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Biomedical subjects

Y Y Shen

Publications and source records attributed to Y Y Shen.

At least 19 recordsLinked to original sources
PubMed2004

Refinement of a locus for Marie Unna hereditary hypotrichosis to a 1.1-cM interval at 8p21.3.

BACKGROUND: Marie Unna hereditary hypotrichosis (MUHH) is a rare autosomal congenital alopecia with progressive hair loss starting in early childhood and accelerating at puberty. A locus for MUHH has been mapped on chromosome 8p21 but no genes for MUHH have been identified to date. OBJECTIVES: To refine the MUHH locus to a narrow chromosome region to facilitate cloning of the gene. METHODS: We performed genotyping and linkage analysis in a multigeneration Chinese family with MUHH, using 18 high-density microsatellite markers spanning the previously mapped interval at 8p21. RESULTS: Significant evidence for linkage was observed in this region, with a maximum two-point LOD score of 3.01 (theta = 0). Haplotype analysis localized the MUHH locus within the region defined by D8S282 and D8S1839. This region overlaps by 1.1-cM with the previously reported MUHH region and represents a physical distance of about 380 kb. CONCLUSIONS: This study provides a refined map location (1.1 cM) for isolation of the gene causing MUHH. These data also indicate the existence of a common MUHH locus at 8p21.3 between affected caucasian and Chinese families.

Aged↗
PubMed2003

Use of autologous buccal mucosa for vaginoplasty: a study of eight cases.

BACKGROUND: Vaginal agenesis is a rare condition and treatment methods are varied. The difference between most of the surgical techniques is the graft material used. The purpose of this study was to describe the procedure and outcome of creating a neovaginal pouch lined with autologous buccal mucosa. METHODS AND RESULTS: Between August 2000 and February 2002, eight patients with Mayer-Rokitansky-Kuster-Hauser syndrome were admitted to our hospital. All of the patients successfully underwent neovaginoplasty with autologous buccal mucosa as graft material. The buccal mucosal wound completely healed 2 weeks after the operation and the neovaginal length and calibre were well formed. Follow-up ranged from 0.5 to 1.5 years. One patient encountered post-operative vaginal bleeding and another patient suffered from urinary bladder injury. CONCLUSION: This is the first reported procedure of vaginoplasty with autologous buccal mucosa as graft material. Our method is ideal in its simplicity, provides good cosmetic results, and improves the vaginal length of the patient.

Adult↗
PubMed2003

The value of 18F-fluorodeoxyglucose positron emission tomography with the additional help of tumor markers in cancer screening.

Cancer screening is a major healthcare issue. Screening modalities are constantly changing due to improvements in technology. Whole body positron emission tomography (PET) with 18F-fluoro-2 deoxy-D-glucose (FDG) and the additional help of the serum levels of tumor markers have been considered as non-invasive methods for cancer screening in asymptomatic subjects. A total of 1283 subjects underwent whole-body FDG PET studies with the additional help of the serum levels of tumor markers in our center for cancer screening. The final diagnoses were confirmed by other imaging modalities or pathological findings in subjects with positive FDG-PET findings, and follow-up for at least 6 months were held in subjects with negative FDG-PET findings. Among a total of 18 (1.4%) subjects with cancers, FDG-PET detected cancers in 15 (1.2%) subjects but with false negative studies in 3 subjects with hepatoma (AFP = 129.6 ng/ml), prostate cancer (PSA = 25.1 ng/ml), and breast cancer (CEA and CA-153 were normal). False-positive FDG-PET studies were found in 24 (1.9%) subjects. However, none had abnormal serum levels of tumor markers. Whole body FDG-PET with the additional help of tumor markers could reduce the false negative and false positive results of FDG-PET only.

Adult↗
PubMed2002

Comparing whole body 18F-2-deoxyglucose positron emission tomography and technetium-99m methylene diphosphate bone scan to detect bone metastases in patients with renal cell carcinomas - a preliminary report.

PURPOSE: Conventional technetium-99m methylene diphosphate whole body bone scan (bone scan) has a high sensitivity but a poor specificity to detect bone metastases. However, positron emission tomography with 18F-2-deoxyglucose (FDG-PET) can offer superior spatial resolution and improved specificity. We have attempted to evaluate the usefulness of FDG-PET for detecting bone metastases in renal cell carcinomas (RCC) and to compare FDG-PET results with bone scan findings. METHODS: Eighteen patients were selected for this study with biopsy-proven RCC. They were suspected of having bone metastases and were undergoing bone scan and FDG-PET to detect bone metastases. The final diagnoses of bone metastases were established by operative, histopathological findings or clinical follow-up longer than 1 year by additional radiographs or following FDG-PET/bone scan findings showing progressive and extensive widespread bone lesions. RESULTS: A total of 52 bone lesions including 40 metastatic and 12 benign bone lesions found on either FDG-PET or bone scan were evaluated. FDG-PET could accurately diagnose all 40 metastatic and 12 benign bone lesions. Bone scan could accurately diagnose only 31 metastatic bone lesions. Diagnostic sensitivity and accuracy of FDG-PET were 100% and 100%, respectively,and bone scan were 77.5% and 59.6%, respectively. CONCLUSIONS: Our data suggest that FDG-PET has a higher sensitivity and a better accuracy than that of bone scan to detect bone metastases in patients with RCC.

Aged↗
PubMed2002

Detection of recurrent nasopharyngeal carcinomas with positron emission tomography using 18-fluoro-2-deoxyglucose in patients with indeterminate magnetic resonance imaging findings after radiotherapy.

PURPOSE: The aim of this study was to evaluate the effectiveness of positron emission tomography (PET) using 18-fluoro-2-deoxyglucose (FDG) to detect recurrent nasopharyngeal carcinomas (NPC) when magnetic resonance imaging (MRI) findings are indeterminate. PATIENTS AND METHODS: After radiotherapy, 28 NPC patients with indeterminate MRI findings were included. MRI, FDG-PET, and biopsy were performed at least 4 months after radiotherapy and within 1 week. The final results were based on histopathologic findings and a clinical follow-up of at least 6 months. RESULTS: For detecting recurrent NPC in indeterminate MRI findings, the sensitivity, specificity and accuracy of FDG-PET were 100.0%, 92.9% and 96.4%, respectively. CONCLUSIONS: Based on these results, we can recommend FDG-PET for detecting recurrent NPC when MRI findings are indeterminate.

Adult↗
PubMed2002

Comparing whole body 18F-2-deoxyglucose positron emission tomography and technetium-99m methylene diophosphate bone scan to detect bone metastases in patients with non-small cell lung cancer.

Despite advances in morphological imaging, some patients with non-small cell lung cancer (NSCLC) are found to have non-resectable disease at surgery or die of recurrence within a year of surgery. At present, metastatic bone involvement is usually assessed using conventional technetium-99m methylene diophosphate (Tc-99m MDP) whole body bone scan (bone scan), which has a high sensitivity but a poor specificity. We have attempted to evaluate the usefulness of whole body positron emission tomography with 18F-2-deoxyglucose (FDG-PET) for the detection of malignant bone metastases of NSCLC, and to compare FDG-PET results with Bone Scan findings. Forty-eight patients with biopsy-proven NSCLC and suspected to have stage IV disease underwent whole body bone scan and FDG-PET to detect bone metastases. The final diagnoses of bone metastases were established by operative, histopathological findings or clinical follow-up longer than 1 year by additional radiographs or following FDG-PET/Tc-99m MDP bone scan findings showing progressively and extensively widespread bone lesions. A total of 138 bone lesions found on either FDG-PET or Tc-99m MDP bone scan were evaluated. Among the 106 metastatic and 32 benign bone lesions, FDG-PET and Tc-99m MDP bone scan could accurately diagnose 99 and 98, as well as 30 and 2 metastatic and benign bone lesions, respectively. Diagnostic sensitivity and accuracy of FDG-PET and Tc-99m MDP bone scan were 93.4% and 92.5%, as well as 93.5% and 72.5%, respectively. In conclusion, our data suggest that FDG-PET with the same sensitivity and a better accuracy than those of Tc-99m MDP bone scan to detect metastatic bone lesions in patients with biopsy-proven NSCLC and suspected to have stage IV disease.

Adult↗
PubMed2002

Usefulness of whole body positron emission tomography (PET) with 18F-fluoro-2-deoxyglucose (FDG) to detect recurrent ovarian cancer based on asymptomatically elevated serum levels of tumor marker.

The aim of this study was to evaluate practice usefulness of whole body positron emission tomography (PET) with 18F-fluoro-2-deoxyglucose (FDG) to detect recurrent ovarian cancer based on asymptomatically elevated tumor marker (CA-125) serum levels. Whole-body FDG-PET was performed in 28 patients with suspected recurrent ovarian cancers and asymptomatically increased serum levels of tumor marker (CA-125 antigen) but negative or equivocal other imaging modality results. All of these 28 asymptomatic patients had serum levels of CA-125 antigen >35 U/ml. The final diagnosis of recurrent ovarian cancer was established by operation/biopsy histopathological findings or clinical follow-up longer than 1 year by additional morphologic imaging techniques. Among the 28 patients, the final diagnoses of recurrent ovarian cancers and benign lesions were established in 20 and 8 patients, respectively. FDG-PET accurately diagnosed recurrent ovarian cancers in 19 patients and benign lesions in 7 patients. When asymptomatically elevated serum levels of CA-125 antigen, the diagnostic sensitivity, specificity, and accuracy of FDG-PET to detect recurrent ovarian cancers were 95.0%, 87.5%, and 92.9%, respectively. FDG-PET is a useful technique to detect recurrent ovarian cancers for patients suspected of recurrent ovarian cancers due to asymptomatically elevated serum levels of CA-125 antigen.

Aged↗
PubMed2001

The role of dopamine transporter imaging agent [99mTc]TRODAT-1 in hemi-parkinsonism rat brain.

This study aims to investigate the relationship between the determination of dopamine level by high performance liquid chromatography (HPLC) with electrochemical detection (ECD) and the detection of dopamine transporter (DAT) counts using autoradiography with DAT image agent [99mTc]TRODAT-1. For striatal lesions, pretreatment of 6-hydroxydopamine (6-OHDA) in the medial forebrain bundle shows that autoradiogaphic labeling of striatum region is reduced to near-background level. Using HPLC with ECD, unilateral 6-OHDA treatment is associated with significant (p < 0. 0002) reductions of dopamine levels. For the striatum of the 6-OHDA-lesioned side, dopamine content and DAT counts are reduced to 97% and 90%, respectively. Thus, our observation indicates a potential of using [99mTc]TRODAT-1 for the evaluation of animal DAT.

Animals↗
PubMed2001

Abscisic acid-specific binding sites in the flesh of developing apple fruit.

Abscisic acid (ABA) specific-binding sites localized in the cytosol were identified and characterized in the flesh of developing apple (Malus pumila L. cv. Starkrimon) fruit. ABA binding activity was scarcely detectable in the microsomes but high ABA binding activity in the cytosolic fraction was detected. The ABA-binding sites possessed a protein nature with both active serine residues and thiol-groups of cysteine residues in their functional binding sites. ABA binding was shown to be saturable, reversible and of high affinity. A Scatchard plot provided evidence for two different ABA binding proteins, one with higher affinity (K(d)=2.3 nM) and the other with lower affinity (K(d)=58.8 nM). Phaseic acid, trans-ABA and (-)-ABA had essentially no affinity for the binding proteins, indicating their stereo-specificity to bind physiologically active cis-(+)-ABA. The time-course, pH- and temperature-dependence of the ABA-binding proteins were determined. It is hypothesized that the detected ABA-binding proteins may be putative ABA-receptors that mediate ABA signals during fruit development.

Abscisic Acid↗
PubMed1999

Regional cerebral blood flow in patients with systemic lupus erythematosus.

Patients with systemic lupus erythematosus (SLE) with or without definite neuropsychiatric symptoms/signs were studied. Technetium-99m (Tc-99m) hexamethylpropylenamine (HMPAO) brain images were used to detect basal ganglion and cerebral cortex regional cerebral blood flow (rCBF) in patients with SLE with brain involvement. One hundred nine female patients with SLE were investigated using Tc-99m HMPAO brain images with fan-beam single-photon emission computed tomography (SPECT) and surface three-dimensional (3D) display. These patients were separated into 2 subgroups: group 1, 74 cases with definite neuropsychiatric symptoms/signs; and group 2, 35 cases without any neuropsychiatric symptoms/signs. Fan-beam SPECT demonstrated unilateral or bilateral hypoperfusion of basal ganglia or thalamus in 22% and 9% of patients in groups 1 and 2, respectively. Local hypoactivity anomalies were found in the brain cortex of 89% and 20% of patients in groups 1 and 2, respectively, using surface 3D display of the brain. In either group 1 or group 2 patients, parietal and frontal lobes are the most common areas and cerebellum and thalamus are the least common areas of brain involvement, respectively. This study suggests that in comparison with traditional brain imaging techniques, Tc-99m HMPAO brain imaging with fan-beam SPECT in combination with surface 3D display may provide objective information for detection of anomalies of rCBF in patients with SLE.

Adult↗
PubMed1998

Detection of nasopharyngeal carcinoma with head and neck Tc-99m tetrofosmin SPECT imaging.

Tc-99m tetrofosmin SPECT imaging of the head and neck was performed on 10 patients with nasopharyngeal carcinoma (NPC) and 10 controls. There was no abnormal nasopharyngeal uptake of tetrofosmin in the 10 controls. In the patients with NPC, 3/10 (30%) of the cases had no abnormal uptake and 7/10 (70%) had increased nasopharyngeal uptake. Considering our preliminary study, we find that Tc-99m tetrofosmin SPECT of the head and neck may be helpful in the detection of NPC. However, further study with a larger number of patients is needed to ascertain the value of Tc-99m tetrofosmin SPECT in such cases.

Adult↗
PubMed1998

Diagnostic value of bone and Ga-67 imaging in skeletal tuberculosis.

Tuberculosis (TB) remains a major cause of skeletal infection in many parts of the world. Bone scintigraphy is an excellent screening test for bone lesions and Ga-67 scintigraphy is a useful tool for detecting inflammatory lesions. This study determined the value of bone and Ga-67 scans in patients with skeletal TB. Tc-99m MDP and Ga-67 whole-body scans were performed in 24 patients with proved skeletal TB. Twenty-six TB lesions were found in these 24 patients, 8 in the spine, 5 in the knee, 5 in the wrist, 4 in the ankle, 2 in the elbow, 1 in the finger, and 1 in the sacroiliac joint. Of the 26 TB lesions, Tc-99m MDP bone imaging detected 24 and Ga-67 scans revealed 23. The sensitivity rates were 92% (24 of 26) and 88.5% (23 of 26) for bone scans and Ga-67 scans, respectively. When the scans were evaluated in combination, the detection sensitivity was 96.1% (25 of 26). Two lesions that the bone scan failed to detect were in the spine. Ga-67 imaging failed to detect two spinal lesions and one lesion in the knee. The detection sensitivities of bone and gallium scans were high for skeletal TB, although neither scan was specific for TB lesions. Either the bone or Ga-67 scan can be used in the clinical setting as a convenient screening test to detect multiple sites of bone involvement in TB, and to indicate the sites for further detailed evaluation by CT, MRI, or biopsy.

Bone and Bones↗
PubMed1998

Technetium-99m-labelled RBC erection penogram to differentiate psychogenic from vasculogenic impotence.

The 99mTc-labelled RBC erection penogram (Tc-RBC penogram) coupled with intracavernosal injection of prostaglandin E1 (PGE1) was used to evaluate the penile hemodynamic changes during tumescence. As expected, the method is useful to differentiate organic from psychogenic impotence, and arteriogenic from venogenic impotence. Thirty-four patients with psychogenic impotence, 23 patients with arteriogenic impotence, and 27 patients with venogenic impotence were included in the study. A Tc-RBC penogram was performed on each patient after intracavernosal injection of PGE1. Several parameters calculated from the time-radioactivity curve of the Tc-RBC penogram were used to evaluate hemodynamic changes of the penis. They included (1) the arterial phase: slope and time to peak (TTP), and (2) the venous phase: washout index (WOI). During the arterial phase, the patients with psychogenic and venogenic impotence had higher slope and shorter TTP than those of patients with arteriogenic impotence (p < 0.01). During the venous phase, the patients with psychogenic and arteriogenic impotence had a lower WOI than that of patients with venogenic impotence (p < 0.01). We conclude that the Tc-RBC penogram is a simple, noninvasive, and valuable method for the objective differentiation among psychogenic, arteriogenic, and venogenic impotence.

Adult↗
PubMed1997

Comparison technetium of Tc-99m disofenin cholescintigraphy with ultrasonography in the differentiation of biliary atresia from other forms of neonatal jaundice.

Technetium Tc-99m disofenin cholescintigraphy (CS) and ultrasonography (US) are two major clinical methods used in differentiating biliary atresia (BA) from neonatal jaundice. To compare the diagnostic utility of these two modalities, 66 patients with neonatal cholestasis (15 BA, 3 choledochal cyst (CC), 32 neonatal hepatitis, 13 prolonged jaundice, 2 total parenteral nutrition, and 1 sepsis) underwent Tc-99m disofenin CS and US. The diagnostic sensitivity, specificity, and accuracy of CS in differentiating BA from other forms of neonatal jaundice was 100%, 87.5%, and 90.5%, respectively, and for US 86.7%, 77.1%, and 79.4%, respectively. Tc-99m disofenin CS after premedication with phenobarbital and cholestyramine is a convenient and reliable method of differentiating BA from neonatal hepatitis, with a diagnostic accuracy superior to that of US. However, US is the initial imaging procedure of choice in patients presenting with jaundice to rule out anatomic anomalies such as CC.

Biliary Atresia↗
PubMed1997

Technetium-99m-tetrofosmin SPECT imaging of lung masses: a negative study.

UNLABELLED: Technetium-99m-tetrofosmin has emerged as a new radiopharmaceutical for myocardial imaging, in competition with 201Tl and 99mTc-MIBI. In this study, 99mTc-tetrofosmin was evaluated for its ability to detect malignant and benign lesions from single solid lung masses. METHODS: Forty-nine patients with a single solid lung mass based on chest radiograph findings received 99mTc-tetrofosmin SPECT of the chest to evaluate the value of 99mTc-tetrofosmin SPECT for detecting malignant and benign lesions. RESULTS: Only 61% of the lung malignancies were detected by 99mTc-tetrofosmin SPECT of the chest, including 53% of epidermoid carcinoma (ca), 67% of adeno ca, 75% of small-cell ca, 0% of undifferentiated large-cell ca and 100% of other lung malignancies. In addition, 50% of the benign lesions were detected by chest 99mTc-tetrofosmin SPECT. The probability of tetrofosmin uptake in the mass was not related to mass size. The diagnostic sensitivity, specificity and accuracy were 61%, 50% and 59%, respectively, for differentiating malignant and benign lesions when diagnosing a single solid lung mass. CONCLUSION: Technetium-99m-tetrofosmin SPECT of the chest is of little or no value for the detection of lung ca from single solid lung masses.

Adenocarcinoma↗
PubMed1996

Superscan in patients with nasopharyngeal carcinoma.

Bone scintigraphy plays an important role in the early detection of bone metastases in patients with nasopharyngeal carcinoma and serial scans may aid the clinician to assess the therapeutic response. A superscan is a pattern described as abnormal bone scan, indicating extensive bony metastases associated with various neoplastic diseases. Bone scans from 407 patients with nasopharyngeal carcinoma were reviewed retrospectively. Only six superscans (1.5%) were found. The appearance of a superscan is frequently accompanied by an abnormal titer of serological markers IgG-VCA and IgA-VCA, liver metastases, and poor survival. Although a superscan rarely occurs in nasopharyngeal carcinoma, its appearance may represent a poor prognosis in these patients.

Adult↗