• Korean Journal of Environmental Agriculture
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• v.18 no.4
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• pp.344-348
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• 1999

To investigate hormetic effect of low dose ${\gamma}$-ray on the uptake of mineral nutrients in Chinese cabbage (Brassica campestris var. Hekjinju var. Surim and) and radish (Raphanus sativas var. Chung-un), seeds of these plants were irradiated with the dose of 1 to 10 Gy. Germination rate and dry weight were examined at pot experiment in greenhouse. Samples for analysis of mineral nutrient were harvested at 17 days and at 59 days after seedling and were analyzed by ICP. Brassica campestris varieties showed higher germination rate and dry weight production with increasing ${\gamma}$ ray dose. Dry weight of Hekjinju Surim and were 143% and 138% at 10Gy dose. respectively. There was no tendency in germination rate and dry weight production for Raphanus sativas var. Chung-un with ${\gamma}$-ray irradiation. The pattern of mineral nutrient content of these plants showed ${\gamma}$ or ${\delta}$ type of dose-reaction curve with no siginificant. This investigation suggests that the more results can be required to understand the hormetic effect of low dose ${\gamma}$ ray on the uptake of mineral nutrient for these plants.

• YAKHAK HOEJI
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• v.46 no.3
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• pp.192-196
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• 2002

To investigate the effect of intravenous ethanol administration on pancreatic exocrine secretion, we measured volume and protein amount in pancreatic juice and assayed amylase activity and phospholipase $A_2$ activity in pancreatic fragments and serum. Acute pancreatitis induced by obstruction of common bile-pancreatic duct (CBPD) and caerulein infusion (5 $\mu\textrm{g}$/kg/hr) showed typical characteristics, such as hyperamylasemia and pancreatic edema and increase of phospholipase $A_2$ activity in pancreatic fragments and serum. Intravenous ethanol infusion (50 mg/kg/hr) significantly stimulated pancreatic exocrine secretion, but such a stimulatory effect of ethanol disappeared at dose of 100 mg/kg/hr without typical symptoms of acute pancreatitis. In microscopic examination, there were no typical changes of edematous pancreatitis in ethanol administrated rats. These results suggest that acute ethanol administration has dual effect on exocrine pancreatic secretion: low dose of ethanol (50 mg/kg/hr) stimulates pancreatic exocrine secretion, whereas high dose of ethanol (100 mg/kg/hr) does not without typical changes of edematous pancreatitis.

• Korean Journal of Biological Psychiatry
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• v.3 no.2
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• pp.240-244
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• 1996

The effects of chronic treatment with haloperidol on the binding capacities of dopamine(DA) $D_2$-like receptor were investigated in rat striatum and olfactory tubercle. The authors tried to confirm the dose-response effects with usual dose and low dose haloperidol. Rats were treated with haloperidol(0.05, 0.15, 0.5, 1.5mg/kg/day in drinking water) for four weeks. Saturation analysis of the binding of [$^3H$]spiperone to striatal membranes showed that the haloperidol treatment(0.05, 0.5, 1.5mg/kg) induced significant proliferation. The changes of dissociation constant(Kd) were not significant in striatum. The maximal binding density(Bmax) and Kd increased remarkably following the treatment with usual dose haloperidol (1.5mg/kg) in olfactory tubercle. Although there was increasing trend other the treatment with low dose haloperidol, the change of Bmax was not significant statistically. The present findings indicate that low dose haloperidol induces the proliferation of DA $D_2$-like receptor in striatum and interact with the dopaminergic transmission which might underlie the antipsychotic effect. This finding may support the recent clinical suggestion on the low dose strategy in the treatment of schizophrenia.

• The Korean Journal of Pain
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• v.27 no.2
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• pp.125-132
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• 2014

Background: To improve residual pain management in acute cervical radiculopathy treated with NSAIDs, the feasibility of early and repeated low-dose interscalene brachial plexus block (IS-BPB) needs to be assessed. Methods: This was a prospective study on patients receiving NSAIDs (loxoprofen) for cervical radiculopathy of ${\leq}2$-week onset. Pain was assessed using the visual analogue scale (VAS). A low-dose ultrasonography (USG)-guided IS-BPB (dexamethasone [1.65 mg; 0.5 ml] and mepivacaine [1%; 3.0 ml]) was performed at baseline and weekly thereafter for 4 weeks in an outpatient setting for the intervention group. All patients were evaluated using a visual satisfaction score (VSS) at week 4. Patients with baseline VAS scores < 70 (mild to moderate pain; MM group) and ${\geq}70$ (severe pain; SE group) were compared to the controls receiving NSAIDs. Results: A total of 316 IS-BPBs were performed in the intervention group. There was a significant difference in the decline in the VAS from week 0 to week 3 in the MM and SE groups (P < 0.05); however, from week 3 to week 4, the therapeutic effect exhibited no significant difference. Thirteen patients at week 2 (15.5%; MM: 27.7%; SE: 0%), 43 at week 3 (51.2%; MM: 83.0%; SE: 10.8%), and 47 at week 4 (56.0%; MM: 85.1%; SE: 18.9%) achieved a VAS score of ${\leq}20$. Patient satisfaction was high, and the decrease in VAS scores in both groups was significant (P < 0.05) compared to the controls. Conclusions: Weekly, low-dose, USG-guided IS-BPB can be implemented for early pain relief in acute cervical radiculopathy, with high patient satisfaction.

• Journal of Radiation Protection and Research
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• v.40 no.4
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• pp.202-210
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• 2015

The low dose radiation is done for a long period, thus researchers have to know the exact dose distribution for the irradiated mouse. This research has been conducted in order to find out methods in transmitting an exact dose to mouse in a mouse irradiation experiment carried out using $^{137}Cs$ irradiation equipment installed in the DIRAMS (Dongnam Institution of Radiological & Medical Sciences) research center. We developed a single mouse housing cage and shelf with adjustable geometric factors such as distance and angle from collimator. The measurement of irradiated dose showed a maximal 42% difference of absorbed dose from the desired dose in the conventional irradiation system, whereas only 6% difference of the absorbed dose was measured in the self-developed mouse apartment system. In addition, multi mice housing showed much difference of the absorbed dose in between head and body, compared to single mouse housing in the conventional irradiation system. This research may allow further research about biological effect assessment for the low dose irradiation using the self-developed mouse apartment to provide more exact doses which it tries to transmit, and to have more reliability for the biological analysis results.

• IMMUNE NETWORK
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• v.1 no.3
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• pp.203-212
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• 2001

Background: Rapid advances in neuroendocrine immunology have established the concept of bidirectional communication between the immune and neuroendocrine systems. Capsaicin suppresses the immune function by destroying substance P acting as mediatior of neuroendocrine immune system. Methods and Results: In this study, effect of capsaicin on mature murine lymphocyte functions and lymphoid tissue morphology was examined. Formally, capsaicin showed the strong cytotoxic effect on splenocyte over $10{\mu}g/ml$ concentration in citro. And proliferation and Th1-cytokine expression of splenic cells in mice that received high dose of capsaicin ($100{\mu}g/mouse$) were significantly diminished. However, low dose of capsaicin treatment did not influence these responses in vivo($1{\mu}g/mouse$) and in vitro (under $5{\mu}g/ml$). And the morphology of spleen and lymph nodes after capsaicin treatment was observed. In the spleen of mice injected with high dose of capsaicin (100, $200{\mu}g/mouse$), the size of white pulp was significantly decreased and the length of red pulp was increased, Moreover, vascularity index was diminished in a dose dependent manner. Conclusion: These results implies that immunosuppressive effect of capsaicin is associated with cytotoxic activity on lymphocyte, Th1-cytokine down-regulation and lymphoid tissue abnormalization, and this report is expected to give a hand to the study for the mechanism of action of neurotoxin of the immune system.

• Radiation Oncology Journal
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• v.1 no.1
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• pp.29-36
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• 1983

The treatment of tumors along curved surfaces with stationary electron beams using cone collimation may lead to non-uniform dose distributions due to a varying air gap between the cone surface and patient. For large tumors, more than one port may have to be used in irradiation of the chest wall, often leading to regions of high or low dose at the junction of the adjacent ports. Electron-beam arc therapy may elimination many of these fixed port problems. When treating breast tumors with electrons, the energy of the internal mammary port is usually higher than that of the chest wall port. Bolus is used to increase the skin dose or limit the range of the electrons. We invertiaged the effect of various arc beam parameters in the isodose distributions, and combined into a single arc port for adjacent fixed ports of different electron beam eneries. The higher fixed port energy would be used as the arc beam energy while the beam penetration in the lower energy region would be controlled by a proper thickness of bolus. We obtained the results of following: 1. It is more uniform dose distribution of electron to use rotation than stationary irradiation. 2. Increasing isocenter depth on arc irradiation, increased depth of maximum dose, reduction in surface dose and an increasing penetration of the linear portion of the curve. 3. The deeper penetration of the depth dose curve and higher X-ray background for the smaller field sized. 4. If the isocenter depth increase, the field effect is small. 5. The decreasing arc beam penetration with decreasing isocenter depth and the isocenter depth effect appears at a greater depth as the energy increases. 6. The addition of bolus produces a shift in the penetration that is the same for all depths leaving the shape of the curves unchanged. 7. Lead strips 5 mm thick were placed at both ends of the arc to produce a rapid dose drop-off.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1773-1777
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• 2016

Diagnostic and therapeutic radiation fields are planned so as to reduce side-effects while maximising the dose to site but effects on healthy tissues are inevitable. Radiation causes strand breaks in DNA of exposed cells which can lead to chromosomal aberrations and cause malfunction and cell death. Several researchers have highlighted the damaging effects of high dose radiation but still there is a lacuna in identifying damage due to low dose radiation used for diagnostic purposes. Blood is an easy resource to study genotoxicity and to estimate the effects of radiation. The micronucleus assay and chromosomal aberration can indicate genetic damage and our present aim was to establish these with lymphocytes in an in vitro model to predict the immediate effects low dose radiation. Blood was collected from healthy individuals and divided into 6 groups with increasing radiation dose i.e., 0Gy, 0.10Gy, 0.25Gy, 0.50Gy, 1Gy and 2Gy. The samples were irradiated in duplicates using a LINAC in the radiation oncology department. Standard protocols were applied for chromosomal aberration and micronucleus assays. Metaphases were stained in Giemsa and 200 were scored per sample for the detection of dicentric or acentric forms. For micronuclei detection, 200 metaphases. Giemsa stained binucleate cells per sample were analysed for any abnormality. The micronuclei (MN) frequency was increased in cells exposed to the entire range of doses (0.1-2Gy) delivered. Controls showed minimal MN formation ($2.0%{\pm}0.05$) with triple MN ($5.6%{\pm}2.0$) frequency at the lowest dose. MN formation increased exponentially with the radiation dose thereafter with a maximum at 2Gy. Significantly elevated numbers of dicentric chromosomes were also observed, even at doses of 0.1-0.5Gy, compared to controls, and acentric chromosomes were apparent at 2Gy. In conclusion we can state that lymphocytes can be effectively used to study direct effect of low dose radiation.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7129-7135
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• 2014

Background: In this study, we aimed to evaluate the growth inhibitory effect of the combination of ethaselen (BBSKE) and low fixed dose of selenite against A549 human non-small cell lung cancer cells in vitro. Materials and Methods: Growth inhibitory effects against A549 cells were determined by SRB assay. Combination index (CI) values were calculated based on Chou-Talalay median-effect analyses. Dose reduction index (DRI) values were applied to calculate dose reduction of selenite. Contents of free thiols and GSH were determined by DTNB assay and intracellular ROS levels by DCFH-DA fluorescence labeling. Results: Compared with BBSKE or selenite single treatment, the combined application of ethaselen and a low fixed dose of selenite shortened the onset time of sodium selenite, reduced $IC_{50}$ values, and increased the maximum inhibition rates, suggesting a possible molecular mechanism of the synergism. Obvious synergistic effects were observed after different times of combination treatment, especially after 24 h. Compared with selenite single treatment, dosage of selenite could be remarkably reduced in combination therapy to gain the same inhibitory effect on cell proliferation. Compared with BBSKE single treatment, the content of free thiols and GSH were significantly reduced and ROS levels greatly elevated in the combination group. For the combination treatment, cell viability increased as greater concentrations of GSH were added. Conclusions: All these results indicate that the combination treatment of BBSKE and selenite showed synergism to inhibit A549 cell proliferation in vitro, and also reduced the selenite dosage to mitigate its toxicity which is very meaningful for combination chemotherapy of lung cancer. The synergism was probably caused by the accelerated exhaustion of intracellular reductive substances, such as free thiols and GSH, which ultimately leads to enhanced oxidative stress and apoptosis.

• Archives of Pharmacal Research
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• v.18 no.6
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• pp.427-433
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• 1995

A microscopic mass balance approach has hsown that the initial saturation (Is), absorption number (An), dose number (Do), and dissolution number (Dn) are four fundamental dimensionless parameters that can be used to estimate the fraction dose absorbed (F)l of suspensions of poorly soluble drugs in humans. The dissolution number of a drug increases with decreasing its particle size. The effect of micronization on F for suspensions was investigated in terms of Dn. About 90% of maximal F can be achieved at $Dn{\approx}2$. Increasing the solubility of a drug results in better oral absorption through increasing Dn and decreasing the solubility of a drug results in better oral absorption through increasing Dn and decreasing Do. The fractions dose absorbed of digoxin, griseofulvin, and benoxaprofen agree with predicted F values sorbed by reducing particle size, while absorption of drugs with high Do and low Dn is limited by solubility and requires higher solubility to enhance the fraction dose absorbed in addition to micronization. Solubility at the physiological pH should be used for the estimation of the fraction dose absorbed.