Use of netting and whitewash spray to protect papaya plants against Nivun Haamir (NH)-dieback disease

A disease causing the decline of papaya (Carica papaya) plants was noticed in the Jordan Valley in 1982. The disease caused severe yellowing of the upper leaves and dieback of the apex. The disease was not transmissible mechanically and continued efforts to associate viruses and viroids have so far been unsuccessful. Epidemiological observations suggested that the disease is airborne and probably caused by a mollicute. In order to test this hypothesis, plots were covered by an insect-proof net and with white nets providing 15, 30 and 50% shade. The 30%, 50% and insect-proof nettings provided complete protection, and the 15% netting reduced disease incidence to <2%, compared with>37% in the uncovered control plot. Spraying plants at weekly intervals with a commercial whitewash solution was also found to be effective in reducing disease incidence. The advantages of using a range of netting field treatments as a simple means for obtaining information on the epidemiological nature of a new disease are described.     

Immunocytochemical Study of the Ultimobranchial Tubule in Wistar Rats

A systematic immunohistochemical study of the ultimobranchial tubule (UBT) has been carried out in 45 Wistar rats of different ages (0, 5, 10, 15, 20, 25, 30, 60 and 120 days). The existence of calcitonin immunoreactive cells in the UBT wall has been demonstrated in a 5-days old rat. In addition, immunohistochemical studies for thyroglobulin revealed positive staining in follicular cells connected to the UBT and, occasionally, in isolated cells lying within solid clusters from the UBT. These last results together with the continued and repeated existence of numerous mitosis and PAS (+) microfollicles, apparently rising from the UBT, support the hypothesis that the ultimobranchial body (UBB) may contribute partially to the formation of a part of the follicular component.     

Porcine urogenital disease.

Porcine urogenital disease is the result of an imbalance of the normal microflora of the urinary and reproductive tracts brought about by hormonal, environmental, and management-related stress factors. Production and economic losses can be substantial, and diagnosing and treating the problem can be frustrating. Through proper hygiene, facility design, and culling procedures, the severity of the problem can be minimized.     

Abattoir condemnation of pigs and its economic implications in Singapore

Losses due to mortality and rejection of carcases and viscera in a population of 2,959,607 pigs admitted for slaughter in Singapore abattoirs between 1984 and 1986 were studied. Mortality losses were 2822 pigs (9.5 per 10,000 admissions) while 3039 whole carcases (10.3 per 10,000 admissions) were condemned at post-mortem examination. The main reason for rejection of carcases was pyaemia (30.3%). Kidneys and livers were the two main organs of economic value rejected. Rejection of kidneys was primarily due to nephritis (54.8%) while liver condemnation was mainly due to cirrhosis (38.6%). The financial loss from abattoir rejection was S$5.27 millions or S$1.78 per pig admitted. The value of abattoir condemnation data as a tool in preventive medicine is discussed.     

The oxygen uptake capacity of swine

Comprehensive studies into domestic pigs and wild boars together with literature data provided a basis for an assessment of aerobic metabolic capacity (VO2max) of swine. The values quoted, from 20 to 94 ml/min-1/kg, had been due to several factors of methodological approach, growth, training, and nutrition as well as to pathophysiological aspects. For full capacity utilisation of VO2max, untrained pigs can be challenged at belt velocities between 0.8 and 1.8 m/s-1 and trained animals at 5 m/s-1.     

Antitumor effect of adriamycin entrapped in liposomes conjugated with anti-bovine tumor antigen monoclonal antibody in leukemic cows

Monoclonal antibody c143 against tumor-associated antigen (TAA) expressed on bovine leukemia cells was conjugated to liposomes containing adriamycin (ADM), and therapeutic effects of conjugates were examined in leukemic or preleukemic cows to prevent the progression of the disease. Five cows with TAA-positive in their peripheral blood lymphocytes were divided into two groups. Each group of cows received 4 injections of ADM alone (0.4 mg/kg) or c143-conjugated liposomes containing the same dose of ADM (L-AMD-c143) through the jugular vein at about 4 day intervals. In three animals treated with L-ADM-c143, the TAA-positive cells gradually decreased with treatment and finally two animals became TAA-negative during a 6 week period and a 14 week period after treatment, respectively. In the control, two animals treated with ADM alone showed only a slight decrease of TAA-positive cells.     

Plasma digoxin concentration in dogs with mitral regurgitation.

Fifteen and eight mature beagles, without (normal group) and with experimental mitral regurgitation (MR group), respectively, were given 0.02 mg/kg/day digoxin powder for 10 days orally. The optimum time for sample collection after administration of digoxin was observed to be 8-18 hr and 10-22 hr in the normal and MR groups, respectively. In both groups, a stable concentration was reached after 3-5 days of treatment. No differences in plasma level were observed between sexes. The optimum concentration of digoxin was attained at an earlier stage than has been previously reported for both dogs and humans.     

Seasonal changes in serum total thyroxine, free thyroxine, and canine thyroid-stimulating hormone in clinically healthy beagles in Hokkaido.

The purpose of this study was to evaluate seasonal influences on thyroid hormone levels of healthy outdoor dogs in Hokkaido. We surveyed serum basal total thyroxine (tT4), free thyroxine (fT4), and canine thyroid-stimulating hormone (cTSH) levels, and tT4 levels after administration of TSH for a year. Basal tT4 levels decreased in January, and increased in August and September. fT4 levels increased in January and November. No significant seasonal variation was found in cTSH. tT4 levels after administration of TSH in August and November increased. These results suggested that the thyroid gland may have been activated in November. We should take seasonal variation into consideration when thyroid function is tested.     

No effect of turkey herpesvirus infections on the outcome of avian pneumovirus infections in turkeys.

To determine whether turkey herpesvirus (HVT) impairs the aspecific and specific defense against an avian pneumovirus (APV) infection, specific-pathogen-free turkeys were inoculated at 7 days of age with HVT and 1, 5, or 7 wk later with APV. Clinical signs, APV replication, and development of antibodies against APV were evaluated. No differences were found between the birds that received both HVT and APV and those that received only APV.