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Biomedical subjects

Yi-Hong Chou

Publications and source records attributed to Yi-Hong Chou.

At least 37 records · Page 2Linked to original sources
PubMed2005

Clinical features of nosocomial infections by extended-spectrum beta-lactamase-producing Enterobacteriaceae in neonatal intensive care units.

AIM: To determine the risk factors for the acquisition of nosocomial extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae infection in infants hospitalized in neonatal intensive care units (NICUs) and to evaluate the therapeutic outcome of these infants. METHODS: We retrospectively reviewed the medical records of infants with nosocomial ESBL-producing Enterobacteriaceae infection hospitalized in NICUs at Chang Gung Children's Hospital in 2001. The clinical features of these infants were compared with a cohort of non-ESBL-producing Enterobacteriaceae-infected infants during the same period. The therapeutic outcome of the infants in the ESBL group was analysed. RESULTS: Seventy infants were included in this study. Thirty-one infants with 34 isolates were identified in the ESBL group and 39 infants with 42 isolates in the non-ESBL group. Of the parameters analysed, including gestational age, birthweight, length of hospital stay before onset, the number of antibiotics used, the duration of third-generation cephalosporin usage and the number of patients receiving a third-generation cephalosporin prior to the onset of infection, no significant difference was found between the two groups. The infection-contributed case fatality rate was 3.0% (1 of 33) in the ESBL group, not significantly different from that in the non-ESBL group (1 of 41, 2.4%). Of the 31 patients in the ESBL group, 18 were treated with a carbapenem as definitive therapy while 13 were treated with a non-carbapenem antibiotic regimen. No significant difference was noted in terms of mortality rate between the two subgroups. CONCLUSION: The outcome of the infants hospitalized in the NICU with ESBL-producing enterobacterial infections was not indispensably grave, even when treated with a non-carbapenem antibiotic regimen. The risk factors for the acquisition of ESBL-producing enterobacterial infections in these infants were not identified in this series.

Anti-Bacterial Agents↗
PubMed2005

High-resolution ultrasonography of primary peripheral soft tissue lymphoma.

OBJECTIVE: The purpose of this study was to evaluate the appearance of primary peripheral soft tissue lymphoma on high-resolution ultrasonography. METHODS: We retrospectively studied the sonograms of 12 patients (5 female and 7 male; age range, 12-90 years; mean, 55 years) with soft tissue lymphoma. All lesions were palpable and in the salivary glands, trunk, upper limb, or lower limb, and the diagnosis was proved by biopsy or open surgery. For each lesion, sonograms were obtained by gray scale and color Doppler ultrasonography. RESULTS: The gray scale imaging showed relatively homogeneous hypoechogenicity in 11 patients and homogeneous hyperechogenicity in 1 patient. The tumors appeared as big masses in 5 patients, nodal or confluent nodes in 3, small disseminated nodules in 2, a myositis type in 1, and a panniculitis type (homogeneous echogenic infiltrate in a subcutaneous fat layer) in 1. CONCLUSIONS: In patients with a soft-tissue mass, routine plain radiography and high-resolution ultrasonography including color Doppler ultrasonography are recommended before further evaluation with ultrasonographically guided biopsy.

Adolescent↗
PubMed2005

Retroperitoneal venous hemangioma.

Venous hemangioma is an extremely uncommon tumor. We report a 61-year-old woman with a surgically proven venous hemangioma in the retroperitoneum. Image studies, including sonography, computed tomography and angiography, revealed a heterogeneous mass lesion with firm adherence to the adjacent organs and engulfing the major vessels. Only subtotal resection of the tumor was done due to technical difficulty. Follow-up magnetic resonance imaging 7 months after surgery showed reduction in size and much delayed enhancement of the residual tumor. In conclusion, firm attachment to adjacent organs and much delayed enhancement are clues for the diagnosis of a venous hemangioma.

Female↗
PubMed2005

Percutaneous placement of metallic stents in the management of malignant biliary obstruction.

BACKGROUND AND PURPOSE: The placement of metallic stents is now a well-established method in the management of malignant biliary obstruction. This study evaluated the long-term clinical efficacy of percutaneous transhepatic insertion of metallic stents in the management of malignant biliary obstruction. METHODS: From January 1999 to December 2002, 102 consecutive patients with malignant biliary obstruction were treated with percutaneous transhepatic placement of metallic stents at a medical center in Taipei. The level of obstruction was at the hepatic hilum in 44 patients, and common bile duct (CBD) in 58 patients. Memotherm stents were used in 78 patients and Wallstents in 38. Among the 44 patients with hilar obstruction, 30 received a single stent and 14 received bilateral stents. Among the 58 patients with CBD obstruction, the stents were placed across the ampulla of Vater in 27. Patient survival rates and stent patency rates were compared using the Kaplan-Meier method. RESULTS: Placement of stents was successful in all patients. The mean (range) serum bilirubin level before, 1 week after, and 1 month after stent insertion was 15.1 mg/dL (4.2-32.4 mg/dL), 7.8 mg/dL (0.5-19.4 mg/dL), and 1.8 mg/dL (0.2-8.2 mg/dL), respectively. The mean survival in all patients was 66.0 weeks (1-130 weeks) and the mean stent patency period (MSPP) in all patients was 59.9 weeks (1-130 weeks). The MSPP was 71.4 versus 49.9 weeks in hilar type versus CBD type patients (p = 0.047). The MSPP was 53.9 versus 73.0 weeks in patients who received Memotherm stents versus Wallstents (p = 0.115). In the hilar obstruction group, the MSPP was 82.1 versus 58.0 weeks in patients receiving bilateral versus a single stent (p = 0.039). In the CBD obstruction group, the MSPP was 46.3 versus 45.5 weeks in stents placed across versus not placed across the ampulla of Vater (p = 0.338). CONCLUSIONS: The efficacy and patency period of percutaneous transhepatic insertion of metallic stents in the management of malignant biliary obstruction is satisfactory in the relief of obstructive jaundice. Both types of metallic stents performed well in relieving malignant biliary obstruction. Bilateral stenting was more effective than single stenting in treating patients with hilar obstruction. In patients with CBD obstruction, no significant difference in the stent patency period was found between stents placed across or not across the ampulla of Vater.

Adult↗
PubMed2004

Splenic hamartoma: presentation on contrast-enhanced sonography.

Splenic hamartoma is a rare benign tumor of the spleen. It is usually found incidentally at autopsy or splenectomy. We report a case of splenic hamartoma that was discovered during medical workup for vague upper abdominal pain. Abdominal sonography demonstrated a well-demarcated, slightly hypoechoic splenic solid mass; the mass was markedly enhanced on color Doppler sonography after injection of microbubble contrast agent. This finding may help to distinguish splenic hamartomas from other relatively common splenic tumors, such as hemangiomas or metastases.

Contrast Media↗
PubMed2004

Computed tomography features of acute pulmonary tuberculosis.

The purpose of this study was to demonstrate the computed tomography (CT) features of pulmonary tuberculosis in patients with acute clinical manifestations. The emergent CT images of 46 non-AIDS patients with acute clinical presentations of pulmonary tuberculosis (TB) were analyzed. The distribution and characterization of the pulmonary and pleural lesions were specifically focused. Multifocal airspace consolidation in multiple lobes was most commonly seen on the CT in 32 of 46 patients (70%), followed by cavitary pulmonary nodular shadows (50%). Other CT manifestations included pleural effusion (40%), TB empyema (20%), and lymphadenopathy (11%). On followup, 12 patients (26%) developed acute respiratory failure. Patients presenting with multifocal pulmonary consolidation, with or without cavitations, on CT should undergo early pulmonary TB workup. These findings could help early detection for pulmonary TB.

Acute Disease↗
PubMed2004

Factor analysis in both spatial and temporal domains of color blooming artifacts in ultrasound investigations utilizing contrast agents.

Color blooming artifacts can cause misinterpretations of normal and pathological structures during color Doppler flow imaging with ultrasound contrast agents (USCAs). These artifacts are characterized in both the spatial and temporal domains: in the spatial domain, artifacts result from wave propagation and the ultrasound system; and in the temporal domain, the color blooming time (CBT) is used to denote the duration of artifacts. In our experiments, CBT decreased from 86.7 to 46.8 s when the transmitting pressure was decreased from 370 to 180 kPa. From this, we conclude that an adaptive mechanical index can significantly shorten the CBT, which may in turn prolong the optimal viewing time during in vivo ultrasound investigations utilizing USCAs.

Artifacts↗
PubMed2004

Prostatic abscess: transrectal color Doppler ultrasonic diagnosis and minimally invasive therapeutic management.

The purpose of this study was to analyze the transrectal ultrasound (US), or TRUS, and color Doppler ultrasonography (CDU) findings and therapeutic strategies with TRUS-guided procedures in 13 patients with prostatic abscess. Over a period of 6 years, 18 prostatic abscesses were diagnosed in 13 patients (mean age: 59 years). Diagnostic workup included TRUS, analysis of midstream urine, and analysis and culture of abscess fluid for leukocytes and pathogens. These patients were treated either conservatively (for abscess cavities < 1 cm in diameter), or by aspiration or draining procedures (cavities > or = 1 cm). The transrectal CDU findings were correlated to the treatment effects. The predisposing factors were also reviewed. In the 13 patients, the most common clinical symptom and sign were urinary frequency (77%) and pus cell in the midstream urine (92%). Predisposing factors were found in 11 men, with diabetes in 5 of them. In 10 patients, the definitive preinterventional diagnosis was based on the TRUS findings. TRUS with probe palpation demonstrated tiny floating echogenic speckles in the abscess cavity in 4 patients. CDU demonstrated increased color-flow signals at the margin and surrounding tissue of the abscess pockets. Abscesses with poorly defined boundaries had more prominent surrounding color-flow signals and achieved, with relative difficulty, a satisfactory aspiration procedure. Aspiration was done for all 11 abscesses between 1 and 3 cm. A total of 4 larger abscesses (> 3.0 cm) were treated with aspiration or drainage using a 5-French pigtail catheter. No surgical drainage was performed. Transrectal CDU may help in the evaluation of maturity of an abscess pocket. US-guided aspiration with an 18-gauge needle or drainage with a 5-French pigtail catheter significantly shortened the hospital stay.

Abscess↗
PubMed2004

Tuberculosis of the parotid gland: sonographic manifestations and sonographically guided aspiration.

OBJECTIVE: Involvement of the parotid gland by tuberculosis (TB) is rare. If treated properly, the prognosis of TB of the parotid gland is good. In this retrospective study, we report our experience with sonography and sonographically guided aspiration in the diagnosis of parotid TB. METHODS: Over 12 years, 9 adults (mean age, 48 years) with parotid gland TB had been examined with high-resolution sonography and color Doppler sonography for their clinical problems of swelling on the mandibular angle. Sonographically guided fine-needle aspiration was done for cytologic study, stains for acid-fast bacilli, and cultures for mycobacterium. RESULTS: The sonographic patterns were classified as chiefly the parenchymal type (4 patients) and chiefly the periparotid type (5 patients). The parenchymal type appeared as a diffusely enlarged, comparatively hypoechoic gland (compared with the contralateral asymptomatic gland), with or without focal intraparotid nearly anechoic zones, which might have a cavity or cavities within it. The periparotid type appeared as hypoechoic nodules located in the peripheral zone of the hyperechoic parotid gland, consistent with enlarged periglandular lymph nodes. The diagnosis of parotid TB was made in 8 of 9 patients on the basis of sonographically guided aspiration for acid-fast bacilli stains, cytologic study, and cultures for mycobacterium. CONCLUSIONS: Sonographic examination contributes substantially in the diagnosis of parotid TB infection. In the presence of diffuse parotid echo pattern changes with periparotid lymphadenopathy, and with or without focal hypoechoic zones, TB infection should be differentiated. Sonographically guided fine-needle aspiration may provide further diagnostic information by means of stains, cultures, and cytologic study.

Adult↗
PubMed2004

Congenital short bowel syndrome with malrotation.

Congenital short bowel syndrome (SBS) associated with malrotation and malabsorption is a very rare condition. We report on an infant girl with congenital SBS associated with malrotation and malabsorption. No polyhydraminos was noted during the regular prenatal examination. Protracted postnatal postprandial vomiting with progressive failure to thrive was noted. A laparotomy showed the small bowel was only about 20 cm in length. She eventually survived with short-term parenteral nutrition and use of oral L-glutamine supplementation. To our knowledge, this might be the shortest length of bowel loop ever reported. Currently, she is 15 months of age with a body weight of about 7 kg and good development.

Digestive System Abnormalities↗
PubMed2003

Peripheral nerve lesions: role of high-resolution US.

The peripheral nerve is demonstrated as a reticular pattern in a transverse section at high-resolution ultrasonography (US). Its echogenicity is between that of tendon and muscle. High-resolution US applied to lesions of peripheral nerves yields impressive results in that the nerve is highly differentiated from surrounding soft tissue. In cases of trauma, high-resolution US can easily differentiate between a rupture of the nerve bundle and fibroblast infiltration that results in traumatic neuroma. In cases of inflammation or compressive syndrome, high-resolution US can easily demonstrate lesion location and cause. In the evaluation of abnormal masses, high-resolution US cannot clearly differentiate neurofibromas from schwannomas but it can clarify the relationship between tumor and neural trunk and help the clinician plan treatment strategies. The authors discuss the success that can be achieved with the application of high-resolution US in the evaluation of peripheral nerve lesions.

Adult↗
PubMed2003

Imaging studies of pyriform sinus fistula.

BACKGROUND: Pyriform sinus fistula (PSF) refers to a persistent embryologic third or fourth pharyngeal pouch, which typically presents as a congenital sinus tract that originates from the pyriform sinus. The sinus tract is often diagnosed by a barium study or direct endoscopic inspection. Utilization of advanced imaging studies, including ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI), may aid in the diagnosis of this disease entity. OBJECTIVES: To review the imaging findings of PSF and demonstrate the value of various cross-sectional imaging (US, CT, and MRI) in the diagnosis of PSF. MATERIALS AND METHODS: PSF in five children was verified surgically. Preoperative barium esophagography, US, CT, and MRI were performed selectively in these patients. The clinical and imaging findings are reviewed retrospectively. RESULTS: Barium studies demonstrated the sinus tract in all five patients. US, CT, and MRI demonstrated an associated inflammatory process. By utilizing the trumpet maneuver, the presence of sinus tract was evident in two patients during US. The sinus tract is also demonstrated by CT in another patient. CONCLUSIONS: Although barium esophagography is advantageous in demonstration of the sinus tract in PSF, US and CT are also capable of showing the sinus tract. The extent of inflammatory process related to PSF is better delineated by US, CT, and MRI.

Adolescent↗
PubMed2003

Support vector machines for diagnosis of breast tumors on US images.

RATIONALE AND OBJECTIVES: Breast cancer has become the leading cause of cancer deaths among women in developed countries. To decrease the related mortality, disease must be treated as early as possible, but it is hard to detect and diagnose tumors at an early stage. A well-designed computer-aided diagnostic system can help physicians avoid misdiagnosis and avoid unnecessary biopsy without missing cancers. In this study, the authors tested one such system to determine its effectiveness. MATERIALS AND METHODS: Many computer-aided diagnostic systems for ultrasonography are based on the neural network model and classify breast tumors according to texture features. The authors tested a refinement of this model, an advanced support vector machine (SVM), in 250 cases of pathologically proved breast tumors (140 benign and 110 malignant), and compared its performance with that of a multilayer propagation neural network. RESULTS: The accuracy of the SVM for classifying malignancies was 85.6% (214 of 250); the sensitivity, 95.45% (105 of 110); the specificity, 77.86% (109 of 140); the positive predictive value, 77.21% (105 of 136); and the negative predictive value, 95.61% (109 of 114). CONCLUSION: The SVM proved helpful in the imaging diagnosis of breast cancer. The classification ability of the SVM is nearly equal to that of the neural network model, and the SVM has a much shorter training time (1 vs 189 seconds). Given the increasing size and complexity of data sets, the SVM is therefore preferable for computer-aided diagnosis.

Breast Neoplasms↗
PubMed2003

Effect of nucleotides on diarrhea and immune responses in healthy term infants in Taiwan.

OBJECTIVES: The aim of this study was to compare the effects of an infant formula fortified with nucleotides (NF) with those of a control formula (CF) on the incidence of diarrhea, respiratory tract infections (RTIs), and immune responses in healthy term infants. METHODS: This 12-month, double-blind study was conducted on 1- to 7-day-old infants randomized to receive NF or CF exclusively until 12 weeks of age, and fed the assigned formula with solid food until 12 months. NF was supplemented with 72 mg/L of nucleotides, based on the total potentially available nucleotide content of human milk. Subjects were evaluated within 1 week of birth, at 4 weeks, and every 4 weeks thereafter until 48 weeks of age. The primary outcome variable was the incidence of diarrhea. Secondary variables included RTIs, serum immunoglobulin concentrations, and response to hepatitis B vaccine. RESULTS: Compared with subjects fed CF (n = 170), those fed NF (n = 166) had a trend toward reduced risk of diarrhea from 8 to 48 weeks of age and a significantly lower risk of 25.4% (P = 0.05) between 8 and 28 weeks. NF subjects had significantly higher serum immunoglobulin A concentrations ( P < 0.05) throughout the 48-week study. The NF group had an increased risk of upper RTIs, the same incidence of lower RTIs, and the same antibody response to hepatitis B vaccination as the CF group, based on one-sided tests. Growth was normal in both groups, and no adverse events were considered to be formula-related. CONCLUSIONS: Healthy term infants from 8 to 28 weeks of life are less likely to experience diarrhea and have higher serum immunoglobulin A concentrations with NF compared with formula without added nucleotides.

Bottle Feeding↗