Knot Security of Suture Materials

The knot security of chromic gut, polyglycolic acid, polyglactin 910, polydioxanone, polypropylene, and monofilament nylon size 2-0 suture materials were tested biomechanically in vitro. Twenty reproducible knots were tied and incubated in canine serum at 37 degrees for 24 hours before testing. A "secure knot" was defined as a knot that, when tested to failure, broke rather than untied by slippage. The minimum number of throws necessary to make a secure, snug (1500 g tension) square knot was three for gut, polyglycolic acid, polyglactin 910, and polypropylene and four for polydioxanone and nylon. All throws including the first were counted. With all suture materials tested, surgeon's knots were as secure as square knots. Only gut, polyglycolic acid, and polydioxanone granny knots were as secure as square knots; no loosely tied (500 g tension) asymmetric square knots were as secure as snug square knots, and only polydioxanone and polypropylene loose square knots were as secure as snug square knots. Square knots used to start a continuous pattern required one additional throw with gut, polydioxanone, and nylon. Square knots used to end a continuous pattern required two to three additional throws with all materials tested.     

Cephalothin and Cefazolin In Vitro Antibacterial Activity and Pharmacokinetics in Dogs

The periods of time that cephalothin and cefazolin serum concentration remained above minimum inhibitory concentration (MIC) for beta hemolytic, coagulase positive staphylococcal, and Escherichia coli clinical isolates were compared. Cephalothin and cefazolin were similarly very effective in vitro against staphylococcal isolates, with an MIC₉₀ of 0.12 μg/mL and 0.25 μg/mL, respectively. In contrast, cefazolin was more effective than cephalothin against E coli isolates; the cefazolin MIC₉₀ for E coli was 16 μg/mL and for cephalothin 64 μg/mL. Cefazolin (20 mg/kg intravenously [IV]) serum concentration remained more than MIC₉₀ for E coli isolates significantly longer than serum concentration of cephalothin (40 mg/kg IV) ( P <.001).     

Effect of Fascial Closure Technique on Strength of Healing Abdominal Incisions in the Dog A Biomechanical Study

Load-deformation data were used to determine the strength of healing abdominal incisions in dogs at 7, 14, and 21 days after wounding. The breaking energy of paramedian incisions closed by suturing the internal and external leaves of the sheath of the rectus abdominis muscle vs. incisions closed by suturing the external leaf only was similar in the 12 dogs studied. Closure of abdominal incisions by suturing only the external leaf of the rectus sheath provided wound strength comparable to the traditional method.     

COMPARISON OF THE IMAGE QUALITY OF A HIGH‐RESOLUTION SCREEN–FILM SYSTEM AND A DIGITAL FLAT PANEL DETECTOR SYSTEM IN AVIAN RADIOGRAPHY

A conventional high‐resolution screen–film system was compared with a digital detector system. A total of 20 birds (14 pigeons and six psittacine birds) with an average body mass of 533 g were examined in dorsoventral as well as lateral projections. Digital radiographs were acquired with the same mAs as well as half the mAs used for the conventional radiographs. Three criteria and one overall assessment were defined for each of four anatomic regions and assessed by five veterinarians using a score system. Comparison of the ratings was done by visual grading analysis. For the majority of criteria, there was no significant difference regarding image quality between the digital and screen–film projections. However, for certain criteria the quality of the digital images was significantly superior. Using the same mAs as for the conventional radiographs, the humeral joint surfaces and the honeycomb structure of the lung were assessed as superior with the digital imaging system. The tracheal rings and the delineation of the trachea from the surrounding tissue were also superior with the digital system. Assessment of the trabecular structure of the humerus was superior when the full mAs was used compared with the reduced mAs. In conclusion the digital technique is equal or superior to the conventional screen–film high‐resolution system for pet birds of a medium size. With some limitations, a dose reduction is possible with the digital system.     

DISPLAY QUALITY OF DIFFERENT MONITORS IN FELINE DIGITAL RADIOGRAPHY

In human medical imaging, the performance of the monitor used for image reporting has a substantial impact on the diagnostic performance of the entire digital system. Our purpose was to compare the display quality of different monitors used in veterinary practice. Two medical‐grade gray scale monitors (one cathode‐ray tube [CRT], one liquid crystal display [LCD]) and two standard consumer‐grade color monitors (one CRT, one LCD) were compared in the ability to display anatomic structures in cats. Radiographs of the stifle joint and the thorax of 30 normal domestic shorthair cats were acquired by use of a storage phosphor system. Two anatomic features of the stifle joint and five anatomic structures of the thorax were evaluated. The two medical‐grade monitors had superior display quality compared with standard PC monitors. No differences were seen between the monochrome monitors. In comparison with the color CRT, the ratings of the color LCD were significantly worse. The ranking order was uniform for both the region and the criteria investigated. Differences in monitor luminance, bit depth, and screen size were presumed to be the reasons for the observed varying performance. The observed differences between monitors place an emphasis on the need for guidelines defining minimum requirements for the acceptance of monitors and for quality control in veterinary radiography.     

Long-term climate forcing of European herring and sardine populations

Records of the herring, Clupea harengus, fishery off the Swedish coast of Bohuslän, in the Skagerrak, date back to the 10th century. Nine periods, each lasting several decades, are known during which large quantities of herring were caught close to the shore. In the 1895–96 season, more than 200 000 tonnes were landed. During the `interim' periods, which stretched over 50 or more years, the herring fishery played little role in the economy of this region. Several other herring fisheries in European waters overlap with recent Bohuslän periods whereas the Norwegian spring-spawning herring and some sardine, Sardina pilchardus, fisheries exhibit alternating periods. A study of the climatological/hydrographic scenario of all Bohuslän periods and those of herring in the English Channel and the Bay of Biscay showed that, on a decadal scale, they coincided with times when there was a strong ice cover off Iceland, severe winters in western Europe with extremely cold air and water temperatures, a reduction of westerly winds as indicated by negative anomalies in the North Atlantic Oscillation (NAO) index and a minimum of south-westerly winds over England in response to meridional migrations of the belt of westerly winds. Periods of the Norwegian spring-spawning herring and sardines in the English Channel coincided with inverse climatological/hydrographic situations. It is concluded that climate variation governed the alternating herring and sardine periods.     

The Small Animal Operative Practice Laboratory

The small animal operative practice laboratory is the technical component of the fundamentals of surgery lecture course and should give students the basic skills necessary to actively participate in the operative and anesthetic management of client's animals in the teaching hospital. The surgery faculty is challenged with structuring a laboratory that will maximize use of available resources, including clinical and morphologic pathology faculty, for the benefit of the student. The laboratory can be structured as a small animal practice to give students the responsibility and equipment for preoperative, operative, and postoperative care of their animals. The keys to the educational success of the laboratory are the attitude and enthusiasm of the surgery faculty.     

Open Peritoneal Drainage in Experimental Peritonitis in Dogs

Peritonitis was induced In 12 dogs by creation of an avascular jejunal loop. After 24 hours, the avascular jejunal loop was removed, and purulent material was removed by aspiration. The abdominal incision in six experimental dogs was left open under a bandage, while the incision was closed in six control dogs. All six open abdomen, and four control, dogs survived the 8 days of the study. The number of bacteria in the peritoneal exudate in experimental animals was less than in control animals. At the end of the 8 day study, experimental animals were more active, had better appetites, and were less likely to have fever, vomition, diarrhea, and dehydration. Experimental animals weighed significantly less than control animals. There were no differences between groups with respect to biochemical and hematologic parameters. At necropsy, experimental animals had fewer adhesions and less peritoneal fluid accumulation than control animals. Complications of open peritoneal drainage included persistent fluid loss, weight loss, adhesions of abdominal viscera to the bandage, and contamination of the peritoneal cavity with cutaneous organisms.     

Cytology of Peritoneal Effusion Following Intestinal Anastomosis and Experimental Peritonitis

Diagnostic peritoneal lavage was performed one, two or three days following experimental resection and anastomosis of the distal jejunum in nine dogs. The lavage fluid was evaluated by total and differential cell counts, cell morphology, and bacterial culture. Microscopic examination revealed large numbers of nondegenerate neutrophils and mononuclear cells. Bacteria were not observed. Bacterial cultures yielded no growth.
Peritonitis was experimentally induced in four dogs by creating an ischemic segment of jejunum. Peritoneal lavage and fluid analysis were carried out one or two days following surgery. The lavage fluid from these dogs contained large numbers of degenerate neutrophils and bacteria.