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Biomedical subjects

J Cao

Publications and source records attributed to J Cao.

At least 271 records · Page 15Linked to original sources
PubMed1996

Cataract extraction and intraocular lens implantation with anterior vitrectomy in children.

OBJECTIVE: Extracapsular cataract extraction (ECCE) with selective intraocular lens (IOL) implantation has been the choice of the treatment for children with cataracts. With regard to surgical technique, ECCE with anterior segment vitrectomy has shown some success in reducing complications. Formation of a secondary membrane and opacity of the posterior capsule, however, are still major postoperative complications. To reduce these complications, we modified current surgical procedures with minimal incisions and manipulations. PATIENTS AND METHODS: ECCE with anterior segment vitrectomy was performed using Storz Protage's system in 84 eyes of 58 children ranging in age from 14 months to 14 years. Of 70 eyes of children aged above 3 years, IOLs were implanted simultaneously. Vision improvement and incidence of postoperative complications were compared with other standard procedures to determine the benefits of the operation for children with cataracts. After the anterior capsule was opened by continuous circular capsulorhexis or envelope-form capsulectomy, the lens cortex was excised. Subsequently, the IOL was implanted into the bag. RESULTS: Nine-30 months follow-up showed that all of the central area of the posterior capsule remained clear except one eye in which a secondary membrane was partially formed on the anterior surface of vitreous. No other operative or postoperative complications occurred. CONCLUSIONS: The results indicate that the modified procedure is beneficial in the prevention of secondary cataract formation and other postoperative complications in a short term follow-up, however, a long-term follow-up is warranted to evaluate its role in pediatric cataract surgery.

Adolescent↗
PubMed1996

[Penetrating keratoplasty in children].

OBJECTIVE: The study was designed to approach the operative techniques of penetrating keratoplasty (PKP) in children and the influential factors on the rate of graft clarity. METHODS: PKP was performed on 33 eyes of 30 children whose corneal opacities resulted from various causes and they were followed for 6 months to 3 years. RESULTS: The rate of graft clarity was 66.7% and 44.8% of these eyes were relieved from blindness. The poorest results achieved were in cases with congenital corneal opacity and the main cause of graft failure is endothelial immune rejection. CONCLUSION: Although the surgical results in children are poorer than that in adults, from the concern of prevention of amblyopia and cosmetic problem, it is necessary to perform the operation earlier.

Adolescent↗
PubMed1996

Quantitative comparison of multiple myeloma tumor contamination in bone marrow harvest and leukapheresis autografts.

Autologous transplantation is increasingly being used to treat patients with multiple myeloma (MM). Recently, peripheral blood progenitor cell (PBPC) harvest have been preferred over autologous bone marrow (BM) harvests due to reduced engraftment time, ease of attainment, and presumptive reduction of occult tumor involvement. To resolve this latter assumption quantitatively, we have used the unique immunoglobulin (Ig) heavy chain variable region sequence of the patient's myeloma cell as a marker of clonality. Samples from PBPC collections and 'back-up' BM harvests were obtained from 13 patients with MM and analyzed for tumor contamination using patient-specific oligonucleotide primers and the polymerase chain reaction. As expected, the percentage of tumor cells contaminating the BM harvest (median, 0.74%) was higher than in the PBPC specimens (median, 0.0024%). Because of the increased total number of cells required for PBPC transplantation, the increase in total number of contaminating cells in the BM vs PBPC autografts was less pronounced, (BM:PBPC tumor contamination ratios ranging from 0.9 to > 4500; median, 14). This confirms that in most but not all cases unmanipulated PBPC products are preferable over BM harvests as a method of reducing myeloma autograft tumor contamination.

Adult↗
PubMed1996

[Clinical trial of an anti-fertility method with testosterone enanthate in normal men].

OBJECTIVE: To establish the feasibility of anti-fertility by ultraphysiological-dosage testosterone in male. METHODS: Ten healthy, fertile men received 200 mg testosterone enanthate weekly by intramuscular injection based on international standard protocol. RESULTS: After 3-month injection, severe oligospermia was achieved. After 6-month injection, azoospermia was achieved. The total consecutive administration lasted for 12 months. During the period of severe oligospermia and azoospermia no partner was pregnant. After stopping injection, the sperm output returned to normal (20 x 10(8)/ml) in 2-3 months up to individual's own level before administration in 6 months. CONCLUSION: Severe oligospermia and azoospermia can be induced by ultra-pathological-dosage tesosterone through inhibiting FSH, LH to cause spermatogenesis inhibition. The sperm output would recover to its previous level in 6 months after stopping injection. It is suggested that there is a strong possibility that high-dosage testosterone may act as a male contraceptive.

Adult↗
PubMed1996

[Surveillance on Vi-II phage typing and antimicrobial susceptibilities of S. typhi strains in Beijing City].

From 1973 to 1989, 961 strains of S. typhi collected in Beijing City were tested for their Vi-II phage typing and antimicrobial susceptibilities. The results of phage typing showed that 38 types were found with a high prevalence of types A, D2, E1, K1, D5, D1, O, D4, and L1. The results of antimicrobial susceptibilities showed that all of the 168 local strains were highly susceptible to chloramphenicol, similar to the 96 phage typing standard strains.

Anti-Bacterial Agents↗
PubMed1996

[Clinical results and hemodynamic changes of portal venous system in transjugular intrahepatic portosystemic stent shunt].

To study the clinical results and hemodynamic changes of portal venous system after TIPSS we created a transjugular intrahepatic portosystemic stent shunt in 140 patients with advanced cirrhosis and portal hypertension, meanwhile we used Doppler sonography, direct portography and measurement of portal pressure to assess the blood hemodynamic changes of portal venous system in 100 patients with TIPSS. The technical success rate of TIPSS was 94.62% in 130 patients except for 10 patients with portal venous occlusion. The complication rate related to TIPSS procedure was 4.62%. Slight encephalopathy was observed in 9.03% of patients with TIPSS. The early mortality within 30 days of treatment was 3.08%. Follow-up for 1 to 24 months showed that the stenosis or occlusion of shunt and variceal rebleeding or ascites were observed respectively in 12% and 9% of patients. Six percent of the patients with TIPSS died. The portal venous pressure and the inflow of collateral circulation remarkably decreased and the portal flow velocity increased by 2.4 times after TIPSS. The flow velocity of shunt and portal vein decreased by 11.39% and 20.14% respectively in the patients with shunt patency, while the flow velocity continued to decrease in the patients with shunt stenosis or occlusion during the follow-up. TIPSS is an effective method for treating the patients with portal hypertension due to cirrhosis. The observation of trends in the hemodynamic changes of portal venous and shunt can early diagnose and treat the shunt stenosis or occlusion.

Female↗
PubMed1996

[Mechanism of vascular desensitization to agonists].

The patterns and mechanism of vascular desensitization to agonists were studied in isolated arteries of Wistar and SHR rats. The results showed that: (1) Arteries were much easier to desensitize peptidergic agonists (A II, AVP) than catecholaminer gic agonists (NE, PE); (2) the desensitization induced by peptidergic agonists and catecholaminer gic agonists were homologous within 30 minutes; (3) the endothelium-EDRF-cGMP pathway was not involved in agonist-induced desensitization; (4) inhibition of surface receptor internalization by phenylarsine oxide (PAO, 10(-5)mol/L) could transiently reverse the desensitization and the blocking of intracellular receptor re-insertion into the membrane by chloroauine (10(-5)mol/L) could accelerate the desensitization in varying degrees with different arteries, which demonstrated the involvement of receptor cycling in homologous desensitization, but was not the unique mechanism; (5) there was no change in the function of voltage-dependent Ca2+ channel during homologous desensitization; (6) the concentration-contraction curve of GTP gamma S shifted down-ward during homologous desensitization, suggesting the functional change of G protein (s); (7) the desensitization to agonists didn't decrease in arteries of SHR compared with the arteries of Wistar rats.

Angiotensin II↗
PubMed1996

[Heterogeneity of adrenoceptors in rat basilar and renal arteries].

A comparative study was made on the distribution of alpha- and beta-adrenoceptors between rat basilar (BA) and renal arteries (RA). The results showed that (1) the endothelium-independent relaxation due to beta-agonism was more significant in BA than that in RA; (2) there was no alpha 1-adrenoceptor-mediated vasoconstriction in most of the BA, only a small part of BA showed constriction in response to alpha 1-agonism, but with low affinity and efficacy and a desensitization tendency; (3) no response to alpha 2-agonist BHT 920 (10(-3) mol/L) in BA was shown, either in the presence or absence of endothelium. But in RA there was relaxation in the presence of endothelium and constriction in its absence. The above results suggest that there is a scarce distribution of alpha 1- and alpha 2-adrenoceptors, but an abundant distribution of beta-adrenoceptor in basilar artery compared with that in renal artery. The alpha 1-subtype in BA is different from the alpha 1-subtype in RA, and the alpha 2-receptor which mediates direct smooth muscle constriction and endothelium-dependent relaxation is highly heterogeneous between basilar and renal arteries.

Adrenergic alpha-Agonists↗
PubMed1996

[Heterogeneities in intracellular Ca2+ pools among different arterial smooth muscle cells and its possible role in vascular reactivities in rat].

The differences in intracellular Ca2+ pool capacities, the mutual relations between different agonist-sensitive Ca2+ pools (ASCaP) and between ASCaP and caffeine-sensitive Ca2+ pool (CSCaP), and the possible role of Ca2+ pool capacity in vascular reactivities in different isolated artery rings of rat in Ca(2+)-free media were studied by using the tension of vascular smooth muscle as an indicator of Ca2+ release. The study showed the following findings: (1) the Ca2+ pools were significantly different in capacities in different arteries (renal artery > mesenteric artery > caudal artery > aorta > pulmonary artery); (2) different ASCaPs were partially "overlapped", i.e., when one ASCaP was depleted, other kind of agonist could still induce a small but significant Ca2+ release; (3) the CSCaP was present in all the arteries tested, but it was not the same pool with the ASCaP; (4) there were no high-K+ depolarization-induced Ca2+ release in all the arteries tested and (5) there was a positive correlation between the maximal contraction (Emax expressed as mg force/mg muscle wet weight) and the Ca2+ pool capacities, suggesting that there is a role of Ca2+ pool capacities in the vascular contractilities.

Animals↗
PubMed1996

[Mannital induced acute renal failure].

14 cases of mannitol-induced acute renal failure were reported. The dosage of mannitol used varied widely. In all cases serum Na+, HCO3- were decreased, K+ and BUN increased significantly. Serum osmolality was measured in 5 cases. The osmolal gap was increased greatly, 77.4mOsm/kg. H2O in average. The increase of osmolal gap may play an important role in acute renal failure by causing intensive renal vasocontraction. Monitoring of serum osmolality or osmolal gap can help to prevent mannitol intoxication. The decrease of serum Na+ may be a warning sign of increased osmolal gap. Hemodialysis is the best way for the treatment of mannitol-induced acute renal failure.

Acute Kidney Injury↗
PubMed1995

Characterization of a cAMP-binding protein from the bivalve mollusc Mytilus galloprovincialis.

Three cAMP-binding proteins have been identified by photoaffinity labeling with 8-azido[32P]cAMP and purified from the mantle tissue of the sea mussel Mytilus galloprovincialis. Their molecular masses, determined by SDS/PAGE, were 54, 42 and 37 kDa. The purified 54-kDa protein, which had two cAMP-binding sites/monomer, was judged to be a regulatory (R) subunit of cAMP-dependent protein kinase since it re-associated with and inhibited purified catalytic (C) subunit of this enzyme from mussel, in the absence but not in the presence of cAMP. The molecular mass of the complex between Mytilus cAMP-binding protein and C subunit, estimated by analytical gel-filtration, was 220 kDa, a value which agrees with a R2C2 stoichiometry for the mussel cAMP-dependent protein kinase holoenzyme. On the basis of the elution pattern from DEAE-cellulose chromatography and its ability to be phosphorylated by purified C subunit of cAMP-dependent protein kinase, the 54-kDa protein could be classified as a type II regulatory subunit. Furthermore, no mobility shift on SDS/PAGE upon phosphorylation/dephosphorylation of Mytilus protein was observed, a similar behaviour to that shown by the mammalian RII beta isoform. The 42-kDa and 37-kDa proteins, which were recognized by a specific antiserum against the 54-kDa protein and fail to be phosphorylated by Mytilus C subunit, are probably products generated by proteolysis of the 54-kDa protein, although they were shown even when inhibitors of the major types of proteases were used.

Affinity Labels↗
PubMed1995

Myeloma Ig heavy chain V region sequences reveal prior antigenic selection and marked somatic mutation but no intraclonal diversity.

The lg VH region sequence in 48 patients with multiple myeloma (MM) was analyzed to characterize the malignant cell of origin. The sequences were obtained after amplification of bone marrow cDNA by using VH family-specific and CH primers, then compared with either directly sequenced patient germ-line or published VH gen sequences to assay for somatic mutation. Because somatic hypermutation of the VH gene occurs late in B cell development, its presence has been helpful in determining the cell of origin in other B cell malignancies. Overall, a median of 8.2% of the nucleotides had evidence of substitution within each VH gene sequence (range=2.7% to 16.5%), which is more prevalent than in any other reported tumor type. Strong evidence of prior antigenic selection pressure was also evident. The ratio of nucleotide substitutions that resulted in amino acid replacement was significantly higher in the complementarity-determining region than in the framework region (3.25 vs 1.56, respectively; p < 0.00005). No VH gene intraclonal diversity was noted, despite sequencing multiple clones (3-16) from each patient, nor was there evidence of further VH gene somatic mutation over the course of three patients' disease. These findings strongly imply that the malignant clone in MM evolves from a cell late in B cell development.

Amino Acid Sequence↗
PubMed1995

Transplantation of CD34+ peripheral blood progenitor cells after high-dose chemotherapy for patients with advanced multiple myeloma.

A major potential problem of autologous transplantation in the treatment of advanced malignancy is the infusion of tumor cells. A multi-institutional study of purified CD34-selected peripheral blood progenitor cell (PBPC) transplantation was conducted in 37 patients with advanced multiple myeloma receiving myeloablative chemotherapy. Fourteen days after intermediate-dose cyclophosphamide, prednisone, and granulocyte colony-stimulating factor (G-CSF), a median of 3 (range, 2 to 5) 10-L leukaphereses yielded 9.8 x 10(8)/kg (range, 3.7 to 28.3) mononuclear cells. The adsorbed (column-bound) fraction contained 5.9 x 10(6) cells/kg (range, 1.6 to 25.5) with 4.65 x 10(6) CD34 cells/kg (range, 1.2 to 23.3). Using Poisson distribution analysis of positive polymerase chain reactions with patient-specific complementarity-determining region 1 (CDR1) and CDR3 Ig-gene primers, tumor was detected in leukapheresis products from 8 to 14 unselected patients and ranged from 1.13 x 10(4) to 2.14 x 10(6) malignant cells/kg. After CD34 selection, residual tumor was detected in only three patients' products. Overall, a greater than 2.7- to 4.5-log reduction in contaminating multiple myeloma cells was achieved. CD34 PBPCs were infused 1 day after busulfan (14 mg/kg) and cyclophosphamide (120 mg/kg), and granulocyte-macrophage colony-stimulating factor was used until hematologic recovery. The median time to both neutrophil and platelet recovery was 12 days (range, 11 to 16 days and 9 to 52 days, respectively). The median number of erythrocyte and platelet transfusions was 7 (range, 2 to 37) and 3 (range, 0 to 85), respectively. Patients receiving fewer than 2 x 10(6) CD34 cells/kg had significantly prolonged neutropenia, thrombocytopenia, and an increased red blood cell and platelet transfusion requirement. Thus, CD34 selection of PBPCs markedly reduces tumor contamination in multiple myeloma and provides effective hematopoietic support for patients receiving myeloablative therapy.

Actuarial Analysis↗
PubMed1995

The C-terminal region of membrane type matrix metalloproteinase is a functional transmembrane domain required for pro-gelatinase A activation.

We identified a new matrix metalloproteinase (membrane type matrix metalloproteinase (MT-MMP)) that has a potential transmembrane (TM) domain at the C terminus and reported its expression on the surface of invasive tumor cells. The expression of MT-MMP induced specific activation of 72-kDa pro-gelatinase A (Sato, H., Takino, T., Okada, Y., Cao, J., Shinagawa, A., Yamamoto, E., and Seiki, M. (1994) Nature 370, 61-65). Thus, MT-MMP on the cell surface is thought to play an important role in various physiological and pathological processes accompanying tissue remodeling. In this study, we demonstrated that the potential TM domain deduced from the amino acid sequence functions as a membrane linker when it is fused to a secretory protein, tissue inhibitor of matrix metalloproteinases-1. The pro-gelatinase A activation function of MT-MMP was abolished by truncation of the TM domain and recovered by fusing the MT-MMP mutant with the TM domain of interleukin 2 receptor alpha-chain. The truncated MT-MMP was released from the cells into the medium and detected as processed or modified forms. In spite of the deletion of the TM domain some portions of the mutant MT-MMP were still retained on the surface of cells. Thus, MT-MMP has an additional device to keep it on the cell surface. The TM domain however, plays an essential role in the pro-gelatinase A activation function of MT-MMP, probably regulating its fine orientation or the localization that is necessary to interact with substrate.

Animals↗
PubMed1995

Multiple myeloma clones are derived from a cell late in B lymphoid development.

We have previously demonstrated that the immunoglobulin (Ig) heavy chain variable region (VH) sequences expressed by the malignant clone in multiple myeloma (MM) contain a high degree of somatic mutation without clonal diversity. This sequence can be used to identify all members of the malignant clone in this B cell malignancy. We sequenced the variable regions expressed by patients with MM and generated primers from the complementarity determining region (CDR) sequences specific for each patient's tumor. Using these primers, we performed PCR amplification on highly purified subpopulations of cells separated by expression of CD10, CD34 and CD38. The results of these experiments demonstrate: 1) there is a small fraction of CD10-expressing tumor cells in MM patients, 2) CD34-bearing malignant cells do not exist in MM, and 3) although the vast amount of tumor is in the CD38-expressing cells, a small amount of tumor is in the CD38-negative population. We also used these primers to determine whether pre-class switch (i.e., Cmu-expressing lymphocytes) clonal cells exist in these patients. After PCR amplification with CDR1 and Cmu primers, colony hybridization was performed using both framework 3 (FR3) and CDR3 probes. Out of > 200 FR3-hybridizing colonies, < or = 5 colonies also hybridized with the CDR3 probe. Colonies which hybridized with both these probes were sequenced, and none of these sequences matched even closely the CDR3 expressed by the malignant clone. These results make the existence of a pre-class switch malignant cell unlikely in MM. Overall, these results suggest that the malignant clone in MM derives from a cell late in B lymphocyte development.

ADP-ribosyl Cyclase↗