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Biomedical subjects

Y S Tang

Publications and source records attributed to Y S Tang.

At least 55 records · Page 3Linked to original sources
PubMed1994

Cephalometric studies on the upper airway space in normal Chinese.

A detailed cephalometric analysis of the soft and hard tissues of the upper airway was conducted with lateral cephalographs from 116 normal Chinese, aged between 18 and 25 years. Normal values and deviation range were preliminarily established for the size of the tongue, soft palate, nasopharynx, oropharynx, and hypopharynx, and for the relative position of the hyoid bone and vallecula in both sexes. Statistical findings showed that there were significant differences between the sexes. Significant relationships (P < 0.001) were observed 1) between the hypopharyngeal depth and the position of the hyoid bone and the vallecula, in which the horizontal position of vallecula appears to be the best predictor of the hypopharyngeal depth, as confirmed by the multiple regression equation; 2) between the upper airway depths at four different levels; and 3) between the naso-oropharyngeal area and tongue, soft palate, and oral area. The present data can be used to investigate further the upper airway in abnormal states.

Adolescent↗
PubMed1994

[One-stage surgical procedure of adult cleft palate with dentofacial deformity]

2 cases with primary adult cleft palate combining severe dentofacial deformities were undergone one-stage procedure of modified Le Fort I segmental osteotomy and Furlow's double reserving Z plasty,and with with satisfactory clinical effectiveness.Follow-up results show that the one-stage procedure is not only reducing treatment time and period,but also correcting velopharyngeal function.

Journal Article↗
PubMed1994

[Orthognathic surgery of dentofacial deformities post surgerical repairing of cleft palate and lip.].

10 cases with maxillary development limited post surgical repairing of cleft palate and lip were undergone modified Le Fort I segmental osteotomy,that is,put the maxilla forward without velopharyngeal function change and oro-nasal fistula.By Computer Aided Simulation System for orthognathic surgery(CASSOS),analysis of dental pulp,evaluation of velopharyngeal function,compacting profile pre-to-post operation, authors described that surgical procedure has the satisfactory effectiveness.

English Abstract↗
PubMed1994

[Treatment of maxillofacial hemangioma with Pingyanmycin :A clinical analysis of 27 cases.].

24 cases of maxillofacial cavernous hemangioma with local injections of Pingyanmycin were reported.The hemangiomas were located in the floor of the mouth,soft palate and parotid glands with an average surface area of 2.5cmx3.5cm,The strawberry hemangioma were with an average surface area of 5cmx6cm,All the cavernous hemogioma were cured with an average of 8.0 injections,using an average total dose of 58mg,After clinical observation from 10 to 30 months,there were no recurrence found and normal maxillofacial appearance and function were maintained,strawberry hemangioma of 3 cases were treated with an average of 5 injections using an average total dose of 34mg,there were no effects.This paper also has studied the mechanism of action of local injection with Pingyanmycin.

English Abstract↗
PubMed1993

Identification of endogenous electrophiles by means of mass spectrometric determination of protein and DNA adducts.

Monitoring exposure to alkylating agents may be achieved by quantitatively determining the adduct levels formed with nucleic acids and/or proteins. One of the most significant results arising from the application of this approach has been the discovery in control populations of "background" levels of alkylated nucleic acid bases or alkylated proteins, in particular hemoglobin (Hb). In the case of Hb, a wide variety of such adducts have been detected and quantitated by mass spectrometric techniques, with methylated, 2-carboxyethylated, and 2-hydroxyethylated modifications being most abundant. Although the source of these alkylation products is unknown, both endogenous and exogenous sources may be proposed. We have recently confirmed the presence of the N-terminal hydroxyethylvaline adduct in control human Hb using tandem mass spectrometry (MS-MS) and have now established background levels using GC-MS in more than 70 samples. Smoking raises the levels of the adduct up to 10-fold and occupational exposure to ethylene oxide up to 300-fold. Background levels of alkylated nucleic acids may be studied by analysis of N7-alkylated guanine or N3-alkylated adenine, which are excised from nucleic acids after their formation and are excreted in urine. Although the presence of some of these urinary constituents may be accounted for by their natural occurrence in RNA or diet, the endogenous or exogenous source of others is unknown. Quantitative methods using MS-MS have now been developed for five of the observed urinary alkylguanines [N7-methyl-, N2-methyl-, N2-dimethyl-, N7-(2-hydroxyethyl)-, and N2-ethylguanine].(ABSTRACT TRUNCATED AT 250 WORDS)

Alkylating Agents↗
PubMed1993

[Reconstruction of large performated maxillofacial defect with immediated revascularized flap]

Patients with large perforated maxillofacial defects resulting from combined craniomaxillofacial resection or extended extra cranio-maxillofacial resection due to malignances in this region had been reconstructed with large revascularized myocutaneous flap or combined pedicled myocutaneous flap with revascularized flap.Since January,1981,a total of 29 flaps was used,of which 28 flaps survived successfuly,whereas one free forearm flap being failed to survive due to venous embolization was replaced with pedicled forehead flap.The results in postoperative appearance and rehabilitation of physiological function were relatively satisfactory.Finally,selection of flap and method of reconstruction were introduced and experiences on immediate reconstruction after malignance resection reported.

Journal Article↗
PubMed1992

Ring test for low levels of N-(2-hydroxyethyl)valine in human hemoglobin.

Hemoglobin adducts are useful for the identification and quantification of electrophilic agents in vivo. A modified Edman degradation method has been extensively used for monitoring exposure to ethylene oxide through gas chromatographic-mass spectrometric measurements of hydroxyethyl adducts to the N-terminal valines in hemoglobin. In a ring test, four laboratories using different versions of the method analyzed eight human globin samples with low adduct levels from ethylene oxide. Measurements of the same adduct by a radioimmunoassay were also included. Strong correlation between the measurements by the different laboratories shows that the method in principle works well. However, there were some systematic quantitative differences.

Hemoglobins↗
PubMed1991

Radioanatomy of the laterosellar veins. Value of dynamic computerized tomography.

Dynamic computerized tomography is a simple and rapid technique which can provide an accurate mapping of the vascular elements of the cavernous sinus. It is not very different from the technique used to visualize the capillary bed of the pituitary gland and its progressive contrast enhancement. From a series of 780 dynamic CT explorations, we were able to individualize 5 groups of veins: (1) the veins of the lateral wall of the cavernous sinus; (2) the veins of the infero-lateral group, located beneath the intracavernous segment of the internal carotid artery (ICA); (3) the vein of the carotid sulcus, located between the intracavernous ICA and the carotid sulcus; (4) the medial vein, situated between the intracavernous ICA and the pituitary gland, and (5) the pericarotid plexus. In some cases the anterior and inferior coronary sinuses and the basilar sinus can be visualized.

Capillaries↗
PubMed1990

Treatment of herniated lumbar disc by percutaneous nucleotomy with aspiration. Preliminary results in 70 cases.

Seventy patients suffering from lumbar pain with sciatica, radiculalgia or lumbodynia were reviewed at least 3 months after automated percutaneous nucleotomy (Nucleotome). There were 26 women and 44 men, aged from 19 to 72 years. Results were highly satisfactory in 39 patients (56.5%). Among these, 10 had lumbar pain of discal origin, 15 had pure radiculalgia and 14 had lumbar pain and radiculalgia. Incomplete improvement requiring medical treatment was obtained in 11 patients (15.5%). The procedure was unsuccessful in 20 patients (28.5%) with persistence or worsening of the initial symptoms; 5 of them subsequently underwent chemonucleolysis with 4 good medium-term results and 1 failure. These preliminary results show that percutaneous nucleotomy seems to be effective in lumbar pain of discal origin, with a 66.5% success rate. In patients with pure radiculalgia or lumbar pain cum radiculalgia the results are less impressive, with a success rate of about 50%. However, this well-tolerated technique may be used as first-line treatment of herniated discs when the discs are small, subligamentous and non migrated.

Adult↗
PubMed1989

Extraforaminal lumbar disc herniations: CT demonstration of Sharpey's fibers avulsion.

Forty-seven extraforaminal lumbar disc herniations (EFLDH) accounting for 7% of all lumbar disc herniations encountered during the same period of time were reviewed. L3-L4 or L4-L5 disc was involved in 89% of the cases giving rise to a L3 or L4 nerve root compression. An abnormal motion of lateral bending with rotation of the trunk was found retrospectively in 60% of the patients. In 53% of all EFLDH a bony avulsion of the vertebral end-plate facing the herniation was demonstrated at the site of attachment of Sharpey's fibers. This study suggests that this previously undescribed bony change witnesses a special injury of the spine responsible for most EFLDH.

Adult↗
PubMed1989

Dynamic CT scan of intracranial tumors.

Of ninety-eight patients with intracranial tumors examined by dynamic CT scanning, 66 were confirmed operatively and pathologically. Our study showed that: 1) Dynamic CT can be performed safely and easily in outpatients; 2) Acoustic neurinoma, meningioma, pituitary chromophobe adenoma, astrocytoma and metastatic tumor have varying levels of time-density curves; 3) The tissue-blood ratio (TBR) at peak time (TBRp) is a useful indicator of the vascularity of tumoral tissues, and analysis of the time-density curve combining with TBRp is helpful to the differential diagnosis of tumors; 4) Differential diagnosis between tumors and vascular abnormalities such as aneurysm and arteriovenous malformation could be made easily with dynamic CT.

Adenoma, Chromophobe↗