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Biomedical subjects

Y C Liu

Publications and source records attributed to Y C Liu.

At least 235 records · Page 13Linked to original sources
PubMed1992

Copulatory behavior and reflexive penile erection in rats after section of the pudendal and genitofemoral nerves.

Two experiments probed the roles of the pudendal and genitofemoral nerves in sexual behavior. Male rats were tested for copulatory behavior and reflexive erections after transection of the sensory (SP) or motor (MP) branches of the pudendal nerves and, in Experiment 2, section of the genitofemoral (GF) nerve alone or in combination with the SP nerves. Damage to the GF nerve had no apparent effects. Division of the SP nerve severely impaired the ability of males to achieve intromission, and hence ejaculation, and reflexive erections were drastically reduced. However, this treatment caused impairments less complete than those previously described for more distal deafferentation by section of the dorsal penile nerves or by application of topical anesthetics to the glans penis. Penile autotomy following SP section was delayed but not avoided by daily treatment with amitriptyline. Transection of the MP nerves had the most drastic effects, preventing reflexive erections, although some intromissions (but no ejaculations) occurred during copulation. Although urinary function was also disrupted by MP transection, the impairment in sexual function is tentatively ascribed to chronic hyperinvolution of the penile corpora following loss of phasic vasoconstrictive stimulation normally supplied via the MP nerves. The pattern of results suggests that the pudendal nerves make different contributions to penile erection in different contexts.

Animals↗
PubMed1992

Paraneoplastic pemphigus: a report of three cases including one long-term survivor.

BACKGROUND: Paraneoplastic pemphigus is a newly described autoimmune disease characterized by painful mucosal ulcerations and polymorphous skin lesions in association with an underlying neoplasm. All reported patients with an associated malignant neoplasm have had a poor prognosis. OBJECTIVE: We present three new cases of paraneoplastic pemphigus associated with a malignant neoplasm and further characterize this disease. METHODS: We used clinical criteria, histologic and immunopathologic examinations, and immunophenotyping to characterize this disease. In addition, we performed immunoprecipitation studies with extracts of radiolabeled human keratinocytes to characterize the antigens to which patient serum binds. RESULTS: All three patients had clinical, histologic, and immunopathologic findings that were strongly suggestive of paraneoplastic pemphigus. Their sera immunoprecipitated a complex of four polypeptides from human keratinocyte extracts with molecular weights of 250, 230, 210, and 190 kd, confirming the diagnosis of paraneoplastic pemphigus. The 250, 230, and 210 kd antigens comigrated with desmoplakin I, the 230 kd bullous pemphigoid antigen, and desmoplakin II, respectively. Lymphocyte immunophenotyping revealed large populations of monoclonal CD19+, CD5+ B cells in two cases. Although two of the patients died, one patient is alive and well 2 years after the diagnosis of paraneoplastic pemphigus. CONCLUSION: We report three cases of paraneoplastic pemphigus. One patient is alive and well 2 years after diagnosis, which suggests that a subgroup of patients may have a more benign course.

Aged↗
PubMed1992

Intracellular localization and partial amino acid sequence of a stress-inducible 40-kDa protein in HeLa cells.

We earlier discovered a novel 40-kDa protein (hsp40) induced by heat shock and other stresses in mammalian and avian cells. In this report, we purified the hsp40 in HeLa cells, using modified two-dimensional gel electrophoresis, and determined the amino terminal amino acid sequence of this protein. The hsp40 is homologous to DnaJ, an Escherichia coli heat-shock protein, as well as to DnaJ-homologous proteins in yeast such as SCJ1, Sec63/Np11, YDJ1 and SIS1. Indirect immunofluorescence staining using an anti-hsp40 polyclonal antibody demonstrated that hsp40 was localized faintly throughout the cell in non-heat-shocked cells and was accumulated in nuclei and nucleoli in heat-shocked cells. The intracellular localization of hsp40 was very similar to that of hsp70, suggesting that these two hsps colocalize in heat-shocked HeLa cells.

Amino Acid Sequence↗
PubMed1992

Effects of continuous heating at mild temperatures on the translocation of hsp70 and protein synthesis in NRK cells.

We investigated intracellular translocation of hsp70 and total protein synthesis during heating at mild temperatures in NRK (normal rat kidney) cells. When cells were heated at 41 degrees C, the hsp70 was translocated into the nuclei/nucleoli, then returned gradually to the cytoplasm during heating. Concomitantly, total protein synthesis first decreased to 80% of the control level, then recovered by 2 hr. This indicates the acquisition of translational thermotolerance during heating at 41 degrees C. The return of hsp70 to the cytoplasm seems to be related to the recovery of total protein synthesis. Similar relationships were obtained at 42 degrees C heating in the presence of glycerol. These results suggest that translocation of hsp70 into the nuclei/nucleoli is important for the recovery of protein synthesis (acquisition of translational thermotolerance) during heating at mild temperatures.

Acclimatization↗
PubMed1992

Relationship between cardiovascular functions and ionic hypocalcemia induced by citrate infusion in anhepatic swines: CaCl2 therapy in severe ionic hypocalcemia.

Baseline and serial values of serum [Ca++], [K+], [Na+], arterial blood gas tensions, acid-base status, temperature and hemodynamic functions were measured during infusion of citrate-phosphate-dextrose (CPD) solution (0.35 ml.kg-1 x min-1) in anhepatic pigs of three randomized groups. Thirteen pigs (group I) continued to receive intravenous infusion of CPD solution until cardiac arrest. When mean arterial pressure (MAP) decreased to about 50 mmHg (group II, n = 7), or 40 mmHg (group III, n = 7) infusion of CPD solution was discontinued, and pigs received CaCl2 (20 mg/kg) intravenously. Serial (1, 4, 8, and 12 min after CaCl2 administration) values of all the above variables and serum citrate at baseline and lowest [Ca++] were measured. After hepatectomy and venovenous bypass, cardiac output (CO) decreased 30%. When ionic hypocalcemia was above 0.7 mM, there was no significant change of cardiovascular functions. When [Ca++] was between 0.34-0.7 mM, there were linear relationships between [Ca++] and CO, systemic vascular resistance (SVR) and MAP, respectively. When [Ca++] was below 0.34 mM, cardiovascular functions decreased abruptly, and the pigs died at [Ca++] of 0.26 +/- 0.06 mM. When [Ca++] decreased to 0.36 +/- 0.06 mM and MAP to 50 +/- 4 mmHg, most hemodynamic functions could be reversed by calcium therapy. However, when [Ca++] decreased to 0.33 +/- 0.05 mM and MAP to 40 +/- 2 mmHg, hemodynamic functions could not be reversed by calcium therapy alone.

Animals↗
PubMed1992

Gene expression of proliferating cell nuclear antigen in rat brain.

Proliferating cell nuclear antigen (PCNA), a non-histone nuclear protein which is preferentially present in rapidly growing cells, was found to express at a significant level in both cerebellum and cerebrum of adult rat brain. Analysis with in situ hybridization did not reveal any region in the brain which is particularly abundant in PCNA transcripts. However, it was noted that the cell bodies of Purkinje cells contained PCNA transcripts. The Purkinje cells are nerve cells of cerebellum and generally thought to be non-proliferative. Regardless the high level of PCNA mRNA in the rat brain, the PCNA protein was not detected in the tissue by immunostaining or immunoblotting analysis. This suggests that regulation of PCNA gene expression in brain may be at translational level.

Animals↗
PubMed1992

Clinical evaluation of fleroxacin in the treatment of bone and joint infections.

The objective of this open label, non-comparative study was to evaluate the efficacy and safety of fleroxacin 400mg administered orally once daily to patients with acute osteomyelitis and/or acute septic arthritis. Nineteen patients (10 males and 9 females) were evaluable for the analysis of clinical efficacy and safety. Of these, 7 (36.8%) had osteomyelitis and 12 (63.2%) had septic arthritis. Bacteriological cures were reported in 6 of 7 patients (85.7%) with osteomyelitis and in 8 of 11 patients (72.7%) with septic arthritis. The median duration of treatment for the clinical cures in osteomyelitis and septic arthritis were 29.5 days and 46 days respectively. The eradication rate for the most common pathogens, Salmonella enteritidis and Staphylococcus aureus were 77.7% and 80.0%, respectively. The clinical response was cure in 4 of 7 patients (57.1%) evaluable for osteomyelitis, and in 9 of 12 patients (75.0%) evaluable for septic arthritis at the three-month follow-up after treatment. Adverse reactions were minimal. It is concluded that fleroxacin appears to be an effective and safe in the treatment of acute osteomyelitis and acute septic arthritis.

Acute Disease↗
PubMed1992

Comparison of antiemetic effect among ephedrine, droperidol and metoclopramide in pediatric inguinal hernioplasty.

Prevention and treatment of postoperative nausea and vomiting with ephedrine, droperidol and metoclopramide have been reported to be effective. To further investigate their efficacy, 100 pediatric patients scheduled to undergo inguinal hernioplasty on ambulatory basis were divided into five groups, namely, group 1: normal saline (iv) control; group 2: ephedrine 0.5 mg/kg, (im); group 3: droperidol 50 micrograms/kg. (iv); group 4: ephedrine 1 mg/kg. (im); group 5: metoclopramide 0.15 mg/kg. (iv). At the end of surgery, each patient received the drug treatment according to the specified group to which he was randomly assigned. The occurrence of postoperative nausea and vomiting was recorded in the recovery room and inquired at home by telephone within 24 h following surgery by a blinded observer. The authors found that there were no significant differences between the control group and ephedrine groups with whichever dose that was used in the prevention of postoperative nausea and vomiting. Droperidol and metoclopramide were effective in dealing with problem in comparison with control group (p less than 0.05). However, metoclopramide was more suitable than droperidol for pediatric outpatient based on duration of somnolence, return of orientation, and time of discharge.

Antiemetics↗
PubMed1991

Membrane-microfilament interactions in ascites tumor cell microvilli. Identification and isolation of a large microfilament-associated membrane glycoprotein complex.

[14C]Glucosamine metabolic labeling and concanavalin A blots were used to identify four major glycoprotein species associated with ascites tumor cell microvillar microfilament cores and with a transmembrane complex containing actin. Phalloidin shift analysis of glucosamine-labeled microvilli showed that glycoproteins of 110-120, 80, 65, and 55 kDa are stably associated with the microfilament cores. Analysis of large (greater than 10(6) kDa) transmembrane complexes from microvillar membranes made under microfilament-depolymerizing conditions (Carraway, C. A. C., Jung, G., and Carraway, K. L. (1983) Proc. Natl. Acad. Sci. U. S. A. 80, 430-434) revealed glycoproteins of the same Mr values, showing the same relative staining or labeling patterns as those observed with the microfilament cores. Gel filtration of high salt, high pH extracts of intact microvilli, microfilament cores, or transmembrane complexes showed that in all of these fractions the glycoproteins are associated in a very large, stable complex. The glycoprotein multimer was isolated essentially free of actin and other components by Sephacryl S-1000 chromatography of microvilli, microvillar membranes prepared at pH 11, microfilament cores, or transmembrane complex fractions in Triton X-100, 1 M KCl, glycine, pH 9.5. Purified glycoprotein complex bound actin when incubated under polymerizing conditions. The presence of the glycoprotein heteromultimer in both microfilament cores and transmembrane complex from isolated membranes and the association of the purified glycoprotein complex with actin are consistent with our hypothesis that the glycoprotein-containing transmembrane complex is an association site for microfilaments at the plasma membrane.

Actins↗
PubMed1991

Spontaneous bacterial peritonitis in patients with hepatitis B-related cirrhosis and hepatocellular carcinoma.

To delineate the natural clinical course of spontaneous bacterial peritonitis in hepatitis B-related cirrhosis and to determine if it occurs in hepatocellular carcinoma, a prospective survey was conducted in 262 patients over 2 1/2 years. The in-hospital incidence and mortality rates of spontaneous bacterial peritonitis were 21.6% and 36.4%, respectively, in cirrhosis and 7.3% and 50% in hepatocellular carcinoma. In cirrhosis, the cumulative probability of annual recurrence of spontaneous bacterial peritonitis was 47.3%, which was significantly higher than the annual probability of occurrence of 11.3% in those with no previous attack (P less than 0.0001). The cumulative probability of annual survival was 27.6% in the spontaneous bacterial peritonitis patients, significantly lower than the probability of 64.0% in the control group (P = 0.0001). A univariate analysis, with Kaplan-Meier curves compared by the Mantel-Cox test, and subsequent multivariate analysis by stepwise Cox regression procedure were used to evaluate 37 variables recorded immediately after admission. Blood urea nitrogen concentration greater than 10.5 mmol/L urea (greater than 30 mg/dL) and ascitic fluid protein concentration less than 7.35 g/L (less than 735 mg/dL) were found to be the only significant predictors of lower annual survival; ascitic fluid protein concentration less than 7.50 g/L (less than 750 mg/dL) was the only significant predictor of higher annual recurrence. The authors conclude that spontaneous bacterial peritonitis has a high risk of recurrence in hepatitis B-related cirrhosis and that the same disease occurring in patients with hepatocellular carcinoma is related to the underlying cirrhosis rather than the hepatocellular carcinoma.

Adult↗
PubMed1991

Mineral-associated hepatic injury: a report of seven cases with X-ray microanalysis.

The patterns of hepatic injury associated with various minerals were studied in seven patients. The subjects included one patient who was a sandblaster (silica by inhalation), one patient who was a dental laboratory technician (silica and chromium-cobalt alloy by inhalation), one patient with inhalational talcum powder abuse, and four chronic intravenous (IV) drug abusers (talc by IV injection). In all cases, the liver was examined by light and polarizing microscopy, and by scanning electron microscopy with energy-dispersive x-ray microanalysis. In the two patients with silica exposure, silica-containing sclerohyaline nodules were diffusely present in portal tracts and lobules. Both chromium-cobalt alloy and silica were present in the dental technician. In contrast, in all cases of talc exposure, aggregates of talc-laden macrophages were present in portal and centrilobular areas. Three IV drug abusers and the talcum powder abuser had histologic evidence of chronic hepatitis, most probably of viral etiology. We conclude that mineral type plays an important role in the pathogenesis and fibrogenesis of hepatic lesions. Compared with silica, talc primarily elicits a macrophage response without granuloma formation or fibrosis. Hepatic silicosis is a rare complication in dental laboratory technicians, and chromium-cobalt alloy may contribute to hepatic injury and fibrosis in this setting.

Adult↗
PubMed1991

Targeting of neuromodulin (GAP-43) fusion proteins to growth cones in cultured rat embryonic neurons.

Neuromodulin (GAP-43) is a membrane protein that is transported to neuronal growth cones. Zuber and co-workers have proposed that the N-terminal 10 amino acid sequence of neuromodulin is sufficient to target proteins to growth cones. We demonstrate that a neuromodulin-beta-galactosidase fusion protein is transported to growth cones of cultured rat neurons, whereas a fusion protein containing the N-terminal 10 amino acids of neuromodulin and beta-galactosidase is not. A mutant neuromodulin lacking cysteines 3 and 4, the palmitylation sites required for membrane attachment, does not target beta-galactosidase to growth cones. We conclude that membrane attachment is required for growth cone accumulation and that structural elements, in addition to the first 10 amino acids of neuromodulin, may be required for growth cone targeting.

Animals↗
PubMed1991

Maintenance of erection of penile glans, but not penile body, after transection of rat cavernous nerves.

Two experiments tested the widely held assumption that the cavernous nerves (CN) are essential not only to erection of the penile body, via the corpora cavernosa, but also to erection of the glans penis, via the corpus spongiosum. In Experiment 1, the copulatory behavior and reflexive erections of male rats were studied before and after the CN were transected bilaterally (n = 8), unilaterally (n = 6), or sham-operated (n = 6). In postoperative tests, bilaterally operated males were severely impaired in their attempts to effect intromission, and they had the expected deficits in reflexive erections of the penile body, but their capacity for erection of the glans penis was only minimally impaired. Sham-operated males were unaffected by surgery, and unilaterally transected males had intermediate values. Experiment 2 tested the hypothesis that activity of the bulbospongiosus muscles was responsible for the residual erectile capacity of the glans after CN transection in Experiment 1. Males had bilateral sections of the CN (n = 9), or of the nerves innervating the bulbospongiosus muscles (n = 10), or of both of these nerves (n = 8), or sham surgery (n = 10). Relative to CN transection alone, the combined denervation further reduced glans penis erections, but did not eliminate them. These results suggest that the cavernous nerves of the rat are not the only peripheral nerves facilitating vascular engorgement of the corpus spongiosum.

Animals↗
PubMed1991

Generation of monoclonal antibodies to bovine follicle-stimulating hormone and application in an enzyme immunoassay.

Twenty monoclonal antibodies (MAbs) to bovine follicle-stimulating hormone (bFSH) were generated by using the hybridoma technique. Twelve of the MAbs have been shown to bind specifically to bFSH and seven of them were purified from the respective ascitic fluids with the methods of caprylic acid precipitation and hydroxylapatite column chromatography. The purity of the MAbs was in the range of 86-95%. Three of the purified MAbs have been coupled to horseradish peroxidase (HRP). By using a matrix cross-matching procedure, two MAbs reacted with discrete antigenic determinants are selected for a double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). The designed ELISA procedure could be performed within 60 min in a two-stage incubation and has a minimum sensitivity of 1ngFSH/ml. For serum samples, its mean intra- and inter-assay coefficients of variation were 3.4% and 7.3% respectively. The DAS-ELISA can be used to establish a complete FSH profile in the field of in vitro diagnosis.

Animals↗
PubMed1991

Peripheral blood neutrophils in inflammatory bowel disease: morphological evidence of in vivo activation in active disease.

Morphological evidence of activation in vivo of circulating neutrophils in patients with inflammatory bowel disease (IBD) was sought by quantitative light microscope examination of toluidine blue-stained preparations made from peripheral venous bloods that had been fixed immediately ex vivo. The proportion of spherical (unactivated) circulating neutrophils was reduced in active Crohn's disease (73%; 46-96 (median; range), n = 11) compared with inactive Crohn's (90%; 45-99; n = 18, P less than 0.01) and normal subjects (94%; 44-98; n = 13, P less than 0.05). There tended to be fewer spherical neutrophils in active ulcerative colitis (77%; 13-96; n = 17) than in quiescent colitis (88%; 57-99, n = 13, P less than 0.1) or normal subjects (P less than 0.05). Activated neutrophils occur in the circulating pool of patients with active IBD and can be detected by light microscopy of peripheral venous blood leucocyte preparations.

Adult↗
PubMed1991

Isolated cryptococcosis of the adrenal gland.

A case of isolated adrenal cryptococcosis is reported. A patient with a history of diabetes mellitus had symptoms of left flank pain. Roentgenological and sonographic findings of the adrenal gland were indicative of a malignant tumour. Tissue obtained from surgery showed fungal granuloma and a poorly encapsulated cryptococcal organism was identified by special stains. A post-operative serum cryptococcal antigen test was positive, and the patient was successfully treated with surgery and a course of amphotericin B. After a 7-month follow-up period, there is no evidence of recurrence or dissemination.

Adrenal Gland Diseases↗
PubMed1991

[Effects of phencyclidine on rabbit basilar artery in vitro and rabbit cerebral blood flow in vivo].

The effect of phencyclidine [1-(1-phenylcyclohexyl)piperidine, PCP] on rabbit basilar arteries was studied with an in vitro model of ring segment arteries. PCP 0.05-500 mumol.L-1 caused vasoconstriction of basilar arteries in a concentration-dependent manner. Its maximal effect (Emax) was 94 +/- 21 mg and the concentration causing half maximal effect (EC50) was 25 +/- 18 mumol.L-1. PCP 0.01-10 mumol.L-1 also concentration-dependently augmented the vasoconstriction induced by electric stimulation in rabbit basilar arteries. Its Emax was 91 +/- 18 mg and EC50 was 0.27 +/- 0.17 mumol.L-1. The effects of PCP on mean arterial blood pressure (MABP) and heart rate (HR) of rabbits were observed. PCP iv 4 mg.kg-1 reduced MABP from 14.3 +/- 0.8 to 12.2 +/- 1.0 kPa and HR from 300 +/- 0 to 278 +/- 5 bpm in 5 min. Using the technique of radionuclide imaging in rabbit brain in vivo, we studied the effect of PCP on cerebral blood flow. After iv PCP 4 mg.kg-1, the tp of radiocerebrogram was increased from 4.5 +/- 1.1 to 6.1 +/- 1.0 s, the tg of radiocerebrogram was increased from 11.7 +/- 0.6 to 18.2 +/- 3.3 s and the rate of clearance was decreased. After iv PCP 2 mg.kg-1, only tg increased from 12.6 +/- 2.1 to 15.9 +/- 0.6 s. Hence PCP increased the transit time of nondiffusible indicators (99mTc) through the cerebral circulation. These results suggest that PCP causes constriction of basilar artery and slows down the cerebral blood flow.

Animals↗