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Biomedical subjects

D Liu

Publications and source records attributed to D Liu.

At least 829 records · Page 46Linked to original sources
PubMed1986

Oriental eyelids. Anatomic difference and surgical consideration.

Fashions change with time and beauty standards differ in different cultures. In recent years, there has been an increase in the number of immigrants to the United States from the Orient. The creation of an upper eyelid crease has been for the past several decades the most popular cosmetic procedure in many Asian countries. In order to perform this procedure to the satisfaction of an Oriental patient, the surgeon must know what the patient perceives as beautiful and the anatomic differences between the Oriental and the Occidental eyelids. In this paper with data collected from over 3,600 patients, we are presenting important statistics that enables the surgeon to understand better the Oriental mind and facilitate communications. The anatomic difference in the upper eyelid is also discussed.

Asian People↗
PubMed1986

Conjunctivochalasis. A cause of tearing and its management.

Conjunctivochalasis is an isolated bilateral condition in which redundant conjunctival tissue overlies the lower eyelid margin or covers the lower punctum. It causes tearing by mechanically disrupting the normal flow of tears. Unlike the boggy conjunctiva seen in an allergic reaction, the extent of this redundant tissue is small, well-localized, and unresponsive to antihistamine drops. During the 40-month period from May 1981 through September 1984, 15 patients complaining of epiphora were found to have this problem. Simple local surgical excision relieved their symptoms. Follow-up period ranged from 10 to 40 months, with an average of 27 months. Conjunctivochalasis can be recognized by a thorough ocular examination and managed by simple excision of the redundant tissue. Consequently, before extensive surgery such as dacryocystorhinostomy, eyelid surgery, or silicone intubation of the lacrimal system is contemplated, conjunctivochalasis should be ruled out and corrected.

Aged↗
PubMed1985

Complications of fine needle aspiration biopsy of the orbit.

When properly used in well-indicated patients, fine needle aspiration biopsy of orbital lesions is an invaluable adjunct diagnostic technique. In experienced hands, the success rates have been high and the complications rare and minor. If the protocols are not followed or the surgeon is inexperienced, serious complications may result. A recent survey among 202 oculoplastic and orbital surgeons, with a total of 152 patients, confirmed this. In 138 patients, the biopsy was performed by an oculoplastic or orbital surgeon, and 10 minor complications were reported. Eleven out of the 14 remaining patients were seen by an oculoplastic or orbital surgeon in consultation for complications arising from a fine needle aspiration biopsy of the orbit performed by someone else. Complications in this group of patients included orbital hemorrhage requiring orbital decompression, motility disturbance, ptosis, and blindness. There were three deaths.

Biopsy, Needle↗
PubMed1985

Extreme intracardiac coiling of a transvenous pacemaker: a case report.

We report an unusual complication of transvenous pacing: extreme coiling of a pacemaker catheter, which formed a redundant, twisted loop protruding into the right ventricular outflow tract. This may be a result of "twiddling" (rotation) of the pacemaker generator by the patient and/or inadequate fixation of the catheter at the venous entry site. Careful fixation of the generator to the venous entry site within the subcutaneous pocket may prevent such a complication.

Adult↗
PubMed1984

Orbital metastasis from prostatic carcinoma. Identification by immunocytology.

We report a case in which the diagnosis of prostatic carcinoma, metastatic to the orbit, was confirmed using an immunoperoxidase technique on cytologic specimens obtained by fine-needle aspiration. Computed tomography was valuable in localizing the tumor for biopsy and subsequent radiation therapy. The results of these studies correlated with the clinical history and other evidence of widespread metastatic disease. Ironically, the first evidence of malignancy in this patient was possibly also ophthalmologic, manifesting 14 months earlier with hemorrhagic retinopathy associated with thrombocytopenia. To our knowledge, this is the first report describing the combination of an immunoperoxidase technique with the fine-needle aspiration biopsy of an orbital tumor.

Adenocarcinoma↗
PubMed1984

Cryosurgical treatment of the eyelids and lacrimal drainage ducts of the rhesus monkey. Course of injury and repair.

Freezing injuries were produced on the eyelids and lacrimal drainage systems in ten rhesus monkeys. The instrumentation produced both single and double freezing cycles at tissue temperatures of -30 and -60 degrees C. The extent of injury and the course of repair were evaluated by clinical observation and by histologic examination of tissue specimens removed at intervals up to three months after freezing. Both cryosurgical techniques produced necrosis of the tissues, but injury was less with single freezing cycles at -30 degrees C. The course of repair was favorable. Even at the three-month observation period, when healing was complete, there was minimal-clinical or histologic evidence of canalicular obstruction or other periocular complications.

Animals↗
PubMed1984

Effects of trypsin and protein modification on the renal transporter of p-aminohippurate.

Basal-lateral membranous vesicles prepared from rabbit renal cortex exhibited Mg2+-stimulated, probenecid-inhibitable transport of p-aminohippurate (PAH). This uptake could be completely eliminated by incubating the membranes with trypsin at a weight ratio of 1:700 (trypsin/membrane protein). The loss of PAH uptake activity occurred in two stages. Over the first ten minutes of the vesicles' exposure to trypsin, there was a nearly linear loss, with respect to time, of about 80% of the PAH uptake activity. The remaining 20% of activity was resistant to further trypsin digestion for the next ten minutes, but by twenty-five minutes a total inactivation of the uptake activity occurred. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of normal and trypsin-treated vesicles showed very little degradation of proteins. However, two minor polypeptides (Mr - 410,000 and 388,000) were degraded during the first ten minutes of the membranes' exposure to trypsin. After twenty minutes of exposure, two other polypeptides (Mr = 94,500 and 87,500) were degraded. Chymotrypsin and clostripain also caused a loss of PAH transport activity. However, compared to the effects of trypsin, the effects of these two proteases were less complete, slower in onset, and for clostripain, a much higher concentration of enzyme was required. Other functions or properties of the vesicles including morphological appearance, degree of vesiculation, glucose space or Na+-dependent L-glutamate transport and Na+,K+-ATPase activity were not altered by the concentration of trypsin which abolished 80% of the transport of PAH. Thus, it is possible that one or more of the degraded polypeptides detected by polyacrylamide gel electrophoresis comprises the PAH transporter.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Transport Systems↗
PubMed1984

Lower-eyelid distractor.

An instrument is designed to measure the distractibility or horizontal laxity of the lower eyelid. It gives precise measurement of laxity independent of the examiner. It enables the surgeon to determine when and how much tightening of the lower eyelid is necessary to achieve the desired result in repair of entropion or ectropion and in cosmetic blepharoplasty.

Ectropion↗
PubMed1984

Thermal orbital injuries from disposable cauteries.

Forty rabbits divided in six groups and three brands of hot wire cautery with temperature ranging from 190 degrees C to 1035 degrees C were used in this experiment. A surgical procedure resembling a cosmetic blepharoplasty was performed on a total of 60 lower eyelids of the rabbits. The remaining eyelids were either shams or normal controls. Cautery application to orbital fat was carefully controlled, i.e., 10 or 20 seconds in single or double applications. Gross observation and microscopic examination of the biopsied specimens taken at 3 hours, 2 days, and 2 weeks after the procedures were performed. Evidence of thermal injury to the lacrimal gland and extraocular muscle damage was found. Although no evidence of thermal injury to the optic nerve was found, it was conceivable that either by a direct transfer of heat or by an indirect inflammatory and compressive effect the health of the optic nerve might be threatened. It is strongly recommended that hot wire cautery be used with extreme caution when working with orbital tissues.

Adipose Tissue↗
PubMed1984

Identification of nitroso compounds from biotransformation of 2,4-dinitrotoluene.

The intermediates of microbial transformation of 2,4-dinitrotoluene by a mixed bacterial culture derived from activated sludge were identified as 2-amino-4-nitrotoluene, 4-amino-2-nitrotoluene, 2-nitroso-4-nitrotoluene, and 4-nitroso-2-nitrotoluene. The biotransformation of 2,4-dinitrotoluene occurred only under anaerobic conditions with an exogenous carbon source. The two nitroso compounds were unstable and could be observed only at the early stage of 2,4-dinitrotoluene anaerobic biotransformation.

Journal Article↗
PubMed1984

Effects of analogs of salicylate on p-aminohippurate uptake into basal-lateral membranous vesicles.

In basal-lateral membranes of the renal cortex, thiol substituted analogs of salicylate inhibited the uptake of p-aminohippurate (PAH). The mercury-containing analogs, thimerosal and mercaptide V (formed from 2 mol of thiosalicylate and 1 mol of Hg++), were highly inhibitory. Compared with probenecid, thimerosal and mercaptide V yielded dose-response curves of steeper slope and higher maximal effect. The dose-response curves of thimerosal and mercaptide V were similar in shape, although mercaptide V was more potent. The inhibition by thimerosal, mercaptide V and mersalyl acid, an anionic sulfhydryl reagent which also inhibits uptake of PAH ( Tse et al., J. Pharmacol. Exp. Ther. 226: 19-26, 1983), was found to be competitive with Ki values of 0.39 +/- 0.05, 0.12 +/- 0.06 and 0.05 +/- 0.02 mM, respectively. The inhibitory effects of thimerosal and mercaptide V were only partially reversible. Thimerosal and mercaptide V reacted 35 and 62%, respectively, with membrane sulfhydryl groups which may explain the nonreversibility of the inhibitor. The nonreversibility is probably not due to irreversible destruction of the vesicles, as the "glucose space" of the vesicles was not affected by these two compounds. That derivatives of salicylates capable of reacting with sulfhydryl groups were more inhibitory than thiosalicylate is consistent with a hypothesis that the PAH transporter contains a sulfhydryl group(s) essential for uptake. Based on the degree of inhibition, the degree of reversibility, the degree of membrane sulfhydryl group oxidation and the computer-generated three dimensional models of thimerosal, mercaptide V and mersalyl acid, a model of the PAH transporter is proposed.

Aminohippuric Acids↗