Relationship of plasma gastrin immunoreactivity and gastroesophageal sphincter pressure in clinically normal dogs and in dogs with previous gastric dilatation-volvulus

Fasting and postprandial gastroesophageal sphincter pressure (GESP) and plasma gastrin immunoreactivity were measured in 6 dogs from 9 through 60 months after treatment for and recovery from gastric dilatation-volvulus (GDV). The GESP was not significantly increased in these dogs, compared with that in clinically normal dogs in either the fasting or postprandial state. Corresponding plasma gastrin immunoreactivity was not significantly increased in dogs of the GDV-recovered group, compared with that in clinically normal dogs (fasting or postprandial). An exaggerated increase in GESP in response to food-induced gastrin release was not observed in dogs of the GDV-recovered group. Exogenously administered pentagastrin (3-micrograms/kg bolus, IV) increased fasting GESP in clinically normal dogs over a 4-minute test period (P = 0.01). Gastric distention in response to oral administration of isosmolar saline solution (500 ml) did not significantly increase GESP or plasma gastrin immunoreactivity in clinically normal dogs. In anesthetized clinically normal dogs, gastric distention in response to use of balloons filled to exert intragastric pressure of 30 mm of Hg also did not cause significant increase in plasma gastrin immunoreactivity. Increased GESP, secondary to hypergastrinemia or gastric distention, is an unlikely cause of eructation failure in dogs with GDV.     

Progressive retinal atrophy in Tibetan terriers

Progressive retinal atrophy was studied in 17 Tibetan Terriers. The diagnosis was made on the basis of clinical signs of the disease, retinal histopathologic findings, or both. Affected dogs were the progeny of matings of affected or ophthalmoscopically normal dogs. Results of the mating supported a simple autosomal recessive mode of inheritance. The disease initially could be diagnosed by findings of night blindness and ophthalmoscopic signs of tapetal hyperreflectivity in affected dogs that were approximately 1 year old. Electroretinograms recorded from affected dogs, compared with those of clinically normal dogs of the same age, did not reveal appreciable abnormalities until affected dogs were 10 months old, at which time a reduction in the amplitude of the b wave was seen in response to a Ganzfeld white-light stimulus. The peak times of the response were unaffected. With progression of the disease, the electroretinographic b-wave amplitude was gradually reduced, and the electroretinographic response was extinguished in affected dogs by the time they were 30 months old. Early in the disease, rod and cone functions were affected equally, with more rapid loss of rod function developing only later in the disease. Fluorescein angiography of affected dogs did not reveal abnormalities earlier than could be detected by ophthalmoscopy. Despite the electroretinographic findings, histopathologic findings included patchy disorientation and disorganization of the outer segments of rods and cones in affected dogs as young as 9 weeks. With progression of the disease, rods were lost at a faster rate than cones, and atrophy of the inner retinal layer was observed.     

Fabrication of conducting polymer interconnects

A nonmechanical approach to the construction of complex three-dimensional interconnect arrays has been developed with the use of conducting polymer dendrites. Electrically independent connections between pairs of wires in an array were successfully grown through alternating-current electrochemical polymerization of poly(3-methylthiophene), without mechanical or optical masking steps. The electrically active links were insulated by subsequent electropolymerization of 4-vinylpyridine or 2-methylthiophene or by the dip-coating of the connections in a polystyrene solution.     

Controlled breeding of dairy cows with cloprostenol

The percentage of dairy cows that were mated and became pregnant during a 42 day breeding period was not significantly different when animals were routinely observed for estrus and mated when detected (71%, n = 56), inseminated at estrus following a single injection of cloprostenol (72%, n = 29), or inseminated at a fixed time after two cloprostenol treatments 11 days apart (69%, n = 28). However, 11 cows in the control group were not detected and mated during the breeding period and inclusion of these animals reduced the actual pregnancy rate to 60%. Results indicated that a controlled breeding program could have practical application in dairy herds but should be used with caution. Practitioners must evaluate management programs and decide, in consultation with the herdsman, if the introduction of controlled breeding technology might be advantageous.     

Suspected Spinal Epidural Empyema and Associated Vertebral Osteomyelitis (Physitis)in a Dog

A 1 year old female Aurstralian Heeler dog was presented for fever and paraplegia of recent onset. Radiography and myelography revealed osteolysis of the first lumber (L₁) vertebra and extensive epidural spinal cord compression from the level of the thirteenth thoracic (T₁₃) to the fourth lumbar (L4) vertebra. A decompressive hemilaminectomy was performed; purulent-appearing fluid and inflamed epidural fat were present in the vertebral canal. The neurologic recovery of the dog was satisfactory 6 months following surgery.     

Experimental transmission of granulocytic ehrlichial organisms in dogs

Canine granulocytic ehrlichial organisms were transmitted from an infected dog from Missouri to two male, 10-month-old dogs by an intravenous injection of whole blood. Physical or behavioral abnormalities were not detected during the 98 days of evaluation other than a mild pyrexia from Day 18 to 20. Ehrlichial morulae were found in blood granulocytes of Dog 1 from Day 13 to 44 and of Dog 2 from Day 14 to 34 with the peak rickettsemia occurring on Day 16 for both dogs. By Day 21 after inoculaiuon, both dogs had positive titers to Ehrlichia canis. The highest titers for both dogs were found 63 days after inoculation, after which the titers decreased. Most of the hematologic abnormalities (i.e., neutropenia, lymphocytosis, thrombocytopenia) and fever occurred between 18 and 24 days after inoculation. The pathologic bases of these abnormalities were not investigated but their concurrent presence suggested an association with the dogs' immunologic responses to the granulocytic ehrlichial agent. Results from the study indicated that the canine granulocytic ehrlichial agent of Missouri may produce subclinical infections and suggested that dogs may be able to clear the organism without antimicrobial therapy.     

Denali: A high dry matter potato with wide adaptation

Denali is a smooth, white-skinned potato bred and selected for high dry matter content early in tuber development at the Matanuska Research Farm. Its flavor is distinctive and pleasant as a baked potato. Chip quality has been excellent directly following harvest or from warm storage. In Michigan trials, Denali consistently has had the highest specific gravity and has been one of the highest yielders of approximately 20 varieties tested each year. Denali’s foliage has shown frost tolerance and heat resistance in tests conducted in Nebraska.     

Possible methods of inhibiting or reversing the evolution of insecticide resistance in mosquitoes

The following possible methods of minimising the risks of resistance are considered: (a) adjustment of the dosage and frequency of spraying so that resistance genes are effectively recessive; (b) detection and eradication of new foci of resistance before they have a chance to spread; (c) spraying a ‘mosaic’ of unrelated insecticides with the intention that immigrants from one sector of the mosaic to another will ‘dilute’ the frequency of resistance genes; (d) re-introduction of susceptibility genes into the progeny of wild females by the release of heterozygous males with resistance genes translocated on to their Y chromosome so that they are protected from insecticidal killing but will pass susceptibility to their female progeny; (e) replacement of a resistant by a susceptible population by means of a negatively heterotic system such as bidirectional cytoplasmic incompatibility. A plausible case can be made for each of these methods based on theoretical models and appropriate assumptions. However, an assessment of whether any of them will really beof any value depends on the answers to certain questions in the field. Therefore field projects have been initiated on Anopheles culicifacies in Sri Lanka and Pakistan, Culex quinquefasciatus in Tanzania and Anopheles arabiensis in Sudan. The results so far are summarised.