Search PubMed⌕ Search

Biomedical subjects

M Kang

Publications and source records attributed to M Kang.

At least 19 recordsLinked to original sources
PubMed2006

Effects of a combined alendronate and calcitriol agent (Maxmarvil) on bone metabolism in Korean postmenopausal women: a multicenter, double-blind, randomized, placebo-controlled study.

INTRODUCTION: A randomized, double-blind, prospective, 24-week clinical trial was performed to evaluate the effects of a combinative agent, Maxmarvil, of calcitriol (0.5 mug) and alendronate (5 mg) on bone metabolism in postmenopausal women. METHODS: A total of 217 postmenopausal women with osteoporosis were enrolled; 199 patients were randomly assigned to one of two treatment groups (Maxmarvil group or alfacalcidol group). None of the patients were vitamin-D-deficient, as assessed by serum 25-hydroxyvitamin D (25(OH)D), nor had they received any drugs affecting bone metabolism before enrollment. Bone mineral densities (BMD) of L1-L4 and the femur were measured by dual-energy X-ray absorptiometry (DXA) at the initial assessment and after 6 months of treatment. Serum biochemical assays, including serum calcium, 24-h urinary calcium excretion, and bone turnover markers (both bone-specific alkaline phosphatase [bsALP] and urine N-telopeptide [NTx]), were performed at the baseline and after 3 and 6 months of treatment. RESULTS: In the Maxmarvil group, the BMD of the lumbar spine increased up to 2.42+/-0.5% from the baseline after 6 months (p<0.05). On the other hand, the change in BMD in the alfacalcidol group was 0.28+/-0.5% after 6 months. There was no significant difference in femoral BMD between the two groups. The levels of bsALP and NTx were significantly lower in the Maxmarvil group than in the alfacalcidol group (-22.04+/-3.9% vs. -11.42+/-2.8% [p<0.05] and -25.46+/-5.2% vs. 1.24+/-6.2% [p<0.001], respectively). Interestingly, there was a significantly smaller amount of 24-h urinary calcium in the Maxmarvil group (p<0.05). CONCLUSIONS: Our study demonstrates that a combination of calcitriol and alendronate is quite effective in preventing bone loss, with the advantage of lesser hypercalciuric effect of calcitriol in the postmenopausal osteoporotic women.

Alendronate↗
PubMed2006

Liver abscess associated with hepatic artery pseudoaneurysm with arteriovenous fistula: imaging and interventional management.

Hepatic artery pseudoaneurysm is an infrequently encountered entity that is usually seen secondary to trauma or surgical procedures. The clinical presentation is often due to complications such as massive intrahepatic or intraperitoneal bleeding as a result of rupture of the pseudoaneurysm into the biliary tree or peritoneal cavity, respectively. Hepatic artery pseudoaneurysm, associated with a liver abscess, has very rarely been described in the literature. We present the imaging features of a case of liver abscess associated with a hepatic artery pseudoaneurysm and complicated by rupture and formation of an arteriovenous fistula. The case was successfully managed by percutaneous endovascular embolization. The association between a hepatic artery pseudoaneurysm and a liver abscess must not be overlooked, bearing in mind the potentially fatal associated complications which can be averted or treated by timely intervention.

Aneurysm, False↗
PubMed2005

Rosai-Dorfman disease: unusual cause of diffuse and massive retroperitoneal lymphadenopathy.

Rosai-Dorfman disease (RDD), originally described as sinus histiocytosis with massive lymphadenopathy, is a rare histiocytic proliferative disorder with a distinctive microscopic appearance. Patients usually present with massive cervical lymphadenopathy. However other nodal sites (mediastinal and inguinal) are also frequently involved. The retro-peritoneum is an infrequent site of involvement. This uncommon entity should also be included in the list of differential diagnoses of diffuse and massive lymphadenopathy, which includes includes infectious/granulomatous conditions, lymphomatous and metastatic disease.

Adult↗
PubMed2004

A novel synthetic method for nanosized crystalline titania for use in the decomposition of dyes.

Photocatalytically active nanocrystalline titania particles were prepared using a hydrothermal process, by controlling the particle size and crystallinity. The crystalline structures and morphologies of the particles were characterized by X-ray diffraction and transmission electron microscopy. The BET method was used to determine the surface area and verify the grain size. To estimate the photocatalytic activity of the synthesized particles, a dye photodegradation experiment was carried out and the activity of the particles was compared with that of conventional titania. The results show that synthesized nanocrystalline titania particles had a higher photocatalytic activity than that of conventional titania. These findings provide a basis for the preparation of more effective and usef ul materials for use in AOP applications.

Catalysis↗
PubMed2003

Health and access issues among Australian adolescents: a rural-urban comparison.

INTRODUCTION: Previous research has reported rural-urban differences in health concerns and access issues. However, very little of this has concerned young people, and what has been published has been mainly from countries other than Australia and may not generalise to Australian youth. The study described in this paper is a subset of a larger study on health concerns and access to healthcare for younger people (12-17 years) living in New South Wales (NSW), Australia. This paper reports findings on rural-urban similarities and differences. The specific study objective was to identify and describe rural-urban differences, especially those associated with structural disadvantage. METHOD: The reported findings form part of a larger state-wide cross-sectional study of access to healthcare among NSW adolescents. Adolescents were drawn from high schools in ten of the 17 Area Health Services in NSW. These Area Health Services were selected because they represent most aspects of rural-urban NSW with respect to population characteristics and health services. Eighty-one focus groups were conducted with adolescents (35 with boys and 46 with girls), of which 56 were conducted in urban, 22 in rural and 3 in regional areas. The focus groups were tape-recorded, transcribed and analysed using the computer software package NUD*IST 4. RESULTS: The analysis revealed certain health concerns that were common to both rural and urban adolescents: use of alcohol and illicit drugs, bullying, street safety, diet and body image, sexual health, stress and depression. However, certain concerns were mentioned more frequently in rural areas (eg depression), and two concerns were raised almost exclusively by rural youth (youth suicide and teenage pregnancy). There were also structural differences in service provision: adolescents in rural areas reported disadvantage in obtaining access to healthcare (limited number of providers and lengthy waiting times); having only a limited choice of providers (eg only one female doctor available), and cost (virtually no bulk billing--ie direct charge to Medicare with no patient co-payment). A lack of confidentiality as a barrier to seeking service access was raised by both rural and urban youth, but was a major concern in rural areas. No issues specific to urban areas were raised by urban youth. Male and female rural adolescents were more likely than urban adolescents to express concerns over limited educational, employment and recreational opportunities, which they believed contributed to their risk-taking behaviour. Gender differences were evident for mental health issues, with boys less able to talk with their peers or service providers about stress and depression than girls. These gender differences were evident among adolescents in both rural and urban areas, but the ethos of a self-reliant male who does not ask for help was more evident among rural boys. CONCLUSIONS: While Australian rural and urban youth shared many health concerns, rural-urban differences were striking in the almost exclusive reporting of youth suicide and teenage pregnancy by rural adolescents. The findings suggest that structural disadvantage in rural areas (limited educational, employment opportunities, and recreational facilities) impact adversely on health outcomes, particularly mental health outcomes, and contribute to risk-taking behaviour. Such disadvantages should be considered by health-service policy makers and providers to redress the imbalance. Gender differences were also evident and efforts to target the specific needs of Australian adolescent boys are warranted.

Journal Article↗
PubMed2001

Ectopic expression of serotonin-positive neurons in the hypothalamus associated with a significant serotonin decrease in the midbrain of food restricted rats.

The effects of food restriction on the serotonergic system were investigated immunohistochemically in both the midbrain and hypothalamic regions of rats. Rats were fed on a restricted feeding schedule consisting of half of the ad libitum quantity for 1, 2, 4 and 6 weeks and a free feeding schedule for 1 week. The optical density of serotonin-positive neurons in the raphe nuclei of the midbrain was found to be significantly lower in the 1 week-food restricted group than in the ad libitum fed control. In the hypothalamus, serotonin-positive neurons were observed in the 1 and 2 week food restricted groups but not in the 4 and 6 week-food restricted groups. This finding was confirmed by immunohistochemistry with tryptophan hydroxylase, a serotonin synthesizing enzyme. In this study, we provide morphological evidence that food restriction has a significant effect on the serotonergic system of the midbrain and hypothalamic regions and suggest some possibilities for the ectopic expression of serotonin-positive neurons after food restriction.

Animals↗
PubMed2001

Electroacupuncture-related changes of NADPH-diaphorase and neuronal nitric oxide synthase in the brainstem of spontaneously hypertensive rats.

The aim of this study was to investigate the electroacupuncture-related changes of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) and neuronal nitric oxide synthase (nNOS) in the brainstem of spontaneously hypertensive rats (SHR). We evaluated the changes of NADPH-d-positive neurons using a histochemical method and the changes of nNOS-positive neurons using an immunohistochemical method. The staining intensities of NADPH-d-positive neurons and nNOS-positive neurons were assessed in a quantitative fashion using a microdensitometrical method based on optical density by means of an image analyzer. The optical density of NADPH-d-positive neurons and nNOS-positive neurons of the Shinsu (BL23) and Choksamni (ST36) electroacupuncture groups were significantly decreased in most brainstem areas as compared to the normal and arbitrary groups, with the exception of the optical density of NADPH-d positive neurons in the prepositus nucleus as compared to the arbitrary group. The present results demonstrated that electroacupuncture changes the activity in the NO system in the brainstem of SHR and the site where electroacupuncture is administered is of importance for this effect.

Animals↗
PubMed2001

Human immunodeficiency virus type 1 (HIV-1) gp120-specific antibodies in neonates receiving an HIV-1 recombinant gp120 vaccine.

Infants born to human immunodeficiency virus type 1 (HIV-1)-infected mothers were immunized at birth and at ages 4, 12, and 20 weeks with low-, medium-, or high-dose recombinant gp120 vaccine with MF59 adjuvant (HIV-1(SF-2); n=52) or with MF59 alone as a placebo (n=9). An accelerated schedule (birth and ages 2, 8, and 20 weeks) was used for an additional 10 infants receiving the defined optimal dose and for 3 infants receiving placebo. At 24 weeks, anti-gp120 ELISA titers were greater for vaccine-immunized than for placebo-immunized infants on both schedules, and 87% of vaccinees had a vaccine-induced antibody response. At 12 weeks, antibody titers of infants on the accelerated vaccine schedule exceeded those of infants receiving placebo (4949 vs. 551; P=.01), and 63% of the vaccinees met the response criteria. Thus, an accelerated schedule of gp120 vaccinations generated an antibody response to HIV-1 envelope distinct from transplacental maternal antibody by age 12 weeks. These results provide support for further studies of vaccine strategies to prevent mother-to-infant HIV-1 transmission.

AIDS Vaccines↗
PubMed2001

A Phase I study of infusional vinblastine in combination with the P-glycoprotein antagonist PSC 833 (valspodar).

BACKGROUND: PSC 833 is a second-generation P-glycoprotein (Pgp) antagonist developed to reverse multidrug resistance (MDR). The authors conducted a Phase I study of orally administered PSC 833 in combination with vinblastine administered as a 5-day continuous infusion. METHODS: Seventy-nine patients with advanced malignant disease were enrolled in the trial and treated with escalating doses of PSC 833. Pharmacokinetic interactions between PSC 833 and vinblastine were anticipated. Accordingly, when dose limiting toxicities were observed, the dose of vinblastine was reduced as PSC 833 was escalated. Three schedules and two formulations of PSC 833 were used in the study. RESULTS: The maximum tolerated doses of PSC 833 were 12.5 mg/kg orally every 12 hours for 8 days for the liquid formulation in combination with 0.9 mg/m(2) per day vinblastine as a continuous intravenous infusion (CIV) for 5 days; and 4 mg/kg orally every 6 hours for 8 days for the microemulsion formulation in combination with 0.6 mg/m(2) per day vinblastine CIV for 5 days. The principal toxicities for PSC 833 were ataxia and paresthesias and for the combination, constipation, fever. and neutropenia. Increased oral bioavailability and increased peak and trough concentrations were observed with the microemulsion formulation. Significant interpatient variability in pharmacokinetic parameters was observed. Ten patients studied at the MTD for PSC 833 (4 mg/kg orally every 6 hours for 8 days) had inhibition of rhodamine efflux from CD56 positive peripheral lymphocytes as a surrogate for Pgp antagonism. Among 43 evaluable patients with clear cell carcinoma of the kidney, 3 patients had complete responses, and 1 patient had a partial response. CONCLUSIONS: PSC 833 in combination with vinblastine can be administered safely to patients provided the vinblastine dose is adjusted for pharmacokinetic interactions. The high interpatient variability is a significant confounding factor. Surrogate studies with CD56 positive cells suggest that Pgp inhibition in the clinical setting is achievable. Improved methods for predicting pharmacokinetic interactions should improve future studies.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

Inhibition of neuronal nitric oxide synthase enhances cell proliferation in the dentate gyrus of the adrenalectomized rat.

Recent studies have demonstrated that the elimination of adrenal steroids by an adrenalectomy (ADX) increases the expression of neuronal nitric oxide synthase (NOS), and that it increases cell proliferation in the rat dentate gyrus. However, no evidence has been presented to date which indicates that NO regulates cell proliferation in the dentate gyrus of the adult rats. In this study, the effect of blocking NO production on ADX-induced increase of cell proliferation and serotonergic innervation was examined in the rat dentate gyrus. 7-nitroindazole (7-NI; 30 mg/kg, intraperitoneally), a selective inhibitor of neuronal NOS, was injected 1 day before an ADX and then once every 24 h for 4 days after the ADX subsequently. The proliferating cells were identified with 5-bromo-2-deoxyuridine (BrdU) immunostaining. Long-term inhibition of the neuronal NOS by 7-NI markedly increased the BrdU-labeled cell population density 4-18-fold in the dentate gyrus of the adrenalectomized rats compared to that in the vehicle-injected adrenalectomized rats. Immunoreactivity of serotonin, known as a mediator of granule cell genesis, was detected only in the dentate gyrus of 7-NI-injected adrenalectomized rats. These results indicate that NO may be involved in the cell proliferation in the dentate gyrus of the adrenalecomized rat and that serotonin may mediate the regulatory effect of NO on the cell proliferation in rat dentate gyrus.

Adrenal Cortex↗
PubMed2001

Atomic size effects in continuum modeling.

Continuum modeling of many physical systems typically assumes that the spatial extent of an atom is small compared to the quantities of interest and can therefore be neglected. We show that this is valid only asymptotically. For many applications of practical interest, the spatial extent of a discrete atom cannot be neglected. We have developed a model for the description of epitaxial growth based on the levelset method, and find that we can accurately predict quantities such as the island densities, if we implement boundary conditions in a region with atomic width, rather than just on a line without any spatial extent. Only in the limit of very large islands and island spacings can this be neglected.

Journal Article↗
PubMed2001

Nd1, a novel murine Kelch family protein, may play the role of a housekeeping gene.

The murine Nd1 gene encodes a novel Kelch family protein and expresses two forms of mRNA, long (Nd1-L) and short (Nd1-S), in various tissues. We characterized the genomic organization of the Nd1 gene, and found that Nd1-L and Nd1-S consist of 16 and nine exons respectively, and that exons I-VIII are shared between them. Three transcription initiation sites were identified in the 5'-flanking region and the most 3' side (+1) is likely to be a major one. Promoter analysis revealed that the region between positions -247 and -86 was sufficient for expression, and that two Sp1-binding sites and one NF-kappaB-binding site in the region were critical for promoter activity. Furthermore, the promoter region lacks a TATA and a CAAT box and has a highly GC-rich region with two important Sp1-binding sites. These characteristics of the Nd1 gene promoter are similar to the properties of housekeeping genes.

Amino Acid Sequence↗
PubMed2001

Observation of multiple magnetorotons in the fractional quantum Hall effect.

Magnetorotons in the dispersions of collective gap excitation modes of fractional quantum Hall liquids are measured in resonant inelastic light scattering experiments. Two deep magnetoroton minima are observed at nu = 2/5, while a single deep minimum is resolved at nu = 1/3. The observations are the first evidence of multiple roton minima in gap excitations of the quantum liquids. The results support Chern-Simons and composite fermion calculations that predict multiple roton minima for states with nu>1/3.

Journal Article↗
PubMed2001

Safety of 2 recombinant human immunodeficiency virus type 1 (HIV-1) envelope vaccines in neonates born to HIV-1-infected women.

To determine the safety of 2 candidate vaccines against human immunodeficiency virus type 1 (HIV-1), a randomized, placebo-controlled, multicenter trial compared low, medium, and high doses of the vaccines or an adjuvant among infants born to HIV-infected women. No local or systemic reactions of grade 2 or greater were reported 48 h after the subjects underwent immunization. Grade 3 or 4 chemistry toxicities occurred in 5 (3%) and grade 3 or 4 hematologic toxicities in 17 (11%) of 154 vaccinated subjects (not significantly different from 29 adjuvant recipients). CD4(+) cell percentages of < or = 20% occurred at least once in 9 vaccinated subjects and 1 control subject. Sustained CD4(+) cell percentages of < or = 20% occurred in 4 HIV-infected children. Fourteen infants (8%) were confirmed to be HIV-infected; median CD4(+) cell counts among these children were 2074, 1674, 1584, and 821 cells/mm(3) at birth and weeks 24, 52, and 104, respectively. Thus, both vaccines were safe and well tolerated in neonates, and there was no evidence of accelerated immunologic decline in HIV-infected infants.

AIDS Vaccines↗
PubMed2001

Differential changes in neuropeptide Y and nicotinamide adenine dinucleotide phosphate-diaphorase-positive neurons in rat hippocampus after kainic acid-induced seizure.

Changes in neuropeptide Y (NPY) and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d)-positive neurons in the hippocampus were investigated 5, 10 and 20 days after kainic acid (KA) administration using a double labeling method. The numbers of NADPH-d-positive-only and NPY/NADPH-d-positive neurons decreased in the CA1/2-CA3 regions of the hippocampus, 5, 10 and 20 days after KA administration, however, the number of NPY-positive-only neurons increased in the same regions 5 and 10 days after KA administration. In the dentate gyrus (DG) region of the hippocampus, the numbers of NPY-positive-only, NADPH-d-positive-only and NPY/NADPH-d-positive neurons increased 5 days after KA administration, and 20 days after KA administration, the number of NADPH-d-positive-only neurons decreased to levels similar to or lower than the level of the controls. However, the numbers of NPY/NADPH-d-positive and NPY-positive-only neurons in the DG region 20 days after KA administration remained at control levels. These results indicate that, NADPH-d-positive-only neurons are vulnerable to, and NPY-positive-only neurons are resistant to KA-induced seizures in the whole hippocampus, but that NPY/NADPH-d-positive neurons have different sensitivities in subregions of the hippocampus to KA-induced seizures. In addition, the present findings provide the first statistical and morphological evidence, which demonstrates that NPY-positive-only, NADPH-d-positive-only and NPY/NADPH-d-positive neurons in the hippocampus have different sensitivities to KA-induced seizures.

Animals↗
PubMed2001

The effects of regular source of care and health need on medical care use among rural adolescents.

OBJECTIVE: To examine those factors associated with the use of different types of ambulatory health services in a rural adolescent population. METHODS: The student bodies of 2 middle schools and 2 high schools in rural areas in a mid Atlantic state (N = 1615) were surveyed using a self-administered health status and health services use instrument. Logistic regression was used to assess factors predicting receipt of (1) preventive services, (2) problem-focused services, and (3) emergency services. RESULTS: One third of the rural youth reported having received preventive services within the previous 3 months; 41% received problem-focused care, and 18% received emergency services. Having the same provider for both preventive and illness care was the most consistent and significant predictor of receipt for all types of ambulatory services. Of special note is the greater use of emergency services when subjects did not have a consistent provider for both preventive and illness care. Health need variables, measured across a wide range of domains, were additionally predictive, and their significance varied according to the type of services received. CONCLUSIONS: This study provides compelling evidence that for rural adolescents, having a regular source of care and medical need are the most important predictors of use across a variety of types of ambulatory care.

Adolescent↗
PubMed2001

Myocardial protection of immature rabbits with an ATP-sensitive K+ channel opener pinacidil.

OBJECTIVE: To investigate the effectiveness of pinacidil, an opener of ATP-sensitive K+ channels, in protecting the myocardium of immature rabbit hearts from ischemic reperfusion injury. METHODS: Rabbit hearts underwent 30 min of global normothermic ischemia followed by 30 min of reperfusion on the modified Langendorff apparatus. Fifty-two isolated hearts of 3-4 week-old immature rabbits were divided into 4 groups randomly. During ischemia, 3 different cardioplegic solutions were administered intermittently by infusion every 15 min (20-25 ml each time in all groups). Group 1: control group (n = 13); group 2: Krebs-Henseleit (K-H) solution with potassium (16 mmol/L) (n = 13); group 3: K-H solution with potassium (16 mmol/L) and pinacidil (50 mumol/L) (n = 13); group 4: K-H solution with potassium (16 mmol/L), pinacidil (50 mumol/L) and glibenclamide (10 mumol/L) (n = 13). The pre-ischemic and post-ischemic myocardial functions were assessed by the percentage recovery of the left ventricular developed pressure (LVDP); the left ventricular end-diastolic pressure (LVEDP); both the positive peak and negative peaks of the first derivative of the left ventricular pressures (+/- dp/dtmax); coronary flow; the level of creatine kinase (CK), lactic dehydrogenase (LDH) and aspartate transcarbamoylase (AST) in coronary sinus venous effluent; and by myocardial ultrastructural changes. RESULTS: Before myocardial ischemia, there were no significant differences among the four groups in any of the parameters mentioned above. Post-ischemic recovery of LVDP, LVEDP, +/- dp/dtmax, coronary flow, the level of CK, LDH and AST, and myocardial ultrastructural changes were better in group 3 than those in the three other groups. CONCLUSIONS: As a new and effective composition, pinacidil can significantly improve myocardial protection from cardioplegia for immature rabbit hearts.

Animals↗