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Biomedical subjects

K Ma

Publications and source records attributed to K Ma.

106 records · Page 6Linked to original sources
PubMed1990

[Clinical application of 3-dimensional image reconstruction of the left ventricle by echocardiography].

In this report is introduced a method of 3 D reconstruction of the LV by echocardiography. It was verified that 3 D image reconstruction could evaluate the function of the LV quantitatively in various cardiac disorders. And according to the specific display features of colored 3 D segmental shortening, it could also make diagnosis for certain heart diseases such as ischemic heart disease; hypertrophic or congestive cardiomyopathy, myocarditis, rheumatic heart disease; etc.

Adult↗
PubMed1990

[Assessment of the diagnostic significance of the pleural indentation sign].

Varying manifestations of the pleural indentation sign as well as their pathologic basis were discussed. It was found that the opacity shadow standing for this kind of sign on radiograph was attributed to not only pleural indentation, but also pleural adhesion, and sometimes, lobular collapse around the lesion. Both its occurrence and morphology showed no significant difference between the lung cancer and the tuberculoma. In the light of pulmonary connective tissue theory, any lesion located at periphery of the lung and accompanied by remarkable desmoplasia and cicatricial contraction, no matter whether malignant or benign, may cause pleural shrinkage or indentation. Therefore, the pleural indentation sign does not exclusively appear in the lung cancer. It would lead us onto a wrong path if differentiation is made by overemphasizing its value. It may be radiologically helpful only in identifying the types of the lung cancer owing to its high occurrence rate in adenocarcinoma and bronchioalveolar carcinoma.

Adenocarcinoma↗
PubMed1988

Neurofibromatosis and psychological processes.

A minimal degree of mental handicap is commonly seen in neurofibromatosis (NF). Despite the prevalence, little is known about the nature of the mental handicap. In this study, schoolchildren with NF and unaffected siblings were studied clinically and given a series of psychological tests. The psychological battery consisted of standardized tests of intelligence and cognitive processing, laboratory tests of cognitive processing, and personality and mood questionnaires. Clinical data included a medical and family history, results of physical, audiological, and ophthalmological examinations, EEG, tissue biopsy when necessary, and (in NF individuals) a CT scan. Results demonstrate slightly deficient cognitive processing in the NF individuals, particularly in terms of visual-spatial integration. These deficits are related to age-independent severity with more severely affected individuals exhibiting more severe deficits. The findings are discussed in terms of their diagnostic and prescriptive implications.

Adolescent↗
PubMed1980

Inhibition of diamine oxidase by antimalarial drugs.

The antimalarial drugs amodiaquine, quinacrine and chloroquine inhibit the catabolism of putrescine by the rat. Amodiaquine, the most potent of the three, does so in a dose-dependent fashion. This is attributed to the action in vivo of the drugs on diamine oxidase, an enzyme that is inhibited by them in vitro.

Amine Oxidase (Copper-Containing)↗
PubMedDate not supplied

Extracellular water: sodium bromide dilution estimates compared with other markers in patients with acquired immunodeficiency syndrome.

Extracellular fluid and closely related extracellular water (ECW) provide information on nutritional status in health and disease. Although various methods exist for ECW determination, little is known about their comparability in patients with wasting diseases such as acquired immunodeficiency syndrome (AIDS). One practical method, the dilution of sodium bromide (NaBr), is used widely in clinical research, although its relationship to other ECW markers has not been well characterized. The present study sought to compare ECW estimates as determined by NaBr and three other methods in 11 male patients with AIDS (mean +/- SD; age, 44+/-12 years; body weight, 64.5+/-8.8 kg; and height, 172+/-4 cm). ECW volumes were determined from NaBr dilution, total body chlorine (TBCl) by delayed gamma-neutron activation analysis, total body water (TBW) by tritium dilution combined with total body potassium (TBK) by whole body 40K counting, and radioactive sulfate dilution (35SO4). All correlations between the NaBr method and other methods were statistically significant (NaBr vs TBCl [r = .91; p < .001]; vs TBW/TBK [r = .76; p < .01]; and vs 35SO4 [r = .89; p < .001]). As expected from previous studies, ECW (L) derived by NaBr provided a group mean (15.1+/-2.2 L) similar to the TBCl method (15.4+/-1.7 L; p = .32), a significantly smaller ECW than by the TBW/TBK method (18.6+/-3.4 L; p = .0004), and a significantly larger ECW than by 35SO4 method (13.3+/-3.0 L; p = .002). Estimating ECW by NaBr dilution was comparable with other research-based ECW methods and, thus, offers a practical alternative for evaluating ECW in patients with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Prevalence of retinitis pigmentosa in urban and rural adult Chinese: The Beijing Eye Study.

PURPOSE: To determine the prevalence of retinitis pigmentosa in the elderly Chinese population. METHODS: The Beijing Eye Study is a population-based, cross-sectional cohort study and included 4439 subjects out of 5324 subjects invited to participate (response rate 83.4%) with an age of 40+ years. Readable fundus photographs were available for 4027 (90.7%) subjects. Diagnostic criteria for retinitis pigmentosa were visual field defects on frequency doubling perimetry, typical ophthalmoscopic abnormalities such as retinal pigment deposits, retinal arteriole attenuation, and pigment epithelial atrophy, and no other reason for perimetric defects and fundus abnormalities. RESULTS: Retinitis pigmentosa was diagnosed in four subjects (all men). Its prevalence was 0.099+/-3.15% (95% CI: 0.00, 0.2). CONCLUSIONS: Retinitis pigmentosa with typical fundus appearance and functional loss may be present in about 1 out of 1000 elderly Chinese in Northern China. Calculated for the whole population in China, the figure would be 1.3 million patients with retinitis pigmentosa.

Adult↗
PubMedDate not supplied

[The mechanism of antiarrhythmic action of the endogenous ORL1 receptor agonist nociceptin].

Prophylactic intravenous (i.v.) injections of a selective agonist of ORL1 receptors nociceptin (orphanin FQ) in a dose of 0.4 mg/kg prevented the development of aconitine-induced arrhythmia in rats narcotized with diethyl ether or chloralose. Pretreatment with L-NAME (50 mg/kg) completely abolished this effect of orphanin FQ, while the pretreatment with indomethacin (10 mg/kg) only attenuated the agonist effect, rather than abolished it completely. At the same time, pretreatment with hexamethonium (10 mg/kg) or glibenclamide (3 mg/kg) had no effect on the nociceptin-dependent cardiac tolerance to the arrhythmogenic action of aconitine. Intracerebroventricular (i.c.v.) infusion of orphanin FQ (36 microg) also prevented the onset of aconitine-induced arrhythmia, but this effect was completely abolished by hexamethonium. It is concluded that the antiarrhythmic action of nociceptin with respect to aconitine-induced arrhythmia upon i.v. and i.c.v. administration is explained by different mechanisms. In the former case, the effect of orphanin FQ is related to the activation of NO synthase and cyclooxygenase, while the central action involves the vegetative nervous system.

Animals↗
PubMedDate not supplied

Induction of nitric oxide production by ganglioside GM3 in murine peritoneal macrophages activated for tumor cytotoxicity.

BACKGROUND: Recently, it was found that ganglioside GM3, known as a potent monocytic cell differentiation inducer, mimicked bacterial lipopolysaccharide (LPS) in the activation of macrophage-mediated tumor cytotoxicity (MTC). Since GM3 and LPS share partial structural and functional similarity, we postulate that the GM3-induced MTC was due to the induction of nitric oxide(NO) production in murine peritoneal macrophages (M phi s). MATERIALS RESULTS, CONCLUSIONS: Ganglioside GM3 was highly purified from canine erythrocytes by the authors. Murine peritoneal M phi s were used as the effector cells, and mouse ascites hepatoma cell line HCa-F25/16A3-F as the target cells. We found that: GM3 induced NO production by macrophages in a time- and dose-dependent manner; GM3 and IFN-gamma synergistically increased NO production; GM3 markedly enhanced MTC; both NO production and MTC were significantly inhibited by aminoguanidine. These results demonstrated for the first time that ganglioside GM3 in vitro induces the production of nitric oxide by macrophages, and the GM3-induced MTC is NO-dependent.

Animals↗