The role of beta-lactamase-producing-bacteria in mixed infections

Beta-lactamase-producing bacteria (BLPB) can play an important role in polymicrobial infections. They can have a direct pathogenic impact in causing the infection as well as an indirect effect through their ability to produce the enzyme beta-lactamase. BLPB may not only survive penicillin therapy but can also, as was demonstrated in in vitro and in vivo studies, protect other penicillin-susceptible bacteria from penicillin by releasing the free enzyme into their environment. This phenomenon occurs in upper respiratory tract, skin, soft tissue, surgical and other infections. The clinical, in vitro, and in vivo evidence supporting the role of these organisms in the increased failure rate of penicillin in eradication of these infections and the implication of that increased rate on the management of infections is discussed

Plantar calcaneal spurs in older people: longitudinal traction or vertical compression?

<p>Abstract</p> <p>Background</p> <p>Plantar calcaneal spurs are common, however their pathophysiology is poorly understood. This study aimed to evaluate the prevalence and correlates of plantar calcaneal spurs in a large sample of older people.</p> <p>Methods</p> <p>Weightbearing lateral foot radiographs of 216 people (140 women and 76 men) aged 62 to 94 years (mean age 75.9, <smcaps>SD</smcaps> 6.6) were examined for plantar calcaneal and Achilles tendon spurs. Associations between the presence of spurs and sex, body mass index, radiographic measures of foot posture, self-reported co-morbidities and current or previous heel pain were then explored.</p> <p>Results</p> <p>Of the 216 participants, 119 (55%) had at least one plantar calcaneal spur and 103 (48%) had at least one Achilles tendon spur. Those with plantar calcaneal spurs were more likely to have Achilles tendon spurs (odds ratio [OR] = 2.0, 95% confidence interval [CI] 1.2 to 3.5). Prevalence of spurs did not differ according to sex. Participants with plantar calcaneal spurs were more likely to be obese (OR = 7.9, 95% CI 3.6 to 17.0), report osteoarthritis (OR = 2.6, 95% CI 1.6 to 4.8) and have current or previous heel pain (OR = 4.6, 95% CI 2.3 to 9.4). No relationship was found between the presence of calcaneal spurs and radiographic measures of foot posture.</p> <p>Conclusion</p> <p>Calcaneal spurs are common in older men and women and are related to obesity, osteoarthritis and current or previous heel pain, but are unrelated to radiographic measurements of foot posture. These findings support the theory that plantar calcaneal spurs may be an adaptive response to vertical compression of the heel rather than longitudinal traction at the calcaneal enthesis.</p

Biomechanical evaluation of two clinical tests for plantar heel pain: The dorsiflexion-eversion test for tarsal tunnel syndrome and the windlass test for plantar fasciitis

Background: Plantar heel pain may result from several conditions such as tarsal tunnel syndrome (TTS) and plantar fasciitis. The dorsiflexion-eversion test is used to diagnose TTS, whereas the windlass test is used for plantar fasciitis. Given the similarity between both tests, the purpose of this study was to evaluate whether these tests are able to selectively load the structures which they aim to examine. Methods: Both tests were evaluated in six cadavers by measuring strain in the plantar fascia, tibial nerve, lateral plantar nerve (LPN), and medial plantar nerve (MPN) using miniature displacement transducers. Longitudinal excursion of the nerves was measured with a digital caliper. Results: With the dorsiflexion-eversion test, dorsiflexion and eversion of the ankle in combination with extension of the metatarsophalangeal (NITP) joints significantly increased strain in the tibial nerve (+1.1%), LPN (+2.2%), and MPN (+3.3%) but also in the plantar fascia (+1.2%) (all: p = 0.016). Both components (dorsiflexion-eversion and MTP extension) resulted in significant increases. With the windlass test, extension of all MTP joints significantly increased strain in the plantar fascia (+0.4%, p = 0.016), but also in the tibial nerve (+0.4%, p = 0.016), LPN (+0.8%, p = 0.032) and MPN (+2.0%, p = 0.016). Excursion of the nerves was always in the distal direction but only reached significance for the tibial nerve (6.9 mm, p = 0.016) and LPN (2.2 mm, p = 0.032) during the dorsiflexion-eversion test. Conclusions: Both tests mechanically challenge various structures that have been associated with plantar heel pain. This questions the usefulness of the tests in the differential diagnosis of plantar heel pain