Ultrastructural analysis of platelets and megakaryocytes from a dog with probable essential thrombocythemia

Blood platelets and bone marrow megakaryocytes from a dog with essential thrombocythemia were analyzed by transmission electron microscopy and compared with those of control dogs. Platelets varied in size and shape and contained enlarged and dilated open canalicular systems. Megakaryocytes were dysmorphic and had evidence of abnormal maturation, with large numbers of megakaryoblasts containing alpha granules and poorly organized and reduplicated demarcation membranes. The fewer, more mature megakaryocytes lacked normal cytoplasmic organization. Most notable was the absence of well-demarcated "platelet fields," due to the excessive and disorderly array of demarcation membranes.     

Pathologic consequences of a severe influenza outbreak (swine virus A/H1N1) under natural conditions in the non-immune sow at the beginning of pregnancy

Pathological consequences of a severe outbreak of swine influenza (H1N1 virus) in the non immune sow at the beginning of pregnancy, under natural conditions. A sudden acute outbreak of fever, depression, anorexia and coughing in a group of nulliparous sows from a herd that was currently under epidemiological investigation lead to build a particular disposal of observation. The clinical signs were daily recorded including rectal temperature. Blood was taken from the sows at the beginning of the troubles and 3 weeks later for the detection of Aujesky's disease, coronavirus TGE-like, Influenza viruses A/H1N1 and A/H3N2 and Mycoplasma hyopneumoniae. Viral detection was attempted from nasal swabs and aborted fetuses during the acute phase. The clinical study showed fever reaching near 41 degrees C on most of the pigs and lasting usually from 2 to 5 days. The diagnosis of Influenza (virus swine H1N1) was established both on serology (massive seroconversion) and on the detection of the virus from the nasal swabs and from an aborted fetus. The control of the lungs of sows "not in pig" and culled showed extended lesions of bronchopneumonia and Pasteurella multocida was found. The technical consequences of this severe outbreak of Influenza on reproduction were mainly important at the beginning of pregnancy. Over 13 sows inseminated less than 1 week before the outbreak, only 3 farrowed (respectively 5.5 and 12 piglets); 7 returned to oestrus and 3 "not a pig" at 21 days (echotomography) did not show signs of heat and were culled. Over 8 pregnant sows (1 month of pregnancy), 6 farrowed normal litters and total embryonic resorption occurred in 2 sows. Over 18 pregnant sows (more than 45 days gestation) one aborted.     

Selenium, vitamin E and polyunsaturated fatty acid concentrations in goat kids with and without nutritional myodegeneration

Mean selenium and vitamin E (alpha-tocopherol) concentrations in the liver, myocardium and skeletal muscle of nine goat kids with nutritional myodegeneration (NMD) were significantly lower than those in a group of nine kids dying from other causes. Each of the 18 kids was from a different property in the southern half of the North Island. The polyunsaturated fatty acid composition of the liver, myocardium and skeletal muscle was not significantly different between the two groups, but the overall level of peroxidisable polyunsaturated fatty acids appeared high in both groups. A further 21 kids with confirmed NMD and live 'controls', submitted as routine cases to Palmerston North Animal Health Laboratory, were included with the above 18 kids in a comparison of liver selenium and alpha-tocopherol concentrations. Kids with NMD had liver selenium concentrations ranging from 170-1100 (mean = 380) nmol/kg and alpha-tocopherol from 0.7-11.0 (mean =2.2) micromol/kg. In control kids, the liver selenium concentration ranged from 530-4300 (mean = 1220) nmol/kg and a-tocopherol from 1.7-14.0 (mean = 5.6) pmollkg. Although these ranges overlapped, the results suggest that liver selenium concentrations <500 nmol/kg and alpha-tocopherol concentrations <2.5 micromol/kg should be regarded as deficient. Liver selenium concentrations from 500-1100 nmol/kg and alpha-tocopherol concentrations from 2.5-10 micromol/kg should be considered marginal. Goat kids appear to require more selenium than lambs or calves which may explain the higher prevalence of NMD in kids. In some cases, however, the disease is associated with low alpha-tocopherol suggesting that supplementation with selenium alone may not always be sufficient.     

The cervical vertebral column of horses--a clinico-radiological study

For various anamnestic reasons the cervical vertebral column of 78 horses was examined radiologically. Statistical comparisons showed that male "warmbloods" were more frequently affected than was expected. Our horses were older than comparable animals in the international literature. Independently of their history the radiologic diagnosis of "cervical spondylarthrosis" was established in 56 horses. Arthrosis and other conditions were clinically manifested by spinal ataxia (44 horses) or mechanical impairment of the neck's mobility (21 horses). 10 of the arthrotic patients had synovial cysts causing compression of the spinal cord. 79 percent of all dorsal intervertebral arthrotic joints were found in the caudal column (C6/7 to C7/Th1). With 38 percent, C6/7 was the most frequently affected joint. Clinical and radiological findings could be compared with patho-anatomic results in 29 horses. The correlation was satisfactory.     

Viruses and virus-like particles detected during examination of feces from calves and piglets with diarrhea

A total of 763 fecal or intestinal samples from diarrheic calves and piglets were examined for viral content by immunofluorescence, electron microscopy or cell culture. Routine fluorescent antibody and cultural tests detected rotavirus (n=126), coronavirus (n=80) and bovine viral diarrhea virus (n=13). Electron microscopy detected rotaviruses (n=24) and coronaviruses (n=17) not identified by standard fluorescent antibody tests. Other viruses detected by electron microscopy included Breda virus-like particles (n=49), astroviruses (n=1), caliciviruses (n=1), rhabdoviruses (n=1), parvoviruses (n=2), enteroviruses (n=3), togavirus-like particles (n=2), and “chained” particles (n=5). Mixtures of several of the viruses were detected in a number of fecal samples.

The survey emphasized the value of electron microscopy as a broad-spectrum diagnostic tool.