Diagnostic value of ultrasonography to distinguish between benign and malignant lesions in the management of thyroid nodules / 대한내과학회지

BACKGROUND: Thyroid ultrasonography can accurately detect nonpalpable nodules, estimate the size of the nodule during follow-up, and discriminate between solid nodules and simple cysts. Many studies have recently been done to detect malignant thyroid nodules by high-resolution ultrasonography. However, the exact role of high-resolution ultrasonography in distinguishing benign from malignant nodules is still unresolved. We analyzed the sonographic characteristics of thyroid nodules and assessed the diagnostic value of ultrasonography. METHODS: We retrospectively analyzed the sonographic feature of thyroid nodules in patients who had been examined with fine-needle aspiration cytology or had surgery for a thyroid nodule at St. Mary's Hospital, Korea from January 2003 to January 2005. Sonographic features that suggested malignancy include microcalcifications, an irregular or microlobulated margin, marked hypoechogenicity, and a shape that was more tall than it was wide. If even one of these sonographic features was present, the nodule was classified as category 3 (malignant). If a nodule had none of the features described, it was classified as category 2 (benign). Anechogenic cystic nodule was classified as category 1 (benign). RESULTS: Of 124 lesions classified as category 3, 60 were malignant. Of 418 lesions classified as category 1 or 2, 409 was benign. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy based on sonographic classification method were 90%, 86.5%, 48.4%, 97.8%, 86.5%, respectively. CONCLUSIONS: Our results identified sonographic classification with calcification, margin, echogenicity and shape as useful tool in the differentiation of malignant from benign nodule. In view of the high value of negative predictive value of sonographic classification, a more aggressive approach is recommended only for nodules with category 3.

The Changes in the Serum RANKL and OPG levels after Bone Marrow Transplantation: Association with Bone Mineral Metabolism / 대한내분비학회지

BACKGROUND: The loss of bone mass is usually detected after bone marrow transplantation(BMT), particularly during the early post-transplant period. We recently reported that enhanced bone resorption following BMT was related to both the steroid dose and increase in IL-6. It was also suggested damage of the marrow microenvironment due to myeloablation and changes in bone growth factors contribute to post-BMT bone loss. Recently, the interactions of OPG and RANKL have been reported to be crucial in osteoclastogenesis and therefore in bone homeostasis. There are few data on the changes in RANKL/OPG status during the post-BMT period. This study investigated the changes in the levels of RANKL and OPG during the post-BMT period, and also assessed whether the changes in these cytokine levels actually influenced bone turnover and post-BMT bone loss. METHODS: We prospectively investigated 110 patients undergoing allogenic BMT and analyzed 36 (32.4+/-1.3 years, 17 men and 19 women) where DEXA was performed before and 1 year after the BMT. The serum bone turnover marker levels were measured before and 1, 2, 3, 4 and 12 wks, 6 Ms, and 1 yr after the BMT. The serum sRANKL and OPG levels were measured in all patients before and 1, 3 and 12 wks after the BMT. RESULTS: The mean bone losses in the lumbar spine and total proximal femur, which were calculated as the percent change from the baseline to 1 yr, were 5.2(P<0.01) and 11.6%(P<0.01), respectively. The mean serum ICTP, a bone resorption marker, increased progressively until 3 and 6 months after the BMT, but decreased gradually thereafter, reaching the basal values after 1 year. The serum osteocalcin levels decreased progressively until 3 wks after the BMT, then increased transiently at 3 and 6 Ms, but returned to the basal level by 1 yr. The serum sRANKL and OPG levels had increased significantly by weeks 1 and 3 compared with the baseline(P<0.01), but decreased at 3 months. The sRANKL/OPG ratio increased progressively until 3 weeks, but then decreased to the basal values. During the observation period, the percent changes from the baseline in the serum RANKL levels and RANKL/OPG ratio showed positive correlations with the percent changes from the baseline serum ICTP levels. Patients with higher RANKL levels and RANKL/OPG ratio during the early post-BMT period lost more bone mass at the lumbar spine. CONCLUSION: In conclusion, dynamic changes in the sRANKL and OPG levels were observed during the immediate post-BMT period, which were related to a decrease in bone formation and loss of L-spine BMD during the year following the BMT. Taken together, these results suggest that increased sRANKL levels and sRANKL/OPG ratios could be involved in a negative balance in bone metabolism following BMT.

The Effect of Simvastatin on the Proliferation and Differentiation of Human Bone Marrow Stromal Cells

Statins have been postulated to affect the bone metabolism. Recent experimental and epidemiologic studies have suggested that statins may also have bone protective effects. This study assessed the effects of simvastatin on the proliferation and differentiation of human bone marrow stromal cells (BMSCs) in an ex vivo culture. The bone marrow was obtained from healthy donors. Mononuclear cells were isolated and cultured to osteoblastic lineage. In the primary culture, 10(-6) M simvastatin diminished the mean size of the colony forming units-fibroblastic (CFU-Fs) and enhanced matrix calcification. At near confluence, the cells were sub-cultured. Thereafter, the alkaline phosphatase (ALP) activities of each group were measured by the time course of the secondary culture. Simvastatin increased the ALP activity in a dose dependent manner, and this stimulatory effect was more evident during the early period of culture. A 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay was performed during the secondary culture in order to estimate the effect of simvastatin on the proliferation of human BMSCs. When compared to the control group, simvastatin significantly decreased the proliferation of cells of each culture well. 10(-6) M of simvastatin also significantly enhanced the osteocalcin mRNA expression level. This study shows that simvastatin has a stimulatory effect on bone formation through osteoblastic differentiation, and has an inhibitory effect on the proliferative potential of human BMSCs.

The Effects of Aging on the Proliferation and Differentiation of Osteoblasts from Human Mesenchymal Stem Cells / 대한내분비학회지

BACKGROUND: Osteoblasts originate from osteoprogenitor cells in bone marrow stroma, termed mesenchymal stem cells (MSCs) or bone marrow stromal cells. Each MSC forms colonies (colony forming units-fibroblasts [CFU-Fs]) when cultured ex vivo. There are some reports about the age-related changes of the number and osteogenic potential of osteoprogenitor cells, but any relationship has not been clearly established in humans. In this study, we counted MSCs using CFU-Fs count and examined the proliferative capacity and differentiation potential of osteoprogenitor cells. Finally, we analyzed how these parameters varied with donor age. METHODS: Bone marrow was obtained from the iliac crest of young (n=6, 27.2+/-8.6 years old) and old (n=10, 57.4+/-6.7 years old) healthy donors. Mononuclear cells, including MSCs, were isolated and cultured in osteogenic medium. In primary culture, we compared the colony-forming efficiency of MSCs between the two groups and determined the matrix calcification. When primary culture showed near confluence, the cells were subcultured. Alkaline phosphatase activity, osteocalcinexpression by RT-PCR and proliferative potential by MTT assay were examined by the time course of secondary culture. RESULTS: At the 15th day of primary culture, the mean number of CFU-Fs was significantly higher in the younger donors (young: 148.3+/-28.9, old: 54.3+/-9.1, p=0.02) and the mean size of CFU-Fs was also larger in the younger donors than the older donors. However, matrix calcification was not different between the two groups (young: 103.6+/-50.6, old: 114.0+/-56.5, p=NS). In secondary culture, alkaline phosphatase activities were significantly lower in the older donors. The younger donors showed peak alkaline phosphatase activity at day 10, while the older donors didn't showed a remarkable peak (young: 935.5+/-115.0U/mg, old: 578.4+/-115.7U/mg, p<0.05). Total cell number as a proliferative index increased progressively during the secondary culture and a significantly greater cell number was noted in the younger donors. Osteocalcin expression was generally upregulated in the younger donors, but this was not statistically significant. CONCLUSION: Our study shows that the number of osteoprogenitor cells is decreased during aging and that the proliferative capacity and differentiation potential of osteoprogenitor cells seem to be reduced during aging.

A Case of Type 1 Renal Tubular Acidosis Accompanying Renal Stone and Nephrocalcinosis Caused by Hypocitraturia / 대한신장학회잡지

Renal stone and nephrocalcinosis are common clinical manifestations of type 1 renal tubular acidosis. In normal state, citrate plays the most critical role in suppressing stone formation as it combines with calcium. In type 1 RTA, increased reabsorption of citrate in proximal tubule results in low citrate excretion, which precipitates renal stone formation. We report a case of type 1 RTA accompanying renal stone and nephrocalcinosis caused by hypocitraturia. A 16-year-old male patient who had renal stone and nephrocalcinosis showed hypocitraturia. Incomplete type 1 RTA was proved as the cause of hypocitraturia by bicarbonate and ammonium loading test in the patient.

Small Intestinal Obstruction due to Phytobezoars: Case reports / 대한소화기내시경학회지

Phytobezoars are the most common type of bezoars composed of nondigestible food material. They are usually formed in stomach and do not migrate to the other intestinal tract. Recently, we experienced two cases of small bowel phytobezoars resulting in obstruction. The first case is a 72-year-old male patient who had no previous history of surgery. He had poor dentition, and the history of eating dry persimmons 20 days before the onset of symptoms. The phytobezoar (4 X 3 cm) obstructed the terminal ileum. Colonoscopic removal was performed successfully. The second case is a 45-year-old male patient undergone previous vagotomy and pyloroplasty for duodenal ulcer perforation. He had a huge phytobezoar (10 X 6 cm) in stomach, which was treated by endoscopic removal. After incomplete endoscopic treatment, it moved into the proximal jejunum and obstructed the lumen. It was removed by operation.

Two Cases of Mallory-Weiss Syndrome During Bowel Preparation for Colonoscopy / 대한소화기내시경학회지

Polyethylene glycol solutions have been usually available for clinical use since 1980 and been considered a standard method of bowel preparations for colonoscopy. There have been many reports about minor complications such as nausea and bloating associated with their use, which are frequently occurred. After ingestion of polyethylene glycol, vomiting occurrs less frequently but it can make major complication such as Mallory-Weiss syndrome and aspiration pneumonia. We have reported here two cases of Mallory-Weiss syndrome, which were occurred after ingestion of polyethylene glycol solution for colonoscopy.