Gold nanoparticles enhance anti-tumor effect of radiotherapy to hypoxic tumor

PURPOSE: Hypoxia can impair the therapeutic efficacy of radiotherapy (RT). Therefore, a new strategy is necessary for enhancing the response to RT. In this study, we investigated whether the combination of nanoparticles and RT is effective in eliminating the radioresistance of hypoxic tumors. MATERIALS AND METHODS: Gold nanoparticles (GNPs) consisting of a silica core with a gold shell were used. CT26 colon cancer mouse model was developed to study whether the combination of RT and GNPs reduced hypoxia-induced radioresistance. Hypoxia inducible factor-1α (HIF-1α) was used as a hypoxia marker. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were conducted to evaluate cell death. RESULTS: Hypoxic tumor cells had an impaired response to RT. GNPs combined with RT enhanced anti-tumor effect in hypoxic tumor compared with RT alone. The combination of GNPs and RT decreased tumor cell viability compare to RT alone in vitro. Under hypoxia, tumors treated with GNPs + RT showed a higher response than that shown by tumors treated with RT alone. When a reactive oxygen species (ROS) scavenger was added, the enhanced antitumor effect of GNPs + RT was diminished. CONCLUSION: In the present study, hypoxic tumors treated with GNPs + RT showed favorable responses, which might be attributable to the ROS production induced by GNPs + RT. Taken together, GNPs combined with RT seems to be potential modality for enhancing the response to RT in hypoxic tumors.

Characteristics and Detection Rate of Thyroidal Incidentaloma using ¹⁸F-FDG PET-CT / 대한내분비외과학회지

PURPOSE: PET-CT is often used to differentiate benign or malignant thyroid incidentalomas. In this retrospective study, we evaluated whether the ¹⁸F-FDG uptake pattern and PET-CT findings improved accuracy over the standardized uptake value (SUV). METHODS: ¹⁸F-FDG PET-CT was performed on 2,178 subjects from August, 2004, to October, 2007, in Sung-ae Hospital. PET-CT was performed on 806 patients (37%) with suspected or known nonthyroidal cancer and 1,372 healthy subjects (63%) without a previous history of cancer. We investigated the clinical characteristics of patients, history, standardized uptake value (SUV), ultrasonography, and hormone levels in blood. Thyroidal cancer was confirmed by ultrasonography-guided fine needle aspiration and pathology after thyroid operation. RESULTS: The prevalence of focal thyroid lesions on PET-CT was 8.8% (191/2178). Thyroid cancer confirmation was 7.9% (15/191). The maximum SUV of malignant thyroid lesions were significantly higher than that of benign lesions (7.00±3.08 vs. 4.49±1.84, P<0.001). CONCLUSION: PET-CT image interpretation that includes 18F-FDG uptake and SUV is better than PET-CT alone for differentiating benign and malignant lesions. Thyroid cancer risk increases as SUVmax levels increase.

Chromosomal Changes in Transitional Cell Carcinoma of the Bladder (Preliminary Report) / 대한비뇨기과학회지

3 cases of transitional cell carcinoma were subjected to detailed cytogenetic analysis. All three were superficial (T1G I , T1G III, T1G I). Case 1 and case 3 (all T1G I) had diploidy modal chromosomal number but case 2 (TtGIII) had partly triploidy and tetraploidy chromosome. Case 3 showed marker chromosomes and in case 2 and 3, breakage of long arm of the second chromosome was seen.

An In-vitro Experimental Study on Antibacerial Effects of Antibiotic-mixed Plaster of Paris Pellets / 대한정형외과학회잡지

Various kinds of bone cements mixed with antibiotics have been widely used for treatment and prevention of infections, especially combined with bone defects. But bone cements have some disadvantages in that they are rather expensive and capable of incurring some complications such ss fibrosis of surrounding soft tissue or local erosion of bone, and furthermore, they must be removed after infection is controlled for bone graft to fill up the defects because they do not have properties of osteoconduction or osteoinduction. So we have come to the idea of using theoretically advantageous plaster of paris to take place of bone cements, and performed in-vitro experiment upon the effectiveness of plaster of paris pellets containing antibiotics, then obtained good results comparable to those from many experimental studies using bone cements. By this, we think that it would be possible in the future to treat and prevent infections supervening bone defects with plaster of paris mixed up with antibiotics. The results are as follows : 1. Sustained release of large amount of antibiotics from plaster of paris enough to exert inhibitory activity on abcterial growth, and there was a direct relationship between concentrations of eluted antibiotics and diameters of inhibitory zones. 2. Tobramycin was capable of inhibiting the growth of S. aureus, E. coli, and Ps. aeruginosa for 7 days at maximum. 3. Cephradine inhibited the growth of S. aureus and E. coli but did not affect that of Ps. aeruginosa. 4. The maximum antibacterial activity wss reached within first 24 hours from the start of elution of antibiotics from plaster of paris.

A Clinical Study of the Myelography in Herniated Lumbar Discs / 대한정형외과학회잡지

The first myelography with air was carried out by Walter Dandy in 1919, and the myelography with positive contrast medium was done by Sicard and Forestier in 1922. Since Pantopaque was adopted as a contrast material by University of Rochester group in 1944, it has been rapidly popularized. Although higher diagnostic accuracy has been made with a development of the diagnostic aids such as electromyography, discography, epidural venography and computerized tomography, myelography has been popularized in our country with electromyography. The authars have seen and studied 107 cases of herniated lumbar disc with respect to the diagnostic accuracy of myelographic examination from January, 1976 to December, 1981 at the department of Orthopedic Surgery, Yonsei University College of Medicine. The results were as follows: l. Of the 107 cases, 59 were found in the age of 20 to 40 years and the ratio of male and female was 2:l. 2. Fifty eight cases (54.2%) had no history of back injury, but 40 cases (37.4%) had sprain of the back and 9 cases had direct trauma history. 3. In all cases, plain X-ray and myelogram were taken. Among them 55 cases showed narrowing of intervertebral space in plain film, and 100 cases showed positive myelographic findings such as lateral indentation of dural sac (41 cases), hour-glass defect (30 cases), root sleeve defect (12 cases), block defect (10 cases) and combined defects (7 cases). 4. Sixty one cases which confirmed by operation, the most frequent level of disc herniation was in L4-5 space. Clinical diagnosis was correct in 57.4%, and myelographic accuracy was coincided with operative finding in 80.3%. 5. Twelve (19.7%) of the 61 cases showed discrepancy between myelographic and operative findings, and these 12 cases consisted of 5 cases of level discrepancy, 3 cases of false positive and 4 cases of false negative.

Non-Ossifying Fibroma (Five Cases Report) / 대한정형외과학회잡지

The term “non-ossifying fibroma of bone” was introduced by Jaffe and Lichenstein in 1942 to describe a distinctive benign lesion occuring near the ends of the long bones in young people, and the lesion was subsequently described by Hatcher as a developmental defect rather than a true tumor. This lesion was presented as a clear-cut entity on the basis of pathological, clinical and roentgenographic manifestations. The diagnosis of non-ossifying fibroma was made by the histopathological findings of the curetted tissues. The authors have seen and studied 5 cases of non-ossifying fibroma from February 1976 to September 1981. The average duration of follow up was 2.2 years, with a range from 0.8 to 5 years, and the results of treatment were as follows: l. Of the five cases, two were associated with pathologic fractures. 2. The sites of the lesions in all cases were the long bones in the lower extremity. 3 In all cases, the complaints were of only a few days or weeks duration before admission to the hospital, and no cases were discovered incidentally by roentgenographic examination. 4. Good results were obtained by treatment with curettage and bone graft.

A Clinical Study of Replantation of Amputated Limbs and Digits / 대한정형외과학회잡지

In 1960 Jacobson and Suarez introduced the operating microscope to vascular surgery and demonstrated the superiority of small vessel repair using magnification. The first clinical replantation of an arm in the western world was performed by Malt in 1962, and Komatsu and Tamai reported the successful replantation of a completely amputated thumb in 1965. To perform a digit or hand replantation, microsurgical anastomosis of blood vessels is absolutely essential to revascularize the severed part. Without accurate repair of bone, nerves and tendons in addition to vascular anastomosis, however, it is impossible to gain functional success when replanting a digit or hand. This is a difficult task because all structures must be reconstructed at the same level and time. Even if the repair of some structures has been postponed, the secondary reconstruction may also be troublesome due to circular scarring at the replantation level. Since replantation surgery has been popularized throughout the world in recent years, the replantation sucess rate has increased and the surgeons interest in functional reconstruction of replanted digits or hands has been stimulated. The authors have seen and studied 6 cases of upper Jimb and 20 cases of finger replantation from May, 1980 through January, 1982 at the department of orthopedic surgery, Yonsei University College of Medicine. The results were as follows: I. The average age was 20 years and the male to female sex ratio was 4.5:1. 2, The causes of injury are detailed as follows: electric saw(6); cutting machine(5); roller(4}; presser(2); stone(2); others(3). 3. The level of amputation in 26 replantations was as follows: thumb, 3 cases; index finger, 4 cases; middle finger, 9 cases; ring finger, 4 cases; palm, I case, wrist, 3 cases; forearm, 1 case; upper arm, 1 case. 4. The maximum ischemic times for successtul results were 16 hours in limb replantation and 22 hours in finger replantation. 5. Six limbs, with four complete and two incomplete amputations, have been replanted and all six limbs survived: Twenty digits, with nine complete and eleven incomplete amputations, have also been replanted and 6.5 cases of nine complete amputations and 10 cases ot eleven incomplete amputations survived. A total of 22.5 cases(86.5%) of replanted limbs and digits survived. 6. The results of joint motion, two point discrimination, sensory recovery and status of sweating due to recovery ot sympathetic nervous function following replantation were satisfactory. 7. In the early stage of our series, postoperative systemic heparinization was used in some cases, but recently we have achieved good recults without it. 8. Main causes of reattachment failure were tissue crushing and secondary thrombosis of the anstomosed vessels.