Search PubMed⌕ Search

Biomedical subjects

P Liu

Publications and source records attributed to P Liu.

At least 253 records · Page 14Linked to original sources
PubMed1996

The effect of posture on central blood volume in patients with preascitic cirrhosis on a sodium-restricted diet.

The status of the central blood volume in cirrhosis is controversial. A combination of sodium restriction and upright posture, which redistributes intravascular volume to dependent parts of the body should further aggravate a contracted central blood volume reduction. The aim of this study was to determine the effect of upright posture and sodium restriction on central blood volume (CBV) in preascitic cirrhotic patients, compared with controls. Eight male, preascitic, alcoholic cirrhotic subjects and eight healthy male controls were studied while on a 20-mmol/d sodium diet. Measurements of CBV by radionuclide angiography, and neurohumoral factors were performed on day 7 in both supine and erect positions and cardiac output and systemic vascular resistance (SVR) was calculated. Sodium restriction resulted in less weight loss in the cirrhotic patients (P = .03), with significantly lower plasma renin activity (P = .001). Similar central blood volumes and systemic hemodynamics were observed in both groups in the supine posture. In contrast to the cirrhotic patients, in the control subjects, upright posture resulted in a significant reduction in cardiac output (P = .002) and increase in SVR (P = .005), associated with a decrease in all blood volumes which were significantly less than in the cirrhotic patients. Mean arterial pressure was maintained in both groups in both postures. In conclusion, with sodium restriction, preascitic cirrhotic patients have less intravascular volume contraction than control patients. Erect posture results in redistribution of this relatively expanded intravascular volume to the CBV. Therefore, a low-sodium diet can be safely administered in preascitic cirrhotic patients.

Adult↗
PubMed1996

Simultaneous electrical impedance tomography and videofluoroscopy in the assessment of swallowing.

Simultaneous videofluoroscopy and electrical impedance tomography (EIT) were performed in 13 patients. Subjects swallowed a low-conductivity and a higher-conductivity bolus of between 5 and 20 ml. EIT images from the two swallows were then subtracted to cancel out movement related changes. The peak in the conductivity change was most closely associated in time with a point at which the pharynx is filled with bolus: this suggests that the subtraction process does produce data and images which are related to the bolus rather than to movement of involved structures. The full width at 50% and 75% of the maximum of the time conductivity plot was correlated with the time taken for the bolus to be cleared from the mouth (r = 0.63 and 0.68 respectively, p < 0.05 for both). Despite the sampling frequency of only 9 frames s-1, compared to 50 frames s-1 for videofluoroscopy, EIT recordings from the neck are able to detect the presence of a conductive bolus in the pharynx and for the first time the relationship between parameters of an EIT time-conductivity plot and a measure of bolus transit using an accepted technique has been established.

Adult↗
PubMed1996

Quantification of cardiac and tissue iron by nuclear magnetic resonance relaxometry in a novel murine thalassemia-cardiac iron overload model.

OBJECTIVE: To determine whether nuclear magnetic resonance (NMR) relaxation parameters can be used to quantify iron in tissues, the relationship between NMR spectrometric T2 relaxation measurements and tissue iron concentration were verified in a novel murine cardiac iron overload model. METHODS: Congenital heterozygous thalassemic mice and controls were injected with intraperitoneal iron or saline and were sacrificed at three weeks. Samples of liver, heart and peripheral muscle were subjected to NMR relaxation measurements and continuous distribution analysis. Tissue ferritin levels were determined with immunoadsorbance techniques, and elemental iron was assayed by flame atomic absorption. Tissues were analyzed pathologically with hematoxylin and eosin and Prussian blue staining to confirm the localization of iron. RESULTS: This murine iron loading model was uniquely successful in loading iron into the major organs, especially the heart, and produced significant reductions in T1 and T2 NMR relaxation values. There was a good correlation between soluble ferritin and total iron levels (r=0.92), indicating that there is a constant and significant fraction of total iron present in ferritin irrespective of absolute iron concentrations. Regression analysis between total iron content and T2 relaxivity showed a linear relationship (r=0.96), suggesting that the T2 relaxation parameter is related to tissue iron concentration. The regression relationship suggested that NMR can detect iron levels as low as 0.1 mg/g of tissue. CONCLUSIONS: Parenteral iron loading in mice produces unique iron overload in major organs, including the heart. Local iron deposition is detectable by NMR relaxometry at 0.1 mg/g or higher. There is a linear relationship between iron concentration and T2 relaxivity. Thus, NMR may be an important and useful clinical tool to quantify iron excess in various pathobiological states of human disease due to iron overload, including heart disease.

Animals↗
PubMed1996

Viral myocarditis: balance between viral infection and immune response.

Myocarditis is an inflammatory disorder of the heart muscle, and is often underdiagnosed in clinical practice. It presents more dramatically in the young with acute heart failure and more insidiously in adults with chronic dilated cardiomyopathy. The etiology is most often viral in North America, with a wide spectrum of natural history. The majority of patients recover spontaneously, but those with persistent ventricular dysfunction face a 20% one-year mortality. Myocarditis initiates as viral disease, and molecular techniques have confirmed viral persistence. The immune response follows as a two-edged sword-both inadequate and excessive immune responses lead to disease. Finally, the myocyte is the target of the above processes, and expresses molecular, cytokine and vascular changes that lead to dilated cardiomyopathy and heart failure. The gold standard for diagnosis still relies on the overly strict Dallas criteria for evaluating myocardial biopsies. Molecular techniques are playing an increasingly important role in both diagnosis and prognosis. Clinical suspicion is still the key towards an early diagnosis. Treatment must be early and persistent-generally supportive initially, with immunosuppression now playing a secondary role in temporizing those with exuberant immune response. Newer treatments for dilated cardiomyopathy such as amlodipine and carvedilol are equally appropriate for postmyocarditis patients. Future treatment may involve specific biological agents, immune therapy, antiviral strategies and molecular gene therapy.

Humans↗
PubMed1996

[A clinico-pathologic study of primary malignant fibrous histiocytoma of bone].

Primary malignant fibrous histiocytoma of bone (PBMFH) is a rare tumor. In this series 11 cases of PBMFH (7 men, 4 women, mean age 39.6 years, range 15-62) were reported. They were studied by using morphology, immuno-histochemistry combined with the relevant clinical materials. It showed that most of the patients complained of local pain as the first symptom, and it generally arose in proximal or distal end of extremities. Roentgenographically, it mainly displayed a lytic destruction of bone. Like soft tissue malignant fibrous histiocytoma, it was composed of a mixture of plump fibroblast-like cells and large round or polymorphic histiocyte-like cells and usually showed a storiform pattern. But there were no myxoid and inflammatory subtypes encountered in these cases, except the storiform-pleomorphic type (9 cases) and giant cell type (2 cases). So it appears to have some difference between the subtypes of MFH of bone and soft tissue. Since the histomorphology and immunohistochemical reaction are less characteristic, especially with the morphological pleomorphism and marked cellular heterogeneity, diagnosis of PBMFH must depend on multifacet observation and comprehensive assessment.

Adolescent↗
PubMed1996

Cryopreservation of embryos in an IVF-ET program.

OBJECTIVE: To evaluate the use of cryopreservation of embryos in an in vitro fertilization and embryo transfer (IVF-ET) program. METHODS: Three cases of successful pregnancy after frozen-thawed embryo transfer were reviewed. The Testart's slow freezing and rapid thawing method was chosen. RESULTS: The first case was a Turner's syndrome patient and her husband had azoospermia. Donated frozen-thawed embryo transfer was done after hormonal replacement therapy. Pregnancy was achieved and a normal baby was delivered. The other two cases of IVF-ET did not achieve pregnancy during the stimulated cycle but became pregnant with frozen-thawed embryos in the natural cycle 4-5 months later. CONCLUSIONS: Pregnancy could be achieved in couples with incurable reproductive defects with donated embryos cryopreserved and ready for use whenever the endometrium is prepared by hormonal replacement therapy to be synchronous with the embryo development. In an IVF-ET program, one egg-retrieval may serve for many future chances of embryo transfer and therefore increase the cumulative pregnancy success rate.

Adult↗
PubMed1996

[Effect of the T4 on the viscera and embryo of perinatal mice].

58 Female Kun Ming mice of perinatal stage (from the 15th day of pregnacy to the 21th day after birth) were fed with Tripcholorolide (T4) isolated from multiglycosides of Tripterygium wilfordii (GTW) at a doze of 0.6 mg/kg for group 1 or 0.3 mg/kg for group 2 per day for 4 weeks. Lactation was decreased in some females and some F1 off spring died. The succinic dehydrogenase (SDH) activity of the mice liver were increased due to the destruction of its mitocondian. Liver cells degenerated and glycogen decreased. Distal tubules of kidney degenerated. Heart and spleen were normal. T4 was also fed to 10 female mice from the 5th to 17th day of pregnacy. However, neither the absorbed fetus nor dead fetus increased.

Animals↗
PubMed1996

[The study of BL21(DE3)/PET-11 as an expression system of human IL-2].

The coding region of hIL-2 cDNA is specifically amplified by PCR. A Nde I site is introduced into its 5'-end and its 3'-non coding region is partly deleted. After filling-in by Klenow enzyme, the DNA fragment is cloned into Sma I site of PUC18. Eight white colonies are screened and one (C1) contains Nde I site. DNA sequencing shows that non-specific mutation has not been found in its coding region. The DNA fragment digested by BamH I, Nde I of C1 plasmid is recovered and subcloned into PET-11 and transfered into BL21 (DE3). After IPTG induction, the Bacteria lysate is run directly on SDS-PAGE. Western blot test shows a specific rhIL-2 McAb binding band. The molecular weight is about 17000. Laser scanning indicates that the absorption area of IL-2 is about 5% of the total area.

Base Sequence↗
PubMed1996

[Hormonal therapy for the synchronization between donor and recipient in an oocyte donation and surrogacy fertilization in vitro-embryo transfer program].

OBJECTIVE: To evaluate the efficacy of hormonal therapy for the establishment of endometrium synchronous with the embryo in an oocyte donation and surrogacy fertilization in vitro-embryo transfer (IVF-ET) program. METHODS: The IVF-ET routine of the Beijing Medical University was employed. The recipients included cases with (1) premature menopause and (2) abnormal chromosomal karyotypes; surrogate mothers. For (1) surrogate mother, low constant doses of estradiol (E2) (17-beta estradiol-Estrace or E2 valerate) 2-4 mg was started 3-5 days before the expected menstruation of the donor progesterone (P) was started intramuscularly 30 mg daily from the day of hCG injection, 50 mg from the day of oocyte pick-up, 100 mg from the day of embryo transfer and 150 mg from the day of positive urinary beta-hCG; E2 was maintained at the 4 mg dose. Both E2 and P were continued until after the luteo-placental shift-about 90 to 100 days of pregnancy with gradual tapering doses. The serum E2 and P levels were measured by radioimmunoassay and compared with those of normal pregnancy. For (2) women with normal menstrual periods, the Chinese made gonadotropin-releasing hormone-A (GnRH-A) 400-600 micrograms was given for down-regulation of pituitary and artificial agonadism when at least amenorrhea of two months was achieved and a quiescent state of the endometrium and ovaries was ascertained by vaginal ultrasonography. Then the E2 and P therapy was started as described above. GnRH-A was stopped on the day of hCG injection. RESULTS: In the hormonal therapy group, the serum E2 levels were quite similar to those of the normal pregnancy, while the P levels were about 3-5 times higher. Two full term deliveries of normal female babies and one in her 36th week of pregnancy were achieved in the premature menopause group. In the normal menstruation group, one was in her 15th week of pregnancy and the surrogate mother was in h34 4 1/2 months of pregnancy. CONCLUSION: The proposed hormonal therapy to synchronize the donor and the recipient may be used with satisfactory clinical outcome in an oocyte donation and surrogacy IVF-ET program.

Chorionic Gonadotropin, beta Subunit, Human↗
PubMed1996

[A study of the effects of chemotherapy with or without G-CSF on neutrophil counts and serum G-CSF levels in leukemia patients].

For studying the relation between the serum G-CSF levels and neutrophil counts, consecutive changes of G-CSF levels and neutrophil counts in 20 cases of acute leukemia receiving chemotherapy with or without administration of G-CSF were observed. The G-CSF levels were detected by ELISA. The results showed: (1) Before chemotherapy G-CSF levels were higher than normal value in acute leukemia patients. (2) Four patterns of consecutive change of serum G-CSF levels in 19 cases receiving chemotherapy alone were observed, viz curves with double peaks, single peak, V type and declining type. Different patterns of G-CSF change were accompanied with different changes of neutrophil counts. (3) Both serum G-CSF levels and neutrophil counts were elevated significantly in nine cases receiving G-CSF after chemotherapy. (4) Comparing chemotherapy with and without G-CSF treatment. The time required for neutrophil count to reach a level more than 1.5 x 10(9)/L was significantly shorter in those administering G-CSF after chemotherapy than the patients not using G-CSF. These results suggest that observation of the changes of serum G-CSF levels is helpful in judging myelosuppression and marrow recovery after chemotherapy. Administration of G-CSF is an effective method to increase the neutrophil counts and to shorten the myelosuppressive period.

Acute Disease↗
PubMed1996

[Effect of fuzheng huayu recipe in treating posthepatitic cirrhosis].

This article deals with the effect of Fuzheng Huayu recipe (FZHYR), composed of Semen Persicae, Cordyceps, Radix Salviae Miltiorrhizae, Pollen pini, etc. in treating posthepatitic cirrhosis. 40 patients treated with FZHYR were observed, and another 40 patients in simila condition treated with symptomatic therapy were taken as control. Results showed that the FZHYR could (1) Increase the serum level of albumin and decrease the gamma-globulin; (2) Elevate the lowered plasma branched-chain amino acid/aromatic amino acid ratio; (3) Reduce the raised level of laminin and hyaluronic acid in serum; (4) Escalate the level of CD3+, CD4+, CD4+/CD8+ ratio, NK cells activity and complement C3, lowered the raised level of IgG and IgM in serum. In addition, it could also adjust the anormal change of hormonal secretion. These results suggested that FZHYR has beneficial effect in treating posthepatitic cirrhosis, it acts multifariously and plays important role either in controlling the development of disease or in preventing the complications.

Adult↗
PubMed1996

[Influence of Cordyceps sinensis (Berk.) Sacc. and rat serum containing same medicine on IL-1, IFN and TNF produced by rat Kupffer cells].

The results indicated that the levels of IL-1, IFN, and TNF, especially those of IL-1 and INF, produced by cultured rat kupffer cells were increased in the presence of Cordyceps sinensis (CS) or the drug serum (DS) from rats fed on CS. The experimental result of DS was similar to that of CS. However, the former had a better repeatability and stability.

Animals↗
PubMed1996

Microleakage of multi-step and simplified-step bonding systems.

PURPOSE: To measure and compare the microleakage of Class V resin composite restorations using the following three pairs of multi- and simplified-step dentin bonding systems (DBS): OptiBond vs. OptiBond FL, All-Bond 2 vs. One-Step, and Tenure vs. Tenure Quik. MATERIALS AND METHODS: V-shaped cavities were prepared in the mesial and distal surfaces of 30 extracted human mandibular molars with margins in both enamel and cementum, and randomly assigned into three equal groups of 10 each. All DBSs were applied strictly following manufacturers' specifications before three incremental layers of resin composite (Pertac-Hybrid) were applied in all cavities. Specimens were stored for 7 days in 37 degrees C water, thermocycled for 300 cycles between 5 degrees C and 55 degrees C, immersed in 0.5% basic fuchsin solution for 24 hours, and embedded in resin before being sectioned longitudinally in multiple sections. Dye solution penetration at the tooth/composite interface was scored from 0 to 4 under a microscope at x100 at both enamel (E) and cementum (C) margins. Data were analyzed by Kruskal-Wallis and Mann-Whitney U tests with alpha = 0.05. RESULTS: OptiBond FL and One-Step showed less microleakage at the cementum margins compared to their multi-step versions. At the enamel margins Tenure Quik showed less microleakage compared to Tenure, and none of the other DBSs tested showed significant dye penetration at that interface. All DBSs showed significantly less microleakage at the enamel margins compared to the cementum margins except for OptiBond FL and One-Step that did not show any significant dye penetration at the cementum margins as well.

Analysis of Variance↗