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R Lyons

Publications and source records attributed to R Lyons.

50 records · Page 3Linked to original sources
PubMed1986

Comparison of laser-welded and sutured arteriotomies.

We compared the histologic features, tensile strength, and collagen synthesis of laser-welded and sutured arteriotomies. Four bilateral canine femoral or carotid arteries, 2 cm long, were studied at one through four weeks postoperatively, with one vessel (control) closed with interrupted 6-0 polypropylene sutures and the contralateral vessel (experimental) welded with an argon laser (0.5 W [1417 J/cm2], four-minute exposure per 1-cm length of incision). Histologic examination revealed that laser-welded arteriotomies had less inflammatory reaction, more normal collagen and elastin reorientation, and similar endothelial continuity when compared with the control, sutured wounds. The tensile strength of the one- and two-week laser-welded specimens was less than that of sutured wounds and became approximately equal to sutured repairs at three and four weeks. There were no significant differences in the rate of collagen synthesis. There was no evidence of abnormal healing in the laser-welded specimens, suggesting that argon laser welding may be an alternative to suture repair of arteriotomies.

Animals↗
PubMed1986

Biological effects of laser welding on vascular healing.

The feasibility of welding thin-walled microvessels by laser has been established. This report summarizes our experience using laser welding to repair thick-walled, high-pressure, 4 to 8-mm canine arteries using CO2, Nd:YAG, and argon lasers. The CO2 laser did not produce seals that could withstand arterial pressure. Nd:YAG laser welds were initially successful, but the majority failed within 20 to 40 minutes. The argon laser uniformly sealed 2-cm-length arteriotomies that healed rapidly within 4 to 6 weeks and had less foreign body response compared to sutured controls. Laser welding may represent an alternative for repair of small- and large-diameter vessels with several advantages compared to conventional suture techniques.

Animals↗
PubMed1986

Comparison of nonwoven and woven gown and drape fabric to prevent intraoperative wound contamination and postoperative infection.

In a prospective, controlled clinical trial, nonwoven, disposable gown and drape fabrics were no better barriers to intraoperative wound contamination or postoperative wound infection than reusable cotton poplin. We observed no difference between the two study groups in either the frequency or level of intraoperative wound contamination as judged by cultures of specimens collected at the time of wound closure. Of procedures in which reusable fabrics were used, 13.1 percent had positive cultures compared with 15.5 percent of those in which disposable fabrics were used (difference not statistically significant). We recovered coagulase-negative Staphylococci from more than 95 percent of contaminated wounds. Rates of postoperative wound infection were virtually identical in the two groups. Our data suggest that either both fabrics were similar in their ability to block bacteria that were shed from skin surfaces from entering the wound, or that bacteria which contaminate the wound in clean surgical procedures are derived from sources other than skin.

Clinical Trials as Topic↗
PubMed1986

Laser welding: an alternative method of venous repair.

This study compared the histology, biochemistry, tensile strength, and extensibility of Nd:YAG laser-welded and sutured venotomies. Two-centimeter-length bilateral canine femoral or jugular venotomies were evaluated with one vessel (control) closed with interrupted 6-0 polypropylene sutures, and the contralateral vessel (experimental) welded with the Nd:YAG laser (1 W power and 30- to 40-sec exposure). Specimens were removed and examined immediately after fashioning (t0) and at 1, 4, or 5 weeks post-operatively to compare the progression of healing. Histologic examination of the 4- and 5-week sutured wounds had granulomatous reaction around the sutures with areas of excessive collagen accumulation. In contrast, the laser-welded wounds had minimal inflammatory response, near normal collagen content, and minimal residual disorientation and break in the elastic fiber continuity. The rate of collagen synthesis in laser-welded wounds was approximately twice that of sutured wounds at 1, 4, and 5 weeks, and correlated with increased tensile strengths of lasered wounds. The extensibility of the 5-week specimens was 0.19 for sutured and 0.29 for laser-welded wounds as compared to 0.29 for normal vein. These preliminary data suggest that laser welding of venotomies may have several advantages over conventional suture techniques.

Animals↗
PubMed1986

Postcholecystectomy wound infection. The impact of prophylactic antibiotics on the epidemiology of infections.

The clinical courses of 347 patients undergoing gallbladder surgeries were monitored to study the epidemiology of postcholecystectomy wound infection in a hospital in which high-risk patients received prophylactic antibiotics. Overall, 3.8% of patients had wound infections. Patients who had positive bile cultures taken during surgery or positive intraoperative wound cultures had higher rates of infection than patients with negative cultures. However, there was a poor correlation among the bacterial isolates that were recovered from the bile or the wound surface during surgery and from postoperative infections. Antibiotic-sensitive enteric bacteria were recovered from bile samples at surgery, gram-positive organisms and enteric gram-negative bacteria were isolated from intraoperative cultures of the wound surface, and antibiotic-resistant gram-negative bacteria or enterococci were recovered from wounds that developed postoperative infections. There was a strong association between the prior receipt of prophylactic antibiotics and infections with antibiotic-resistant bacteria. Data suggest that bactibilia is still an important epidemiologic marker that identifies patients at high risk for subsequent wound infection. However, in patients who have received prophylactic antibiotics, intraoperative cultures cannot be relied on to guide the choice of empiric therapeutic antibiotics for postoperative infections. Bacteria responsible for these infections are not identified by cultures taken at the time of surgery and are often resistant to the class of antibiotics used for prophylaxis.

Adolescent↗
PubMed1986

Sexual Pavlovian conditioned approach behavior in male Japanese quail (Coturnix coturnix japonica).

A localized visual stimulus presented immediately prior to access to a female conspecific stimulated approach behavior in male Japanese quail after several conditioning trials. Development of this conditioned approach behavior was observed with two different types of signal lights, 10-s and 30-s signal durations, large and small experimental chambers, and with male birds housed continually in the conditioning chambers or only placed in the chamber for brief daily sessions. Conditioning also resulted in shorter latencies to initiate copulation in males given access to a female following the signal light, in comparison with males that received access to a female unannounced by the light. Although some aspects of the conditioning experience were retained over a 6-week interval, some loss of the behavior was also observed. The conditioned behavior also decreased with repeated extinction trials, during which the signal light was presented in the absence of access to a female conspecific. The results are discussed in relation to other aspects of the social behavior of Japanese quail and other studies of sexual conditioning.

Animals↗
PubMed1976

Endemicity of multiple staphylococcal phage types: relation of two common source outbreaks.

An outbreak of Staphylococcus aureus bacteremia occurred among patients treated in the hemodialysis unit in 1971. A second outbreak of S. aureus peritonitis occurred in 1973 in patients with chronic indwelling peritoneal catheters cared for together in the medial intensive care unit. Although the attending personnel, patients, and geographical locations were different in each outbreak, the following similarities were notes: (1) more than one phage type was epidemic: (2) an exogenous mode of spread with cross-contamination between personnel and patient as well as between patient and patient, and (3) breaks in sterile technique when handling the arteriovenous shunt site or the peritoneal catheter were made without the staff conducting the procedure being aware of their occurrence. Culture surveys of the same phage types found during the two epidemics. Thus, an endemic reservoir of several different staphylococcal phage types was present. Careful, consistent application of aseptic technique when handling either arteriovenous shunts or peritoneal catheters and hand washing in between patients was required to prevent the endemic strains from becoming epidemic.

Asepsis↗
PubMedDate not supplied

Botulism as a cause of respiratory failure in injecting drug users.

BACKGROUND: Wound botulism occurs as a consequence of inoculation of Clostridium botulinum spores into a wound. AIM: To describe such a case of wound botulism. RESULTS: A 23-year-old drug-injecting user presented with bulbar symptoms and progressive signs over a three-day period. The diagnosis of botulism was suspected and was treated with large doses of penicillin and botulinum antitoxin. The diagnosis was confirmed by the presence of serum botulinum toxin A. CONCLUSION: Physicians should be aware of the association of botulism in injecting drug users, particularly in Ireland.

Adult↗
PubMedDate not supplied

Laser welding of large diameter arteries and veins.

Based on our preliminary studies and the results of this study, we conclude that argon laser welding of 4-8 mm internal diameter veins, arteries, and arteriovenous fistulas may have several potential advantages compared to conventional suture techniques. The benefits of laser repairs may include improved mechanical properties, and absence of the foreign body response related to sutures. Laser welding is sterile, nontactile and possibly time conserving, and the wounds heal rapidly without aneurysms or excess tissue proliferation.

Animals↗