Biomedical subjects

S C Huang

Publications and source records attributed to S C Huang.

At least 55 records · Page 3Linked to original sources

PubMed2001

Acute flaccid paralysis in infants and young children with enterovirus 71 infection: MR imaging findings and clinical correlates.

BACKGROUND AND PURPOSE: Enterovirus 71 (EV71) infection is now considered an important cause of childhood acute flaccid paralysis. The purpose of our study was to determine whether EV71-infection-related acute flaccid paralysis in infants and young children has characteristic MR imaging patterns. METHODS: Seven infants and young children with acute paralysis of the upper or lower extremities and positive EV71 cultures underwent spinal MR studies during an outbreak of hand-foot-and-mouth disease in Taiwan in 1998. RESULTS: Acute paralysis was observed in one upper extremity in two patients, in one lower extremity in three patients, and in both lower extremities in two patients. None of the patients had sensory impairment or bulbar palsy. MR studies showed unilateral or bilateral hyperintense lesions in the anterior horn regions of the cord on T2-weighted images in six patients. No abnormal signal was present in one patient. Two of three patients who received intravenous injections of contrast material had ventral root enhancement on T1-weighted images. One of them also had enhancement of the unilateral anterior horn cells. At clinical follow-up, both patients with bilateral anterior horn abnormalities had residual motor weakness, whereas only one of the five patients with unilateral involvement had residual weakness. CONCLUSION: EV71 radiculomyelitis tends to be unilateral and to specifically involve both the anterior horn cells of the cord and the ventral roots. MR imaging allows early detection of spinal cord and root lesions.

Acute Disease↗

PubMed2001

Acute necrotizing encephalopathy of childhood.

Symmetric change of the entire area of the bilateral thalami, as with panthalamic lesions, plus involvement of other regions in the brain rarely occurs to previously healthy children. The term, acute necrotizing encephalopathy of childhood, has recently been proposed. Its clinical, radiological, and pathological features are described. This disease predominantly affects infants and young children living in Taiwan and Japan, and manifests itself as acute encephalopathy following 2 to 4 days of fever and minor symptoms of the respiratory and/or gastrointestinal systems. The hallmark of this encephalopathy consists of multifocal, symmetric brain lesions affecting the bilateral thalami, and/or cerebral periventricular white matter, brainstem tegmentum, or cerebellar medulla, which can be documented by ultrasonography, computed tomography, and magnetic resonance imaging of the brain. The prognosis is usually poor. Less than 10% of patients recover completely. Cases with good outcome were reported to have reversible imaging changes. Focal neurologic deficits are common sequelae. The pathogenesis of acute necrotizing encephalopathy of childhood is still not known. Some diseases, such as Reye's syndrome, vascular occlusion, tumor, hemorrhage of the thalamus, Sandhoff disease, or Leigh and Wernicke encephalopathies must be differentiated clinically, radiologically, or pathologically. By excluding other disease entities, acute necrotizing encephalopathy of childhood can be diagnosed.

Acute Disease↗

PubMed2001

Clinical features and outcome of appendicitis in children younger than three years of age.

BACKGROUND: Acute appendicitis is the most common surgically amenable cause of acute abdominal pain in children. We analyzed our past experience of appendectomies in children and present the clinical characteristics of appendicitis in children younger than 3 years of age. A better understanding of appendicitis in early childhood would allow us to achieve an earlier diagnosis. METHODS: A group of 475 children from 4 months to 15 years of age who underwent appendectomy for appendicitis was studied over a 5-year period from July 1994 to June 1999. Excluding cases with negative pathological findings (n = 34), they were divided into 2 age groups: group I (< or = 3 years old) and group II (> 3 years old). Medical records were reviewed and comparisons between clinical findings, laboratory data, pathology findings, and complications were made. RESULTS: Of 441 cases enrolled in our study, 24 (5.4%) were 3 years of age or younger. Of all children older than 3 years of age, 32 (7.1%) had negative pathological findings compared to children younger than 3 years of age (7.7%). The duration of symptoms prior to diagnosis in group I was 3.6 days compared to group II at 2.0 days. Children from group I frequently showed a higher incidence of fever (90% vs. 53.4%), abdominal distention (50% vs. 9.8%), perforation (50% vs. 40.1%), and missed first impression (29% vs. 2.4%) than those from group II. Children of group I also had a higher complication rate (41.7% vs. 11.5%). CONCLUSIONS: In early childhood the symptoms and signs of appendicitis usually are nonspecific. There is a longer duration before diagnosis, more instances of fever and abdominal distention, less right lower quadrant pain, less local tenderness and rebounding pain, and no obturator sign. Close observation and on-going evaluation of patients are essential.

Appendicitis↗

PubMed2001

Pancreatitis with gallbladder ascariasis in a child: case report.

A 10-year-old girl was admitted for abdominal pain for 1 week. Morning vomiting with 5 Ascaris and diarrhea with Ascaris were found. Radiograph of the abdomen disclosed no significant abnormality. Abdominal sonogram revealed a normal biliary tree; but mildly enlarged pancreatic thickness, and thickened gallbladder wall. Within the thickened gallbladder wall a linear echogenic structure with worm-like movement suspected of being Ascaris was found. We report this case because pediatric pancreatitis and a gallbladder wall thickened with worm-movement have rarely been reported. Urgent treatment and surgery are required for the very ill child with a tensely distended abdomen or signs of peritoneal irritation. Early diagnosis is very important to prevent further complications. We emphasize the role of sonography in the diagnosis of this case and the prevention of progressive deterioration.

Ascariasis↗

PubMed2001

Pregnancy after intentional cryopreservation of percutaneous sperm aspiration specimens and intracytoplasmic sperm injection. A report of two cases.

BACKGROUND: Microsurgical epididymal sperm aspiration (MESA) and percutaneous epididymal sperm aspiration (PESA) are two methods of obtaining spermatozoa from patients with irreparable obstructive azoospermia. Intentionally using frozen-thawed spermatozoa obtained from MESA had been reported to be successful. With minimal invasiveness, intentionally cryopreserved PESA specimens and intracytoplasmic sperm injection (ICSI) were carried out in two cases. CASES: Two cases of irreparable obstructive azoospermia received PESA, and the spermatozoa were cryopreserved intentionally. Successful ICSI was performed later, utilizing frozen-thawed spermatozoa. CONCLUSION: PESA and ICSI are promising methods for these patients. The major advantages are minimal invasiveness and flexibility for further treatment.

Adult↗

PubMed2001

Genetic aspects of pheochromocytoma.

We here review the literature on genetics related to pheochromocytoma. About 10 percent of these neuroendocrine tumors are hereditary and are most often associated with multiple endocrine neoplasia type 2 (MEN 2), von Hippel-Lindau disease, and neurofibromatosis type 1 (NF 1). Hereditary tumor syndromes such as the aforementioned ones, are ideal to study the molecular pathogenesis of tumorigenesis as opposed to sporadic tumors in which genetic alterations often merely represent epigenetic tumor progression phenomena. Recent advances in molecular genetics, especially of RET, VHL, NF1, and SDHD, helped better understand the pathogenesis of pheochromocytoma. In this paper, we not only summarize key points of genetic discoveries related to pheochromocytoma, but also report in table format all known RET germline mutations related to pheochromocytoma.

Drosophila Proteins↗

PubMed2001

Diagnosis and results of treatment with radiation therapy in gliomatosis cerebri patient: case report.

Gliomatosis cerebri (GC) is a rare disease loosely defined as a diffusely infiltrating glioma involving extensive areas of the brain. The prognosis is poor and no definite treatment has proven effective for GC. Little information exists regarding the role of radiation therapy (RT) for GC, but some researchers have suggested that it is a good choice of treatment from their limited experience. In this report, we present a case with imaging and histological diagnosis of GC and demonstrate the treatment results of RT. The patient was a 39-year-old woman with progressive symptoms of dizziness, unsteady gait, headache, vomiting, and consciousness disturbance for 6 months. She received a series of radiographic examinations and surgical interventions for diagnosis. The definite diagnosis of GC was made by a combination of magnetic resonance imaging (MRI) findings and histological examinations. Forty Gray (Gy) of whole brain irradiation followed by 14 Gy reduced-field boosts were given to her. The MRI, following treatment, showed regressive changes, and clinical symptoms were slightly improved. The patient survived 19 months after the diagnosis, which is longer than the average survival time of patients without treatment.

Adult↗

PubMed2001

Surgical treatment of subluxation and dislocation of the hips in cerebral palsy patients.

BACKGROUND AND PURPOSE: Progressive subluxation and dislocation of the hip are major complications in patients with cerebral palsy (CP), causing functional deterioration and difficulties in personal hygiene. Treatment of these problems is difficult and complicated. The purpose of this study was to describe the surgical results and long-term follow-up in a group of CP patients. METHODS: Twenty-three CP patients with subluxated (15 hips) or dislocated hips (12 hips) underwent corrective surgery between 1985 and 1993. This included 11 quadriplegic, eight diplegic, and four hemiplegic patients. Before surgery, four patients were bed-ridden, eight were sitters, six were house-ambulators, and five were community-ambulators. The average age at surgery was 8 years and 5 months. The surgical procedures consisted of femoral varus derotational osteotomy in 21 patients (25 hips), selected soft tissue release in 18 patients (22 hips), and pelvic osteotomy in 18 patients (20 hips). The center-edge angle, acetabular index, and neck-shaft angle were used as parameters to evaluate preoperative and postoperative radiographic changes. RESULTS: After an average follow-up of 4.8 years, 19 patients (22 hips) had gained hip stability, and also had improved functional status. The four bed-ridden patients all became sitters; six of the eight sitters became house-ambulators and one became a community-ambulator; all six house-ambulators became community-ambulators, and the five community-ambulators had functional improvement. Complications included nonunion at the femoral osteotomy site in one hip, redislocation in two hips, and resubluxation in one hip. CONCLUSIONS: We conclude that subluxated or dislocated hips in patients with CP can be effectively treated with aggressive correction, which may include soft tissue release, femoral derotational osteotomy, and pelvic osteotomy for improvement of hip range of motion and functional status.

Adolescent↗

PubMed2001

One-stage correction of neglected developmental dysplasia of the hip by open reduction and pemberton osteotomy.

BACKGROUND AND PURPOSE: Pemberton osteotomy is commonly used for correction of hip-dysplasia. Its application in treating hip dislocation is rarely reported. The purpose of this study was to determine the efficacy of one-stage open reduction and Pemberton osteotomy of neglected developmental dysplasia of the hip (DDH). METHODS: We retrospectively reviewed the clinical and radiographic results of one-stage total correction in 75 patients with neglected DDH (86 hips) from 1984 through 1996. Sixty-nine patients (77 hips) aged 13 to 76 months (mean, 21.5 mo) underwent open reduction, Pemberton osteotomy, and hip spica for 8 weeks. Seven patients (9 hips) aged 29 to 73 months (mean, 46.6 mo) underwent additional femoral shortening (another hip in one bilaterally involved patient underwent only open reduction and Pemberton osteotomy). RESULTS: Acetabular index improved markedly from 40.4 degrees (range, 25-60 degrees) preoperatively to 16.2 degrees (range, 0-30 degrees) postoperatively. Complications included redislocation in four patients (4 hips) and avascular necrosis in three patients (3 hips). Reoperation was performed in four patients (4 hips). All patients were followed up for at least 3 years. By Severin's classification, all operated hips had excellent (18) or good (68) final radiographic results. The functional results, evaluated by McKay's criteria, were also excellent (52 patients/60 hips) and good (23 patients/26 hips). CONCLUSIONS: Neglected DDH was safely and effectively treated by open reduction, Pemberton osteotomy, and optional femoral shortening with limited complications.

Age Factors↗

PubMed2001

Pulmonary valvular stenosis complicated by cerebrovascular accident and congestive heart failure in a young child.

Pulmonary valvular stenosis (PS) with intact ventricular septum is a common congenital heart disease. In general, mild PS has a benign clinical course. However, in severe PS and some cases of moderate stenosis, increasing severity of the lesion may occur. The manifestations of either cerebrovascular accident (CVA) or congestive heart failure (CHF) are rarely reported in pediatric patients with PS. In this report, we describe a girl with severe PS complicated by seizures and sudden onset of hemiparesis at 13 months of age who developed CHF when 16 months old. CHF was cured after successful balloon valvuloplasty. She remained well without residual hemiparesis or recurrent seizures during the 1-year follow-up. Early balloon valvuloplasty should be emphasized in patients with severe PS, even if there are no significant clinical symptoms. With prompt balloon valvuloplasty, these complications can be effectively prevented.

Female↗

PubMed2001

Hepatic focal nodular hyperplasia in children: report of three cases.

Hepatic focal nodular hyperplasia is very rare in children. We present 3 cases aged from 8 to 17 years. All of them are girls, none of whom used oral contraceptives. Case 1 was a hepatitis B carrier and was incidentally found to have focal nodular hyperplasia (FNH). The other 2 cases presented with abdominal pain. Abdominal computed tomography revealed a solitary liver tumor in cases 2 and 3, but no abnormalities in case 1. A 7-cm tumor was located in the left lobe of the liver with compression of the stomach in the 2nd case. Abdominal magnetic resonance imaging (MRI) showed a mass with isointense density to liver parenchyma on T1WI and hyperdensity on T2WI in the 1st and the 3rd cases. The inferior vena cava was compressed and displaced anteriorly in the 1st case. Because of differences in the clinical presentation and imaging studies, the 1st and 2nd cases received resection while the 3rd case was treated conservatively. Pathologic findings confirmed the diagnosis of focal nodular hyperplasia in all 3 cases. We emphasize the importance of an MRI scan in the diagnosis of hepatic focal nodular hyperplasia, and different clinical manifestations and imaging studies may lead to different management.

Adolescent↗

PubMed2000

Genetic heterogeneity in familial juvenile polyposis.

Juvenile polyposis syndrome (JPS) is an autosomal dominant syndrome characterized by multiple gastrointestinal hamartomatous polyps in the absence of the extraintestinal features that are classic for other hamartomatous polyposis syndromes, such as Bannayan-Riley-Ruvalcaba syndrome (BRRS) and Cowden disease (CD). About 50% of BRRS and >80% of CD demonstrate germ-line mutations in the tumor suppressor and dual phosphatase, PTEN. Germ-line mutation of PTEN as a cause for JPS in a child is controversial because extraintestinal manifestations that would exclude JPS could appear after adolescence, altering the clinical diagnosis. Here, we investigated a family in which the 55-year-old father, who lacks thyroid or skin findings characteristic of CD, demonstrated a germ-line mutation in PTEN that was passed to identical twin daughters, who both manifested JPS. The mutation was a deletion of five bases beginning seven bases from the start of exon 4 of PTEN, which caused aberrant transcripts by reverse transcription-PCR that were absent from a normal individual. Thus, mutations in PTEN are associated with JPS in addition to CD and some BRRS families, although the incidence of PTEN germ-line mutations in JPS might be more rare than that reported for SMAD4, a gene found to be mutated in approximately one-half of the JPS families investigated.

Adenomatous Polyposis Coli↗

PubMed2000

Duplication of the mutant RET allele in trisomy 10 or loss of the wild-type allele in multiple endocrine neoplasia type 2-associated pheochromocytomas.

Inherited mutations of the RET proto-oncogene are tumorigenic in patients with multiple endocrine neoplasia type 2 (MEN 2). However, it is not understood why only few of the affected cells in the target organs develop into tumors. Genetic analysis of nine pheochromocytomas from five unrelated patients with MEN 2 showed either duplication of the mutant RET allele in trisomy 10 or loss of the wild-type RET allele. Our results suggest a "second hit" causing a dominant effect of the mutant RET allele, through either duplication of the mutant allele or loss of the wild-type allele, as a possible mechanism for pheochromocytoma tumorigenesis in patients with MEN 2.

Adrenal Gland Neoplasms↗

PubMed2000

Somatic von Hippel-Lindau gene mutations detected in sporadic endolymphatic sac tumors.

Endolymphatic sac tumors (ELSTs) occur sporadically or in association with an autosomal dominantly inherited tumor syndrome, von Hippel-Lindau (VHL) disease. In VHL disease, a germline mutation of the VHL tumor suppressor gene is inherited, and loss of function of the wild-type allele occurs through genetic deletion with subsequent development of neoplastic growth. Genetic alterations associated with sporadic ELSTs are less well understood. In this study, we used tissue microdissection to selectively analyze neoplastic cells from four sporadic ELSTs. In two cases, we detected somatic mutations involving VHL gene exons 1 and 2, respectively. Additionally, one of these cases revealed deletion of the VHL gene locus. Two cases did not reveal VHL gene mutation; one of these two cases showed VHL gene deletion. These results suggest that mutations and allelic deletions of the VHL tumor suppressor gene play a role in the tumorigenesis of sporadic ELSTs.

Adult↗

PubMed2000

Characterization of the interaction between protein 4.1R and ZO-2. A possible link between the tight junction and the actin cytoskeleton.

Multiple isoforms of the red cell protein 4.1R are expressed in nonerythroid cells, including novel 135-kDa isoforms. Using a yeast two-hybrid system, immunocolocalization, immunoprecipitation, and in vitro binding studies, we found that two 4.1R isoforms of 135 and 150 kDa specifically interact with the protein ZO-2 (zonula occludens-2). 4.1R is colocalized with ZO-2 and occludin at Madin-Darby canine kidney (MDCK) cell tight junctions. Both isoforms of 4.1R coprecipitated with proteins that organize tight junctions such as ZO-2, ZO-1, and occludin. Western blot analysis also revealed the presence of actin and alpha-spectrin in these immunoprecipitates. Association of 4.1R isoforms with these tight junction and cytoskeletal proteins was found to be specific for the tight junction and was not seen in nonconfluent MDCK cells. The amino acid residues that sustain the interaction between 4.1R and ZO-2 reside within the amino acids encoded by exons 19-21 of 4.1R and residues 1054-1118 of ZO-2. Exogenously expressed 4.1R containing the spectrin/actin- and ZO-2-binding domains was recruited to tight junctions in confluent MDCK cells. Taken together, our results suggest that 4.1R might play an important role in organization and function of the tight junction by establishing a link between the tight junction and the actin cytoskeleton.

Actins↗

PubMed2000

Norcantharidin-induced post-G(2)/M apoptosis is dependent on wild-type p53 gene.

Norcantharidin (NCTD), a synthetic analogue of phosphatase type 2A inhibitors, cantharidin, was shown to have limited effects in treating human and animal tumors. The tumor cell killing mechanisms by norcantharidin, however, remain unclear. In this report, we wished to investigate the mechanisms of norcantharidin-mediated cytotoxicity. Effort was made to investigate whether norcantharidin exerted its cytotoxicity through a p53-dependent or -independent mechanism. RT-2 (wtp53) and U251 (mutant p53) glioblastoma cell lines were exposed to norcantharidin at different dosages. Time-course fluorescent-activated cell sorting (FACS) analysis showed that high doses of norcantharidin arrested the cells at the G(2)/M phase and subsequent post-G(2)/M apoptosis in RT-2 cell line. In comparison, the U251 cell line was found resistant to norcantharidin-induced cytotoxicity. Restoring wild-type p53 gene function in the U251 cell line after adenoviral infections induced tumor cell cytotoxicity after exposure to norcantharidin. These results showed that norcantharidin kills tumor cells efficiently corresponding to their endogenous p53 gene status. The results also showed the feasibility of using adenoviral p53 gene therapy to enhance chemosensitivity of tumor cells to norcantharidin.

Antineoplastic Agents↗

PubMed2000

Cerebral metabolic and cognitive decline in persons at genetic risk for Alzheimer's disease.

The major known genetic risk for Alzheimer's disease (AD), apolipoprotein E-4 (APOE-4), is associated with lowered parietal, temporal, and posterior cingulate cerebral glucose metabolism in patients with a clinical diagnosis of AD. To determine cognitive and metabolic decline patterns according to genetic risk, we investigated cerebral metabolic rates by using positron emission tomography in middle-aged and older nondemented persons with normal memory performance. A single copy of the APOE-4 allele was associated with lowered inferior parietal, lateral temporal, and posterior cingulate metabolism, which predicted cognitive decline after 2 years of longitudinal follow-up. For the 20 nondemented subjects followed longitudinally, memory performance scores did not decline significantly, but cortical metabolic rates did. In APOE-4 carriers, a 4% left posterior cingulate metabolic decline was observed, and inferior parietal and lateral temporal regions demonstrated the greatest magnitude (5%) of metabolic decline after 2 years. These results indicate that the combination of cerebral metabolic rates and genetic risk factors provides a means for preclinical AD detection that will assist in response monitoring during experimental treatments.

Aged↗

PubMed2000

Expression of p16(INK4A) induces dominant suppression of glioblastoma growth in situ through necrosis and cell cycle arrest.

Tumor suppressor genes may represent an important new therapeutic modality in the treatment of human glioblastoma (GBM). p16(INK4A) is a tumor suppressor gene with mutation and/or deletion found in many human tumors, including glioblastomas, melanoma, and leukemias. RT-2 rat GBM cell line was used to investigate if the p16 gene induces dominant suppression of glioblastoma growth. Close to 100% of tumor cells were infected by high titer pCL retrovirus encoding the full-length human p16 cDNA at 5 m.o.i. Infected cells showed a 98% reduction in colony forming assay and a 60% reduction in growth curves in vitro compared to vector control. Exogenous overexpression of p16 induced hypophosphorylation of Rb protein by Western blot analysis. Intracranial injection of p16-infected tumor cells into syngeneic rats resulted in a 95% reduction in tumor volume compared to the controls. Intratumoral injection of p16 retrovirus resulted in tumor necrosis and prominent human p16 transgene expressions. Proliferation marker PCNA was not detected in these human p16-expressed RT-2 tumor cells, suggesting the cells were unable to enter into S phase after p16 expression. In addition, direct repeat intracranial injections of p16 retrovirus prolonged animal survival 3.2-fold compared to the controls (48.4 +/- 13.4 vs 15.0 +/- 2.1 days, p < 0.001). Two out of ten rats were found with dormant tumors at day 60 after p16 retrovirus injection. These results showed that p16 is effective in inhibiting GBM growth in situ. The mechanisms of tumor growth reduction and necrosis in vivo might be due to G1 arrest triggered by p16 expression.

Animals↗