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W T Yang

Publications and source records attributed to W T Yang.

At least 19 recordsLinked to original sources
PubMed2004

Extended experience in the use of laparoscopic ultrasound to detect pelvic nodal metastasis in patients with cervical carcinoma.

OBJECTIVE: To evaluate the use of laparoscopic ultrasound (USG) to detect pelvic nodal metastasis in patients with early stage cervical carcinoma. METHODS: Laparoscopic USG was used to search for pelvic lymph node metastasis in stage Ia2 to IIa cervical carcinoma patients before radical hysterectomy. Suspicious lymph nodes identified by laparoscopic USG were removed laparoscopically for pathological confirmation by frozen section. If nodal metastasis was diagnosed, radical hysterectomy would be cancelled but enlarged lymph nodes were removed preferably by laparoscopic approach before closing the abdomen. These patients were treated with radiotherapy after recovering from the surgery. By comparing the laparoscopic USG and pathological findings of lymph nodes removed with or without radical hysterectomy, diagnostic accuracy of laparoscopic USG was determined. RESULTS: Ninety-three patients were recruited and the final analysis included 90 patients. Laparoscopic USG found suspicious lymph nodes in 17 patients and nodal metastases were confirmed pathologically in 14 of them. Three patients with macroscopic and five patients with microscopic pelvic nodal metastases were missed by laparoscopic USG. The accuracy, sensitivity, specificity, positive and negative predictive value of laparoscopic USG in detecting pelvic lymph node metastasis were 87.8%, 63.6%, 95.6%, 82.4%, and 89%, respectively. Macroscopic metastatic nodes were successfully removed laparoscopically in 11 out of 14 patients and laparotomy was required for the other three patients. CONCLUSIONS: Laparoscopic USG can be performed with no major morbidity. This technique is sensitive in detecting macroscopic but not microscopic metastatic pelvic lymph nodes. Removal of macroscopic metastatic nodes identified via laparoscopic USG via laparoscopic approach could be accomplished in majority of patients.

Adult↗
PubMed2002

Ultrasound and MR imaging of diabetic mastopathy.

AIM: To review the imaging findings of diabetic mastopathy, and document the colour flow ultrasound and MR imaging features in this benign condition. MATERIALS AND METHODS: Diabetic mastopathy was clinically and histologically diagnosed in eight lesions in six women. All six women underwent conventional mammography and high frequency grey-scale ultrasound. Colour flow ultrasound was performed additionally in six lesions in four women and MR imaging in four lesions in three women before biopsy. The imaging findings were reviewed and correlated with final histological diagnosis. RESULTS: Mammography showed regional asymmetric increased opacity with ill-defined margins in all lesions. A heterogeneously hypoechoic mass with ill-defined margins was identified on high frequency grey-scale ultrasound in all lesions. Marked posterior acoustic shadowing was present in seven of eight (88%) lesions. Six lesions interrogated with colour flow ultrasound showed absence of Doppler signal. MR imaging in three women revealed non-specific stromal enhancement. CONCLUSION: Diabetic mastopathy shows absence of Doppler signal on colour flow ultrasound and non-specific stromal enhancement on MR imaging.

Adult↗
PubMed2002

Spermatozoan morphology of four species of bivalve (Heterodonta, Veneridae) from Taiwan.

Using transmission and scanning electron microscopy, the mature spermatozoa of four bivalves of the family Veneridae--Gafrarium tumidum and Circe scripta (Circinae), Pitar sulfureum (Pitarinae) and Gomphina aequilatera (Tapetinae)--are described for the first time and compared with those of other bivalves, particularly other heterodonts. As our observations show, the spermatozoa of these four species are of the primitive type or ect-aquasperm form. The head contains a slightly curved nucleus with a short cone-shaped acrosome. The structure of the acrosome is typical of heterodont bivalves and two major components of the acrosomal vesicle material can be distinguished. The midpiece exhibits four or five mitochondria which surround the proximal and the distal centrioles. Variation in the shape and dimensions of the acrosomal vesicle and nucleus is substantial in these four Veneroidea species.

Animals↗
PubMed2002

The ultrastructure of the mature spermatozoon of the bivalve Gafrarium tumidum (Bivalvia, Heterodonta, Veneridae, Circinae).

Using transmission and scanning electron microscopy, we have described the mature spermatozoon of the bivalve Gafrarium tumidum (Heterodonta, Veneridae, Circinae) for the first time. The spermatozoon of G. tumidum is the ect-aquasperm type. The head contains a slightly curved nucleus. At its apex is a short cone-shaped acrosome. The structure of the acrosome is typical of heterodont bivalves and two major components of the acrosome vesicle material can be distinguished. The midpiece is an annular band of five mitochondria which surround the centriole complex. Sperm ultrastructure of G. tumidum provides additional information for the existing Veneridae phylogeny.

Animals↗
PubMed2001

Benign and malignant breast masses and axillary nodes: evaluation with echo-enhanced color power Doppler US.

PURPOSE: To evaluate microbubble contrast enhancement in distinguishing malignant from benign breast masses and malignant from benign axillary nodes in patients with breast cancer. MATERIALS AND METHODS: Eighty-six patients with 86 breast masses and 32 patients with breast cancer (subgroup of 86 patients) with 32 axillary nodes underwent color power Doppler ultrasonography with and without contrast material. Vascular features and contrast material transit times were recorded. Nodal enhancement was compared with corresponding primary breast cancer enhancement in the subset of 32 patients. RESULTS: Pathologic analysis revealed 58 breast carcinomas and 28 benign breast lesions and 20 malignant and 12 benign axillary nodes in the 32 patients with breast cancer. Breast cancers had a greater total number and greater number of peripheral vessels than did benign lesions before and after contrast material administration (P <.001). Malignant nodes had a greater total number and greater number of peripheral vessels at baseline and after contrast enhancement (P <.05), and a longer enhancement duration (P =.004) compared with benign nodes. Malignant nodes enhanced more than did corresponding primary breast cancers. Postcontrast number of peripheral vessels was an independent predictor of primary breast cancer (P <.05), and increased number of peripheral vessels after contrast enhancement and enhancement duration were independent predictors of nodal malignancy (P <.05). CONCLUSION: Primary breast cancers and malignant axillary nodes had a greater total number and greater number of peripheral vessels compared with benign breast masses and axillary nodes, respectively.

Adult↗
PubMed2001

Sonographic features of primary breast cancer in men.

OBJECTIVE: The imaging studies of eight men with proven primary breast cancer and preoperative sonography and mammography were reviewed and correlated with final pathology reports. CONCLUSION: There were five cases of invasive breast carcinoma and three cases of ductal carcinoma in situ of the papillary subtype. All three cases of papillary ductal carcinoma in situ showed cystic features on sonography. Most (4/5) invasive cancers were solid on sonography. The appearance of a complex cystic mass in the male breast on sonography should suggest the possibility of malignancy and therefore warrants biopsy.

Aged↗
PubMed2000

A phase II study of gemcitabine plus oral etoposide in the treatment of patients with advanced nonsmall cell lung carcinoma.

BACKGROUND: The authors have designed a non-cisplatin-based chemotherapy regimen for the treatment of patients with advanced nonsmall cell lung carcinoma (NSCLC). This regimen capitalizes on the mild toxicity of gemcitabine, a novel nucleoside analog. METHODS: A total of 46 chemotherapy-naive patients with histologically confirmed Stage IIIB or IV NSCLC were enrolled. Eligible patients were treated with gemcitabine 1000 mg/m(2) on Days 1, 8, and 15, plus oral etoposide 50 mg daily for 14 days, which was increased to 21 days if there was no World Health Organization (WHO) Grade 3 or 4 toxicity in the 1st 2 cycles (each cycle was 28 days long). All patients were included for analysis of response and survival according to an intention-to-treat principle. RESULTS: The overall response rate was 43.5% (95% confidence interval [CI], 30. 7-60.2%). There was 1 complete response (2.2%) and 19 partial responses (41.3%). The median survival was 48.0 weeks (95% CI, 38. 1-75.9 weeks) and the 1-year survival rate was 45% (95% CI, 29-62%). The median time to progression for all patients was 39.2 weeks (95% CI, 35.7-49.7 weeks). World Health Organization (WHO) Grade 3 and 4 anemia, neutropenia, and thrombocytopenia was reported in 29%, 32%, and 18% of patients, respectively. Two patients had reactivation of hepatitis B viral infection that resulted in WHO Grade 4 hepatic dysfunction. Other nonhematologic toxicities were uncommon. CONCLUSIONS: This non-cisplatin-based regimen of gemcitabine and oral etoposide achieved a high response and survival rate. Toxicity appeared to be less severe than that associated with existing cisplatin-based regimens. A randomized study of this regimen versus a cisplatin-based regimen is indicated.

Adult↗
PubMed2000

Nonmammary malignancies of the breast: ultrasound, CT, and MRI.

The three major categories of nonmammary malignancies of the breast include primary and secondary lymphoreticular malignancy, primary and secondary sarcoma, and hematogenous metastasis. This article describes the imaging features of 35 nonmammary malignancies of the breast and axilla with histopathologic confirmation. These include primary and secondary breast lymphoma, primary axillary nodal lymphoma, metastatic acute lymphatic leukemia, metastatic plasmacytoma, granulocytic sarcoma, primary angiosarcoma, metastatic rhabdomyosarcoma, hematogenous metastasis from primary lung, ovarian, cervical, thyroid, and colonic carcinoma, malignant melanoma, carcinoma of the nasal cavity, and adenocarcinoma of unknown primary. Wherever possible, correlation between mammography and ultrasound, computed tomography (CT), and/or magnetic resonance (MR) imaging is made.

Adenocarcinoma↗
PubMed2000

Detection of parametrial invasion in cervical carcinoma: role of short tau inversion recovery sequence.

AIM: To investigate the role of short tau inversion recovery (STIR) sequence in the detection of parametrial invasion in patients with carcinoma of the cervix. MATERIALS AND METHODS: Axial magnetic resonance imaging (MRI) images of the cervical region using T1 weighted turbo spin echo (TSE), TSE T2, STIR and T1 weighted dynamic gadolinium enhanced SE sequences were obtained in 38 patients with cervical carcinoma. All the images were assessed for the presence or absence of parametrial invasion using a standard scoring system. The diagnostic confidence, image quality, sensitivity, specificity, positive and negative predictive values and accuracy of each sequence were compared. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for each sequence in the diagnosis of parametrial invasion were: 60%, 80%, 32%, 93% and 78% for unenhanced T1W sequence; 90%, 92%, 64%, 98% and 92% for TSE T2 sequence; 90%, 94%, 69%, 98% and 93% for STIR sequence; and 90%, 80%, 41%, 98% and 82% for dynamic T1W sequence, respectively. Image quality and diagnostic confidence were both better for STIR and T2 compared to the dynamic T1 sequence. CONCLUSION: Dynamic T1W imaging is inferior to STIR and TSE T2 sequences. STIR is of similar value in the detection of parametrial invasion in cervical carcinoma as a TSE T2W sequence; their simultaneous use is not justified.

Adenocarcinoma↗
PubMed2000

Patients with breast cancer: differences in color Doppler flow and gray-scale US features of benign and malignant axillary lymph nodes.

PURPOSE: To document differences in color Doppler flow and gray-scale ultrasonographic (US) features between benign and malignant axillary lymph nodes in women with primary breast cancer. MATERIALS AND METHODS: The longitudinal-transverse axis ratio and hilar status on color Doppler flow and gray-scale US images were prospectively studied for each of 145 axillary nodes in 135 women (74 palpable nodes in 69 women, 71 nonpalpable nodes in 66 women) with primary breast cancer. Intranodal flow distribution was described as peripheral, central, or central perhilar. Resistive and pulsatility indexes and peak systolic velocity were documented. For comparison of benign and malignant features, nodes were divided into three groups: palpable and nonpalpable, palpable, and nonpalpable. RESULTS: Color flow was demonstrated equally well in benign and malignant axillary lymph nodes for all three groups. For all nodes, peripheral flow was significantly higher in malignant (118 of 153 nodes [77%]) than benign (45 of 160 nodes [28%]) nodes (P <.001); central flow and central perhilar flow were significantly greater (P <.002 and <.001, respectively) in benign than malignant nodes. Similar differences were not observed in nonpalpable nodes. The mean longitudinal-transverse axis ratio (+/- SD) was significantly lower in malignant (1.8 +/- 0.6) than benign (2.6 +/- 0.8) nodes. Logistic regression analysis showed peripheral, central, and central perhilar flow and the mean longitudinal-transverse axis ratio to be significant independent predictors of malignancy. CONCLUSION: Color Doppler flow and gray-scale US features applicable to the identification of disease in palpable axillary nodes in patients with breast cancer are not applicable to nonpalpable nodes.

Adult↗
PubMed2000

Sequencing a specific kinetoplast DNA fragment of Leishmania donovani for polymerase chain reaction amplification in diagnosis of leishmaniasis in bone marrow and blood samples.

A set of oligonucleotide primers I and II was developed by analyzing the specificity of a cloned kinetoplast DNA (kDNA) fragment of Leishmania donovani and sequencing the fragment. Polymerase chain reaction (PCR) was conducted with the primers to amplify a minicircle kDNA fragment (297 bp) to detect L. donovani in the bone marrow (22 samples), whole blood (16 samples), and serum (17 samples) of 22 patients with visceral leishmaniasis. All of 22 patients were diagnosed by microscopic identification. Control samples of bone marrow, whole blood, and serum were obtained from patients with leukemia and from healthy volunteers. In addition, 12 dogs were infected with L. donovani promastigotes for the PCR test. The total number of patients positive by PCR testing was 95.5% (21/22), with 91.0% (20/22) from the bone marrow, 68.8% (11/16) from the blood, and 29.4% (5/17) from the sera. Similar results were obtained in infected dogs. No amplification products were seen in control samples from humans or dogs. Our results suggest that PCR may be useful in detecting kDNA in the bone marrow and blood of patients with visceral leishmaniasis.

Animals↗
PubMed2000

Comparison of dynamic helical CT and dynamic MR imaging in the evaluation of pelvic lymph nodes in cervical carcinoma.

OBJECTIVE: This study compares dynamic helical CT with dynamic MR imaging in the evaluation of pelvic lymph nodes in cervical carcinoma. SUBJECTS AND METHODS: Women with biopsy-proven cervical carcinoma prospectively underwent dynamic helical CT and MR imaging before surgery. A metastatic node on CT and MR imaging was defined as a rounded soft-tissue structure greater than 10 mm in maximal axial diameter or a node with central necrosis. Imaging results were compared with pathology, and receiver operating characteristic curves for size and shape were plotted on a hemipelvis basis. Nodal density and signal intensity on CT and MR images, respectively, were reviewed for differences between benign and malignant disease. RESULTS: A total of 949 lymph nodes were found at pathology in 76 hemipelves in 43 women, of which 69 lymph nodes (7%) in 17 hemipelves (22%) were metastatic. Sensitivity, specificity, positive and negative predictive values, and accuracy of helical CT and MR imaging in the diagnosis of lymph node metastasis on a hemipelvis basis was 64.7%, 96.6%, 84.6%, 90.5%, and 89.5% and 70.6%, 89.8%, 66. 7%, 91.4%, and 85.5%, respectively. Receiver operating characteristic curves for helical CT and MR imaging gave cutoff values of 9 and 12 mm in maximal axial diameter, respectively, in the prediction of metastasis. Central necrosis had a positive predictive value of 100% in the diagnosis of metastasis. Signal intensity on MR imaging and density-enhancement pattern on CT in patients with metastatic nodes did not differ from those in patients with negative nodes. CONCLUSION: Helical CT and MR imaging show similar accuracy in the evaluation of pelvic lymph nodes in patients with cervical carcinoma. Central necrosis is useful in the diagnosis of metastasis in pelvic lymph nodes in cervical cancer.

Adult↗
PubMed2000

Diagnostic accuracy of abdominal ultrasonography compared to magnetic resonance imaging in siderosis of the spleen.

A prospective study to compare the diagnostic performance of ultrasonography with magnetic resonance imaging using gradient-recalled echo technique in cases of siderosis of spleen was conducted in 53 cirrhotic patients with endoscopic proof of gastroesophageal varices. Of the 34 patients with splenic siderosis on MR imaging, punctate hyperechoic foci were detected in the spleen on ultrasonography in 24 patients. Using MR imaging as the reference standard for the diagnosis of splenic siderosis, the sensitivity of ultrasonography is 70.6%; specificity is 78.9%; positive predictive value is 85.7%; and negative predictive value is 40%. We conclude that ultrasonography is a fairly accurate technique in the diagnosis of splenic siderosis.

Adult↗
PubMed2000

[Cloning and sequence analysis of SSU rRNA gene of cutaneous leishmaniasis pathogen from Xinjiang of China].

OBJECTIVE: By sequencing of SSU rRNA gene cloning from Xinjiang cutaneous leishmaniasis pathogen (XJCLP) to provide evidence for identification of the pathogen. METHODS: By PCR assay with primers R222 and R333, the specific fragment had been produced from SSU rRNA gene of XJCLP, L. infantum, L. tropica and cloned into pGEM-T Easy vector. The clones were sequenced by the Sanger dideoxy-mediated chain termination method, analysis of SSU rRNA gene sequences from XJCLP, L. tropica, L. infantum with DNASIS. RESULTS: Sequence analysis showed that the specific fragment of SSU rRNA gene from XJCLP, L. infantum, L. tropica, were all 394 bp in length. There were 391 bases identical and three point mutations between the sequences of XJCLP and L. tropica, the similarity being 99.2%; 390 bases identical and three point mutations and one insertion/deletion between the sequences of XJCLP and L. infantum, the similarity being 99.0%. One insertion/deletion between the sequences of L. tropica and L. infantum, the similarity being 99.7%. The primary and secondary structures of SSU rRNA gene from XJCLP differed from those of L. infantum and L. tropica. A retrieval from GenBank confirmed that these 394 bp sequence are new gene sequences. CONCLUSION: The primary and secondary structures of SSU rRNA gene from XJCLP, L. infantum, L. tropica were different. 394 bp sequence from SSU rRNA gene of XJCLP is a new gene sequence.

Animals↗
PubMed1999

Imaging of iliopsoas metastasis.

The imaging features of four patients with metastasis to the iliopsoas are presented with emphasis on the ultrasound, CT and MRI appearances. In patients with a known primary tumour, the possibility of iliopsoas metastasis, although uncommon should be considered.

Adult↗
PubMed1999

Monitoring response to treatment in liver tumours.

New imaging techniques offer better ways of measuring response to treatment and remain central to the formal assessment of response in clinical trials and routine clinical practice. Increasing tumour size is consistently associated with progressive disease. However, there is evidence that the designation 'partial response', as determined by conventional imaging techniques, may not always accurately reflect the degree of treatment-induced tumour necrosis. Thus, responses classified as partial on imaging grounds have, in some cases, been shown to be complete pathological responses after surgical resection, implying that residual tumour and necrotic/fibrotic tumour remnants cannot always be accurately distinguished by imaging. In this situation, serological tumour markers such as alphafetoprotein may be useful in measuring the true degree of response. While radiological imaging is likely to remain the main method of assessing response in phase II trials of drugs for the treatment of liver cancer, it may in some instances be useful to apply additional parameters such as alphafetoprotein level.

Biomarkers, Tumor↗