Respiratory pathogens in monkeys

Respiratory disease in a dynamic colony of nonhuman primates during a 4-year period was due primarily to infections caused by Klebsiella pneumoniae, Diplococcus pneumoniae, Bordetella bronchiseptica, Pasteurella multocida, and Haemophilus influenzae. The principal secondary invaders were Escherichia coli, Staphylococcus aureus, and streptococci. A high fatality rate was associated with infections caused by each of the primary pathogens, and females appeared to be more susceptible than males. Incidence of respiratory disease was greatest in the fall and early winter; however, at all times newly colonized monkeys had a higher infection rate than conditioned monkeys. Infections were occasionally confined only to the lungs and were sometimes present without grossly observable lung lesions. The information given on susceptibility of 10 species of nonhuman primates to respiratory infections provides a basis for developing disease models.

Functional outcome after operative treatment for ankle fractures in young athletes: a retrospective case series

BACKGROUND

No reports describe the outcome for distal fibula and tibia fractures in athletes, although 10 to 15% of all athletic injuries occur around the ankle joint.

MATERIALS AND METHODS

Forty-seven competitive or recreational athletes with ankle fractures underwent open reduction and internal fixation (ORIF). Thirty-six met the inclusion criteria, of which 27 returned for clinical and radiographic exams and also completed validated surveys and a subjective questionnaire.

RESULTS

Nineteen of the 27 were male. The average age of all patients was 18.1 +/- 5.9 years. The final evaluations occurred 12 months to 3.7 years after surgery. Injuries occurred in 13 different sports, of which football had the most (n = 10). Bimalleolar fractures were the most prevalent (n = 10) followed by isolated lateral malleolar fractures (n = 6), syndesmosis injury (n = 4), Salter-Harris (n = 4), medial malleolar fracture (n = 2) and pilon fracture (n = 1). The patients with isolated lateral malleolar fractures returned to competition soonest (6.8 +/- 2.4 weeks) while patients with isolated medial malleolus fractures took the longest to return at a mean of 17.0 +/- 9.9 weeks. Scores for function and pain on the Lower Limb Core Module and for pain on the Foot and Ankle module were all greater than 90.

CONCLUSION

Athletes who undergo ORIF followed by early motion and early weightbearing are able to return to their pre-injury level of competition within 2 to 4 months with minimal functional morbidity or pain.

The effects of duration and frequency of Achilles tendon stretching on dorsiflexion and outcome in painful heel syndrome: a randomized, blinded, control study

The American Orthopedic Foot and Ankle Society recommends at least six months of nonsurgical treatment before considering surgical intervention for painful heel syndrome. Achilles tendon stretching exercises are consistently reported to be one of the more effective nonsurgical modalities for treatment of painful heel syndrome. However, the optimal duration and frequency of the exercises has not been reported. The purpose of this study was to evaluate and compare the effectiveness of sustained and intermittent Achilles tendon stretching for the relief of pain associated with painful heel syndrome. This prospective, randomized, blinded study was performed from May 1997 to July 2000. A total of 94 people (122 affected feet) fit the inclusion criterion and agreed initially to participate in a treatment study group. To achieve our purpose, study participants were randomized into two stretching groups. One group performed sustained Achilles tendon stretches (three minutes, three times daily), the other performed intermittent stretches (five sets, 20 seconds each, two times daily). Participants were evaluated once a month for a period of four months subsequent to diagnosis. At each monthly visit, participants completed subjective questionnaires about their pain. Also, a physical therapist measured each participant's Achilles tendon flexibility. The study determined that both sustained and intermittent Achilles tendon stretching exercises increase Achilles tendon flexibility. This increase in flexibility correlated with a decrease in pain. There was no significant difference in outcome between the sustained and intermittent stretching groups. The data suggest that both sustained and intermittent Achilles tendon stretching exercises were effective nonsurgical treatments for painful heel syndrome.

Docosahexaenoic acid (DHA) alters the phospholipid molecular species composition of membranous vesicles exfoliated from the surface of a murine leukemia cell line

Previously, we presented evidence that the vesicles routinely exfoliated from the surface of T27A tumor cells arise from vesicle-forming regions of the plasma membrane and possess a set of lateral microdomains distinct from those of the plasma membrane as a whole. We also showed that docosahexaenoic acid (DHA, or 22:6n-3), a fatty acyl chain known to alter microdomain structure in model membranes, also alters the structure and composition of exfoliated vesicles, implying a DHA-induced change in microdomain structure on the cell surface. In this report we show that enrichment of the cells with DHA reverses some of the characteristic differences in composition between the parent plasma membrane and shed microdomain vesicles, but does not alter their phospholipid class composition. In untreated cells, DHA-containing species were found to be a much greater proportion of the total phosphatidylethanolamine (PE) pool than the total phosphatidylcholine (PC) pool in both the plasma membrane and the shed vesicles. After DHA treatment, the proportion of DHA-containing species in the PE and PC pools of the plasma membrane were elevated, and unlike in untreated cells, their proportions were equal in the two pools. In the vesicles shed from DHA-loaded cells, the proportion of DHA-containing species of PE was the same as in the plasma membrane. However, the proportion of DHA-containing species of PC in the vesicles (0.089) was much lower than that found in the plasma membrane (0.194), and was relatively devoid of species with 16-carbon acyl components. These data suggested that DHA-containing species of PC, particularly those having a 16-carbon chain in the sn-1 position, were preferentially retained in the plasma membrane. The data can be interpreted as indicating that DHA induces a restructuring of lateral microdomains on the surface of living cells similar to that predicted by its behavior in model membranes.

An outbreak of infection by Yersinia pseudotuberculosis in nonhuman primates

Between October 1970 and June 1971, at the National Center for Primate Biology, Yersinia pseudotuberculosis of serotypes I-B and III was isolated from 9 monkeys (one during life and 8 at necropsy) of the following species: Macaca cynomolgus, Macaca nemestrina, Macaca radiata and Cercocebus fulliginosus. All these animals had characteristic gastrointestinal lesions consisting of superficial erosions or ulcerations with masses of gram-negative coccobacilli and an acute inflammatory exudate. Involvement of mesenteric nodes, livers and spleens by similar lesions was common. A more granulomatous reaction was rarely seen. Similar lesions without bacteriologic confirmation were found at necropsy in 20 other animals. When guinea pigs were inoculated intraperitoneally with our isolates, they developed focal splenic and hepatic necrosis resembling the septicemic form of the disease which is seen rarely in man. When inoculated intraperitoneally, they developed mesenteric lymphadenitis resembling human nonspecific mesenteric lymphadenitis; no intestinal lesions could be detected in the animals inoculated orally. The granulomatous component of the inflammatory response was better developed in guinea pigs than in the monkeys. It is concluded that infection by Yersinia pseudotuberculosis in nonhuman primates and probably also in other species, including man, is primarily a gastrointestinal disease. The primary intestinal lesions may be conspicuous, as in the monkeys, or inconspicuous, as in the guinea pig and man. The acuteness of the inflammatory response in the monkeys, when compared to the more granulomatous reaction in guinea pigs, suggests that the great majority of the monkeys died from an overwhelming infection before they could develop hypersensitivity to the organism.

Enteric pathogens in monkeys

From 1964 to 1967, 6,646 monkeys, representing 10 primate species, were examined for Shigella and Salmonella infections upon arrival at the National Center for Primate Biology. Of these animals, 12% were infected with Shigella, and 75% of the Shigella isolates were S. flexneri 4. The incidence of Salmonella infections decreased from 12 to 3% during the period of study. Epidemiological studies of animals in the colony for 90 days or more indicated no seasonal variation in the occurrence of Shigella and Salmonella. Many of the isolates from incoming monkeys as well as from laboratory-conditioned animals were resistant to chloramphenicol, dihydrostreptomycin, and tetracycline. The possible operation of drug-resistance factors in these infections is discussed.