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Biomedical subjects

Yongsoo Kim

Publications and source records attributed to Yongsoo Kim.

16 recordsLinked to original sources

The new frontier in understanding human and mammalian brain development.

Neurodevelopmental disorders that cause cognitive, behavioural or motor impairments affect around 15% of children and adolescents worldwide1, with diagnoses of profound autism and attention deficit hyperactivity disorder increasing in the USA and contributing to a major economic burden2,3. Yet the origins and mechanisms of these conditions remain poorly understood, limiting progress in therapies. Comprehensive cell atlases of the developing human brain, alongside those of model organisms such as mice and non-human primates, are now providing high-resolution measures of gene expression, cell-type abundance and spatial distribution. In this Perspective, we highlight recent studies that have identified novel developmental cell populations, revealed conserved and divergent patterns of cell genesis, migration and maturation across species, and begun testing hypotheses that link them to processes ranging from transcriptional control of cell fate specification to the emergence of complex behaviours. We present remaining conceptual and technical challenges and provide an outlook on how further studies of human and mammalian brain development can empower a deeper understanding of neurodevelopmental and neuropsychiatric disorders. Future efforts expanding to additional developmental stages, including adolescence, as well as whole-brain, multimodal and cross-species integration, will yield new insights into how development shapes the brain. These atlases promise to serve as essential references for unravelling mechanisms of brain function and disease vulnerability, and for advancing precision medicine.

Humans↗

Computed tomographic differentiation between alcoholic and gallstone pancreatitis: Significance of distribution of infiltration or fluid collection.

AIM: To evaluate the usefulness of various computed tomography (CT) findings including distribution of infiltration or fluid collection in differentiating the major etiologies of acute pancreatitis. METHODS: We reviewed 75 relatively severe cases of acute pancreatitis of alcoholic (n = 43) or biliary stone (n = 32) etiology having infiltration or fluid collection on CT. We compared the pancreatic size, CT grading, presence or absence of biliary calculi, and dilatation of pancreatic or bile duct. We also evaluated degree and the distribution of infiltration and fluid collection in each group. RESULTS: The sizes of pancreas were not different between alcohol group and stone group. Alcohol group showed higher CT grading than stone group (P < 0.05). Presence of biliary stone and duct dilatation was statistically significant in differentiating etiology (P < 0.05). Alcohol group showed significantly prominent peripancreatic pathology than stone group only in left peritoneal compartment (P = 0.020). CONCLUSION: Alcoholic pancreatitis tends to form more prominent peripancreatic changes than gallstone pancreatitis in relatively severe cases. This is evident on the anterior aspect of left abdomen. Although clinical history and some CT findings usually are a major determinant of the etiology, this pattern of peripancreatic pathology may have an ancillary role in determining the etiologies of acute pancreatitis in the equivocal cases.

Acute Disease↗

Cavernous mesenteric lymphangioma (2006: 4b).

We describe a case of mesenteric lymphangioma, a very rare disease in adults that is considered to be a developmental abnormality. Since treatment involves complete excision of the mass to prevent recurrence, it is important to understand the exact extent of the tumor prior to surgery. Magnetic resonance imaging (MRI) is the most useful preoperative approach for diagnosis and surgical planning.

Adult↗

Intrahepatic recurrence after percutaneous radiofrequency ablation of hepatocellular carcinoma: analysis of the pattern and risk factors.

PURPOSE: To evaluate the pattern and risks for intrahepatic recurrence after percutaneous radiofrequency (RF) ablation for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: We studied 62 patients with 72 HCCs (< or =4 cm) who were treated with percutaneous RF ablation. The mean follow-up period was 19.1 months (6.0-49.1). We assessed the incidence and cumulative disease-free survival of local tumor progression (LTP) and intrahepatic distant recurrence (IDR). To analyze the risk factors, we examined the following, for the LTP: (1) tumor diameter, (2) contact with vessels, (3) degree of approximation to hepatic hilum, (4) contact with hepatic capsule, (5) presence of ablative safety margin, (6) degree of benign periablational enhancement and (7) serum alpha-fetoprotein; for the IDR: (1) severity of hepatic disease, (2) presence of HBsAg, (3) serum alpha-fetoprotein, (4) whether RF ablation was the initial treatment and (5) multiplicity of tumor for IDR. RESULTS: The incidence of overall recurrence, LTP and IDR was 62.9%, 26.4% and 53.2%, respectively. The cumulative disease-free survival rates were 52%, 82% and 56% at 1 year, 26%, 63% and 30% at 2 years, respectively. Univariate analysis showed that the significant risk factors for LTP were: a tumor with a diameter >3 cm, contact of HCC with a vessel and an insufficient safety margin (p<0.05). A multivariate stepwise Cox hazard model showed that the measurement of a tumor diameter >3 cm and insufficient safety margin were independent factors. Only the increased serum alpha-fetoprotein was a significant risk factor for IDR (p<0.05). CONCLUSION: Intrahepatic recurrence after percutaneous RF ablation is common. Large HCC (>3 cm) with high serum alpha-fetoprotein should be treated more aggressively because of higher risk for recurrence.

Adult↗

Bronchobiliary fistula after radiofrequency thermal ablation of hepatic tumor.

A broad spectrum of complications can occur after radiofrequency (RF) ablation of hepatic tumors, even though it has been accepted as a safe and effective technique for unresectable hepatic tumors. Recently, the rare complication of brochobiliary fistula was encountered after RF ablation in a patient with a metastatic tumor from stomach cancer. It was assumed to have developed from collateral damage to the adjacent diaphragm and lung base as well as biloma formation at the ablation zone. Symptomatic improvement was achieved by conservative management with an external drainage catheter, but the fistula was still persistent on a 2-month follow-up image.

Adenocarcinoma↗

A positive role of the PI3-K/Akt signaling pathway in PC12 cell differentiation.

Activation of phosphatidylinositol 3-kinase (PI3-K) is considered to be a key event upon stimulation of cells with growth factors. Akt is known to be a downstream target of PI3-K when it is activated by nerve growth factor (NGF). NGF induces cell differentiation of PC12 cells as indicated by neurite outgrowth. In order to investigate the role of PI3-K/Akt in NGF-induced differentiation of PC12 cells, we generated cells ectopically expressing constitutively activated (CA), wild type (WT) and dominant negative (DN) forms of Akt. NGF-induced neurite outgrowth was greatly accelerated in the cells expressing CA-Akt, and dramatically inhibited in those expressing DN-Akt. Pre-treatment with an Akt inhibitor, ML-9 [1-(5-chloronaphthalene-1-sulfonyl)-1H- hexahydro-1,4-diazepine], inhibited NGF-induced Akt phosphorylation as well as neurite outgrowth but did not markedly affect the activities of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK). The PI3-K inhibitors wortmannin and LY294002 blocked NGF-induced Akt phosphorylation as well as neurite outgrowth. These results indicate that PI3-K/Akt is a positive regulator of NGF-induced neuronal differentiation in PC12 cells.

Androstadienes↗

Basal cell adenoma in the parotid gland: CT and MR findings.

Basal cell adenoma is a rare benign salivary gland epithelial tumor, usually involving the parotid gland. We report CT and MR findings of three cases with basal cell adenoma occurring in the parotid gland. The three cases presented here demonstrate a well-circumscribed tumor, which showed a cystic and solid, or the pure solid mass. They were well enhanced after contrast matter injection. The solid portion of the mass was isoattenuated at CT, with intermediate signal intensity on T1- and T2-weighted MR images. Its cystic portion was hyperintense on both T1- and T2-weighted MR images. It had a hypointense rim on T2-weighted image.

Adenoma↗

A study on the incidence of ABL gene deletion on derivative chromosome 9 in chronic myelogenous leukemia by interphase fluorescence in situ hybridization and its association with disease progression.

Fluorescence in situ hybridization for the BCR/ABL rearrangement in 138 bone marrow specimens from 59 Philadelphia(+) (Ph(+)) chronic myelogenous leukemia (CML) patients, 35 Ph(+) acute lymphoblastic leukemia (ALL) patients, and 57 Ph(-) ALL patients was used. Sixteen (27.1%) of the 59 CML patients had deletions of the residual ABL gene on the derivative chromosome 9. During the study period, 32 of the 59 CML patients progressed to blast crisis or accelerated phase. Of these, nine patients had residual ABL gene deletions on the derivative chromosomes 9 and 23 patients had no deletions. The mean duration from first diagnosis to blast crisis or accelerated phase for the nine patients with ABL deletions was 32.8 months, and for the 23 patients without ABL deletions, it was 62.4 months (P = 0.017). The overall survival time for the 16 patients with deletions was 32.8 months, and for the 43 patients without deletions, it was 60.1 months (P = 0.164). ABL deletions were not detected among the 35 ALL patients (17 with major BCR/ABL, 18 with minor BCR/ABL), and it appears that this deletion occurs rarely or not at all in Ph(+) ALL patients, which is in contrast to the CML patients (27.1%). However, we detected two ALL cases with ABL deletion but without BCR/ABL rearrangement among 49 Ph(-) ALL and 66 Ph(-) AML patients. In conclusion, patients with ABL deletions progress to blast crisis or accelerated phase in a significantly shorter time than do those without such deletions. It is therefore suggested that the ABL deletion is an indicator of a poor prognosis in CML.

Acute Disease↗

Primary retroperitoneal synovial sarcoma: a case report.

A case of a 36-yr-old woman with retroperitoneal synovial sarcoma is described. Her presenting symptom was epigastric pain that radiating to the back. On radiologic study, bulky retropancreatic soft tissue mass was detected which showed cystic and solid components. At operation, complete resection of the tumor was not possible because of the adhesion to the vena cava and the liver. During the follow-up, extensive tumor recurrence and liver metastasis were revealed. Primary retroperitoneal synovial sarcoma is a very rare malignant tumor with high mortality and recurrence rates. Retroperitoneal synovial sarcoma usually appears as a nonspecific soft tissue mass that do not have specific imaging features differentiating it from other mesenchymal tumors. However general radiologic findings and anatomic location of the tumor may help the diagnosis. In addition, synovial sarcoma should be included in the differential diagnosis of retroperitoneal soft tissue mass detected in young adults.

Adult↗

Segmental colonic involvement of plexiform neurofibroma in neurofibromatosis type 1.

In a 36-year-old man with neurofibromatosis type 1, rare colonic involvement of plexiform neurofibroma is presented. The diagnosis was confirmed by operation. Radiologic findings consisted of marked concentric thickening of the colonic wall with variable attenuation, namely, a "multilayer appearance," as well as clusters of multiple soft tissue nodules in the mesentery.

Adult↗

Does contrast enhancement on CT suggest tumor response for chemotherapy in small cell carcinoma of the lung?

PURPOSE: The purpose of this article is to assess the correlation between contrast enhancement on CT and the tumor reduction ratio in small cell carcinoma of the lung after first-line chemotherapy. MATERIALS AND METHODS: Twenty-eight patients with small cell carcinoma of lung underwent preenhancement and postenhancement CT scans before and after first-line chemotherapy, followed by second-line chemotherapy in 7 patients who had relapsed. The authors retrospectively analyzed the correlation between the tumor reduction ratio and the CT numbers of contrast enhancement in each case by multiple regression analysis using SPSS. RESULTS: The mean tumor-reduction ratio was 58.2 +/- 43.2% after first-line chemotherapy, and the mean CT enhancement was 33.2 +/- 11.0 Hounsfield units (HU). The correlation coefficient between the tumor reduction ratio and the CT numbers of contrast enhancement was 0.57 (r = 0.32), and p value was < 0.002. After chemotherapy, more than 90% tumor reduction was seen in 11 patients. They revealed an average 41.9 +/- 7.6 HU tumor enhancement. Less than 50% tumor reduction was seen in 10 patients. They revealed an average 26.2 +/- 7.9 HU tumor enhancement. If these criteria of 30 HU contrast enhancement and 80% tumor reduction ratio were applied as a guide for chemotherapy response, the sensitivity, specificity, positive predictive value, and negative predictive value would be calculated as 85.7%, 84.6%, 85.7%, and 84.6%, respectively. CONCLUSION: In small cell carcinoma of the lung, it is statistically proven that the more enhanced tumor on CT, the better response to chemotherapy. Tumor enhancement of 30 HU is a suggestive guide for chemotherapy response in patients with small cell carcinoma.

Aged↗

Heterotopic paragonimiasis in the omentum.

Paragonimus westermani is a lung fluke but may be found in organs other than the lungs. A case of omental paragonimiasis was found incidentally by plain radiography and computed tomography and showed multiple, irregularly shaped, conglomerated calcifications in the intraperitoneum. Many P. westermani ova were detected in the resected omentum. This uncommon calcification on the plain abdominal radiography and computed tomography scan was considered to represent radiologic findings of ectopic paragonimiasis.

Calcinosis↗

Extrapelvic and extraperitoneal spread of recurrent stomach cancer: two case reports.

We report two cases of unusual combined extrapelvic and extraperitoneal extension of recurrent gastric adenocarcinoma and describe the imaging findings of the preferential anatomic pathway of disease spread. Extrapelvic and extraperitoneal extension of recurrent gastric adenocarcinoma is rare, and its symptoms may be vague and nonspecific. If patients with a surgical history of gastrointestinal neoplasm present with diffuse abdominal pain or painful swelling of the lower extremities, disease spread to the extrapelvic and extraperitoneal spaces should be suspected.

Adenocarcinoma↗