Reversal of spinal cord ischemia resulting from aortic dissection.
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Biomedical subjects
Publications and source records attributed to W A Reed.
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The ability of arginine-glycine-aspartic acid (RGD; a sequence recognized by integrins) or non-RGD-containing peptides to block fertilization, induce intracellular Ca(2+) oscillations, and initiate parthenogenetic development in bovine oocytes was investigated. Addition of a soluble RGD peptide during fertilization at concentrations ranging from 10 to 1000 microg/ml significantly decreased (P<0.05) fertilization as compared to the in vitro-fertilized controls. The addition of non-RGD peptide had no effect on fertilization. Two intracellular Ca(2+) transients 21.5+/- 1.9 min apart were observed in 56 of 60 oocytes incubated in RGD peptide concentrations ranging from 20 to 1000 microg/ml. No intracellular Ca(2+) transients were observed in medium alone, non-RGD treatment groups or in the RGD peptide at 10 microg/ml. The percentage of oocytes activated with ionomycin and 6-dimethylaminopurine (63% cleavage and 34% blastocyst development) was significantly higher (P<0.05) than those activated with the RGD peptide and 6-dimethylaminopurine (35% cleavage and 19% blastocyst development). These groups were significantly higher (P<0.05) than either peptide alone, 6-dimethylaminopurine alone, or the non-RGD peptide and 6-dimethylaminopurine treatment groups. These data provide evidence that ligation of an integrin on bovine oocytes with a soluble RGD peptide is capable of blocking fertilization, inducing intracellular Ca(2+) transients, and initiating parthenogenetic development.
All patients with an abdominal aortic aneurysm treated during a 27-year period by one surgical group at the MidAmerica Heart Institute were included in this study. A prospective routine postaneurysmectomy hemodynamic assessment of the inferior mesenteric artery (IMA) circulation was performed in a test group of consecutive patients operated on by one surgeon. When a mean IMA stump pressure </= approximately 50 mmHg was found, the IMA was reimplanted. Postoperatively, patients were monitored for clinical evidences of ischemic colitis. The occurrence of ischemic colonic injury was documented by colonoscopy, laparotomy, or autopsy. The incidences of ischemic colitis in the test group, a historical control group, and a concomitant control group were determined and compared. Routine hemodynamic assessment of the postaneurysmectomy IMA circulation did not favorably affect the outcome with regard to the occurrence of clinically evident ischemic colitis.
BACKGROUND: Advances in immunosuppression and reports of improved survival after cardiac transplantation have led to a liberalization of traditional recipient eligibility criteria, especially age. While age alone is not a contraindication to transplantation, conflicting data exists regarding long-term survival of the older transplant recipient. METHODS: One hundred-fifty three patients undergoing consecutive first time cardiac transplantation from June 7, 1985 through February 1, 1997 were studied. For purposes of analysis, patients were stratified according to age (<55 years vs. >55 years) and hospital and late outcomes determined. RESULTS: The incidence of early and late acute cellular rejection was not different based up on age. The freedom from infection at 12 months was 54+/-5% for patients < or =55 compared to 32+/-8% for patients >55 years old (p = .04). Five year estimated survival for patients >55 years old was only 56+/-9% compared to 78+/-5% for patients < or =55 years old (p = .005). The hazard for death was highest within the first post-transplant year for older patients and was most commonly due to infection. Both advanced age and pre-transplant diagnosis of ischemic cardiomyopathy were found to be independently and additively predictive of reduced late survival. CONCLUSIONS: In the present study, late survival was adversely influenced by advanced age. Older patients (>55 years) with pre-transplant diagnosis of ischemic cardiomyopathy were particularly at high risk (risk ratio 4.6:1) for death. Given little prospect of expanding the number of donor hearts, careful selection of patients over the age of 55 with pre-transplant ischemic cardiomyopathy is warranted.
Cloning mammalian species from cell lines of adult animals has been demonstrated. Aside from its importance for cloning multiple copies of genetically valuable livestock, cloning now has the potential to salvage endangered or even extinct species. The aim of this study was to investigate the effect of the bovine and domestic (Ovis aries) ovine oocyte cytoplasm on the nucleus of an established cell line from an endangered argali wild sheep (Ovis ammon) after nuclear transplantation. A fibroblast cell line was established from skin biopsies from an adult argali ram from the People's Republic of China. Early karyotype analysis of cells between 3-6 passages revealed a normal diploid chromosome number of 56. The argali karyotype consisted of 2 pairs of biarmed and 25 pairs of acrocentric autosomes, a large acrocentric and minute biarmed Y. Bovine ovaries were collected from a local abattoir, oocytes aspirated, and immediately placed in maturation medium consisting of M-199 containing 10% fetal bovine serum, 100 IU/mL penicillin, 100 microg/mL streptomycin, 0.5 microg/mL follicle-stimulating hormone (FSH), 5.0 microg/mL luetinizing hormone (LH) and 1.0 microg/mL estradiol. Ovine (O. aries) oocytes were collected at surgery 25 hours postonset of estrus from the oviducts of superovulated donor animals. All cultures were carried out at 39 degrees C in a humidified atmosphere of 5% CO2 and air. In vitro matured MII bovine oocytes were enucleated 16-20 hours after onset of maturation and ovine oocytes within 2-3 hours after collection. Enucleation was confirmed using Hoechst 33342 and UV light. The donor argali cells were synchronized in G0-G1 phase by culturing in Dulbecco's modified Eagle's medium (DMEM) plus 0.5% fetal bovine serum for 5-10 days. Fusion of nuclear donor cell to an enucleated oocyte (cytoplast) to produce nuclear transfer (NT) embryos was induced by 2 electric pulses of 1.4 kV/cm for 30 microsc. Fused NT embryos were activated after 24 hours of maturation by exposure to ionomycin (5 microM, 4 minutes) followed by incubation in 6-dimethylaminopurine (0.2 mM, 4 hours) and cultured in microdrops of CR1aa medium. From a total of 166 constructed nuclear donor cell-bovine cytoplasm NT couples, 128 (77%) successfully fused, 100 (78%) developed to 8-16 cell stage, and 2 (1.56%) developed to the blastocyst stage. The presence of argali nuclei in 8-16 cell stage embryo clones was confirmed after observation of Hoechst 33342 stained embryos under UV light and chromosome analysis of metaphase spreads from blastomeres. A total of 127 constructed nuclear donor cell-ovine cytoplasm NT couples were produced, 101 (80%) successfully fused, 81 (80% of fused) developed to the 16- to 32-cell stage. A total of 28 hybrid (argali-sheep) and 21 sheep-sheep NT embryos were transferred into 6 recipients and 4 recipients, respectively. Two of these recipients, 1 carrying argali-sheep and 1 sheep-sheep, were confirmed pregnant at 49 days by ultrasound, but both pregnancies terminated by 59 days. The results of this study demonstrate the possibility of using xenogenic oocytes to produce early-stage embryos and pregnancies from an established fibroblast cell line of an endangered species.
The present study was carried out to evaluate the effects of different activation protocols, enucleation methods, and culture media on the development of parthenogenetic and nuclear transfer (NT) rabbit embryos. Electroporation of 25 mM inositol 1,4, 5-trisphosphate (IP3) in calcium- and magnesium-free PBS immediately induced a single intracellular calcium transient in 6 out of 14 metaphase II-stage rabbit oocytes evaluated during a 10-min recording period. The percentage of oocytes treated with IP3 followed by 6-dimethylaminopurine (IP3 + DMAP) that cleaved (83.9%) and reached the blastocyst stage (50%) was significantly higher (p < 0.05) than those activated with multiple pulses (61.6% and 30.1%, respectively) or treated with ionomycin + DMAP (52.9% and 5.7%, respectively). Development of IP3 + DMAP-activated rabbit oocytes and in vivo-fertilized zygotes in different culture media was studied. Development of activated oocytes to the blastocyst stage in Earle's balanced salt solution (EBSS) supplemented with MEM nonessential amino acids, basal medium Eagle amino acids, 1 mM L-glutamine, 0.4 mM sodium pyruvate, and 10% fetal bovine serum (FBS) (EBSS-complete) (40.6%) was significantly higher (p < 0.05) than those that developed in either Dulbecco's Modified Eagle's medium (DMEM)/RPMI + 10% FBS (15.5%) or CR1aa + 10% FBS (4%) medium. In addition, 100% of in vivo-fertilized rabbit zygotes developed to the blastocyst stage in EBSS-complete. A third set of experiments was carried out to study the efficiency of blind versus stained (Hoechst 33342) enucleation of oocytes. Twenty-nine of 48 blind enucleated and IP3 + DMAP-activated oocytes cleaved (60.4%), and 15 (31.2%) subsequently reached the blastocyst stage, whereas 9 of 52 oocytes enucleated using epifluorescence (17.3%) cleaved, and none of these reached the blastocyst stage. When the above parameters that yielded the highest blastocysts were combined in an NT experiment using adult rabbit fibroblast nuclei, 72.2% (39 of 54) of the fused nuclear transplant embryos cleaved and 29.6% (16 of 54) reached the blastocyst stage.
An attempt was made to document trends that have occured over a 25-year period in clinical presentation, preoperative evaluation, operative management, and patient outcome in patients with an abdominal aortic aneurysm. The experience (574 aneurysmectomies) of one cardiovascular surgical group was analyzed by retrospective review of hospital and office records. Changes over time of patients' ages, aneurysm sizes and statuses, prior myocardial revascularization, operative mortality, and certain other parameters were evaluated. During the period of study, there was a significant decrease in aneurysm size, increase in patients' ages, and an increased incidence of previous coronary artery bypass. No ruptured aneurysm was < 5 cm in diameter. The incidence of rupture and the operative mortality in patients with a ruptured aneurysm did not change significantly. There was a significantly (p = 0.03) lower operative mortality of 0.4% in the latter half of the series for elective aneurysmectomy. Increased utilization of preoperative cardiologic evaluation, and myocardial revascularization, has been associated with a decreased operative mortality in patients undergoing elective aneurysmectomy even though the patients are now older and have more age-related comorbidities. Elective aneurysmectomy should be offered to most patients when an abdominal aortic aneurysm is > or =5 cm in diameter.
We have previously reported that injection of ryanodine receptor agonists into mature bovine oocytes induces intracellular calcium release, indicative of the existence of ryanodine receptors. In this experiment, further evidence of the ryanodine receptor localization, and developmental regulation in bovine oocytes is presented. The possible physiological significance is also suggested. Using a rabbit antibody against the rabbit cardiac muscle ryanodine receptor, the ryanodine receptor was observed uniformly localized in the periphery of mature bovine oocytes, while a weak and discontinuous signal was observed in the germinal vesicle intact stage of bovine oocytes. As oocytes progress to the metaphase I stage, the ryanodine receptor localization became more intense and continuous, yet not comparable to that observed in the metaphase II oocytes. These modifications correlate with the intracellular calcium responsiveness to ryanodine. A 200-microM injection of ryanodine induces a low intracellular calcium transient in germinal vesicle-stage bovine oocytes, while peaked intracellular calcium transients are subsequently observed in the metaphase II-stage oocytes. However, no significant changes in the amplitude of intracellular calcium transients induced by 250 nM inositol 1,4,5-trisphosphate and 10 microM ionomycin were observed in oocytes at a comparable stage. Fertilization induced a significant decrease in ryanodine receptor signal; similar changes were also observed in oocytes injected with 200 microM ryanodine or incubated with 10 microM ionomycin. However, no changes in ryanodine signal were observed in oocytes injected with vehicle medium. Furthermore, injection of either ryanodine or inositol 1,4,5-trisphosphate induced subsequent pronuclear formation and cleavage. These data indicate that the ryanodine receptor is closely regulated and associated with early cellular changes following fertilization; stimulation of this receptor results in the activation of bovine oocytes, and it is likely that this receptor may play a role at fertilization.
We studied a series of 648 consecutive patients who underwent coronary artery bypass grafting for isolated primary disease of the anterior descending coronary artery. We evaluated the patients periodically during a long-term follow-up period of up to 17 years. We studied factors such as survival, survival without acute event (i.e., acute myocardial infarction, repeat coronary artery bypass, and percutaneous transluminal coronary angioplasty), and asymptomatic survival (i.e., survival without acute event or angina). We further analyzed these factors as they occurred in patients who received only saphenous vein grafts versus their occurrence in patients who received internal mammary artery grafts. There was 1 death in the early postoperative period (defined as 30 days or earlier after the operation). The 5-, 10-, and 15-year survival rates were 94.8%, 86.6%, and 72.2%, respectively. These survival rates are slightly better than those of an age- and sex-matched United States census population. In our series, the rates of survival, event-free survival, and asymptomatic survival were better, although not significantly so, in the group of 108 patients in whom the internal mammary artery was used as the bypass conduit. We conclude that patients who undergo coronary artery bypass grafting for isolated disease of the left anterior descending coronary artery enjoy normal survival rates, in comparison with the survival rates of an age- and sex-matched United States census population, through at least the 1st 16 postoperative years. Additionally, patients who receive an internal mammary artery bypass graft have slightly better rates of survival, event-free survival, and asymptomatic survival than do those who receive only saphenous vein grafts.
BACKGROUND: Postinfarction rupture of the interventricular septum is usually fatal without surgical intervention. The optimal timing and the most appropriate technique of surgical repair remain unsettled. METHODS: The results of surgical closure of postinfarction ventricular septal defect in a consecutive series of patients seen over a 24-year period were reviewed and analyzed. Late follow-up was obtained in all patients who survived the operation. RESULTS: Sixty of 76 patients treated surgically exhibited cardiogenic shock, low cardiac output syndrome, or both at the time of operation. A plan of early operative intervention was followed in these unstable patients, with 60% of them undergoing repair within 24 hours of septal rupture. For the entire series of patients, the hospital mortality rate was 40.8%; survival was 41.5% at 5 years and 25.6% at 10 years postoperatively. CONCLUSIONS: Significant trends observed during the period of study were a more aggressive stance regarding surgical intervention in all patients who presented with hemodynamic instability and improved survival in those patients who presented with septal rupture complicating an inferior myocardial infarction.
The addition of an antimicrobial that can be synthesized by the mammalian immune system at the point of challenge may enhance disease resistance. A possible group of agents are cecropins, broad-spectrum antimicrobial peptides, which have been described and characterized. They are relatively non-toxic to normal cells from multicellular organisms but are toxic to a wide range of bacteria, protozoa and fungi, as well as infected and abnormal cells. Twenty-six lines of transgenic mice were produced by pronuclear injection of DNA consisting of the 5'-flanking region from -593 to +110 of the mouse interleukin 2 (IL-2) gene, Shiva 1a (a synthetic cecropinclass lytic peptide), and the SV40 polyadenylation/splice signal. A reverse-transcription PCR assay determined that two lines of transgenic mice were produced whose spleen-derived lymphocytes could be induced to transcribe and mature mRNA for Shiva 1a by exposure to 3.25 mg ml-1 of Con A. Two lines were challenged with an inoculation of 5 x 10(4) Brucella abortus strain 2308. After four weeks, there were significantly fewer B. abortus organisms in the spleens of transgenic mice than in non-transgenic control mice of the same strain (p < 0.05). Since the controlling regions of the IL-2 enhancer and the amino acid sequence of the signal peptide are highly conserved among several species, it is likely that this recombinant gene will function in other mammals.
The mink reproductive cycle includes an obligatory period of embryonic diapause and delayed implantation, which continues in vitro and reduces the efficiency of embryonic stem (ES) cell establishment. Blastocysts recovered on day 7 and on days 13-16 after final mating were cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with various concentrations of prolactin to determine optimal conditions for embryo attachment and subsequent establishment of embryonic stem cells. Five treatments were applied to both ages of blastocyst: A, DMEM control (n = 16); B, DMEM + 5 micrograms prolactin ml-1 after 10 days initial culture in DMEM alone (n = 17); after 1 day of initial culture: C, DMEM + 10 ng prolactin ml-1 (n = 17); D, DMEM + 1 microgram prolactin ml-1 (n = 19); and E, DMEM + 5 micrograms prolactin ml-1 (n = 17). Prolactin terminated diapause of day 13-16 blastocysts at all concentrations tested. The maximum attachment of embryos in vitro and subsequent production of ES-like cells occurred in medium supplemented with 5 micrograms prolactin ml-1. Prolactin did not affect attachment rates for day 7 blastocysts when 5 micrograms prolactin ml-1 was added, but prolactin at concentrations of 1 microgram ml-1 and 5 micrograms ml-1 when added on day 1 of culture enhanced ES-like cell line establishment. Two principal cell types were observed in the colonies: small stem cells and trophoblast-like cells with large areas of cytoplasm. The morphological evaluation of mink ES-like cell colonies was confirmed by cytochemical staining for alkaline phosphatase. Mink embryonic stem-like cells were found to stain positive for alkaline phosphatase. Alkaline phosphatase activity was lost upon cellular differentiation.
Co-culture with various cell types can enhance development of bovine embryos, especially through the transition from maternal to embryonic mRNA utilization, a stage of growth refractory to most in vitro methods. Bovine oviductal epithelial (BOE) cells have been particularly successful for culturing embryos through the refractory stage; however, Buffalo rat liver (BRL) cells are a readily available, long-lived, easy-to-care-for alternative. This study compared the embryotrophic activity of BOE to BRL cells with particular emphasis on the transition stage of growth. A total of 7158 immature bovine oocytes, matured and fertilized in vitro, were divided into 4 different culture treatments: Treatment 1: BRL conditioned medium for 72 h then BRL co-culture; Treatment 2: BRL co-culture; Treatment 3: BOE co-culture for 72 h in 5% oxygen then BRL co-culture; and Treatment 4: BOE co-culture for 72 h in 5% oxygen followed by BOE co-culture in air. Those same treatments were used to evaluate embryotrophic differences of early (4 to 5) versus late (14 to 15) passage BRL cells maintained in M-199 medium with 10% serum. Two bulls were also evaluated to determine if there exists a bull-by-culture system interaction. Treatment 3 resulted in the best development after 9 d; 9.1% of selected immature oocytes developed to expanded blastocyst. Early passage BRL cells were significantly more embryotrophic than later passage cells; this was most pronounced for Treatment 2. There was a treatment-by-bull interaction, which should be considered when comparing results among similar studies.
Acceptable function of an internal defibrillator can be achieved with different patch orientations. For patients requiring defibrillator patches concomitant with a cardiac procedure requiring extracorporeal circulation, application of one of the patches within the pericardium adjacent to the right atrium has provided excellent defibrillation thresholds. We describe 4 such patients in whom a compressing thrombus subsequently developed between the patch and the atrium. The thrombus was small and asymptomatic in 1 patient, but caused localized tamponade requiring reexploration in 2 patients and a fatal superior vena caval obstruction in 1. The precise etiology of this serious complication remains unclear, but its occurrence argues against the application of intrapericardial defibrillator patches in this orientation.
Intracellular Ca2+ (Ca2+i) transients during fertilization are critical to the activation of eggs in all species studied. Activation of both the inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) and ryanodine receptor (RYR) are responsible for the calcium oscillations during fertilization in sea urchin eggs. Using in vitro matured bovine oocytes loaded with Fura-2 AM ester as Ca2+i indicator, we addressed whether IP3Rs and RYRs coexist in mammalian eggs. Our results indicate that microinjection of 50-250 nM IP3 or 10-20 mM caffeine, 100-200 microM ryanodine and 4-8 microM cyclic ADP-ribose all induced Ca2+i release. The Ca2+i release induced by 250 nM IP3 could only be inhibited by prior injection of 1 mg/ml heparin which was overcome by continuous injection of IP3 to 1 microM. Prior injection of either 50 microM ruthenium red, 50 microM procaine or 1 % vehicle medium (VM) did not affect the Ca2+i release induced by IP3. Prior injection of heparin or VM did not affect the Ca2+i release induced by 10-20 mM caffeine or 200 microM ryanodine, but prior injection of 50 microM ruthenium red or procaine completely inhibited the effect of 10-20 mM caffeine. In addition, continuous injection of caffeine up to 40 mM overcame the inhibitory effect of ruthenium red or procaine. The same 50 microM concentration of ruthenium red or procaine only partially blocked the effect of 200 microM ryanodine, but 200 microM ruthenium red or procaine completely blocked the effect of 200 microM ryanodine.(ABSTRACT TRUNCATED AT 250 WORDS)
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Preliminary studies on the proliferative effects of lytic peptides were carried out using NIH 3T3 murine fibroblast cells and human lymphocytes. Cells were cultured in various concentrations of three different amphipathic peptides (SB-37, Shiva-1, and Vishnu), and enhanced proliferation was determined by uptake of 3H-thymidine with treated cells compared with control cultures. Enhanced proliferation of 3T3 cells was observed in cultures containing 50 microM or less SB-37. The primary study consisted of 263 four-cell- to eight-cell-stage mouse embryos from naturally bred mice and incubated in Whitten's medium containing 0.2, 1, or 10 microM of the amino terminus of an amphipathic cecropin B analog (Vishnu) or in Whitten's medium alone. Embryos were cultured to the hatched blastocyst stage, and effect of treatment was determined by the rate of growth to that stage of development. Statistical analysis revealed that culture in all three levels of Vishnu significantly accelerated in vitro growth of these stages of preimplantation embryos compared with controls. These results indicate that Vishnu promotes increased cleavage rates of embryos in vitro. A growth factor receptor clustering mechanism of action is proposed. This peptide may have some potential as an embryo culture medium additive to enhance in vitro growth rate.
To assess the outcome of emergency coronary artery bypass grafting (CABG) after failed percutaneous transluminal coronary angioplasty (PTCA), 91 patients undergoing emergency CABG after failed PTCA over a 30-month period ending July 31, 1991, were studied. For reference, a cohort of patients (91) concurrently undergoing elective CABG equally matched for age, sex, number of grafts, ventricular function, and reoperative status was compared. Specific outcomes including death, hospital length of stay, use of blood products, and development of myocardial infarction were analyzed. More than half the patients undergoing emergency CABG for failed PTCA required three or more grafts. Operative mortality was 12.1% (11/99) for emergency CABG compared with 1% (1/91) for elective case-matched CABG patients (p = 0.007). Emergency CABG patients required frequent use of postoperative inotropes (p = 0.02) and intraaortic balloon counterpulsation (p = 0.001). Length of hospital stay (p = 0.005), administration of blood products (p = 0.009), postoperative myocardial infarction (p = 0.0005), and ventricular arrhythmias (p = 0.0004) were increased after emergency compared with elective CABG. The presence of multivessel disease or use of a reperfusion catheter had no influence on clinical outcome. Despite accumulated experience and improved operative management, patients requiring emergency CABG for failed PTCA remain at increased risk for postoperative complications and death.