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Biomedical subjects

C Liu

Publications and source records attributed to C Liu.

At least 865 records · Page 48Linked to original sources
PubMed1986

Enteral nutrition in patients receiving mechanical ventilation. Multiple sources of tracheal colonization include the stomach.

Nutritional therapy of patients receiving mechanical ventilation includes enteral feeding. To determine the frequency of gastric microbial colonization in patients receiving enteral nutrition, 18 patients with acute respiratory failure receiving ventilation were studied. Multiple sources of tracheal colonization were then evaluated to determine the frequency of tracheal transmission of gastric flora and the relationship of gastric colonization and transmission to nosocomial respiratory infection. The stomach was colonized in every patient who received enteral feeding. Tracheal colonization occurred in 89 percent (16 of 18) of patients. In 12 of these 16 patients, 14 organisms colonized the trachea after transmission from the stomach and/or oropharynx. Thirty-six percent (five of 14) of organisms transmitted to the trachea originated from the stomach, whereas another 36 percent (five of 14) were first recovered from the oropharynx. Four tracheally transmitted organisms were first recovered simultaneously from the stomach and oropharynx. Nosocomial respiratory infection developed in 11 patients (63 percent). Three infections occurred during the six-day study period, one of which was associated with transmission of a gastric organism. Multiple sources of tracheal colonization occur in patients receiving enteral nutrition. The stomach is an important source of tracheal colonization. Enteral nutrition can be associated with gastric flora colonizing the trachea and causing nosocomial respiratory infection.

Acute Disease↗
PubMed1986

Prefabricated ossicular homografts in middle ear reconstructions.

This paper is a review of 132 cases of ossicular reconstruction utilizing prefabricated homografts by clinical staff members of the UCLA Division of Head and Neck Surgery (specializing in ear surgery) in their private practice over the past decade. Another 20 cases completed over the past 2 1/2 years in the UCLA teaching programme are also reviewed. Although ossicular homografts have been used for some time in middle ear reconstruction, this report presents the innovation of prefabricating homografts into specific shapes that lend themselves appropriately to reconstruction problems. In such an ossicular bank, a variety of different shapes, in a number of sizes, is maintained for quick selection. This greatly decreases operating room time and, in addition, provides an effective method for ossicular reconstruction that has already been applied to a resident training programme. The cases in this review can be divided into 3 basic categories: (1) mastoidectomy ossicular reconstruction; (2) exploratory tympanotomy with reconstruction; (3) stapedectomy. This study indicates that ossicular homografts are very well tolerated in their new transplanted positions. Our very low extrusion rate, extremely rare evidence of absorption, and lack of foreign body reaction to these ossicles coincides with the experience of others. This is an advantage over plastic prostheses. In addition to pre- and postoperative air conduction level data, analysis of changes in bone conduction and speech discrimination scores are also presented to evaluate possible neurosensory damage related to manipulation in placing these ossicles.

Adult↗
PubMed1986

Clonal origins of lymphoproliferative disease induced by Epstein-Barr virus.

Analysis of immunoglobulin gene rearrangements in 16 B-cell lineages clonally propagated from two mononucleosis patients supported the notion that mononucleosis is a polyclonal B-lymphoproliferative disorder. Three of seven cell clones from a patient with a fatal B lymphoma revealed the same pattern of immunoglobulin gene rearrangement, indicating that this patient's disease was oligoclonal. The three similar clones were propagated from two sites (blood and spleen), indicating that they represent a metastatic cell lineage which arose during the patient's fatal B lymphoproliferation.

Burkitt Lymphoma↗
PubMed1986

Effects of dietary alteration of bicarbonate and magnesium on rat bone.

To study the effects of bicarbonate and magnesium on bone, mild acidosis and/or hypermagnesemia were produced in growing rats by feeding ammonium chloride and/or magnesium sulfate. Bone composition, quantitative histomorphometry, and mineral x-ray diffraction (XRD) characteristics were measured after 6 wk of treatment. The results demonstrated that both acidosis (decreased HCO3) and hypermagnesemia inhibited periosteal bone formation, and, when combined, results were summative; and the previously observed in vitro role of HCO3- and Mg2+ as inhibitors of crystal growth were confirmed in vivo. XRD measurements demonstrated that decreased plasma HCO3 resulted in larger crystals and increased Mg resulted in smaller crystals. However, the combined XRD effects of acidosis and hypermagnesemia resembled acidosis alone. It is postulated that the final composition and crystal structure of bone are strongly influenced by HCO3- and Mg2+, and the effects are mediated by the combined influence on both osteoblastic bone formation and the growth of hydroxyapatite.

Animals↗
PubMed1985

Leishmania infecting man and wild animals in Saudi Arabia. 1. General survey.

Using up to 13 enzymes, biochemical characterization of 75 isolates of Leishmania made from man, wild animals and sandflies from a wide variety of localities in the Kingdom of Saudi Arabia has revealed the presence of L. major (two similar zymodemes), L. tropica (two zymodemes) and a parasite of the L. donovani-L. infantum complex. Zymodeme LON-4 of L. major has been found in 52 of 53 isolates so far characterized from man, from one specimen of Phlebotomus papatasi, from 15 Psammomys obesus, from one Meriones libycus and from one dog. One isolate from man has been identified as a new variant of L. major. This variant, zymodeme LON-65, varies from zymodeme LON-4 in a single enzyme. While this is the only example of zymodeme LON-65 identified so far, zymodeme LON-4 has also been obtained from Kuwait and Iraq. These are the first reports of L. major in Meriones libycus from Saudi Arabia and the first proven isolate from the dog in any country. L. tropica was identified from only two foci, whereas L. major appears to be widely distributed in the Kingdom. Two infants with kala-azar were found to be infected with a parasite apparently identical to zymodeme LON-42 of L. donovani (sensu lato) which also occurs in the highlands of Ethiopia.

Animals↗
PubMed1985

Immunoglobulin JH, C mu, and C gamma gene rearrangements in human B lymphocytes clonally transformed by Epstein-Barr virus.

Somatic rearrangements and deletions of immunoglobulin gene segments have been demonstrated in several types of murine B cells. In addition, rearrangements of the JH, C mu, and light chain immunoglobulin gene segments have been reported in human pre-B-cell leukemias and B-cell lymphomas. We have used recombinant DNA probes for the human JH, C mu, and C gamma immunoglobulin gene loci to analyze the genetic events associated with heavy chain gene expression in human B cells clonally transformed by Epstein-Barr virus. Southern hybridization analysis of BamHI-digested cell clone DNAs shows that these human B-cell clones often have bi-allelic JH rearrangements and that heavy chain isotype switching is associated with bichromosomal C mu and C gamma gene rearrangements. Deletions of germ line C mu and C gamma segments were observed that were sometimes bi-allelic. Overall, the observed rearrangements and deletions of heavy chain constant region genes suggest that human heavy chain class switching proceeds in a general order consistent with the proposed order of the heavy chain gene classes along chromosome 14.

B-Lymphocytes↗
PubMed1984

Prospective randomized reappraisal of 5-fluorouracil in metastatic colorectal carcinoma. A comparative trial with 6-thioguanine.

In order to redefine the effectiveness of 5-fluorouracil (5-FU) as palliative therapy in patients with metastatic colorectal carcinoma, and to compare the effectiveness of 6-thioguanine (6-TG) with that of 5-FU, we studied 176 patients with metastatic colorectal carcinoma in a randomized prospective trial (SEG 79G1268 ). The pretreatment performance status of all patients was greater than 50% (ambulatory), and there was an equal distribution of patients with favorable pretreatment characteristics into each of the treatment regimens. Complete responses were only seen to 5-FU, but were obtained in only 3% of instances. The overall complete plus partial response rates were not different for 5-FU (8%) versus 6-TG (3%), or for patients who had shown prior progression on chemotherapy and who then received 6-TG in a nonrandomized fashion (7%). The time to tumor progression on each of the treatment programs was similar, 1.0 months. Survival was also similar in each regimen in the randomized study (6.3 months for 5-FU versus 7.9 months for 6-TG). However, survival was only 4.8 months for patients with previously drug-resistant tumors treated with 6-TG in the nonrandomized arm. In 16 patients failing 6-TG who then received 5-FU, there were no objective responses. Similarly, in patients failing 5-FU on this study who then received 6-TG, there were no responses in nine patients. Dose-limiting toxicity was observed in 40% to 51% of patients, and consisted of myelosuppression, vomiting, or diarrhea. It is concluded that 5-FU is a minimally effective agent in a very small number of patients with metastatic colorectal carcinoma. The drug 6-TG is equally ineffective in this setting. Alternative treatment programs to the systemic use of 5-FU should be considered in patients requiring palliative chemotherapy.

Adenocarcinoma↗
PubMed1984

Infectious mononucleosis: a polyclonal B cell transformation in vivo.

We obtained spontaneous formation of Epstein-Barr virus-transformed B lymphocyte colonies from the blood of four patients with mononucleosis with the use of soft-agar medium. The colonies were propagated into separate cell lines and analyzed for their immunoglobulin secretion. Of 52 such lines, 44 produced immunoglobulin composed of a single class of heavy chain and single type of light chain. Among these clonal transformants, 27 (62%) of 44 produced mu-chain, 13 (29%) of 44 produced gamma-chain, and 4 (9%) of 44 produced alpha-chain. Analysis of light-chain secretion revealed that of the 44 cell clones secreting complete, monoclonal immunoglobulin products, 31 produced kappa-chain and 13 produced gamma-chain. One clone secreted mu-heavy chain and no light chain, an observation suggesting the clone is a pre-B cell phenotype. Seven lines derived from clones had aberrant patterns of immunoglobulin secretion that produced either two heavy chains or two light chains. B lymphocytes in different states of immunoglobulin gene expression are, therefore, transformed in vivo by Epstein-Barr virus.

Antibodies, Viral↗
PubMed1984

A rapid staining procedure for Anaplasma marginale in bovine erythrocytes.

A commercial product that stains cells in less than 1 minute was compared with the Giemsa and the Wright-Giemsa methods for detection of the intraerythrocytic parasite, Anaplasma marginale, in bovine blood smears. The total number of A marginale-infected erythrocytes detected in 5 microscope fields of 18 different samples was determined for each staining procedure. In samples where less than 2% to greater than 25% of the RBC were infected, statistical analysis of the data indicated that the rapid staining method was superior to the Giemsa and Wright-Giemsa methods with regard to determination of the percentage of bovine erythrocytes infected with A marginale.

Anaplasma↗
PubMed1984

A histological comparison of the temporal bone in strangulation and drowning.

The temporal bones from a two year old drowning victim are compared with those of a 13 month old strangulation victim. Tympanomastoid hemorrhage and submucosal edema and petechiae with moderate vascular congestion were characteristic in drowning. Marked congestion with edema but no sign of hemorrhage was found in strangulation. It is concluded that respiratory effort against a closed glottis is not solely responsible for the tympanomastoid hemorrhage known to occur frequently as a result of drowning.

Airway Obstruction↗