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Biomedical subjects

Y Yang

Publications and source records attributed to Y Yang.

At least 1,405 records · Page 78Linked to original sources
PubMed1988

Intraoperative hemostasis and wound healing in intestinal anastomoses using the ILA stapling device.

Intraoperative hemostasis and wound healing of 24 side-to-side intestinal anastomoses constructed with the ILA stapling device were studied in 12 dogs by comparing the ILA-32 and ILA-52 staple cartridges. Hemostasis was evaluated by intraoperative measurement of blood loss and bleeding time at the staple line. There was no statistically significant difference in mean blood loss (p greater than 0.05) or mean bleeding time (p greater than 0.10) between the two cartridges. Wound healing was studied using bursting strength measurements and silicone rubber casting of the microvasculature at the staple line. At 3 days, 1 week, and 2 weeks postoperatively, there was no significant difference between bursting strength values achieved with the two cartridges. Microscopic examination revealed that wound healing in the ILA-52 anastomoses lagged behind healing in the ILA-32 anastomoses at each postoperative time period studied. The silicone rubber casting study showed a paucity of microvasculature at the healing staple line with the ILA-52 cartridge as compared with the ILA-32 cartridge. Our findings suggest that the ILA-52 cartridge does not offer significantly improved intraoperative hemostasis over the ILA-32 cartridge and may affect the microvasculature at the staple line in a way that delays wound healing.

Anastomosis, Surgical↗
PubMed1988

Clinical and immunologic responses to the capsular polysaccharide of Haemophilus influenzae type b alone or conjugated to tetanus toxoid in 18- to 23-month-old children.

The safety and immunogenicity of Haemophilus influenzae type b (Hib) capsular polysaccharide (CPS) alone, or covalently bound to tetanus toxoid in saline solution (Hib-TT) or adsorbed onto AI(OH)3 (Hib-TT ads), were evaluated after one injection into 18- to 23-month-old healthy children in Sweden. No side reactions were elicited by Hib CPS; side reactions elicited by the two conjugates were similar and comparable to those reported for diphtheria and tetanus toxoids adsorbed. Hib-TT was the most immunogenic of the three vaccines, eliciting about 10-fold higher antibody levels than Hib CPS; of 28 vaccinees, all had greater than 1.0 microgram Ab/mL serum after immunization with Hib-TT. Increases of Hib CPS antibodies within immunoglobulin classes induced by the three vaccines were, in decreasing order, IgG greater than IgM greater than IgA. Within IgG subclasses, rises in IgG1 Hib CPS antibodies were the most frequent, followed by IgG2; some vaccinees with high postimmunization levels also had rises in IgG3 and one in IgG4. Immunization-induced Hib CPS antibodies were bactericidal. Hib-TT also elicited higher levels of tetanus toxoid antibodies than Hib-TT ads; these tetanus toxoid antibodies neutralized tetanus toxin in vivo.

Aluminum Hydroxide↗
PubMed1988

Effects of argon laser on vascular materials.

The laser has been shown to vaporize arterial atheromatous plaque, but little information is available about its effect on various vascular materials. This study attempts to determine a safe margin for laser graft thrombectomy. An 18 watt argon laser with a 2 mm metal-encased sapphire tip fiberoptic system was used. Specimens such as autogenous vein, polytetrafluoroethylene (PTFE), and Dacron grafts as well as polypropylene and PTFE sutures were harvested from amputated human legs. Laser energy was delivered from the tip of the fiberoptic system while perpendicular to and in direct contact with these materials. The effects were examined histologically and compared by determining the bursting pressure of the grafts and the breaking strength of the sutures. The results indicate that seven sections of autogenous vein grafts and 11 sections of PTFE grafts were perforated by laser delivery of 32.9 +/- 9.9 and 50.0 +/- 7.1 joules, respectively, whereas two sections of Dacron grafts were easily perforated after only 10 joules was delivered. The bursting pressure of PTFE and autogenous vein grafts after laser application was determined to be more than 300 mm Hg. The breaking strength of 6-0 PTFE sutures was compared before and after receiving 200 joules by contact laser application. No significant difference was found; in a before laser application the breaking strength was 585.0 +/- 9.6 gm compared with 560.0 +/- 16.4 gm after laser application (n = 4, p greater than 0.1). However, 6-0 polypropylene sutures were easily melted after receiving 10 joules of laser energy.(ABSTRACT TRUNCATED AT 250 WORDS)

Argon↗
PubMed1988

DNA gyrase binds to the family of prokaryotic repetitive extragenic palindromic sequences.

A family of repetitive extragenic palindromic (REP) sequences is composed of hundreds of copies distributed throughout the chromosome. Their palindromic nature and conservation suggested that they are specifically recognized by a protein(s). We have identified DNA gyrase [DNA topoisomerase (ATP-hydrolysing), EC 5.99.1.3] as one of the REP-binding proteins. Gyrase has at least a 10-fold higher affinity for DNA containing REP sequences than for DNA not containing REP sequences. Binding effectiveness correlates directly with the number of REP sequences in the DNA. DNase I footprinting shows that gyrase protects 205 base pairs on a REP-containing DNA fragment enclosing the REP sequences. In agreement with the above results, a comparison of the REP consensus sequence with the sequence of previously identified pBR322 "strong" gyrase cleavage sites reveals a high degree of homology. Because REP sequences are numerous and found throughout the genome, we suggest they have physiological functions mediated through their interaction with gyrase, such as being sites of action for the maintenance of DNA supercoiling. In addition, we speculate that these interactions may be of a structural nature, such as involvement in the higher-order structure of the bacterial chromosome.

Base Sequence↗
PubMed1988

Activity of temocillin and other penicillins against beta-lactamase-inducible and -stably derepressed enterobacteria.

MICs of temocillin, carbenicillin, ticarcillin, mezlocillin, piperacillin and ampicillin were determined for mutant series of Enterobacter cloacae, Citrobacter freundii, Proteus vulgaris, Morganella morganii and Serratia marcescens with inducible, stably derepressed or basal expression of chromosomal Class I beta-lactamases. Ampicillin was inactive (MIC greater than 256 mg/l) both against beta-lactamase-inducible organisms (except C. freundii) and their stably derepressed mutants, whereas basal mutants were sensitive (MIC 2-8 mg/l). Carbenicillin, ticarcillin, mezlocillin, piperacillin (and ampicillin for C. freundii) were active against both inducible and basal organisms (MIC less than 16 mg/l), but inactive against the derepressed mutants (MICs usually greater than 64 mg/l). Temocillin inhibited all the organisms, including the stably derepressed mutants, at 16 mg/l. Derepressed S. marcescens, M. morganii and Pr. vulgaris were as susceptible as the inducible strains and basal mutants. MICs of temocillin for derepressed mutants of E. cloacae and C. freundii were 4-16 fold above those for their inducible parent strains, but remained within the clinical range.

Enterobacteriaceae↗
PubMed1988

A retrospective look at Rn-induced lung cancer mortality from the viewpoint of a relative risk model.

The potential contribution to U.S. lung cancer deaths from 1930 to 1987 from indoor 222Rn exposures is investigated from the standpoint of a constant relative risk model. Based on this model, which assumes a Rn risk proportional to the baseline lung cancer risk from other causes, the rate of Rn-induced lung cancer mortality has been increasing sharply since 1930. However, the estimated proportion of lung cancer deaths attributable to Rn has remained fairly constant. Applying the range of coefficients the U.S. Environmental Protection Agency employs in assessing the risk from indoor Rn, it is estimated that 8-25% of all current lung cancer deaths are "attributable to" past Rn exposures. The major sources of uncertainty in the estimates are discussed.

Environmental Exposure↗
PubMed1988

A new DNA immune adsorbent for hemoperfusion in SLE therapy: a clinical trial.

This investigation studied the preparation and clinical trial of DNA immunoadsorbent for hemoperfusion in systemic lupus erythematosus (SLE) therapy. DNA was complexed with blue tetrazolium (BT), then mixed with collodion, and finally adsorbed on macroporous spherical polymeric adsorbent. The percentage of DNA thus immobilized was 98-98.5%, and no release was detected during hemoperfusion. A patient with severe SLE was treated with the above adsorbent in hemoperfusion. The patient was in coma, with high anti-DNA antibody and abnormal immune complex levels, which fell sharply from 56.34% to 0.8% after 2.5 h of whole-blood hemo perfusion. There were no major clinical complications, and 2 weeks later, her proteinuria level became normal and immune complex levels were sustained. She was then discharged from the hospital and has been in good health for more than 1 year.

Adult↗
PubMed1988

Development of neutralizing antibodies and group A common antibodies against natural infections with human rotavirus.

We determined the levels of group A common and neutralizing antibodies against human rotavirus in paired serum specimens obtained from 38 infants within 12 days of the onset of diarrhea. Thirty of the infants excreted rotavirus in stools, and eight did not. Nine patients (30%) with rotavirus diarrhea and seven patients (88%) with diarrhea due to other causes had detectable levels (greater than or equal to 1: 80) of immunoglobulin (IgG) common antibodies in acute-phase sera. All the patients with rotavirus diarrhea showed at least fourfold rises in titers of IgG or IgM common antibodies or both, while only two control patients showed significant rises in either IgG or IgM common antibodies in their convalescent-phase sera. Of the 19 patients excreting "short" electropherotypes of rotavirus, 18 showed at least fourfold rises in titers of neutralizing antibodies against serotype 2 human rotavirus but not against serotype 1, 3, or 4. Nine of the ten patients excreting "long" electropherotypes showed significant rises in neutralizing antibodies against serotype 3, and the other patient showed a significant rise in neutralizing antibodies against serotype 1. One patient excreted long and short electropherotypes simultaneously, and he also showed a significant rise in neutralizing antibodies against serotype 2 and 3 viruses. The control patients with diarrhea did not show significant changes in titers of antibodies against any of the serotypes. These results demonstrated that the neutralizing antibody response within 2 weeks after clinical onset is specific for the infecting serotype of rotavirus.

Antibodies, Viral↗
PubMed1988

Laser angioplasty.

Clinical trials for Argon Laser angioplasty of patients with severe ischemia of the lower extremities are presented. All instances were limited to those in whom no conventional reconstructive operation was ideal. Laser angioplasty proved to be beneficial when used in conjunction with standard vascular surgical procedures under appropriate conditions. The short term evaluation was favorable; however, a long term study must be followed and completed prior to routine use of laser angioplasty.

Aged↗
PubMed1987

Thermolabile proton translocating ATPase and pump activities in a clathrin-coated vesicle fraction from an acidification defective Chinese hamster cell line.

We have recently described a mutant of Chinese hamster ovary cells, termed G.7.1, that contains a temperature-sensitive, conditionally lethal mutation resulting in defective vacuolar acidification (Marnell, M. H., Mathis, L. S., Stookey, M., Shia, S.-P., Stone, D.K., and Draper, R. K. (1984) J. Cell Biol. 99, 1907-1916). To further characterize the lesion, clathrin-coated vesicles were partially purified from wild type and G.7.1 cells, and the thermolabilities of vanadate and oligomycin-insensitive, N-ethylmaleimide-sensitive, H+-ATPase activity, 32Pi-ATPase exchange activity, and proton pumping were compared. All three parameters of H+ pump activity were markedly diminished by preincubation at 44 degrees C for vesicles harvested from the G.7.1 cells, but not for those from wild type cells. Phosphatidylserine did not protect against heat inactivation in vesicle fractions prepared from G.7.1 cells. The results suggest that the mutation responsible for defective acidification in G.7.1 cells is expressed at the level of the proton pump of organelles present in our clathrin-coated vesicle-enriched preparation.

Adenosine Triphosphate↗
PubMed1987

Role of enteric plexuses in the competency of telescoped intestinal valves.

The mechanism of preventing intestinal regurgitation by means of a telescoped intestinal valve has been investigated in this study. Ten telescoped intestinal valves were uniformly created in dogs. A tolerance test to barium reflux was performed before the animals were sacrificed 16 weeks postoperatively, which yielded various barium tolerance values. Statistical analysis revealed that the differences in barium tolerance values in the uniformly constructed valves were closely related to the proportion of the enteric plexuses which contained ganglion cells with normal shapes (r = 0.97, p less than 0.001) and their intestinal segment coverage (r = 0.94, p less than 0.001), but no correlation was found between barium tolerance and the thickness of the valvular musculature (r = 0.04) or the length of the artificial valve (r = 0.39). The results in this study suggest that the intact enteric plexuses play an important role in modulating the competency of the telescoped intestinal valve.

Animals↗
PubMed1987

Use of intragastric balloons for weight reduction. An experimental study.

The effect of intragastric balloons as a noninvasive method for weight reduction was observed in nine castrated Yorkshire pigs. None of the animals lost weight. The appetites of the experimental animals were inhibited for only a short period of time. A significant dilatation of the stomach after balloon insertion was noted which resulted from increased food intake and obliterated the effect of the intragastric balloons. A long-standing lower blood glucose level played an important role in the increments in food intake and dilatation of the stomach. At the same time, ulceration was seen in 83.3 percent of the animals that received balloons. We conclude that intragastric balloon therapy may not be an effective approach for managing morbid obesity in human subjects.

Animals↗