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Biomedical subjects

D S Zhang

Publications and source records attributed to D S Zhang.

At least 37 records · Page 2Linked to original sources
PubMed1992

The role of membrane lipid in the platelet storage lesion.

Because of their hemostatic and structural importance and their chemical and physical lability, membrane lipids are likely to be involved in the development of the platelet storage lesion. Chemical analysis using the new method of high-performance liquid chromatography with laser light scattering detection (HPLC-LLS) reveals platelet lipid to be composed of more than 22 individual components, the most abundant of which are phosphatidylcholine (PC), phosphatidylethanolamine (PE), cholesterol (C), sphingomyelin (SM), phosphatidylserine (PS), and phosphatidylinositol (PI). Surprisingly, an asymmetric distribution of these lipids is maintained in the resting platelet with PS concentrated in the inner leaflet of the plasma membrane. The exposure of PS may be important in platelet activation because of its powerful procoagulant effect. Studies of the effect of blood bank storage on platelet lipid composition have repeatedly shown a steady loss of all components, which may be temperature dependent. Studies of platelet factor 3 activity and flow cytometry of stored platelets have revealed the lipid is lost through the process of microvesiculation. Coupled to this storage induced depletion of platelet lipid is a loss of more than half of the potential capacity of lipid-dependent platelet functions by day 5. The most likely underlying mechanism for this loss of lipid mass and functional capacity is lipid peroxidation, a process that could be blocked with antioxidants. Lipid peroxidation may also interfere with other membrane constituents such as glycoprotein IIb/IIIa and the aminophospholipid-specific translocase. Thus, lipid peroxidation should be a major focus in studies aimed at preventing or reversing the platelet storage lesion.

Blood Platelets↗
PubMed1992

[Surgical correction of 34 patients with hypertelorism].

In 34 patients with hypertelorism aged on the average 12.6 years, 24 underwent intracranial surgery (combined intra- and extracranial approach), 2 (moderate) U-osteotomy (subcranial approach), and 8 (mild) canthoplasties. Improved results were obtained in the patients with various types of hypertelorism. The complications were reviewed. Of the 24 patients undergone intracranial surgery, one died, 4 had cerebrospinal fluid leakage, and 4 had keratitis. No seizure, cerebral edema, meningitis, blindness, and ptosis were observed in these patients. Average blood loss was 72% of blood volume. Average duration of surgery was 7.5 hours. The causes of hypertelorism such as craniofacial cleft, craniosynostosis, frontoethmoidal meningoencephalocele, frontonasal fibrous dysplasia, and trauma were also discussed. Satisfactory appearance was seen in most of the patients.

Adolescent↗
PubMed1991

[Influence of GABAergic neurons in the brain on central effects of kainate on the cardiovascular system].

Microinjection of kainate (KA 0.125, 0.25, or 0.5 microgram), a special agonist for KA receptor, into rat lateral cerebral ventricle produced dose-dependent increases in blood pressure and heart rate. Pretreatment with semicarbazide (SCZ 140 mg/kg, ip), an inhibitor of GABA biosynthesis, or picrotoxin (PIC 1 mg/kg, iv), an antagonist for GABA, significantly enhanced the effects of KA on the cardiovascular system. These effects of KA were reduced by aminoxyacetic acid (AOAA 25 micrograms/rat, icv), an inhibitor of GABA aminotransferase. All these results described above imply that the function of GABA ergic neurons in brain can influence the effects of KA on the cardiovascular centre. We speculate that the central regulation of the cardiovascular system is involved in the interaction of GABA ergic neurons and glutamergic neurons in brain, thus, influencing the central sympathetic effects of efferent activity.

Aminooxyacetic Acid↗
PubMed1991

Indirect lymphography with Isovist-300 in various forms of lymphedema.

Twenty patients with various forms of lymphedema were studied by indirect lymphography. Isovist, a new non-ionic, water-soluble, dimeric contrast media, was used for intradermal infusion. Simultaneous indirect lymphography showed characteristic patterns of lymphatics. The initial lymphatics were visualized by intradermal infusion of the newly developed isovist. However, they were not opacified with direct lymphography unless in the presence of valvular insufficiency. No systemic side-effects were observed except for a feeling of discomfort at the injection site. The results showed that indirect lymphography with intradermal infusion of Isovist is useful for demonstrating dermal lymph vessels and for the diagnosis of lymphedema.

Adolescent↗
PubMed1991

[A pharmacological analysis of the amino acid components of Cordyceps sinensis Sacc].

An artificial complex of amino acids (C I) was made by mixing 18 synthetic amino acids, according to the kinds and contents the amino acid contained in the natural Cordyceps sinensis Sacc., It showed the same sedative action as the natural C. sinensis, as indicated by the spontaneous activity inhibition in mice (photocell method). However, the action of commercial complex amino acid injection (12 X, total amino acid components are similar to C I) was more attenuated than that of C I. Comparing amino acid components of 12 X with C I, the latter was found to contain 5 times as much glutamic acid, tryptophan and tyrosine as those of 12 X. Another artificial amino acid complex (C II) consisting of the above mentioned 3 amino acids, also showed the same sedative action. This suggests that tryptophan is the principal component by orthogonal test. However, C II did not enhance the phagocytic action of mononucleophagocyte as the natural C. Sinensis did in the clear rate test of carbon granule from mice serum.

Amino Acids↗
PubMed1991

Purification and partial characterization of a new group of gastric cancer associated antigens.

The corresponding antigens of MG series monoclonal antibodies (MG5, MG9, MGd1 and MGe1) against gastric cancer were purified and partially characterized. Each of these monoclonal antibodies was purified by passing through a DEAE-52 cellulose columns and covalently coupled with CNBr-activated sepharose 4B successively. By means of concanavalin A and antibody affinity chromatography, the corresponding antigens of MG series McAb were extracted from gastric cancer tissue respectively. Immunological and biochemical studies confirmed that the corresponding antigens of MG series McAb were a new group of gastric cancer associated neutral glycolipid and glycoprotein antigens.

Antibodies, Monoclonal↗
PubMed1990

Detection of exfoliated bladder cancer cells by monoclonal antibodies to tumor-associated cell surface antigens.

Monoclonal antibodies (Mabs) to human tumor antigens have potential for tumor detection and treatment. For bladder carcinoma, the detection of exfoliated tumor cells in urinary specimens may be accomplished with Mabs reacting to tumor cell-surface components. This method may be useful for screening and monitoring carcinogen-exposed workers. A Mab generated by our laboratory, 3G2-C6, reacts with high affinity to a cell-surface component expressed by bladder tumor cells. The potential utility of this Mab in detecting exfoliated tumor cells was evaluated in bladder wash specimens. The Mab method detected positive cells in 87% (56/64) of specimens from patients with bladder cancer, including a great majority with grade 1 tumor and carcinoma in situ, superior to the routine cytology done on the same specimens. Cells in specimens from patients with urinary calculi, chronic cystitis, and history of bladder cancer also reacted with the Mab, suggesting that other stimuli can induce antigen expression. The Mab method can also be performed on urine samples, thus allowing evaluation of the ability of the Mab to identify premalignant, malignant, and other abnormal exfoliated cells in urine. The Mab method represents a unique opportunity to develop noninvasive detection of bladder cancer and to monitor and screen bladder cancer high-risk groups.

Antibodies, Monoclonal↗
PubMed1989

Immunochemical and biochemical characterizations of two monoclonal antibody-reacting antigens associated with human bladder carcinoma.

Two murine monoclonal antibodies (Mabs), 3G2-C6 and C3, which react to surface components on human bladder carcinoma cells, were produced using cultured human bladder tumor cells as immunogens. The expression of these antigens is highly restricted to malignant cells, and as such these Mabs are potentially useful for cancer diagnosis and treatment. We report here the immunochemical characterizations and molecular size determinations of these two Mab-reacting bladder tumor-associated antigens. The 3G2-C6 antigen has a molecular weight of 92,000, while the C3 antigen is a macromolecule with a molecular weight of about 600,000, consisting of 4 subunits of identical size, as determined by high pressure liquid chromatography gel filtration and sodium dodecyl sulfate and gradient-gel electrophoresis. The apparent affinity constants for the binding of these two Mabs and the number of antigenic determinants per cell were determined in 4 human bladder tumor cell lines (MGH-U1 through MGH-U4) with different degrees of malignancy. The apparent affinity constants for 3G2-C6 ranged from 1.8 x 10(-10) to 1.7 x 10(-8) M, while those for C3 ranged from 1.9 x 10(-9) to 4.4 x 10(-8) M. The number of antigenic determinants per cell ranged from 3 x 10(5) to 2.9 x 10(3) for 3G2-C6 and from 2 x 10(6) to 1.2 x 10(5) for C3. This coincides with our earlier observation that bladder tumor cells of higher malignancy tend to express higher numbers of determinants of these antigens, particularly of 3G2-C6. Very low levels of both of the antigens were released from the cells; less than 10% of the antigens could be detected in 3-day spent culture medium. Radioactively labeled Mabs were used to assess the stability of the antibody bound to MGH-U1 cells. More than 70% of 3G2-C6 remained bound to the cell after 24 h, whereas more than 60% of C3 was lost from the cell and recovered in the culture medium as small fragments. This information may be useful for the clinical applications of these Mabs, including the improvement of in vitro detection of bladder cancer through identification of exfoliated tumor cells and determining the potential utilities of these Mabs in in vivo localization of in situ and metastatic bladder tumors.

Antibodies, Monoclonal↗
PubMed1989

A study of the immunofunction in patients of coronary heart disease with the fundamental deficiency and outward excess syndrome.

The fundamental deficiency and outward excess syndrome of coronary heart disease can be classified into Qi Yang deficiency with blood stasis (QYD) and Yin deficiency with blood stasis (YD). The patients showed disturbances in immunofunction manifested as marked increase of serum IgG, CIC, IC-IgG and IC-C3 levels and the percentage of B cells in the peripheral blood, while the percentages of OKT3+, OKT4+ and OKT8+ cells markedly decreased, especially the percentage of OKT8+ cells, resulting in an increase of the ratio of T4/8 and imbalance between TS and TH. The authors deem that the fundamental deficiency of coronary heart disease is related to the low cellular immunity, especially the imbalance between TS and TH cells, while outward excess of coronary heart disease is related to hyperactivity of humoral immunity.

Angina Pectoris↗
PubMed1989

[Scrotopenile inversion: a report of 4 cases].

From Sep. 1980 to July 1987, 4 cases of scrotopenile inversion were treated surgically. There were complete and partial scrotopenile inversion in 2 cases respectively. A pedicle skin tube of scrotum was used to prolongate the urethra and correct the curved penis. The operation was performed at a time in 3 cases and satisfactory results were obtained in all 4 cases.

Adolescent↗
PubMed1989

[Effects of kuo guan powder on immunologic functions in patients with ben-xu biao-shi syndrome in ischemic heart disease].

Ischemic heart disease (IHD) is correlated with the Immunodisturbances. In this study, the immunological effects of Kuo Guan No 1, a powder for aiding Qi and activating the blood, in 17 cases of Qi Yang Xu Xue Yu (QYXXY, ) syndrome, Kuo Guan No 2, powder for nourishing the Yin and activating the blood, in 14 cases of Yin-Xu Xue-Yu (YXXY, ) syndrome had been observed in one month treatment. After treatment with both powder of Kuo Guan No 1 and Kuo Guan No 2, the increased levels of IgG, CIC, IC-IgG and IC-C3 in serum and the numbers of B cells in peripheral blood lymphocyte (PBL) of the patients with Ben-Xu Biao-Shi (BXBS, ) syndrome of IHD angina were markedly decreased and showed no significant difference while compared with the normal controls (P greater than 0.05); the numbers of OKT+3, OKT+4 and OKT+8 cells in PBL, which were lower before treatment in both groups, were obviously increased and showed no marked difference with the controls (P greater than 0.05); the higher ratio of T4/T8 was lowered in group of YXXY syndrome, and showed no difference while compared with the controls (P greater than 0.05), but the ratio in QYXXY syndrome group was lowered than that in the controls (P less than 0.05). After the treatment with Kuo Guan No 1, the increased level of C3 in serum in QYXXY group was lowered down to that of the controls (P greater than 0.05). The results indicated that it is reasonable to consider that "Kuo Guan" powder is an immunoregulative preparation for patients with BXBS syndrome of IHD angina.

Adult↗
PubMed1989

[Postabortion complications and recovery of ovarian function in nulliparous women].

Induced abortions performed in 481 cases of nulliparous women were carefully investigated. The incidence of complications during operation was 2.1%, of which the majority was the induced abortion syndrome. The early postabortal complication rate was 6.4% and the majority was mild pelvic inflammatory disease. The late complication rate was 10.2% and manifested mainly by menstrual disturbance. Ovulation occurred in 67.4% of the first postabortal cycles. It is suggested that the induced abortion is not a safe procedure for nulliparous women.

Abortion, Induced↗
PubMed1989

[Effects of cerebral GABA level on learning and memory].

In step-down tests, icv GABA 0.1 micrograms (3 min before training) or ip amino-oxyacetic acid 20 mg/kg (1.5 h before training) both significantly impaired memory acquisition in mice. But semicarbazide (ip 110 mg/kg 3.5 h before training), an inhibitor of GABA synthesis, improved the anisodine-induced impairments of learning. The effects of GABA was also enhanced by aminooxyacetic acid. The results suggest that the increase of cerebral GABA contents is unfavourable to learning and memory.

Aminooxyacetic Acid↗
PubMed1988

[Route and preparation of 5-Fu administration as preoperative adjuvant chemotherapy in rectal cancer. I. Concentration and distribution of 5-Fu in tissues monitored by 14C-isotopically tagged 5-Fu].

Experimental studies on more rational route and preparation of preoperative administration of 5-Fu were undertaken from March 1981 to June 1985. The experimental observation shows that intrarectal administration of radioisotope 14C tagged 5-Fu (suppository and emulsion) produces a much higher concentration in the rectal wall and mesenteric lymph nodes compared with its intravenous administration (40 rabbits) and produces a much higher concentration in cancer tissue than in surrounding tissues and in mesenteric lymph nodes than in the inferior mesenteric veins (4 patients). These findings favor the attenuation or destruction of cancer cells in the tumor and regional lymph nodes-the main route of spread. Also, after intrarectal administration of 14C tagged 5-Fu, its concentration in the lung, liver and bone marrow is much lower than that after intravenous administration (40 rabbits), and hence systemic toxicity is decreased. The above results indicate that the intrarectal route stands better than the conventional intravenous route for 5-Fu preoperative adjuvant chemotherapy in rectal cancer. Administration of 5-Fu emulsion produces a higher concentration in the rectal wall and mesenteric lymph nodes than that of 5-Fu suppository and peak concentration also appears earlier, i.e. 2 hours after the administration of 5-Fu emulsion. This will lessen the interference of 5-Fu absorption owing to its premature evacuation, indicating that emulsion is a better form for intrarectal 5-Fu.

Absorption↗
PubMed1988

[Route and preparation of 5-Fu administration as preoperative adjuvant chemotherapy in rectal cancer. II. Morphologic, ultrastructural and histochemical changes of the cancer cells after intrarectal and intravenous 5-Fu administration].

From March 1981 to October 1985, 5-Fu was preoperatively given to 65 Dukes B and C rectal cancer patients (intrarectal suppository 40 and emulsion 20, intravenous 5). The results indicated that after intrarectal administration, marked changes and destruction of the cancer cells in morphology were observed in 40% of the resected rectal specimens for suppository and in 45% for emulsion; marked retrograde degeneration in ultrastructure was found in 47.5% for suppository and in 50% for emulsion; DNA synthesis was obviously reduced in 63% for suppository and in 75% for emulsion. It is suggested that the emulsion be a better preparation. No obvious changes or destruction in morphology and ultrastructure were observed in cancer cells treated by intravenous drip of high dose 5-Fu though leukopenia below 4000 was found in 2/5. However, it was 0/60 by rectal administration. This implies that the intrarectal route is more rational than the conventional intravenous route. This study presents an alternate supplementary treatment in addition to radiotherapy for the reduction of postoperative local recurrence of Dukes B and C rectal cancers.

Administration, Rectal↗