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Biomedical subjects

Y R Chen

Publications and source records attributed to Y R Chen.

At least 163 records · Page 9Linked to original sources
PubMed1990

Facial bone fracture associated with carotid-cavernous sinus fistula.

Out of 989 cases of facial bone fracture, ten patients had carotid-cavernous sinus fistulas (1.01%). Their ages ranged from 25 to 48 years. Seven were male and three female. Two of the ten patients had lower third, three patients had middle third, three patients had upper third, and two patients had combined middle and lower third facial bone fractures. The signs and symptoms of a fistula appeared from the first postinjury day up to 50 days after the injury (mean, 21 days). Four patients had symptoms after operation for facial bone fracture. Most fistulae were identified by arteriography before treatment. Followup ranged from 1 year, 8 months, to 5 years, 9 months (mean, 2 years, 9 months). One patient had a malocclusion. Nine patients had complete resolution of their bruits. Complications included unilateral complete visual loss (two), CSF rhinorrhea (two), and stroke in one of the two CSF rhinorrhea patients. One patient expired due to a severe head injury, and there was one death from an unrelated cause.

Adult↗
PubMed1990

Human cells contain a DNA-activated protein kinase that phosphorylates simian virus 40 T antigen, mouse p53, and the human Ku autoantigen.

HeLa cells contain a serine/threonine protein kinase (DNA-PK) that is strongly activated in vitro by low concentrations of double-stranded DNA (dsDNA). Activation was specific for dsDNA; both natural DNAs and synthetic oligonucleotides functioned as kinase activators. The fact that DNA-PK activity was rapidly inhibited by incubation with dsDNA and ATP suggests that DNA-PK activity also may be regulated by autophosphorylation. During gel filtration, DNA-PK activity behaved as a 350-kDa protein, and highly purified DNA-PK contained a dsDNA-binding, 350-kDa polypeptide that was phosphorylated in a dsDNA-dependent manner. We conclude that this 350-kDa polypeptide is likely to be DNA-PK. Previously we showed that the dsDNA-activated kinase phosphorylates two threonines at the N terminus of hsp90 alpha (S. P. Lees-Miller and C. W. Anderson, J. Biol. Chem. 264:17275-17280, 1989). Here we show that DNA-PK also phosphorylates the simian virus 40 large tumor antigen, the mouse tumor-suppressor protein p53, the human Ku autoantigen, and two unidentified HeLa DNA-associated polypeptides of 52 and 110 kDa. Identification of these and other newly identified DNA-binding substrates suggest that the dsDNA-activated kinase may regulate transcription, DNA replication, or cell growth.

Amino Acid Sequence↗
PubMed1990

Active oxygen radicals produced by leukocytes of malignant lymphoma.

The electron spin resonance (ESR) spectra of active oxygen radicals produced during the respiratory burst of PMA-stimulated leukocytes and oxygen consumption are studied by ESR spin trapping and spin probe oxymetry for 31 times in 17 cases of malignant lymphoma. The results showed that the spectra produced from PMA-stimulated patients' leukocytes were predominantly spin adducts of DMPO-hydroxyl radicals (DMPO-OH). The decrease in oxygen consumption during respiratory burst suggested that respiratory burst function was inhibited. Kinetic observations of patient condition showed that respiratory burst and oxygen consumption were improved and even approached normal, when the patient was in remission or the condition was ameliorated. This paper is the first of its type and helps clarify the mechanism of malignant proliferation and metastasis.

Adult↗
PubMed1990

Treatment of craniomaxillofacial fibrous dysplasia: how early and how extensive?

Twenty-eight craniomaxillofacial fibrous dysplasia patients were treated as early as the symptoms occurred. The principles of surgical treatment were based on the zones of involvement: total excision of dysplastic bone of fronto-orbital, zygoma, and upper maxillary origin (zone 1) and bone reconstruction primarily; conservative excision on hair-bearing skull (zone 2), central cranial base (zone 3), and tooth-bearing bones (zone 4); and optic canal decompression on patients with orbital dysplasia and decreasing visual acuity. Patients were followed for 1 to 11 years (average 5.3 years). No recurrence or invasion of the fibrous dysplasia into the grafted bone was seen. One patient had orthognathic maxillary osteotomy on the reconstructed maxilla 6 years after initial reconstruction. Five of 19 patients with alveolar dysplasia had a recurrence and were reshaped. One patient had mandibular sagittal osteotomies to set back the prognathic, fibrous dysplasic mandible after three attempts at conservative shaving. Another patient with mandibular fibrous dysplasia had recurrence with pain and a hemimandibulectomy with successful immediate free vascularized iliac bone graft reconstruction.

Adolescent↗
PubMed1990

Traumatic eyelid invagination: case reports.

Three rare cases of upper eyelid trauma are presented. In high-speed traffic accidents, the upper eyelids were penetrated by glass, avulsed, and then, together with pieces of glass, pushed over the globe and buried deeply in the retrobulbar area. The invaginated eyelids were pulled out gently, the conjunctiva still attached to the globes. They were repaired primarily. In these patients eyelid function and cosmesis were preserved.

Accidents, Traffic↗
PubMed1989

[Cleft lip and cleft palate in the Craniofacial Center, Chang Gung Memorial Hospital: incidence, sex, seasonality and topographic distribution].

Of 2963 patients registered at the Chang Gung Craniofacial Center, 1755 patients (906 males and 849 females) who did not have any previous surgery were carefully delineated according to cleft side, involvement of primary or secondary palate and severity of cleft. Cleft lip and palate (43.88%) was the most common cleft, cleft palate (30.88%) the second, while cleft lip (25.24%) the least. More males were found in cleft lip group or cleft lip and palate group, and more females in the cleft palate group. Regarding clefts involving both primary and secondary palates, the cleft of both palates was usually complete, but when the clefts involved either the primary or secondary palate, the cleft was usually incomplete. With regards to the laterality of unilateral cleft lip and/or palate, the left side was affected more than right side. With regard to seasonal variation, cleft palate patients showed the highest incidence from August to October and the lowest incidence from November to January. Cleft lip or cleft lip and palate patients showed the highest incidence from November to February but no obvious difference in the rest of the months. Topographic distribution disclosed that more patients were domiciled in the area north to Hsien-Chu, especially the urban Taipei area.

Adolescent↗
PubMed1989

Facial elephantiasis neurofibromatosa--excision and skin graft.

A case of left facial elephantiasis neurofibromatosa was treated with near-total excision and skin graft. Results were favorable. Repositioning of canthal ligaments, preserving part of relatively normal masseter muscle and primary nasal reconstruction with forehead flap were performed. The skin graft over the myxomatous muscle was successful. Troublesome bleeding was avoided or controlled by incising the normal skin, subperiosteal dissection, hypotensive anesthesia, and chromic catgut suture ligature.

Adult↗
PubMed1989

[Anatomic observation and clinical significance of vertebral pedicle].

To be aware of the security in fixing the spine through posterior approach with instrumentation, a study of the regional anatomy of the pedicle was done by measuring various parameters in 51 thoraco-lumbar (T-9 to L-3) specimens, including the thickness, height, and length of pedicle, the angles made by line of the pedicle axis with both the sagittal and longitudinal lines of the same vertebral body, and the distance between pedicles of each vertebra. The space between spinal cord and pedicles on cross section of 35 cadaveral specimens was also measured. For purpose of comparison to find out the anatomical significance for clinical application, measurement of corresponding parameters on CT scan films of 50 cases were carried out. Taking into account of all these parameters, findings and some clinical experience, detailed discussion about operative indications, procedures of internal fixation and the inserting point along with the direction of drilling screws in were made.

Anthropometry↗
PubMed1989

Duplication of stomatodeal structures: report of three cases with literature review and suggestion for classification.

Three cases of duplications of stomatodeal structures are reported. One had an accessory mouth that could move simultaneously with his mouth at sternal notch. Another had a teeth-bearing bony mass at left maxilla with excessive upper lip and a false pouch. The third had an excessive upper lip, upper jaw with teeth, and hard and soft palate. The literature is reviewed, and a classification is suggested: type I, a duplicated mouth; type II, duplication of maxilla-upper lip or mandible-lower lip complex; and type III, centrally located, poorly developed lip-jaw duplication.

Abnormalities, Multiple↗
PubMed1988

Combined cleft and craniofacial team--multidisciplinary approach to cleft management.

A combined cleft palate and craniofacial was organized at Chang Gung Memorial Hospital, Taipei, in 1980. The team includes four plastic surgeons, four orthodontists, one prosthodontist, one otolaryngologist, one pediatrician, two speech pathologists, one social worker, one psychologist, two neurosurgeons, one ophthalmologist and a medical artist. Weekly combined clinics and meetings are held regularly to evaluate cleft lip/palate and all craniofacial cases. The team members set up treatment plans for each cleft palate and craniofacial patient, and follow up the patient's facial growth with critical evaluation of the result, complication, relapse and patient's or parent's satisfaction after surgery. Parents' support groups, summer speech camps and conferences between patients, parents and other public resources are held regularly. Longitudinal studies are strictly carried out on specific groups of cleft patients and major craniofacial patients.

Adaptation, Psychological↗
PubMed1988

Articulation proficiency and error pattern of cleft palate children with delayed hard palate closure.

Prior to 1982, children with cleft palate received delayed hard palate closure at Chang Gung Memorial Hospital. In this treatment, soft palate is usually repaired with Widmaier palatoplasty at about 18 months with surgery; hard palate is not closed until the age of 6 or 7. Our previous study indicated that the articulation skill of the cleft palate children before delayed hard palate closure is generally far inferior to the non-cleft children of the same age. Further investigation was carried out to look into the articulation proficiency and error patterns of the cleft palate children undergoing delayed hard palate closure. Data of 47 children (32 boys, 15 girls) were analyzed. Articulation proficiency was compared in four phoneme categories: nasals, plosives, fricatives and affricates. The results indicated that affricates are most difficult for Chinese cleft palate children to pronounce. At age 5, just before the hard palate closure, none of the phonemes is produced correctly except nasals.

Age Factors↗
PubMed1987

Purification and partial characterization of a calmodulin-stimulated nucleoside triphosphatase from pea nuclei.

A nucleoside triphosphatase/deoxynucleoside triphosphatase associated with the chromatin fraction from a highly purified preparation of pea nuclei has been isolated and characterized. The purified enzyme has a molecular weight of 47,000 as checked by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and it has an isoelectric point of 6.6. In the presence of divalent cations (Mg2+ = Mn2+ greater than Ca2+), this enzyme hydrolyzes nucleoside triphosphates or deoxynucleoside triphosphates. Hydrolysis is optimal at pH 7.5 and is significantly inhibited by relatively low concentrations of quercetin, but is not sensitive to vanadate, nitrate, or oligomycin. The enzyme has a rather broad nucleotide substrate specificity and has a Km for MgATP2- of 0.6 mM. The enzyme activity is stimulated over 3-fold by Ca2+ and calmodulin, and the stimulation is blocked by the Ca2+ chelator EGTA and by the calmodulin antagonists compound 48/80 and chlorpromazine.

Adenosine Triphosphate↗
PubMed1987

Simultaneous determination of gastrodin and its metabolite by HPLC.

A rapid and specific HPLC method for the simultaneous determination of gastrodin and its metabolite gastrodigenin (p-hydroxybenzyl alcohol) in rat plasma, bile, liver, urine and faeces is described. The separation was achieved by using a reversed phase column (YWG-C18) eluted with methanol-water (2.5:97.5 v/v). Phloroglucinolum was used as internal standard and the peaks were detected at UV 221 nm. The protein precipitation with ethanol was a very simple and rapid method for sample preparation. The gastrodin and gastrodigenin were quantitated by measuring the peak-height ratios. There was a linear concentration range of 10-320 micrograms/mL in the assay for both compounds. The coefficients of variation (within-day) for samples spiked with gastrodin and gastrodigenin were 2.94% and 3.08%, respectively. The method demonstrated a high specificity and was suitable for use in pharmacokinetic studies.

Animals↗
PubMed1986

Simultaneous total correction of temporomandibular ankylosis and facial asymmetry.

Ankylosis of the temporomandibular joint not only prevents mouth opening and chewing, but also affects the growth and position of the mandible. This produces progressive facial distortion with devastating psychosocial effects compounding the already difficult problem of not being able to open the mouth. Over the past 6 years, 18 patients in Canada and Taiwan were treated by excision of a large block of bone at the ankylosis and repositioning of the jaw, with the addition of osteotomies as necessary to produce a symmetrical face with good occlusion. Bilateral cases were treated at one operation in a similar way. The temporomandibular joint and absent ramus were constructed with a costochondral graft taken from the opposite chest. Some patients were treated with intermaxillary fixation for 8 weeks, while others had no fixation, but there was no difference in the effectiveness of correction of the ankylosis.

Adolescent↗