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Biomedical subjects

A H Andrews

Publications and source records attributed to A H Andrews.

At least 19 recordsLinked to original sources

Treatment and control of an outbreak of fat cow syndrome in a large dairy herd.

An outbreak of fat cow syndrome occurred in a herd of 300 Friesian and Friesian/Holstein dairy cows calving predominantly between January and May. The herd came in off grass in good condition despite a long and hot summer. The dry cows received a diet of grass silage, brewing waste and minerals until the end of December, but the grass silage was butyric and was partially replaced by maize silage. By January 23, 16 of 70 calving cows (23 per cent) had appeared to suffer milk fever. Subsequent blood tests revealed that the cows may have been ketotic, and clinical and post mortem examination showed that they were probably suffering from fat cow syndrome. The freshly calved sick cows were treated with glucose, and corticosteroids were injected every second day into those which remained ill. The cattle had received a high energy diet, but the cows still to calve were placed on a diet of low metabolisable energy (77 MJ/cow) but adequate levels of undegradable protein. The problem was associated with a possible clostridial infection in two cows and with reduced fertility.

Adrenal Cortex Hormones

Long-acting antibiotic formulations in the treatment of calf pneumonia: a comparative study of tilmicosin and oxytetracycline.

The treatment of an outbreak of acute pneumonia in 50 four- to eight-month-old Friesian and Friesian cross calves is described. At the first visit (day 0) 16 calves received 20 mg/kg bodyweight of oxytetracycline dihydrate intramuscularly and 15 received 10 mg/kg of the macrolide tilmicosin subcutaneously. The remaining 19 in-contact animals were not considered ill enough to be included in the trial and received 20 mg/kg of oxytetracycline dihydrate. The rectal temperature, demeanour, respiratory rate and respiratory effort of each calf was assessed on days 1, 2, 3, 9, 14, 21 and 28, and calves which had not responded were given repeat injections of the same antibiotic. All the calves recovered from the outbreak and of the 19 calves treated strategically, three required a second injection. Among the calves with clinical pneumonia, fewer treatments (P less than 0.01) were required by those treated with tilmicosin. The rectal temperatures of both groups decreased (P less than 0.05) after the first injection, but on day 3 the decrease was greater (P less than 0.05) in the group treated with tilmicosin. Respiratory rates varied widely but respiratory effort was less (P less than 0.05) on day 2 in the calves treated with tilmicosin. When long-acting antibiotic injections are used to treat enzootic pneumonia it is suggested that a second visit should be made on day 3 to assess the animals' response to treatment.

Acute Disease

Suspected poisoning of a goat by giant hogweed.

A five-year-old male African pygmy goat became ill four weeks after transfer from a zoological garden to a municipal park. The animal was subdued, refused to eat and drink and showed profuse salivation. Examination of the mouth revealed severe ulceration. The condition gradually responded to nursing and supportive therapy. Circumstantial evidence suggested the possibility that the lesions were caused by giant hogweed (Heracleum mantegazzianum). Supportive evidence that the plant could produce lesions was provided by the application of a cut stem to the hard palate and a solution of various dilutions to clipped areas of the backs of two ewes. Both ewes produced reddened skin when the concentrated solution was applied and both showed marked reddening of the gingival mucosae and in one animal small ulcers developed in the rostral part of the mouth. It is suggested that H mantegazzianum may be a potential hazard for grazing ruminants.

Animals

A practical method of reducing spread of disease by hypodermic needles.

Transmission of infection between animals is possible when using multidose syringes. The possibility of infection spreading can be reduced by using a telescopic device which fits the syringe barrel and is topped by a cap containing plastic foam impregnated with biocide. Under laboratory conditions, and continually contaminating the needle with various bacteria, infection could not be cultured in broth until after at least 25 injections and in most cases contamination did not occur after 50 injections. When culture was undertaken on solid media breakdowns occurred more frequently, possibly because the agar became lodged in the needle and shielded the bacteria from the biocide.

Animals

The use of the CO2 laser in otolaryngology: ten years of experience.

Accessory instruments have been developed consisting of retractors, the axial adapter, the slip-on adapter for the laryngoscope and the lynch suspension apparatus, the upper-hand abdominal retractor modified, and chain for neurological sponges, and mirrors. The initial bronchoscopic coupler was used until a manufactured one was obtained from Cavitron. In addition to the cases shown in the table, the laser has been used in conjunction with the Department of Ophthalmology, the Department of Orthopedic Surgery, and the Department of Gynecology. The advantages to laser surgery are stated.

Carbon Dioxide

Clinical and histologic evaluation of laser reanastomosis of the uterine tube.

Conventional microsurgical reanastomosis was compared with laser microsurgical reanastomosis of previously ligated uterine tubes in 14 rabbits. A final laparotomy was performed to determine adhesion formation and uterine tube patency, and a histologic examination was done of the anastomosis sites using four histologic indices for grading. Laser microsurgery produced significantly less adhesions (mean +/- standard error of the mean adhesion score, 0.79 +/- 0.24) than conventional microsurgery (2.29 +/- 0.13, P less than 0.001). However, there was no significant difference in all four histologic indices of tissue reunion at the anastomosis site between the two types of surgical technique. In a separate experiment, CO2 laser was found to be unable to weld uterine tubes successfully. Thus, the CO2 laser can significantly reduce postoperative adhesions in microsurgical uterine tube reanastomosis but without any significant histologic difference in tissue reunion, compared with conventional microsurgery.

Animals

General techniques and clinical considerations in laryngologic laser surgery.

The carbon dioxide laser, one of the great advances in otolaryngology, has the characteristics of accuracy, reduced bleeding, reduced reaction, faster healing, and less scarring as compared with conventional surgery. Its beam is produced by creating an electric discharge within a cylinder containing carbon dioxide, nitrogen, and helium. The emitted beam is invisible, and special means are used to show exactly where the beam is going to impinge on the tissue. The effect of the power delivered to the tissue by the laser beam depends on the character of the tissues, the presence of char, the delivery device, and the condition of the lenses and mirrors. The imprint size varies with the power and the duration of exposure and is not necessarily the same as spot size. Repeated exposures increase the amount of tissue destruction and can be used to completely eradicate a lesion until the junction of normal and abnormal tissue is encountered. The following points and techniques are important in determining the results of carbon dioxide laser surgery. Increasing the power and reducing the duration of the beam result in less charring, less reaction, and faster healing. Overheating of tissues is avoided by using a skip technique. Char must be removed to prevent overheating of tissues and to aid in identifying accurately the junction of normal and pathologic tissues. Palpation may help identify pathologic tissue not readily apparent on inspection alone. The edge of the beam can be used to shave away pathologic tissue accurately while preserving normal tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbon Dioxide

Conventional versus laser reanastomosis of rabbit ligated uterine horns.

Conventional microsurgical reanastomosis was compared with laser microsurgical reanastomosis of the ligated uterine horn in the rabbit. Fourteen virgin female New Zealand white rabbits had both uterine horns ligated and divided at laparotomy. Four weeks later, seven rabbits had conventional microsurgical reanastomosis of the divided uterine horns after the ligated stumps were excised (group 1). The ligated uterine horns of the other seven animals were incised with a carbon dioxide laser with a power density of 637 to 796 W/cm2 followed by conventional microsurgical reanastomosis using polyglactin (Vicryl) 8-0 sutures (group 2). After six weeks, a laparotomy was performed to determine adhesion formation and uterine horn patency by chromopertubation. Adhesion formation was graded 0 (no adhesions) through 3 (extensive, dense adhesions) for each uterine horn. Only one uterine horn in the control group was not patent. Laser microsurgery produced significantly less adhesion (mean +/- SE, 0.79 +/- 0.24) than conventional microsurgery (2.29 +/- 0.13) (P less than .001). The findings indicate that laser microsurgical tubal reanastomosis produces significantly better results with less adhesion than the conventional microsurgical technique.

Animals