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Biomedical subjects

C M Liu

Publications and source records attributed to C M Liu.

At least 73 records · Page 4Linked to original sources
PubMed1995

Prenatal diagnosis of Meckel-Gruber syndrome case reports.

Two cases of Meckel-Gruber syndrome are presented. In the first case, abdominal tumor and decreased amniotic fluid were initially suspected. In the second case, Omphalocele was diagnosed by local practitioners. Thorough obstetric sonographic studies revealed encephalocele, bilateral renal cystic dysplasia, polydactyly, microcephalus, intrauterine growth retardation (IUGR) and oligohydramnios. Chromosomal analysis by percutaneous umbilical cord blood sampling (PUBS) was normal with 46,XY in Case 1 and 46,XX in Case 2. The prenatal diagnoses were confirmed by autopsy. The pathologic reports revealed type I polycystic kidney, bile duct proliferation, fibrosis of the portal area, encephalocele and polydactyly. It is interesting to note that the two cases came from two different families without any family history of inherited disease.

Abnormalities, Multiple↗
PubMed1995

[Brain abscess as a complication of ear malignancy: a case report].

Ear infection is the most common cause of brain abscess. A suppurative process in the ear has access to the central nervous system by direct extension or through preformed pathways, either developmental, traumatic or pathologic, or by retrograde spread along the thromobophlebitic vein. Squamous cell carcinoma of middle ear or mastoid cavity is a rare disease and often associated with chronic otitis or chronic draining ear. Ear malignancy easily produces the destruction of temporal bone which may serve as a route for coexistent infection spreading into the brain. This paper reports a case of brain abscess occurring in a patient with temporal bone cancer. To the best of our knowledge, no more than three similar cases have been reported in the literature. The authors suggest that if an otogenic brain abscess is concomitant with infection and granulomatous mass in the ear, biopsy should be performed to rule out malignancy.

Brain Abscess↗
PubMed1994

Alkaline phosphatase activity in cultured cells of human healthy and hyperplastic gingivae: a preliminary study.

The present study compared the alkaline phosphatase (ALP) expression in cultured cells derived from different types of gingival hyperplasia. Tissue biopsies were obtained from patients with clinically non-inflamed, enlarged gingivae of idiopathic gingivofibromatosis (IGF) and phenytoin-induced hyperplasia (PHG). Fibroblasts obtained from the gingivae or periodontal ligaments (PDL) of the same or different healthy subjects were used as controls. Fibroblasts were plated and the ALP activity and total amount of DNA per well were studied in each isolated cell type at 4, 7 and 9 days of culture. The results revealed that fibroblasts derived from IGF tissue synthesized a large amount of ALP by day 7 and day 9 of culture. The amount of ALP activity was cell density-dependent and the strongest expression of enzyme activity was noted after cell confluence. In contrast, only very low ALP activity was detected in cells derived from normal gingivae and PHG. Cytochemical examination of these cells revealed similar observations. The fact that fibroblasts derived from PHG tissue did not exhibit ALP in vitro suggests that there was a shift of cell phenotype in this tissue. The increased expression of ALP in IGF cells may imply a developmental trend toward osteoblastic phenotypes.

Alkaline Phosphatase↗
PubMed1994

Increased interleukin-1 beta levels in gingival crevicular fluid of Chinese periodontal patients.

One hundred and twenty-four gingival crevicular fluid (GCF) samples were harvested from 13 healthy and 111 diseased gingival sites in 10 patients with periodontitis. The total amount and concentration of interleukin-1 beta (IL-1 beta) in each sample was measured by the enzyme-linked immunosorbent assay (ELISA) technique using an ELISA Kit specific for this cytokine. The IL-1 beta was undetectable in 23% of the GCF from clinically non-inflamed sites (three out of 13), while it could mostly be identified in diseased sites (109/111). The amount of IL-1 beta varied from 4.03 to 511.12 pg/site in diseased GCF samples. The average IL-1 beta amount from diseased sites was three-fold that from non-inflamed sites. Total IL-1 beta amount and the GCF volume were significantly increased with elevated gingival index (GI) score and deeper probing depth (PD). However, no significant difference of crevicular IL-1 beta concentration (pg/microL) could be found among groups with different clinical parameters. Our results indicate that IL-1 beta was present in the GCF of most clinically non-inflamed gingiva and almost all diseased pockets. The significant elevation of total IL-1 beta amount and GCF volume in diseased sulci suggests that it is closely associated with the severity of periodontal disease.

Adult↗
PubMed1994

Lymphocyte subsets and antigen-specific IgE antibody in nasal polyps.

We tried to elucidate the role of allergic factors in the pathogenesis of nasal polyps. Nasal polyps were obtained from 22 patients with chronic sinusitis which included eight patients proved to have nasal allergy by history, skin test, and serum-specific IgE against houst dust mite. Immunohistochemical studies of lymphocyte subpopulations in the mucosa of nasal polyps were performed with monoclonal antibodies, and the concentrations of antigen-specific IgE in nasal polyps were measured by the fluoroallergosorbent test. In the epithelium, few HLA-DR+ cells were constantly present. In the submucosa, pan T cell marker CD2 was detected more often than CD19 (B cell), and more CD8 (T suppressor/cytotoxic) cells than CD4 (T helper/inducer) cells were found. IgE-producing plasma cells were rarely present. The lymphocyte subpopulations and the levels of antigen-specific IgE in nasal polyps were not different between the allergic and nonallergic groups. This suggests that allergy may not be the cause, and cellular immunity of antigen presenting cells and T lymphocytes, which consecutively induce infiltration and degranulation of mast cells by the production of cytokines, may be involved in the formation of nasal polyps with sinusitis.

Adolescent↗
PubMed1993

Isolation and characterization of four polyether antibiotics, X-14889A, B, C, and D, closely related to lysocellin and the ferensimycins.

Streptomyces sp. X-14889 (NRRL 15517) has been found to produce a number of novel polyether antibiotics and an orange pigment. One of the antibiotics, X-14889B (3) was identified as ferensimycin A, which in turn is an isomer of the well-studied polyether antibiotic, lysocellin (1). Of the three other antibiotics, X-14889C (4) is a lower homolog of ferensimycin A and antibiotics X-14889A (2) and D (5) which are respectively the descarboxy and anhydro-descarboxy forms of this same molecule. The latter compound, X-14889D is of interest as it contains an ether bridge across the terminal tetrahydrofuranyl ring in an analogous relationship to that reported earlier for antibiotics X-14873A (6) and G.

Anti-Bacterial Agents↗
PubMed1993

[Synthesis and antifungal activity of 1-(2-[(4-substituted-phenyl) methoxy]-2-(substituted-phenyl) ethyl)-1H-azoles].

Twenty nine 1-(2-[(4-substituted-phenyl) methoxy]-2-(substituted-phenyl) ethyl)-1H-azoles were synthesized for searching of more potent and less toxic antimycotic agents. Nine of the title compounds are first reported. Results of preliminary biological tests showed that most of the title compounds exhibited activity against the common pathogenic fungi such as Candida albicans, Microsporum bodin, Trichophyton gypsum, Epidermophyton floccosum, Trichophyton violaceum, Microsporum ferrugincum, Trichophyton rubrum and Microsporum gypsum. The antifungal activity of compound 14 was roughly comparable to clotrimazole and econazole against Candida albicans, but was more active against other test fungi than clotrimazole and econazole. Compounds 4, 5, 6, 12, 23 also have good antifungal activity, but are less active against Candida albicans.

Antifungal Agents↗
PubMed1993

Collagenase activity in the gingival crevicular fluid of periodontal patients.

A total of 51 gingival crevicular fluid (GCF) samples were collected, and their associated gingival index (GI) and probing pocket depth (PD) were recorded. The active and latent collagenase activities in the GCF were determined by an assay measuring the intact alpha 1 chain of collagen after sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and autoradiography with 3H-collagen (type I) as an enzyme substrate. The collagen digestion patterns showed that GCF samples generated predominantly 3/4 alpha and 1/4 alpha collagen fragments, typical of vertebrate collagenase. The active collagenase activity was significantly associated with the severity of the measured GI. Active enzyme activity was also elevated in sites with attachment loss (PD > 4mm). However, the enzyme activity in the group with a 7-10 mm probing depth was not greater than that of those with a 4-6 mm pocket depth. The elevation of active collagenase activity was found to be highly correlated with GI, while it was low with respect to the probing depth. The latent collagenase activity increased with the GI score, but not with the pocket depth. These results suggest that most collagenase present in GCF is derived from polymorphonuclear leukocytes which are markedly increased in more severe cases of periodontal disease. Thus, the measurement of active collagenase in GCF samples of patients is a scientifically reliable and sensitive method of assessing disease activity possibly associated with tissue destruction.

Collagenases↗
PubMed1992

Investigation into allergic response in patients with chronic sinusitis.

We attempted to investigate the role of nasal allergy in sinusitis to elucidate whether it results from an immediate-type allergic reaction of the sinus mucosa or from allergic edema-induced sinus ostial obstruction. Forty-two patients with chronic sinusitis were selected for allergen skin tests, measurements of serum total and specific IgE, and sinus tissue-specific IgE. The data were then correlated to examinations of nasal mucosal scrapings and histopathology of the sinus mucosa. We found that serum levels of total IgE and house dust mite-specific IgE antibodies were significantly higher in patients (n = 12) allergic to house dust than in the nonatopics (n = 30; p less than 0.0001). There was no difference in the sinus tissue-specific IgE antibody. Eosinophils and basophilic cells in epithelial scrapings from the inferior turbinates, assessed by Hansel staining, were high in 66.7% and 50% of the atopic patients, respectively, and 36.7% and 26.7% of the nonatopics, respectively. The rates were influenced by the existence of infection and nasal polyps. The increase in eosinophils, mast cells and plasma cells, assessed by histopathologic examination, were not prevalent in the sinus mucosa of atopic patients. It is concluded that nasal allergy may be a predisposing factor to sinusitis and that the pathologic change of the sinus mucosa is mainly secondary, due to sinus ostial obstruction.

Adult↗
PubMed1991

[Proptosis and optic nerve compression caused by unilateral ethmoidal pyocele: a case report].

This paper presents the case of a 29 year-old male with a left ethmoidal pyocele with orbital and intracranial extensions causing proptosis and a temporal visual field defect of the left eye. The patient had a history of nasal injury as a result of traffic accident eleven years ago, and was well until four months prior to his first visit at which time he had an onset of left eye pain, proptosis, and blurring of vision developed following a URI episode. Since then, fluctuation of symptoms was noted with exacerbation when contracting a common cold. The left ethmoidal pyocele was diagnosed via clinical features and roentgenographic findings. The patient received a Caldwell Luc Operation with endonasal ethmoidectomy and the postoperative condition was good except for constriction of the entire visual field and the depression of temporal internal isopters of the left eye.

Adult↗
PubMed1991

Immunomodulation of human cytomegalovirus infection on interferon system in patients with systemic lupus erythematosus.

On the basis of the research on the relationship between human cytomegalovirus (HCMV) infection and systemic lupus erythematosus (SLE) a study of the effects of HCMV infection on the immunological pathogenesis of SLE was undertaken. Presented in this paper is a brief account of the study. It was found that SLE patients with active HCMV infection had significant higher level of serum interferon-alpha (IFN-alpha) than those without active HCMV infection, but the IFN-alpha induction capacity of peripheral blood mononuclear cells (PBMC) from SLE patients with active HCMV infection was evidently poorer than that from patients without it. There was not any statistically significant difference between the two SLE groups in the IFN-gamma induction capacity of PBMC.

Adult↗
PubMed1991

Capillary electrophoresis--a new clinical tool.

The potential clinical diagnostic utility of capillary electrophoresis in an open-tubular column is established. Separation patterns for serum proteins by conventional agarose gel electrophoresis can be faithfully reproduced by a capillary electrophoresis procedure that provides the complete run data in 8 min. Hemoglobin variants can be separated within 10 min. The capillary electrophoresis separations are performed reliably and reproducibly in an untreated 75 micron (i.d.) x 25 cm fused-silica column. Diluted serum or hemoglobin samples can be loaded on an automated instrument with on-line injection, detection, and quantification, providing a truly "walkaway" electrophoresis system.

Blood Proteins↗
PubMed1990

Maintenance and cure of the L5178Y murine tumor-dormant state by interleukin 2: dependence of interleukin 2 on induced interferon-gamma and on tumor necrosis factor for its antitumor effects.

We reported previously that treatment of peritoneal cell (PC) cultures prepared from mice which harbor L5178Y lymphoma cells in a tumor-dormant state in their peritoneal cavity with interleukin 2 (HuIL-2) stimulated antitumor cytotoxic activity in both the nonadherent and adherent populations derived from such cultures. We report here that HuIL-2 induced the production of murine gamma interferon (MuIFN-gamma) in these PC cultures and required Lyt-1-, Lyt-2-, and L3T4-expressing lymphocytes to do so. HuIL-2 required and synergized with this induced MuIFN-gamma to stimulate cytotoxic activity in the nonadherent PC and the MuIFN-gamma itself stimulated cytotoxic activity in the adherent PC. Cyclosporin A prevented both the induction of MuIFN-gamma and the development of antitumor cytotoxic activity in HuIL-2-treated PC cultures. An addback of exogenous MuIFN-gamma to HuIL-2-cyclosporin A-treated PC cultures and to the nonadherent subpopulation of such cultures, at a concentration which itself produced no antitumor effect, permitted HuIL-2 to induce its antitumor effect. We previously reported that MuIFN-gamma requires the action of murine tumor necrosis factor (MuTNF) to induce cytotoxic activity in PC cultures from tumor-dormant mice. We report here that HuIL-2 also requires the action of (MuTNF) to stimulate antitumor cytotoxic activity in PC cultures from tumor-dormant mice. These results indicate that HuIL-2 induces MuIFN-gamma and requires and synergizes with this MuIFN-gamma and with (MuTNF) to stimulate antitumor cytotoxic activity in PC cultures from tumor-dormant mice.

Animals↗
PubMed1990

Maintenance and cure of the L5178Y murine tumor-dormant state by interleukin 2: in vivo and in vitro effects.

We studied the antitumor effects of recombinant human interleukin 2 (HuIL-2) in DBA/2 mice which harbor L5178Y lymphoma cells in a tumor-dormant state in the peritoneal cavity and in peritoneal cell (PC) cultures prepared from such mice. Intraperitoneal injection of 10,000 to 100,000 units of HuIL-2/day for 10 days eliminated tumor cells from 30-45% of the mice, whereas no mice became tumor-free in the phosphate-buffered saline-treated control group. In vitro, as little as 10 units/well HuIL-2 failed to stimulate cytotoxic activity in PC from normal mice. HuIL-2 directly stimulated antitumor cytotoxic activity in nonadherent but not in adherent PC cultures from tumor-dormant mice; however, treatment of whole PC from tumor-dormant mice with HuIL-2 resulted in the development of antitumor cytotoxic activity in the adherent PC population which were derived from such cultures. This suggests that the HuIL-2-treated nonadherent PC contributed to the cytotoxic activation of the adherent PC. Flow cytometric analysis of the PC from tumor-dormant mice revealed a polyclonal expansion of T-lymphocytes. Lyt-1+, Lyt-2+, and L3T4+ lymphocytes were all required for HuIL-2 to induce antitumor cytotoxic activity.

Animals↗
PubMed1990

Aortic regurgitation shortens Doppler pressure half-time in mitral stenosis: clinical evidence, in vitro simulation and theoretic analysis.

Mitral valve areas determined by Doppler pressure half-time were compared with areas obtained by planimetry in two groups of patients with mitral stenosis: 24 patients without aortic regurgitation and 32 patients with more than grade 1 aortic regurgitation. The severity of aortic regurgitation was assessed by color flow mapping; 17 patients had grade 2, 10 had grade 3 and 5 had grade 4 aortic regurgitation. Regression equations for pressure half-time area versus planimetry mitral valve area were calculated separately for the aortic regurgitation (r = 0.88) and the nonaortic regurgitation group (r = 0.86); analysis of covariance revealed a significant (p less than 0.001) difference between the two groups leading to overestimation of planimetry area by the pressure half-time method in the aortic regurgitation group. The mitral valve areas in the group without regurgitation were best calculated with the expression 239/T1/2 (r = 0.77) as compared with a best fit of 195/T1/2 (r = 0.85) for the aortic regurgitation group. To elucidate the mechanisms affecting pressure half-time in aortic regurgitation, an in vitro model of mitral inflow in the presence of varying regurgitant volumes and different ventricular chamber compliances was used. Aortic regurgitation shortened directly measured pressure half-time proportional to the regurgitant fraction but an increase in left ventricular compliance could offset this effect. Finally, in a mathematic model of mitral inflow the competing effects of aortic regurgitation and chamber compliance could be confirmed. In conclusion, aortic regurgitation results clinically in a significant net shortening of pressure half-time leading to mitral valve area overestimation. However, the effect is moderate and individually unpredictable because of changes in chamber compliance.

Adult↗