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Biomedical subjects

Z Li

Publications and source records attributed to Z Li.

At least 1,441 records · Page 80Linked to original sources
PubMed1995

On the foundation and structure of medical informatics.

The authors from China and the United States take medical informatics from theory to practice by improving its research, application, and dissemination and by expanding its educational potential. We built a theoretical model and discussed its definition, approach, foundation, principles, and structure. Medical informatics is the interdisciplinary study of information science applied to medicine and health care. Its developing approach is transplantation. The foundation of medical informatics has "building blocks" of knowledge. They are: information procedure models; information classification principles; information processing methodologies; and functional hierarchical principles of information systems. The structure of medical informatics includes the main knowledge branches and their logical relations. There are four big branches: computer tools and systems methods; engineering equipment and methods; medical fields information systems; and health care management systems. Based on the investigation of the professional status (its theory and application, and its forms and the contents) of medical informatics, it can be seen that this new discipline is becoming mature.

China↗
PubMed1995

Human immunodeficiency virus load. Quantitative assessment in semen from seropositive individuals and in spiked seminal plasma.

OBJECTIVE: To establish criteria for the quantitation of the human immunodeficiency virus (HIV) in seminal plasma, seminal cells and the whole semen of HIV-infected individuals. The reverse transcription polymerase chain reaction (RT-PCR), DNA-PCR and semen HIV culture assays were standardized by testing seminal plasma spiked separately with serial dilutions of cell-free and cell-associated HIV stocks of known titers. The standardized assays were then used to assess the quantity of virus in the freshly collected seminal cells and seminal plasma. RESULTS: Analysis of freshly collected peripheral blood mononuclear cells (PBMCs) and paired semen from HIV-seropositive men who had received antiviral drugs and/or immunemodulators indicated that HIV could be isolated from 42 of 55 (76%) samples of peripheral blood mononuclear cells (PBMCs) and 13 of 55 (24%) samples of ejaculates. Since no semen sample was culture positive in the absence of culturable HIV in PBMCs of the same individual, RT-PCR was 5-125 times more sensitive than cell cultures for the quantitation of HIV spiked in seminal plasma, freshly collected seminal fluid and whole semen. Further, HIV-RNA was detected in samples containing higher dilutions of virus from which HIV was not isolated by culture. CONCLUSION: We conclude that cell-free HIV is present in excess of the culturable virus in all specimens tested and that the high sensitivity of HIV-RNA detection is useful for quantitation of the virus directly in seminal fluid, seminal cells and whole semen.

Cell Survival↗
PubMed1995

High expression of HBV S gene in Bombyx mori cell culture and in silkworms.

The coding sequence of human hepatitis B virus (HBV) subtype adr surface antigen S gene was inserted into the genome of the nuclear polyhedrosis virus of Bombyx mori (BmNPV) under control of the polyhedrin promoter, and a recombinant BmNPVS virus was constructed. Upon infection of the recombinant virus, the yield of HBsAg was 35.5 micrograms per 10(6) cells, 750 micrograms per larva, and 690 micrograms per pupa. Western blot and electron microscope observation of the preliminary purified HBsAg particles showed that they were well glycosylated and assembled as regular 22-nm (diameter) particles. The CsCl buoyant density was 1.2 g/mL, which is consistent with that of HBsAg in the blood of patients.

Animals↗
PubMed1995

Cardiovascular system related peptides and hypothalamic neurons.

The hypothalamus is known to be an integrative site of cardiovascular, endocrine and autonomic functions. Our previous studies, using extracellular, intracellular and/or whole cell patch-clamp recordings in rat hypothalamic slice preparations, revealed that cardiovascular related peptides such as atrial natriuretic polypeptides (ANP), B-type polypeptides (BNP), endothelin (ET), angiotensin II (AII) and interleukin-1 beta (IL-1 beta) influence the hypothalamic neurons. ANP modulated the firing rates in the supraoptic nucleus (SON). BNP inhibited the SON neurons and these effects were mediated through cGMP and cGMP-dependent protein kinase. ET also inhibited approximately 60% of SON neurons. By using slice patch-clamp techniques, AII inhibited the transient outward potassium current in the SON neurons. IL-1 beta increased the firing rate and depolarized the membrane of the most SON neurons. A new type of transmitter, nitric oxide (NO), identified as an endothelial-derived relaxing factor (EDRF), modulated the glutaminergic inputs of the SON neurons. The results suggest that cardiovascular related peptides and NO modulate the neuronal activity of neurosecretory cells in the SON.

Angiotensin II↗
PubMed1995

[Multiple gene alterations involved in the processor of human gastric carcinogenesis].

The investigation of molecular evidence of gastric carcinoma will be contributable to the prevention, gene diagnosis and therapy of human gastric neoplasms. To determine the specific genetic change in human gastric cancer (HGC) and precancerous lesions, we analysized FISH, PCR/SSCP, IHC and DNA sequencing by using multiple probes to detect the gene abnormalities (mutation, deletion, amplification or overexpression of genes) of 67 fresh tumors, 63 endoscopic biopsies including 30 dysplasia (DYS) and 33 intestinal metaplasia (IM, and 4 tumor cell lines from HGC patients. Multiple genetic abnormalities including hypomethylation of H-ras gene, amplification and overexpression of met and erbB2, deletion of APC, mts1/p16, p53 and nm23 gene and point mutation of p53 gene were noted in HGC and precancerous lesion of human gastric mucosa. Among these changes, p53 gene was the highest frequence genetic alteration in 39/67 (54-58%) of gastric carcinoma. These results indicate that overexpression of met and H-ras occurs at early stage in progression of neoplasia, amplification of met, erbB2 and akt2 gene occurs at progressing stage of tumorigenesis, deletion of p53, APC, mts1/p16 and nm23 occurs at advanced stage in the progression of cancer. The abnormalities should be associated with malignant phenotypes: poor differentiation, vascular invasion, lymph nodes metastasis, and low survival time. We detected p53 gene mutation in both cancer and precancerous lesions of IM and DYS. These results suggest that p53 may be a susceptible gene and alteration of p53 gene plays an important role in the development of HGC.

Gastric Mucosa↗
PubMed1995

[A clinicopathological analysis of 11 patients with pulmonary sclerosing hemangioma].

Eleven cases of pulmonary sclerosing hemangioma proved by operation and pathological examination were reported. All patients showed at least 3 different typical pathological features and infiltration of the histocytes and dilated blood vessels with papillary projections were the commonest manifestations. The clinical manifestations, pathology and histogenesis were discussed and related literature reviewed.

Adult↗
PubMed1995

[Experimental steroid osteonecrosis in rabbits and pathologic findings].

Osteonecrosis of femoral head was experimentally induced in adult rabbits by employing a combined protocol of hypersensitive vasculitis and administration of high dose corticosteroids. By using India ink introartery infusion microangiography and pathologic examination, we found that the damage of terminal arterioles and interruption of blood supply of terminal arteriole was causative pathogenesis. In the early phase, the haemopoietic necrosis and enlargement of fat cell in the bone marrow occurred. The perfused arterioles decreased, especially in the subchondrol bone. In the later phase, the osteocytes showed necrotic fibrosis in bone marrow. The perfused arterioles increased gradually and repairtive changes began.

Animals↗
PubMed1995

[Low dosage of homoharringtonine for prevention of cicatrization after glaucoma filtering surgery].

To prevent the cicatrization of filtering blebs after glaucoma filtering surgery, subconjunctival injections of low dosage homoharringtonine were administered to 22 glaucomatous eyes (20 patients) postoperatively. The percentage of functional filtering blebs was 90.9% and the mean postoperative IOP was 2.04 +/- 0.68 kPa (1 kPa = 7.5 mmHg). In comparison with the control group, the differences were very significant (P < or = 0.01). The results suggest that the toxicity of low dosage of homoharringtonine be very low, it inhibit fibroblast proliferation and play important roles in the formation of the functional filtering blebs and elevation of the success rate of filtration operation.

Adult↗
PubMed1995

[Examination and analysis on keratometry and axis of myopia].

In this study, we applied SYSTAT software package to deal with the data, measured the keratometric values and axes of 276 patients with myopia (523 eyes), analyzed on the data of keratometry and astigmatism, correlations between the myopic degree and keratometric value and between the former and length of axis, and pathogenesis of myopia. The results revealed that the vertical corneal refractive power was stronger than the horizontal value, the vertical corneal refractive power in high and superhigh myopia was greater than that in mild and medium myopia, the axial lengths are significantly different among mild, medium, high and superhigh myopia (P < 0.01), and the myopic degree is correlated with the keratometric value and axial length. We can conclude that keratometry and axis are two main factors for the formation of myopia.

Adolescent↗
PubMed1995

[Clinical effects of bisoprolol in congestive heart failure due to dilated cardiomyopathy].

Bisoprolol was administered orally at doses of 1.25-5 (mean 3.2 +/- 1.1)mg/day for 3-10 (mean 4.1 +/- 1.6) months in 19 patients with congestive heart failure secondary to dilated cardiomyopathy. All patients heart rate and blood pressure were sensitive to the first dose 1.25 mg bisoprolol and when the dose was titrated to 2.5 mg, it was effective and led to a smooth course during a 10-hour period of observation. After treatment, the patients heart function, including fractional shortening, ejection fraction and exercise ability increased significantly and both the severity and the incidence of ventricular arrhythmias decreased significantly. The response of heart rate to exercise and isoproterenol infusion tended to be normal lymphocyte beta-adrenergic receptor density was increased. It is shown that bisoprolol is a promising beta-blocking agent in treating congestive heart failure. The mechanisms of its effects may be related to depression of excessive sympathetic activity, decrease of heart rate and up-regulation of beta-adrenergic receptor.

Adrenergic beta-Antagonists↗
PubMed1995

[Orthotopic heart transplantation: a case report].

In July 1994, we performed orthotopic heart transplantation for a patient with hypertrophic myocardiopathy, who had had open heart surgery enlarging the right ventricular outlet. The patient had an excellent postoperative result. He received triple-drug immunosuppressive therapy. Large dose of methyl-prednisolone was used successfully for his acute rejection reaction. At present, the patient is living well with good cardiac, hepatic and renal function. We described donor heart harvest, myocardial protection, operative procedure, immune monitoring, anti-rejection and anti-infectious therapy. We introduced the process of protecting donor heart on the way to hospital by retrograde perfusion with medium hypothermic oxygenated-blood combined with St. Thomas cardioplegia. Besides endomyocardial biopsy, other noninvasive examinations such as noninvasive cardiac output monitoring could be helpful to monitor acute rejection reaction.

Adult↗
PubMed1995

[Clinical application of expanded thin skin flap].

Fifteen patients were treated with the expanded thin skin flaps with the large area defects of soft tissue resulting from scar, pigmented nevus, hemangioma, chronic ulcer and neurofibroma. The operative procedure includes tissue expansion and defatted flap transplantation. All flaps that preserved only a thickness of 3 mm adipose tissue or superficial fascia beneath the subdermal vascular network survived with the primary healing of 12 cases and the delay healing of 3 cases in the maximal ratio of length to width 4.3:1. The details of clinical experience and primary experiment were presented.

Adolescent↗
PubMed1995

[Detection of serum isoferritin level in 195 patients with cancer].

ELISA (double-determinant) was used to detect the serum isoferritin (SIF) levels in 42 patients with nasopharynx cancer (NPC), 38 with lung cancer (LC), 26 with esophageal cancer (EC) and 89 with other cancers, a total of 195 cases (151 males and 44 females). The results revealed that the positive rate of SIF in patients with cancer was 73.8% (144/195), among which, the positive rates in patients of stage I-II, stage III-IV, in patients not operated upon and in those after operation were 64.8%, 81.3%, 81.4% and 63.4%, respectively. Statistics was significantly different in SIF level between the stage I-II and III-IV groups, and between the un-operation and after operation groups (P < 0.001) by rank sum testing. The positive rates of NPC, LC and EC were 73.8%, 86.8% and 73.1%, respectively. The results have demonstrated that isoferritin is a malignant neoplasm associated antigen, and SIF level is related closely with the development of the tumor and operative treatment.

Biomarkers, Tumor↗
PubMed1995

[Smoking and the development of Warthin tumor of the parotid gland].

The smoking history was surveyed in 128 cases with Warthin tumor of parotid gland in order to investigate the relationship between smoking and the development of the tumor. Two hundred cases of middle or old age normal persons and 136 cases with pleomorphic adenoma in parotid gland served as the controls. The percentage of smoker in patients with Warthin tumor (96.9%) was much higher than that of middle or old age normal persons (25.5%) and patients with pleomorphic adenoma (24.3%). Morever, the amount of smoking was greater and the smoking history was longer in patients with Warthin tumor. When the male and female patients were analysed respectively, the same results were shown. This case--control study suggests that smoking may be one of the etiologic factors associated with the development of Warthin tumor.

Adenolymphoma↗
PubMed1995

Factors affecting removal and prognosis of thymic tumors.

One hundred and ten cases of thymic tumors were intervened surgically, including 92 thymoma, 8 thymic carcinoid, and 10 thymic carcinoma. In this series, 50.9% of the cases were complicated with various syndromes, 44.5% with myasthenia gravis (MG). Resection rate was correlated with the size and invasion of the tumor. There was significant difference in resection rate among thymoma, thymic carcinoid and thymic carcinoma. The degree of invasion undoubtedly influenced on resection. The 3-, 5- and 10- year survival rate of the thymoma were 82.7%, 68.1% and 40.0%, respectively. The prognosis depended on the pathological classification and the severity of the neighbouring invasion, but MG had no significant effect on prognosis. Recurrence and metastasis of the tumor were the main cause of late death.

Adult↗
PubMed1995

Effect of the multiglycoside of Tripterygium Wilfordii Hook f. (Tii) on cornea allograft rejection model in rabbit.

PURPOSE: To examine the effect of Tii treatment of cornea graft survival in a rabbit model. METHODS: Tii was administered orally after eccentrical corneal transplantation. Survival times were determined by biomicroscopy. Cytotoxic T lymphocytes (CTL) and delayed-type hypersensitivity (DTH) responses to donor alloantigens were assessed at day 16 after heterotopic corneal grafts. RESULTS: Administration of Tii reduced the incidence and prolonged the graft survival time. Both CTL and DTH responses to donor alloantigens were severely depressed in hosts treated with Tii. However, combination of Tii and cyclosporine further enhanced the immunosuppressive effects described above. CONCLUSIONS: Tii is a potent immunosuppressant with the ability to prolong allograft survival in the rabbit penetrating keratoplasty model and may have coordinative effects with CsA through different mechanisms. Further studies are necessary to define any potentially coordinative role in the prevention of allograft rejection in human keratoplasty.

Animals↗