Tempo and mode in coevolution of Agave sensu lato (Agavoideae, Asparagaceae) and its bat pollinators, Glossophaginae (Phyllostomidae).

The genus Agave sensu lato contains ca. 211 described species, many of which are considered keystone species because of their ecological dominance and the quantity of resources they provide with their massive, nectar-rich inflorescences. The large diversity of Agave species has been hypothesized as being related to their reproductive strategy (predominantly monocarpic) and diverse pollinators (e.g., bats, hummingbirds, hawkmoths). In particular, Agave species provide resources that a few genera of nectar feeding bats from the subfamily Glosophaginae are dependent upon. To explore a possible coevolutionary relationship between Agave and the bat species that pollinate them, we calibrated molecular phylogenies of both groups and looked for a correlation in their dates of divergence. One coding and two non-coding regions of the chloroplast genome were sequenced from 49 species of the Agavoideae (Asparagaceae), and the mitochondrial gene Cyt-b and nuclear coding gene RAG2 were either sequenced or obtained from gene bank for 120 Phyllostomid bats. Results from the analyses indicate that Agave sensu lato is a young genus (estimated crown age 2.7-8.5/stem age 4.6-12.3 Ma), with an increasing diversification rate, and the highest speciation rate among Agavoideae's clades. The origin of the Glossophaginae bats (stem age 20.3-23.5 Ma) occurred prior to the stem age of Agave sensu lato, while the origin of the current pollinators of Agave species, members of the genera Glossophaga, Leptonycteris, Anoura, Choeronyscus, Musonycteris and Choeronycteris, was estimated to be around 6.3-16.2 Ma, overlapping with the stem age of Agave sensu lato, supporting the hypothesis of diffuse coevolution.

Mid-term outcomes of mobile-bearing lateral unicompartmental knee arthroplasty.

BACKGROUND: This research was undertaken to evaluate Oxford Domed Lateral unicompartmental knee replacement (UKR) survival and clinical and radiological outcomes. The study also considered the influence of body mass index (BMI) on results and proposed contralateral healthy knee anatomic femorotibial angle (AFTA) as a predictor of postoperative knee alignment. METHODS: A retrospective evaluation of 41 primary Oxford Domed Lateral UKR performed in 41 patients in the same institution was undertaken on a patient group comprising of 10 men and 31 women with a mean age of 63 years (range: 38-81 years). A minimum follow-up of two years was required. RESULTS: The total revision rate was one out of 41 patients (2.4%), with a mean follow-up of 49 months (range: 25-84 months). One patient presented with a traumatic medial dislocation of the bearing after 15 months (resulting in an overall dislocation rate of 2.4%). The visual analogue scale (VAS) and the Oxford knee score (OKS) demonstrated significant postoperative improvement (P < 0.001). Survival at five years, with revision for any reason as the endpoint, was 97.5%. No significant correlation was observed between BMI and postoperative flexion angle, radiologically measured parameters, or pre- and postoperative VAS and OKS. Significant correlation was found (r = 0.77, P < 0.001) between postoperative and contralateral healthy knee anatomic femorotibial angles. CONCLUSIONS: The Oxford Domed Lateral UKR presents a low dislocation rate and excellent mid-term clinical and functional results. Contralateral healthy knee AFTA appears to be a predictor of postoperative knee alignment.

Diaphyseal forearm fractures, 20 years after surgical treatment. Is there still an indication for percutaneous fixation? / Fracturas diafisarias de antebrazo, 20 años después. ¿Está indicada la osteosíntesis percutánea?

OBJECTIVE: This is a retrospective study of 98 diaphyseal forearm fractures in adults, treated by a percutaneous technique with intramedullar Kirchner wires. MATERIALS AND METHOD: We reviewed 64 patients with 98 forearm fractures with a radiographic follow-up, assessing the presence of pseudarthrosis or delayed bone union and evaluating functional outcomes with the Anderson and the Disability of the Arm, Shoulder and Hand scale. RESULTS: Clinical and radiological bone union was achieved in an average of 12 weeks. We obtained 77% of excellent and good results following Anderson's scale. There were 4 cases of pseudarthrosis and 6 cases of delayed bone union. CONCLUSION: This surgical technique provides several advantages, such as a low incidence of complications and a total absence of infections, refractures and iatrogenic neurovascular injuries. It allows a lower hospital stay and a shortening of the surgery time compared with other techniques such as plates and intramedullary nails, that have similar results, in terms of bone union and functional outcomes, as we have verified from the published literature.

[Cervical emphysema after tonsillectomy. A case report]. / Enfisema cervical post amigdalectomía: reporte de un caso.

Tonsillectomy is one of the surgical procedures most frequently performed by the ENT specialist. It is considered easy and safe, but many complications have been described. Cervical subcutaneous emphysema and pneumomediastinum are immediate complications relatively infrequent. Deep dissection of the superior pharyngeal constrictor muscle creates a continuity that dries the cervicofacial planes, until it reaches the parapharyngeal, retropharyngeal and prevertebral spaces. It can even reach the mediastinum producing a pneumothorax, which is facilitated by coughing, vomiting or manual ventilation after extubating.

Evaluation of the capacity of oral streptococci to produce hydrogen peroxide.

The capacity of 11 strains of oral streptococcal species (Streptococcus sanguis, S. oralis, S. mitis and S. sobrinus) to produce hydrogen peroxide (H2O2) was studied in vitro. Detection of this property in solid media, particularly with trypticase soy agar-benzidine-peroxidase, was more sensitive than in liquid media. The addition of carbohydrates (arabinose, xylose, mannose, sorbose and lactose), sorbitol and saccharine to buffered trypticase soy broth increased H2O2 production in S. oralis NCTC 11427, although the concentrations obtained with some substrates (glucose, galactose, mannitol and xylitol) were lower than those obtained in controls. In S. sanguis NCTC 7863, H2O2 production was detected only with galactose, sorbitol, lactose and saccharin.

In vitro activity of macrolides and lincosamides against oral streptococci: a therapeutic alternative in prophylaxis for infective endocarditis.

Susceptibility to macrolides and lincosamides was tested in a total of 446 strains of oral streptococci belonging to eleven species, all isolated from dental plaque and/or saliva in 1991. Minimum inhibitory concentrations (MIC) were determined by the double serial dilutions method in agar. Clindamycin was the most effective antibiotic against all species tested. The results of nearly all parameters (range, mean, MIC(50), MIC(90)) in all species showed erythromycin to be less effective than josamycin, making the latter antibiotic a possible alternative to erythromycin in prophylaxis for infective endocarditis caused by oral streptococci, not only in patients allergic to penicillin, but also in all patients with low-risk lesions, who will be treated with low-risk dental procedures. In these latter patients, antibiotic prophylaxis may be indicated if, after careful evaluation of the individual's situation, no other alternatives are available.

An alternative to the reference method for testing the radiochemical purity of 99Tcm-tetrofosmin.

The recommended method for controlling the radiochemical purity (RCP) of 99Tcm-labelled tetrofosmin is thin-layer chromatography (TLC) with silica gel as the stationary phase and acetone:dichloromethane (35:65, v/v) as the mobile phase. However, this test is time-consuming and uses a toxic substance. We propose an alternative method to control RCP, based on a solid-phase extraction method (SPE) using a Sep Pak C18 cartridge. We used both methods to analyse 35 samples and to determine the percentages of colloid, radiopharmaceutical and free 99Tcm-pertechnetate. Normal labelling processes were modified to obtain a wide range of values. The range of RCP values obtained was 63.4-96.5% (median = 93.8%) by the standard TLC method and 70.1-96.4% (median = 94.1%) by the SPE method. A significant difference was observed only for the percentage of free 99Tcm-pertechnetate (P < 0.05). The agreement between the two methods, using 90% RCP as the limit, gave a kappa index = +1 (P < 0.001), indicating total agreement between them. The proposed method is useful to control RCP because it yields results that are in good agreement with those of the standard method, and because it is safer and less time-consuming.

Initial pH as a determining factor of glucose consumption and lactic and acetic acid production in oral streptococci.

Lactic and acetic acid production was evaluated from six strains of oral streptococci, viz Streptococcus gordonii, Streptococcus mutans, Streptococcus oralis, Streptococcus salivarius, Streptococcus sanguis and Streptococcus sobrinus cultured in the presence of 1, 5, 10 mM glucose and without glucose, at initial pH values of 5, 5.5, 6 and 7. S. sobrinus and S. salivarius caused the greatest decreases in pH. At pH values of 5 and 5.5, lactic acid and acetic acid production in the species tested was discordant with residual glucose levels. Acid production from protein was especially great in S. mutans and S. salivarius.

In-vitro susceptibility, tolerance and glycocalyx production in Streptococcus mutans.

We studied the presence of high-level resistance to aminoglycosides, penicillin tolerance and glycocalyx production in 160 isolates of Streptococcus mutans. Susceptibility to amoxycillin, cefazolin, imipenem, erythromycin, clindamycin, vancomycin and teicoplanin was also investigated. Of the isolates analysed, 58.8% produced glycocalyx in vitro and 2.5% were penicillin-tolerant. High-level resistance to streptomycin was found in 16.3% of the isolates, but all were sensitive to all other antibiotics tested. We found no significant relationship between glycocalyx production and high-level streptomycin resistance, penicillin tolerance or antibiotic susceptibility, except for a greater susceptibility to clindamycin and vancomycin in isolates that produced glycocalyx. Although our findings reflect the clinically favourable pattern of susceptibility currently found in this species, the appearance in some isolates of resistance, tolerance and glycocalyx production should be investigated because of the risks involved in endocarditis caused by S. mutans.

Evaluation of the automicrobic system for the identification of Streptococcus mutans.

The performance of the Automicrobic System with the Vitek gram-positive identification card (bioMérieux, France) in identifying strains of Streptococcus mutans was studied. Of 160 strains assayed, 72.5% were confirmed to be Streptococcus mutans; the remainder were identified as other species of streptocci (Streptococcus bovis, Streptococcus uberis, Streptococcus anginosus, Streptococcus sanguis I and II, Streptococcus intermedius, and Streptococcus constellatus).