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Biomedical subjects

Z Wu

Publications and source records attributed to Z Wu.

At least 703 records · Page 39Linked to original sources
PubMed1993

Identification of IgG Fc receptor type II on human megakaryoblastic cell lines (MEG-01 and UT-7).

In this study, Fc gamma receptors (Fc gamma R) on the cells of human megakaryoblastic leukaemia cell lines (Meg-01 and UT-7) were investigated. Binding of the anti-Fc gamma RII monoclonal antibody (MoAb) IV. 3 but not anti-Fc gamma RI MoAb (32.2), anti-Fc gamma RIII MoAb (3G8) nor control murine IgGs to Meg-01 and UT-7 cells was demonstrated by immunocytochemical staining and flow cytometric analysis. There was specific and saturable binding of 125I-labelled IV.3 Fab fragments to the megakaryoblasts but no binding of 125I-labelled 32.2 Fab nor 3G8 Fab fragments. MoAb IV.3 immunoprecipitated a 40 kD protein (Fc gamma RII) from detergent cell lysates of surface radiolabelled Meg-01 and UT-7 cells. More importantly, IV.3 Fab almost completely inhibited the binding of 125I-labelled human aggregated IgG to the Meg-01 cells. In contrast, neither 32.2 Fab, 3G8 Fab nor Fab fragments of the control murine IgGs were inhibitory. These results indicate that only Fc gamma R Type II is expressed on megakaryoblasts in these two cell lines.

Antigen-Antibody Reactions↗
PubMed1993

Effects of OPC-18790, a new positive inotropic agent, on canine ventricular arrhythmias.

OPC-18790 is a positive inotropic and vasodilating agent that increases intracellular cyclic AMP and stimulates Ca currents. We examined its direct electrophysiological effects in isolated blood-perfused canine cardiac preparations. OPC-18790 caused an acceleration of the intraventricular conduction in association with an increase of the contractile force and the coronary blood flow. We also examined the effects of OPC-18790 on ventricular arrhythmias in canine ventricular tachycardia (VT) models. OPC-18790 in doses producing submaximal inotropic effects, 3 mg/kg, i.v., increased the total heart rate, atrial rate and decreased the blood pressure, but did not suppress or aggravate 24- and 48-hr coronary ligation VTs. OPC-18790 up to 3 mg/kg, i.v. also did not suppress or aggravate digitalis-induced VTs. However, this dose of OPC-18790 aggravated halothane-adrenaline induced VT into ventricular fibrillation and eventually death, but a lower dose of 0.3 mg/kg did not aggravate this VT. These results in canine VTs indicate that OPC-18790 is similar to other positive inotropic agents, vesnarinone, amrinone, milrinone and sulmazole. The absence of an aggravating effect of this new positive inotropic agent on digitalis and coronary ligation VTs may be advantageous in a clinical setting of combined therapy with digitalis for myocardial ischemia.

Animals↗
PubMed1993

Influence of microbial colonization of feed particles on determination of nitrogen degradability by in situ incubation.

Stable 15N isotope was used to determine the extent of microbial colonization of in situ incubation residues and the influence of colonization on estimates of ruminal degradability of feed N. In an in vitro trial, 15N:total N ratio remained unchanged after the soluble (by water, saline, or buffer solution) fraction of plant N was removed, suggesting that 15N was uniformly distributed in the soluble and insoluble N fractions. In three in situ trials, corn grain, corn husks, and alfalfa hay labeled with 15N as an internal marker were incubated in Dacron bags in the rumen of two lactating Holstein cows for 3, 6, 12, 24, 36, and 48 h. Enrichment of 15N in samples decreased with increased time of incubation for all feeds. At 48 h of incubation, 31, 71, and 65% of the residual N was microbial N for corn grain, corn husks, and alfalfa hay, respectively. Bacterial cell DM, as a percentage of residual DM, increased in a quartic manner, suggesting that microbial colonization depended on substrate availability. For 24, 36, and 48 h incubation, bacterial DM, as a percentage of total residue, averaged 10.0 +/- 1.0% for corn grain, 17.5 +/- 1.4% for corn husks, and 22.0 +/- .2% for alfalfa hay. Apparent degradability of N after 48 h of incubation was approximately 65% for corn grain and alfalfa hay and 19% for corn husks. When corrected for bacterial N, degradabilities of N in all feeds increased and the degradabilities for corn husks became similar to those for corn grain.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1993

Effect of three supplemental fat sources on lactation and digestion in dairy cows.

Tallow, Ca salts of palm fatty acids, or prilled fatty acids were added at 2.5% to a control diet (3.7% fatty acids) containing 7.2% ammoniated whole cottonseed. Diets were fed to midlactation cows (6 cows per treatment) for 72 d to determine effects of fat supplementation and fat source on lactation performance and nutrient digestibilities. Dry matter intake did not differ among treatments. Milk yield was 31.6 kg/d for the control and increased an average of 2.1 kg/d with fat supplementation. Source of supplemental fat did not significantly affect lactation performance. Added fat decreased milk protein content but did not affect protein yield. Milk fat, lactose, and SNF contents did not differ among treatments. Overall fat supplementation did not affect digestibilities of DM, ADF, or NDF but decreased digestibility of fatty acids. Contribution of de novo fatty acids to milk fat was decreased with fat supplementation. Addition of 2.5% fat to a diet containing a medium amount of fat from whole cottonseed increased milk yield. Tallow, Ca salt of palm fatty acids, and prilled fatty acids did not differ in milk yield response.

Adipose Tissue↗
PubMed1993

Color Doppler imaging in the diagnosis and follow-up of carotid cavernous sinus fistulas.

This report describes color doppler imaging (CDI) in the evaluation and follow-up of nine patients with carotid cavernous sinus fistulas. The orbits and carotid arteries were examined with CDI. In all cases, the diagnosis was confirmed by angiography. CDI clearly demonstrated the dilated superior ophthalmic veins (SOVs) with retrograde flow and low resistance arterial doppler waveform in all nine patients (10 eyes). After the study of quantitative hemodynamics, we found that direct carotid cavernous sinus fistulas showed a high-velocity blood flow in the abnormal SOVs in all seven patients and a very low resistance, high flow volume circulation in the involved internal carotid artery (ICA) in six patients that had been examined; however, two patients with dural cavernous sinus fistulas had a lower blood flow in the SOVs than direct fistulas and no significant hemodynamic changes were found between the ipsilateral ICA and the contralateral ICA. These results were helpful for the diagnosis and the differential diagnosis between direct fistulas and dural fistulas. CDI also provides a convenient way to track the natural history and response to treatment of these arteriovenous fistulas. CDI offer several advantages, namely noninvasive and can be performed easily, quickly, inexpensively and reproducibly.

Adolescent↗
PubMed1993

[Color Doppler imaging in the study of normal orbital vessels and its hemodynamics].

Color Doppler Imaging (CDI) is a recent development in ultrasonography, which can display simultaneously two dimensional images of structure and Doppler evaluation of blood flow. Using the technique, we examined 74 normal eyes. Orbital vessels including ophthalmic artery (OA), posterior ciliary arteries (PCA), center retinal artery (CRA) and central retinal vein (CRV) could be located to make Doppler spectrum analysis and quantification of hemodynamics. Blood velocity (Unit cm/s) in these vessels was obtained as following: the average peak systolic flow velocity for OA was 31.9 +/- 5.01; for PCA, 14.74 +/- 3.85 and for CRA, 11.5 +/- 2.45. The time-averaged maximum velocity for OA was 14.91 +/- 1.83 and for PCA, 8.09 +/- 2.00 and for CRA, 5.78 +/- 1.14. The end-diastolic velocity for OA was 9.04 +/- 1.15; for PCA, 5.46 +/- 1.61 and for CRA, 3.73 +/- 1.06. The resistivity indices for OA were 0.715 +/- 0.04 and for PCA, 0.63 +/- 0.04 and for CRA, 0.68 +/- 0.04. The blood velocities in these vessels significantly declined with increasing age of subjects (P < 0.05). CDI is a noninvasive, accurate and reproducible modality for the study of ocular and orbital hemodynamics.

Adolescent↗
PubMed1993

Tn5-Mob transposon mediated transfer of salt tolerance and symbiotic characteristics between Rhizobia genera.

Rhizobium meliloti 042B is a fast-growing, salt-tolerant and high efficiency nitrogen-fixing symbiont with alfalfa. Bradyrhizobium japonicum USDA110 grows slowly, and cannot grow in YMA medium containing 0.1M NaCl, but nodulates and fixed nitrogen efficiently with soybean. Eighty-six transconjugants, called SR, were obtained by inserting Tn5-Mob randomly into genomes of 042B using pSUP5011 and helper plasmid RP4. Selecting 4 SR strains randomly and introducing DNA fragment of SR into USDA110 with helper plasmid R68.45 by triparental mating, 106 transconjugants, called BSR, were constructed. Most of BSR strains had the fast-growing phenotype and could tolerate 0.3-0.5M NaCl generally. Some of them produced melanine. When soybean and alfalfa were inoculated with these transconjugants BSR, 47 out of 90 BSR were found to nodulate in both of these plants, but no nitrogenase activity was observed with alfalfa; 26 strains could only nodulate and fix nitrogen in soybean; 13 strains could nodulate in alfalfa but did not fix nitrogen; 4 strains failed to nodulate in either soybean or alfalfa. Among them, 4 transconjugants which tolerated and fixed nitrogen efficiently in soybean were constructed.

Conjugation, Genetic↗
PubMed1993

Application of Steffee operation in spinal surgery.

Steffee operation is a surgical method of internal fixation for unstable conditions of the spine. Up to March 1991, 32 cases of various spine disorders were treated with the Steffee system in our hospital. These operations brought good results, as 83.4% of the cases received either good or excellent functional and clinical ratings postoperatively. Among patients with spondylolisthesis, the degree of slip correction averaged 58.5% postoperatively. Neurological complications are avoided by accurate localization of the screws.

Adult↗
PubMed1993

[Spiral shaped bacteria in the human gastric biopsy].

Biopsy specimens from the gastric mucosa of 149 patients who underwent gastroduodenal endoscopy for upper gastrointestinal complaints were studied by light microscopy and culture. Spiral shaped bacteria were detected in four of the specimens by smears with Gram stain. The positive rate was 2.68%, but these bacteria and HP did not grow in culture. The characteristic helical morphology of the bacteria appears to be similar to that of the bacteria found in the stomach of cats and dogs. And what of significance in these cases is the presence of spiral shaped bacteria in association with chronic gastritis.

Adult↗
PubMed1993

[CT scan in 52 cases of retinoblastoma].

The results of CT scan in 52 patients (61 eyes) with retinoblastoma (Rb) managed and confirmed by clinical and pathological examination are reported. The features and value of imaging of CT scan are described and discussed. In this series, 96.72% of cases revealed Rb and 90.16% of the cases with Rb tumor showed evidence of calcification on CT scan. The contrast enhancement of the tumor was slight. 19.67% of the cases with Rb tumor showed retrobulbar extension and invaded intracranium (including 3 cases of intracranical tumor extension and one case of trilateral Rb). We think it is important to perform CT scan in suspected cases of Rb, and in patients with Rb invading the orbit or intracranium as well as in bilateral Rb. Some problems in the diagnosis and differential diagnosis are briefly discussed.

Child↗
PubMed1993

The changing pattern of cardiovascular diseases in China.

In China, morbidity and mortality attributable to cardiovascular disease increased rapidly from the 1950s to the 1980s due to an increased life expectancy and changes in lifestyle. Cardiovascular disease has become the leading cause of death in the country. There is a high incidence of stroke, which is the commonest or second commonest cause of death. Hypertension, the main risk factor for stroke and an important risk factor for coronary heart disease, is the most prevalent cardiovascular disease, and should be given first priority in control programmes. Smoking, a common habit in males, is to be a principal focus of preventive activities over the next few years. Between 1970 and 1990, several community programmes for the prevention and control of cardiovascular diseases were established. The WHO MONICA Project has developed standardized methodologies that are used to establish systems for monitoring and evaluating control programmes. There is an urgent need to develop a long-term national strategy for the management and control of cardiovascular diseases.

Adult↗
PubMed1993

Antilipogenic action of synthetic C-terminal sequence 177-191 of human growth hormone.

The synthetic C-terminal peptide fragment of human growth hormone, Leu-Arg-Ile-Val Gln-Cys-Arg-Val-Ser-Glu-Gly-Ser-Cys-Gly-Phe (hGH 177-191), was shown to have antilipogenic activity identical with that of the intact molecule of human growth hormone (hGH). No significant lipolytic effect of hGH 177-191 was found as determined by the rate of glycerol release from epididymal fat pads of the peptide-treated rats. The results support the suggestion that the functional domain responsible for the antilipogenic activity of hGH resides in the C-terminal region of the molecule and that the main physiological effect of hGH in lipid metabolism is at the level of lipogenesis.

Adipose Tissue↗
PubMed1993

[Histopathology and ultrastructural changes of the musculature and nerves during methamidophos toxication in chicken].

After exposure to methamidophos (Via digestive or respiratory tract or just by skin contamination) for 1, 2, 3, 4, 8 and 12 weeks respectively, ultrastructure of the myofibrils in chicken with methamidophos toxication via the digestive tract showed mild degeneration in the first week and serious degeneration by the end of the fourth week. Light microscopy of the muscle-fibril showed atrophy and necrosis in the third week, including both myopathic atrophy and neuropathic atrophy. Recovery of the lesions took place from the 8th to the 12th week (Light or elcetion microscopy). Those chickenstaking immunosuppressive drug simultaneously with methamidophos exposure (via digestive tract) showed less degeneration of the myofibrils and nerves. Ultrastructure of the myofibril in chickens with methamidophos intoxication through the respiratory tract also developed less degeneration of myofibrils and nerves than those obtained through digestive intoxication. There was no lesion obtained in chicken taking methamidophos via the respiratory tract coexistently with the immunosuppressive drug or just by skin contamination.

Animals↗