Coronavirus and Pasteurella infections in bovine shipping fever pneumonia and Evans' criteria for causation.

Respiratory tract infections with viruses and Pasteurella spp. were determined sequentially among 26 cattle that died during two severe epizootics of shipping fever pneumonia. Nasal swab and serum samples were collected prior to onset of the epizootics, during disease progression, and after death, when necropsies were performed and lung samples were collected. Eighteen normal control cattle also were sampled at the beginning of the epizootics as well as at weekly intervals for 4 weeks. Respiratory bovine coronaviruses (RBCV) were isolated from nasal secretions of 21 and 25 cattle before and after transport. Two and 17 cattle nasally shed Pasteurella spp. before and after transport, respectively. RBCV were isolated at titers of 1 x 10(3) to 1.2 x 10(7) PFU per g of lung tissue from 18 cattle that died within 7 days of the epizootics, but not from the lungs of the remaining cattle that died on days 9 to 36. Twenty-five of the 26 lung samples were positive for Pasteurella spp., and their CFU ranged between 4.0 x 10(5) and 2.3 x 10(9) per g. Acute and subacute exudative, necrotizing lobar pneumonia characterized the lung lesions of these cattle with a majority of pneumonic lung lobes exhibiting fibronecrotic and exudative changes typical of pneumonic pasteurellosis, but other lung lobules had histological changes consisting of bronchiolitis and alveolitis typical of virus-induced changes. These cattle were immunologically naive to both infectious agents at the onset of the epizootics, but those that died after day 7 had rising antibody titers against RBCV and Pasteurella haemolytica. In contrast, the 18 clinically normal and RBCV isolation-negative cattle had high hemagglutinin inhibition antibody titers to RBCV from the beginning, while their antibody responses to P. haemolytica antigens were delayed. Evans' criteria for causation were applied to our findings because of the multifactorial nature of shipping fever pneumonia. This analysis identified RBCV as the primary inciting cause in these two epizootics. These viruses were previously not recognized as a causative agent in this complex respiratory tract disease of cattle.

Ovine fetal telencephalic white matter necrosis.

Discrete foci of white matter necrosis were observed in the telencephalic white matter in 6 cases of spontaneous ovine abortion. All fetuses were in the third trimester of gestation and 2 of the 6 were term fetuses. The lesions were distributed randomly throughout the cerebrocortical white matter and consist of pale hypocellular plaques with a variable glial cell response and encrustation of necrotic cellular processes. A variety of additional lesions were present in the brains of the aborted fetuses. The lesions of telencephalic white matter necrosis have not been reported previously and are unlike those associated with known viral infections of the developing fetus. Based on the character of the lesions, a hypoxic-ischemic or hypotensive mechanism is suggested. The lesions are compared with a similar condition in human fetuses and neonates.

Host response to infection of a subperiosteal hydroxylapatite implant.

Particulate, nonresorbable hydroxylapatite is currently a popular implant material for the augmentation of atrophic alveolar ridges. Most reports have demonstrated favorable biocompatibility with common usage, but how the host bone will respond to the implant in the presence of an infection has not yet been investigated. Hydroxylapatite was implanted subperiosteally on one side of the mandible in four New Zealand White rabbits. After 3 months were allowed to elapse for stabilization of the implant, an infection was induced in both sides of each mandible by inoculation with Bacteroides melaninogenicus. One month later the animals were put to death and both sides of each mandible were examined microscopically. On the nonaugmented side there was total resolution of the infection. The side of each mandible containing the hydroxylapatite implant showed very mild chronic inflammation throughout the medullary space and periosteum. Although the number of animals used was small, the results suggest that the presence of the hydroxylapatite implant may have interfered with the host's ability to resolve the infection in the underlying bone. The possible mechanism of this interference is discussed.

A prospective double-blind evaluation of penicillin versus clindamycin in the treatment of odontogenic infections.

In a prospective, double-blind trial, penicillin and clindamycin were compared in treatment of moderate to severe orofacial infections of odontogenic origin, which yielded pus on aspiration. Among 27 patients randomized to receive penicillin, 22 (81%) had a successful outcome, and five (19%) were improved. In the 28 clindamycin-treated patients, 23 (82%) had a successful outcome, and five (18%) were improved. No failures were noted in either group. One patient who was receiving penicillin and two who were receiving clindamycin developed diarrhea. Bacteriologic results showed an average of 6.1 organisms per culture (2.5 aerobes and 3.6 anaerobes). Resistance rates for anaerobic isolates were 8.9% to penicillin and 1.9% to clindamycin. It was concluded that penicillin and clindamycin produce similar good results in treating odontogenic infection when the rate of penicillin resistance among oral anaerobic bacteria is at a relatively low level.

Closed percutaneous catheter drainage of a cervical abscess.

The advantages offered by a percutaneous catheter system are: The procedure is done using only local anesthesia. Computed tomography is used for exquisite anatomical detail and pinpoint guidance. If required, aspiration, irrigation, and dependent or suction drainage can all be done. Isolation of purulent material from the skin and site of drainage is accomplished. A true anaerobic culture specimen is obtainable with the initial aspiration. The esthetic results, are superior to surgical management. Percutaneous abscess drainage should thus be seriously considered as an alternative to surgery in the treatment of head and neck abscesses.

Factor XI deficiency resulting in severe postoperative hemorrhage after odontectomy.

A case of factor XI deficiency has been presented. The patient required 91 units of fresh frozen plasma for hemostasis, which is more vigorous therapy than was to be expected from reviewing the current literature.