by both rat pituitary cell culture and in vivo experimentation in order to develop them to novel drugs. Through a calibration curve of the rGH released by addition of rat growth hormone-releasing hormone (rGHRH) to rat pituitary cells, the 70 % ethanol extracts of PR and PS increased rGH release by about 1.6 and 1.7 times as high, respectively, as the control group (264.6 +/- 13.6 pM). However, each puerarin type as a representative constituent of PR in Korea Pharmacopeia (KP) and tectorigenin and an important ingredient of PF were twice as effective as in the control group. The acid hydrolysate of Puerariae Surculus (HPS) increased rGH release concentration-dependently, and its EC (50) was approximately 10.4 microg/ml. The T (max) value for rGH after injection of 20 microg/kg of rGHRH was 10 - 30 min, while the C (max) value was increased by approximately 12-fold compared to the control group (198.2 +/- 25.0 pM) and the AUC (0 - 45) was increased to 10 times the level of the control group (10,840.9 +/- 845.5 min. pM). On the other hand, T (max) for the HPS was 60 min, while C (max) was increased approximately to 5.8 fold compared to control (244.1 +/- 36.4 pM). C (max) for puerarin was 1,028.6 +/- 502.7 pM, that is, approximately 5.2 times as high as the control level. However, tectorigenin (20 microg/kg) was of no statistical significance. Therefore, we suggest that the HPS and puerarin act either on GH secretagogue receptors or on GHRH receptor of somatotrophin as possible agonists or an inhibitor on somatostatin receptor to release rGH, respectively.

Animals↗

PubMed2004

Nifedipine encapsulated core-shell type nanoparticles based on poly(gamma-benzyl L-glutamate)/poly(ethylene glycol) diblock copolymers.

The diblock copolymers based on PBLG and PEO (GE) were synthesized and characterized. Nanoparticles showed spherical shape from the observations of TEM and approved core-shell structure. Drug contents were increased with use of higher initial drug concentration and higher Mw of GE. Nifedipine (NFD) release rate was slower in longer PBLG chain length and higher NFD contents than short PBLG chain length and lower drug contents of NFD due to the hydrophobic interaction between PBLG domain and NFD.

Calcium Channel Blockers↗

PubMed2004

Role of individual predisposition in orthostatic intolerance before and after simulated microgravity.

Orthostatic intolerance (OI) is a major problem after spaceflight. Its etiology remains uncertain, but reports have pointed toward an individual susceptibility to OI. We hypothesized that individual predisposition plays an important role in post-bed rest OI. Twenty-four healthy male subjects were equilibrated on a constant diet, after which they underwent tilt-stand test (pre-TST). They then completed 14-16 days of head-down-tilt bed rest, and 14 of the subjects underwent repeat tilt-stand test (post-TST). During various phases, the following were performed: 24-h urine collections and hormonal measurements, plethysmography, and cardiovascular system identification (a noninvasive method to assess autonomic function and separately quantify parasympathetic and sympathetic responsiveness). Development of presyncope or syncope defined OI. During pre-TST, 11 subjects were intolerant and 13 were tolerant. At baseline, intolerant subjects had lower serum aldosterone (P < 0.01), higher excretion of potassium (P = 0.01), lower leg venous compliance (P = 0.03), higher supine parasympathetic responsiveness (P = 0.02), and lower standing sympathetic responsiveness (P = 0.048). Of the 14 subjects who completed post-TST, 9 were intolerant and 5 were tolerant. Intolerant subjects had lower baseline serum cortisol (P = 0.03) and a higher sodium level (P = 0.02) compared with tolerant subjects. Thus several physiological characteristics were associated with increased susceptibility to OI. We propose a new model for OI, whereby individuals with greater leg venous compliance recruit compensatory mechanisms (activation of the renin-angiotensin-aldosterone system and sympathetic nervous system, and withdrawal of the parasympathetic nervous system) in the face of daily postural challenges, which places them at an advantage to face orthostatic stress. With head-down-tilt bed rest, the stimulus to recruit compensatory mechanisms disappears, and differences between the two subgroups attenuate.

Adaptation, Physiological↗

PubMed2004

Role and regulation of interleukin-1 molecules in pro-asthmatic sensitised airway smooth muscle.

Interleukin (IL)-1beta is a pleiotropic, pro-inflammatory cytokine that has been importantly implicated in driving the inflammatory response and resultant changes in airway smooth muscle (ASM) responsiveness in asthma. IL-1beta belongs to a family of molecules, known as the IL-1 axis, which exert both pro- and anti-inflammatory effects. Since dysregulation of IL-1 axis molecules may be critical in the pathobiology of asthma, the present study examined the expression and activation of both the inhibitory and stimulatory IL-1 axis molecules in human ASM cells and their roles in modulating cytokine and immunoglobulin (Ig)E immune complex (IgE cx)-mediated changes in rabbit ASM constrictor and relaxant responsiveness. The results demonstrate the following. 1) Pre-treatment of isolated rabbit tracheal rings with the inhibitory IL-1 axis members, IL-1 receptor antagonist and IL-1 type-II receptor abrogated both IL-5- and IgE cx-induced changes in ASM responsiveness. 2) Administration of IL-5, IL-1beta and IgE cxs to human ASM cells increased mRNA and protein expressions of both stimulatory and inhibitory IL-1 axis molecules. 3) The time course of IL-5-induced IL-1 axis molecule expression preceded that of both IL-1beta and IgE immune cxs. Collectively, these findings suggest that modulation at the level of the interleukin-1 axis of molecules may have significant therapeutic potential in the treatment of asthma.

Animals↗

PubMed2003

An increased estimate of the merger rate of double neutron stars from observations of a highly relativistic system.

The merger of close binary systems containing two neutron stars should produce a burst of gravitational waves, as predicted by the theory of general relativity. A reliable estimate of the double-neutron-star merger rate in the Galaxy is crucial in order to predict whether current gravity wave detectors will be successful in detecting such bursts. Present estimates of this rate are rather low, because we know of only a few double-neutron-star binaries with merger times less than the age of the Universe. Here we report the discovery of a 22-ms pulsar, PSR J0737-3039, which is a member of a highly relativistic double-neutron-star binary with an orbital period of 2.4 hours. This system will merge in about 85 Myr, a time much shorter than for any other known neutron-star binary. Together with the relatively low radio luminosity of PSR J0737-3039, this timescale implies an order-of-magnitude increase in the predicted merger rate for double-neutron-star systems in our Galaxy (and in the rest of the Universe).

Journal Article↗

PubMed2003

Patterns of co-morbidity in male suicide completers.

BACKGROUND: Psychiatric co-morbidity is thought to be an important problem in suicide, but it has been little investigated. This study aims to investigate patterns of co-morbidity in a group of male suicide completers. METHOD: One hundred and fifteen male suicide completers from the Greater Montreal Area and 82 matched community controls were assessed using proxy-based diagnostic interviews. Patterns of co-morbidity were investigated using latent class analysis. RESULTS: Three subgroups of male suicide completers were identified (L2 = 171.62, df = 2012, P < 0.05). they differed significantly in the amount of co-morbidity (Kruskal-Wallis chi2 = 71.227, df = 2. P < 0.000) and exhibited different diagnostic profiles. Co-morbidity was particularly found in subjects with disorders characterized by impulsive and impulsive-aggressive traits, whereas subjects without those traits had levels of co-morbidity which were not significantly different from those of controls (chi2 = 8.17, df = 4, P = 0.086). CONCLUSIONS: Suicide completers can be divided into at least three subgroups according to co-morbidity: a low co-morbidity group, a substance-dependent group and a group exhibiting childhood onset of psychopathology.

Adult↗

PubMed2003

Milrinone improves lung compliance in patients receiving mechanical ventilation for cardiogenic pulmonary edema.

BACKGROUND: Cardiogenic pulmonary edema is a frequent cause of respiratory failure. We investigated whether milrinone improved lung compliance. METHODS: We selected 10 patients with respiratory failure due to severe cardiogenic pulmonary edema to receive mechanical ventilation. Patients were administered a bolus injection of milrinone (50 microg kg-1) over 10 min, followed by continuous intravenous infusion (0.5 microg kg-1 min-1). Lung compliance, blood gas values, hemodynamic parameters, and sample plasma milrinone levels were assessed over 120 min after the onset of the continuous infusion of milrinone. RESULTS: Ten min following milrinone infusion, dynamic compliance (Cdyn) and static compliance (Cst) increased from 37 +/- 12 to 42 +/- 12 ml cmH2O-1 and from 40 +/- 13 to 45 +/- 12 ml cmH2O-1, respectively (P < 0.01). Plasma milrinone levels reached a therapeutic level for vasodilator and positive inotropic effect at 10 min after milrinone infusion. A significant decrease in mean pulmonary artery pressure and pulmonary artery wedge pressure occurred simultaneously with an increase in respiratory system compliance. However, an increase in cardiac index was observed later than these changes. There were significant correlations between the mean pulmonary artery pressure and Cdyn (r = -0.39, P < 0.01) and Cst (r = -0.38, P < 0.01). CONCLUSIONS: Milrinone-induced improvement in lung compliance along with an improvement of hemodynamics was found together with an inverse relationship between compliance and mean pulmonary artery pressure.

Aged↗

PubMed2003

Muscle fibre size and capillarity in Korean diving women.

AIM: Effects of prolonged habitual cold-water immersion on fibre size and capillarity in vastus lateralis muscle were studied in human beings. The hypothesis tested in the present study was that cold acclimatized human skeletal muscle would have reduced muscle fibre size and higher capillarity, favouring the idea of efficacy of recruitment under cold environment. METHODS: Ten women breath-hold divers (BHDs) and 10 active women (controls CONs) participated in this study. Muscle biopsy was obtained from vastus lateralis and determined fibre type composition and capillary density. RESULTS: A major finding was that all BHDs revealed a markedly smaller cross-sectional area (CSA) in all fibre types than the CONs, or even than any other morphological data reported in previous investigations. Furthermore, mean CSA of type II fibre (range 1205-2766 microm2) was much smaller than type I fibre (2343-4327 microm2). The number of capillaries per fibre in different fibre types in the BHDs was higher than in the CONs (P < 0.001), and diffusional area was smaller in type II fibres than in type I fibres (P < 0.001). The BHDs and the CONs have similarity in the percentage of type I fibres, but type II fibre was predominant in both groups. Interestingly the proportion of type IIx fibre in the BHDs was higher (31%) than in the CONs (22%). No significant difference was found in the thigh circumference between the groups. CONCLUSION: The present study demonstrates that prolonged habitual cold-water immersion may induce a decrease in fibre size and an increase in capillarity in human skeletal muscle.

Adipose Tissue↗

PubMed2003

Clinical experience of e-PTFE membrane implant surgery for refractory glaucoma.

AIMS: To evaluate the clinical efficacy of membrane tube implant made of expanded polytetrafluoroethylene (e-PTFE, Gore-Tex) membrane and silicone tube in treating refractory glaucoma. METHODS: A retrospective chart review was performed on 43 eyes of 40 patients who underwent glaucoma tube shunt implant surgery using double layered e-PTFE membrane and silicone tube to treat refractory glaucoma. The surgeries were performed from May 1991 to September 1995, and the subjects were patients with terminal glaucoma without useful vision on the study eye. RESULTS: The mean follow up period was 32.9 months. The Kaplan-Meier survival for intraocular pressure (IOP) control (IOP between 6 and 21mm Hg without significant complication) was 80.9% at 1 year, 73.9% at 2 years, and 62.2% at 3 years after surgery. After excluding three eyes of three patients who were dropped within 3 months after surgery and did not have any serious complication or problem in IOP control, the average preoperative IOP was 42.5 (SD 14.6) mm Hg and IOP on the last visit was 17.3 (10.2) mm Hg (p = 0.000, n = 40). The number of antiglaucoma medications before surgery (2.2 (0.6)) was reduced to 0.5 (0.8) on the last visit (p = 0.000). The IOP was controlled within the range of 6-21 mm Hg in 26 eyes (65.0%). In the remaining 14 eyes (35%), we could not control the IOP or additional surgery was needed to control the IOP or to treat severe complications. Two cases of endophthalmitis and three of phthisis were found as serious complications. The other complications were similar to those of other commercially available glaucoma implants. CONCLUSION: A comparable clinical result was obtained with this new implant as with the other commercially available implants. This implant with a thin and non-rigid reservoir has a potential to reduce some complications associated with the large volume and rigid consistency of the other implants, although it is not yet proved. This membrane tube implant may be considered as another substitute in the surgery of refractory glaucoma.

Adult↗

PubMed2003

Functional impact of lymphangiogenesis on fluid transport after lymph node excision.

When a lymph node is excised, lymphangiogenesis occurs to maintain flow in the affected area. However, a complex network of small vessels replaces the node and these newly formed vessels might increase resistance to lymph transport. To test this in sheep, the popliteal lymph node from one hind limb was removed surgically. The contralateral node was left intact. After 4 to 6 weeks (a period that allowed regenerated vessels to restore flow), a prenodal lymphatic vessel in each limb was cannulated with a polyethylene catheter to permit saline infusion into the node or lymphatic regeneration site. Infusion pressures were monitored from t-pieces inserted between the infusion pump and the point of entry of the catheters in the prenodal ducts. We observed that the flow rate versus perfusion pressure relationships were significantly different in the 2 experimental preparations (node intact limbs, n = 13; node excised limbs, n = 10). In the limbs undergoing lymphangiogenesis, much higher infusion pressures were required to generate a given flow rate. Additionally, the regenerated lymphatic network provided a significantly increased resistance to flow. The data suggested that lymphangiogenesis restored fluid continuity to some extent in the area occupied originally by the popliteal lymph node. However, the transport properties exhibited by the newly formed lymphatics were insufficient to restore flow parameters to their original state.

Animals↗

PubMed2002

Doping dependence of an n-type cuprate superconductor investigated by angle-resolved photoemission spectroscopy.

We present an angle-resolved photoemission doping dependence study of the n-type cuprate superconductor Nd(2-x)Ce(x)CuO(4+/-delta), from the half-filled Mott insulator to the T(c) = 24 K superconductor. In Nd2CuO4, we reveal the charge-transfer band for the first time. As electrons are doped into the system, this feature's intensity decreases with the concomitant formation of near- E(F) spectral weight. At low doping, the Fermi surface is an electron-pocket (with volume approximately x) centered at (pi,0). Further doping leads to the creation of a new holelike Fermi surface (volume approximately 1+x) centered at (pi,pi). These findings shed light on the Mott gap, its doping evolution, as well as the anomalous transport properties of the n-type cuprates.

Journal Article↗

PubMed2002

Electronic structure of the trilayer cuprate superconductor Bi(2)Sr(2)Ca(2)Cu(3)O(10+delta).

The low-energy electronic structure of the nearly optimally doped trilayer cuprate superconductor Bi(2)Sr(2)Ca(2)Cu(3)O(10+delta) is investigated by angle-resolved photoemission spectroscopy. The normal state quasiparticle dispersion and Fermi surface and the superconducting d-wave gap and coherence peak are observed and compared with those of single- and bilayer systems. We find that both the superconducting gap magnitude and the relative coherence-peak intensity scale linearly with T(c) for various optimally doped materials.

Journal Article↗

PubMed2002

Free radical scavenging effect of Diospyros kaki, Laminaria japonica and Undaria pinnatifida.

Diospyros kaki folium, Laminaria japonica thallus and Undaria pinnatifida thallus have been used traditionally in Korea to promote maternal health. The scavenging activity against DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals of the methanol extracts of these plants were investigated. The extract of D. kaki was found to be the most potent, with an IC(50) value of 0.11 mg/ml.

Biphenyl Compounds↗

PubMed2002

Atracurium and vecuronium block nicotine-induced carotid body chemoreceptor responses.

BACKGROUND: Vecuronium depresses carotid body chemosensitivity during hypoxia. We hypothesized that this is caused by inhibition of cholinergic transmission of the carotid body. METHODS: The carotid body with its sinus nerve was removed en bloc from thiopentone-anaesthetized adult male New Zealand rabbits and perfused in vitro with modified Tyrodes buffer solution at constant perfusion pressure, temperature, a buffer pH of 7.4 and normocapnia. Chemoreceptor discharge and spike frequencies (fx) were recorded from the whole sinus nerve after administration of 500 microg nicotine, given as duplicated controls and thereafter following 30 min perfusion of equipotent concentrations of atracurium (28.1 microM) or vecuronium(10 microM), after 30 min of neostigmine perfusion (9.2 microM) and finally after 30 min wash-out with buffer solution only. A short-lasting hypoxic test was performed before and at the end of the experimental period to confirm the responsiveness and validity of the preparation. RESULTS: Atracurium (n = 7) and vecuronium (n = 6) reduced chemoreceptor responses to nicotine by 70 +/- 30% and 66 +/- 19% (SEM) (P<0.05). Chemoreceptor discharges showed full recovery after neostigmine in the atracurium group and partial recovery in the vecuronium group (P<0.05). Finally, after wash-out the chemoreceptor responses to nicotine had fully recovered in both groups. CONCLUSION: Atracurium and vecuronium in equipotent concentrations block nicotine-induced chemoreceptor responses of the carotid body.

Animals↗

PubMed2002

Cerebrospinal fluid outflow resistance in sheep: impact of blocking cerebrospinal fluid transport through the cribriform plate.

Recent studies in sheep suggest that a significant proportion of global cerebrospinal fluid (CSF) drainage (50% or greater) occurs through the cribriform plate into nasal mucosal lymphatics. If this is true, obstructing CSF clearance through the cribriform plate should have an impact on the ability of the intracranial pressure regulating systems to compensate for volume infusions. To test this concept, bolus infusions of artificial CSF were administered into one lateral ventricle in sheep and the intracranial pressure monitored from the contralateral side. Peak intracranial pressures (ICP) were measured and CSF outflow resistances were calculated from the pressure patterns observed in response to bolus infusions administered before and after the cribriform plate was sealed in the same animal. To obstruct the cribriform plate, a portion of nasal bone was removed to expose the nasal mucosa. The olfactory mucosa, a portion of the nasal mucosa and all soft tissue on the extracranial surface of the cribriform plate were scraped away with a curette and the bone surface sealed with bone wax. Obstruction of CSF transport through the cribriform plate increased the peak ICP after infusion (P = 0.016) and augmented the time required for ICP to return to baseline. CSF outflow resistance was elevated approximately 2.7 times (P = 0.006). When the cribriform plate was left intact (sham surgery), no significant changes in peak ICP or CSF outflow resistance were observed. We conclude that the cribriform plate represents an important site for CSF clearance. Obstruction of this pathway reduces volumetric CSF transport significantly.

Animals↗