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Biomedical subjects

J Kim

Publications and source records attributed to J Kim.

At least 1,225 records · Page 68Linked to original sources
PubMedDate not supplied

Accurate prediction of the amount of in situ tumor in palpable breast cancers by core needle biopsy: implications for neoadjuvant therapy.

BACKGROUND: Neoadjuvant chemotherapy facilitates breast conservation in stage II breast cancer patients, whose primary tumors are assumed to be invasive because they are palpable. However, chemotherapy may not be indicated in the minority of patients whose clinically T2 tumors are completely or predominantly in situ. Almost all previous studies of core needle biopsy in breast cancer have been concerned with nonpalpable, mammographically detected tumors, and none have evaluated its ability to quantitatively determine the amounts of in situ and invasive disease. METHODS: From September, 1992 to December, 1997, core needle biopsy was performed on all patients presenting to the Kings County Hospital Breast Clinic with palpable breast masses. Carcinoma was present in both core needle biopsy samples and surgical specimens subsequently obtained from 95 of 99 patients. Each specimen was evaluated for tumor type, histologic grade, and the amounts of in situ and invasive carcinoma it contained, and the results from surgical and core needle biopsy specimens from the same patients were then compared. RESULTS: The surgical specimens of 14 patients had completely or predominantly in situ disease. Completely or predominantly invasive disease was present in 67 specimens, and the remaining 14 had significant amounts of both. The high level of agreement between the amounts of in situ and invasive disease in core needle biopsy and surgical specimens is indicated by Pearson and intraclass correlation coefficients of 0.91 (P < .001 and < .00001, respectively). Tumor type was correctly predicted by core needle biopsy in each case. Variables among these patients, including primary tumor size, interval between biopsy and surgery, or administration of neoadjuvant systemic therapy, did not alter agreement between core needle biopsy and surgical specimens. CONCLUSIONS: Core needle biopsy can identify palpable breast tumors that are predominantly or completely in situ, and, thus, avoid unnecessary neoadjuvant chemotherapy. It also can demonstrate that a tumor is predominantly invasive, but cannot rule out small invasive foci. For that purpose, complete surgical excision of the tumor is required.

Biopsy, Needle↗
PubMedDate not supplied

Biologic effects of the adoptive transfer of cells depleted of monocytes with L-phenylalanine methyl ester.

Monocytes macrophages have negative regulatory effects on many immunologic responses. Depletion of monocytes from peripheral blood using the lysosomotropic agent, L-phenylalanine methyl ester (PME), has been shown to improve lymphokine activated killer (LAK) cell expansion in vitro. A pilot study of the adoptive transfer of LAK cells expanded with PME was performed in patients with metastatic renal cell carcinoma. Patients received interleukin-2 (IL-2) by continuous infusion for 5 days. Leukopheresis was performed daily for 4 days during the second week. Cells obtained from 8 patients were depleted of monocytes using PME in an one-step procedure; < or = 3% of the remaining cells were monocytes. All cells were expanded for 10 days in air-porous plastic bags with IL-2. Cells expanded 2.7-fold when depleted with PME and 1.7-fold when not depleted (P = 0.02). Expanded cells were administered together with IL-2. Patients received up to 60 x 10(10) PME-depleted cells (mean = 26 x 10(10)) with LAK activity (% lysis) of 60 +/- 12%. Lymphocyte phenotype and cytolytic activity were not modulated by PME-depletion, and clinical toxicities and systemic immunologic effects observed in patients receiving PME-depleted cells were similar to that of 5 patients receiving cells not expanded with PME. Thus, the use of PME to deplete monocytes ex vivo can result in the yield of large number of effectors that retain immunologic activity for potential clinical use. The process is convenient, efficient, and does not add clinical toxicity.

Carcinoma, Renal Cell↗
PubMedDate not supplied

A biotin-avidin based screening test for methamphetamine in urine.

A biotin-avidin based screening test for methamphetamine in urine samples has been developed. The assay method utilizes the immunoprecipitin reaction between an antibody to methamphetamine and a conjugate prepared by complexing avidin with a biotinyl amphetamine derivative. The rates of the immunoprecipitin reaction is monitored on the Beckman ARRAY 360 nephelometer. Methamphetamine inhibits the precipitin reaction, and the extent of inhibition allows the quantitation of methamphetamine in the urine samples. Using a cut-off value of 0.7 microgram ml-1, the assay correctly predicted 83 of 84 samples (98.8%) confirmed to be positive by GC-MS (> 500 ng ml-1). Of 59 GC-MS confirmed negative samples, 46 samples were found to be negative by this method as compared to 34 samples determined with the EMIT assay. Within-run and between-run relative standard deviations near the cut-off value were less than 4%. Cross-reactivity with amphetamine was < 7%.

Antibodies↗
PubMedDate not supplied

Expression of monocyte chemoattractant protein-1 and macrophage inflammatory protein-1 in porcine circovirus 2-induced granulomatous inflammation.

The expression of monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1 (MIP-1) in granulomatous inflammation of lymph nodes was determined in 1-day-old piglets inoculated intranasally with porcine circovirus 2 (PCV2). The methods used were reverse transcription-polymerase chain reaction (RT-PCR), granulomatous lesion scoring, and in-situ hybridization. Maximum MCP-1 expression and MIP-1 expression were observed at 17 and 21 days post-inoculation (dpi), respectively. Granulomatous lesions of maximum severity were observed somewhat later (28 dpi). A close cell to cell relation between PCV2 and the two cytokines in serial sections from lymph nodes suggested that their induction was a direct response to PCV2. The results provide evidence of the ability of MCP-1 and MIP-1 to induce granulomatous inflammation in vivo.

Animals↗
PubMedDate not supplied

Birth abnormalities in pregnant sows infected intranasally with porcine circovirus 2.

Six pregnant sows were inoculated intranasally at 3 weeks before the expected farrowing date with porcine circovirus 2 (PCV2). The PCV2-inoculated sows showed abortion and premature farrowing, whereas two uninfected negative control sows remained clinically healthy and farrowed normally. PCV2 antigen and DNA were detected by immunohistochemistry and in-situ hybridization, respectively, in lymph node, spleen, thymus, lung, tonsil and liver from both stillborn and liveborn piglets. Simultaneous detection of viral protein and DNA provided molecular evidence of PCV2 infection and replication. The experiment suggested that PCV2 is capable of crossing the placenta, replicating primarily in lymphoid tissues, and inducing reproductive failure.

Abortion, Veterinary↗
PubMedDate not supplied

In vitro establishment of cis-diammine-dichloroplatinum(II) resistant lung cancer cell line and modulation of apoptotic gene expression as a mechanism of resistant phenotype.

After exposure of H460 cells to an increasing concentrations of cis-diammine-dichloroplatinum(II) (cisplatin, CDDP) for 6 months, cisplatin resistant cells were isolated (H460/CIS). The biologic behaviors of H460 and H460/CIS cells were tested using animal experiments. Only the resistant cells developed lung metastases despite cisplatin treatment. The characteristics of H460/CIS cells are as follows, MTT analyses revealed that H460/CIS cells were markedly resistant to cisplatin compared with their parental cells. Also, H460/CIS cells exhibited cross-resistance to DNA damaging agents such as doxorubicin (DXR) and etoposide. Cisplatin treatment dramatically increased p53 expression in parental cells but not in H460/CIS cells which expressed basal levels of p53. Without cisplatin treatment, Bcl-2 and Bax were expressed in H460/CIS cells, but not in parental cell. Our data suggested that p53, Bax and Bcl-2 were up-regulated in H460/CIS cells. These changes could explain some of the mechanisms of cisplatin resistance. Thus, H460/CIS could be useful to investigate the mechanisms of drug resistance to cisplatin including apoptotic gene expressions conferring drug resistance, thereby making progress in the treatment of cisplatin-resistant tumor cells.

Animals↗
PubMedDate not supplied

Effect of Rehmannia glutinosa on immediate type allergic reaction.

We investigated the effect of aqueous extract of Rehmannia glutinosa steamed root (RGAE) on the allergic reactions in vivo and in vitro. RGAE dose-dependently inhibited systemic allergic reaction induced by compound 48/80. When RGAE was pre-treated at the same concentrations with systemic allergic reaction test, the plasma histamine levels were reduced in a dose-dependent manner. RGAE dose-dependently inhibited skin allergic reaction activated by anti-dinitrophenyl (DNP) IgE. RGAE also dose-dependently inhibited the histamine release from the rat peritoneal mast cells (RPMC) by compound 48/80 or anti-DNP IgE. Moreover, RGAE had significant inhibitory effect on anti-DNP IgE-induced tumor necrosis factor-alpha production of RPMC. These results indicate that RGAE may be beneficial in the regulation of immediate type allergic reaction.

2,4-Dinitrophenol↗
PubMedDate not supplied

The women's health initiative estrogen replacement therapy is neurotrophic and neuroprotective.

The current study investigated the neurotrophic and neuroprotective action of the complex formulation of conjugated equine estrogens (CEEs), the most frequently prescribed estrogen replacement therapy in the United States and the estrogen replacement therapy of the Women's Health Initiative. Morphologic analyses demonstrated that CEEs significantly increased neuronal outgrowth in hippocampal, basal forebrain, occipital, parietal and frontal cortex neurons. Dose-response analyses indicated that the lowest effective concentration of CEEs exerted the maximal neurotrophic effect with greatest potency occurring in hippocampal and occipital cortex neurons. CEES induced highly significant neuroprotection against beta amyloid(25-35), hydrogen peroxide and glutamate-induced toxicity. Rank order of potency and magnitude of CEE-induced neuroprotection in the brain regions investigated was hippocampal neurons > basal forebrain neurons > cortical neurons. In hippocampal neurons pre-exposed to beta amyloid(25-35), CEEs halted Abeta(25-35)-induced cell death and protected surviving neurons from further cell death induced by Abeta(25-35). Because CEEs are the estrogen replacement therapy of the Women's Health Initiative, results of the current study could provide cellular mechanisms for understanding effects of CEEs on cognitive function and risk of Alzheimer's disease derived from this prospective clinical trial.

Adenosine Triphosphate↗
PubMedDate not supplied

Effect of select antioxidants on malondialdehyde modification of proteins.

To determine whether commonly used antioxidants alter malondialdehyde (MDA) modification of proteins, a known mechanism of free radical-related tissue injury, we studied the effect of adding 1 mg/mL of pycnogenol, 5 mM of alpha-tocopherol, 5 mM of ascorbate, and 0.2 mg/mL of an ethanol equivalent of red and white wine on MDA-protein content of endothelial cells in culture. The addition of pycnogenol but not of the other antioxidants was associated with significant reduction in MDA-protein content compared with controls (0.521 +/- 0.041 in arbritrary units versus 1.011 +/- 0.021, P < 0. 001). To determine whether the observed effect occurs distal to MDA generation, the effect of these antioxidants on the modification of bovine serum albumin with MDA generated in a cell-free system was studied. In this cell-free assay, pycnogenol but not the other antioxidants reduced MDA-BSA generation by approximately 50%. It is concluded that pycnogenol may reduce MDA modification of proteins at a step distal to MDA generation. This may be an additional mechanism of protective effects of pycnogenol against oxidative stress.

Antioxidants↗
PubMedDate not supplied

Reconstruction of a painful post-traumatic medial plantar neuroma with a bioabsorbable nerve conduit: a case report.

Although nerve injuries to feet may be common, primary repair of a damaged nerve in the foot is rare. Secondary digital nerve reconstruction in the foot has not been previously reported. This report describes a patient with post-traumatic neuroma of medial plantar nerve who was treated by neuroma resection; the nerve defect was reconstructed with bioabsorbable nerve conduit. This case illustrates successful, secondary reconstruction of nerve injury in the foot using a new surgical technique. A bioabsorbable polyglycolic acid nerve conduit eliminated the need for a short nerve graft and was effective in relieving the neuroma pain by providing an appropriate distal site for neural regeneration.

Absorbable Implants↗
PubMedDate not supplied

A model for motion coherence and transparency.

A recent model for two-dimensional motion processing in MT has demonstrated that perceived direction can be accurately predicted by combining Fourier and non-Fourier component motion signals using a vector sum computation. The vector sum direction is computed by a neural network that weights Fourier and non-Fourier components by the cosine of the component direction relative to that of each pattern unit, after which competitive inhibition extracts the signals of the most active units. It is shown here that a minor modification of the connectivity in this network suffices to predict transitions from motion coherence to transparency under a wide range of circumstances. It is only necessary that the cosine weighting function and competitive inhibition be limited to directions within +/- 120 deg of each pattern unit's preferred direction. This network responds by signaling one pattern direction for coherent motion but two distinct directions for transparent motion. Based on this, neural networks with properties of MT and MST neurons can automatically signal motion coherence or transparency. In addition, the model accurately predicts motion repulsion under transparency conditions.

Animals↗
PubMedDate not supplied

Probing biomolecule recognition with electron transfer: electrochemical sensors for DNA hybridization.

Identifying infectious organisms, quantitating gene expression, and sequencing genomic DNA on chips all rely on the detection of nucleic acid hybridization. Described here is a novel assay for detection of the hybridization of products of the polymerase chain reaction using electron transfer from guanine to a transition-metal complex. The hybridization assay was modeled in solution by monitoring the cyclic voltammetry of Ru(bpy)3(2+) (bpy = 2,2'-bipyridine) in the presence of a probe strand containing only A, T, and C prior to and after hybridization to a complement that contained seven guanines, which led to high catalytic current due to the oxidation of guanine by Ru(bpy)3(3+). To allow recognition of all four bases in the target sequence, it was shown that inosine 5'-monophosphate was 3 orders of magnitude less reactive than guanosine 5'-monophosphate, suggesting that effective hybridization sensors could be realized by immobilization of probe strands in which inosine was substituted for guanosine; hybridization to guanosine-containing target strands would then provide high catalytic currents. A sensor design was tested in a model system for the detection of a synthetic 21-mer oligonucleotide patterned on the sequence of the ras oncogene, which gave an increase in charge collected of 35 +/- 5 microC after hybridization and of only 8 +/- 5 microC after exposure to noncomplementary DNA. Independent quantitation of probe and target by radiolabeling showed that the hybridized electrode contained 3.0 +/- 0.3 ng of target. New sensor electrodes were then prepared for the detection of PCR-amplified genomic DNA from herpes simplex virus type II, genomic DNA from Clostridium perfringens, and genomic RNA from human immunodeficiency virus and gave an additional charge of 35-65 microC for hybridization to complementary amplicon and of only 2-10 microC after exposure to noncomplementary DNA.

Biosensing Techniques↗
PubMedDate not supplied

Enzymatically and combinatorially generated array-based polyphenol metal ion sensor.

Phenolic polymers were synthesized via soybean hull peroxidase catalysis and used as metal-based sensor components in a polymer array. A sensor array for Fe(3+), Cu(2+), Co(2+), and Ni(2+) has been developed consisting of 15 phenolic homopolymers and copolymers generated from five phenolic monomers by peroxidase-catalyzed oxidative polymerization. Sensing was based on the change of intrinsic polyphenol fluorescence upon addition of a metal ion or a metal ion mixture to an aqueous suspension of a polyphenol. Importantly, the fluorescence response of copolymers differed, in some cases dramatically, from the constituent homopolymers and was dependent upon the relative ratio of monomers that comprise the polymer. This finding suggests that an extremely broad range of sensor arrays can be generated from a limited number of phenolic monomers. Using a statistical analysis, histograms constructed for the four different metal ions yielded unique fingerprints of the array response and can be used to identify specific metal ions.

Biosensing Techniques↗
PubMedDate not supplied

Polypodoside A, an intensely sweet constituent of the rhizomes of Polypodium glycyrrhiza.

Polypodoside A, a novel intensely sweet constituent of the rhizomes of Polypodium glycyrrhiza, was established by spectral and chemical methods as 26-O-alpha-L-rhamnopyranosyl-polypodogenin-3-O-alpha-L-rhamnopyran osyl- (1----2)-beta-D-glucopyranoside [1]. At the doses tested, this isolate was not acutely toxic for mice and was nonmutagenic with Salmonella typhimurium strain TM677. This compound was rated by a human taste panel as exhibiting 600 times the sweetness intensity of a 6% w/v aqueous sucrose solution.

Animals↗
PubMedDate not supplied

Intraperitoneal gene therapy with adenoviral-mediated p53 tumor suppressor gene for ovarian cancer model in nude mouse.

In an effort to develop a method for better local control of advanced ovarian cancers, we have established a peritoneal tumor model of ovarian cancer in the nude mouse and applied intraperitoneal gene therapy with the recombinant adenoviral-mediated wild-type p53 tumor suppressor gene (Avp53). The results indicate that: (a) the recombinant adenoviral vector system effectively infected the tumor and normal cells in the peritoneal cavity; and (b) Avp53 treatment effectively suppressed the growth of peritoneal tumors and prolonged the survival of the treated group, especially when the tumor burden was less. These results suggest that intraperitoneal gene therapy using Avp53 is potentially useful as an adjuvant therapeutic modality in human ovarian cancer.

Adenoviridae↗
PubMedDate not supplied

Assessment of disinfection by-products in drinking water in Korea.

The main purpose of applying the chlorination process during water treatment is for disinfection. Research results, however, indicate that disinfection byproducts (DBPs) including trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), haloketones (HKs), and chloropicrin (CP) can be produced by the chlorination process. Some of these DBPs are known to be potential human carcinogens. This 3-year project is designed to establish a standard analysis procedure for DBPs in drinking water of this country and investigate the distribution and sources of specific DBPs. The occurrence level of DBPs in drinking water was below 50 micrograms/l in most cases. THMs in plant effluent accounted for 60% of all DBPs measured, whereas HAAs accounted for 20%, HANs 12%, HKs 5% and CP 3%. Chloroform was found to be the major THMs compound (77%), followed by bromodichloromethane (BDCM, 18%) and bromoform (BF, 3%). The concentration of DBPs formed in distribution systems increased from those detected in plant effluent. Comparison of humic acid and sewage as precursors for THMs formation showed that humic acid was the major THMs precursor. Results would play an important role in exposure assessment as a part of the risk assessment process, and would give basic information for establishment of DBPs reduction and management procedures.

Chlorine↗
PubMedDate not supplied

Anti-VEGF antibody treatment of glioblastoma prolongs survival but results in increased vascular cooption.

Vascular endothelial growth factor (VEGF) is an important mediator of the intense angiogenesis which is characteristic of glioblastoma. While genetic manipulation of VEGF/VEGF receptor expression has previously been shown to inhibit glioblastoma growth, to date, no study has examined the efficacy of pharmacologic blockade of VEGF activity as a means to inhibit intracranial growth of human glioblastoma. Using intraperitoneal administration of a neutralizing anti-VEGF antibody, we demonstrate that inhibition of VEGF significantly prolongs survival in athymic rats inoculated in the basal ganglia with G55 human glioblastoma cells. Systemic anti-VEGF inhibition causes decreased tumor vascularity as well as a marked increase in tumor cell apoptosis in intracranial tumors. Although intracranial glioblastoma tumors grow more slowly as a consequence of anti-VEGF treatment, the histologic pattern of growth suggests that these tumors adapt to inhibition of angiogenesis by increased infiltration and cooption of the host vasculature.

Animals↗