Electromyographic evaluation of a novel surgical preparation to enhance nerve-muscle specificity that follows mammalian peripheral nerve trunk transection

Previous studies indicated that axons from proximal stumps of transected peripheral nerves "prefer" to grow through Silastic tubes attached to their native (originally associated) rather than foreign (not originally associated) distal stumps. We determined whether or not this specificity is expressed at the level of the neuromuscular junction. Proximal stumps of transected rat sciatic nerves (peroneal and tibial branches) were attached to single inlet ends of 6-mm-long, Y-shape Silastic implants. One outlet was attached to the distal peroneal and the other to the distal tibial stump. Ten weeks later, innervation of the anterior tibialis and interosseous muscles (normally innervated predominantly by peroneal and tibial nerve fibers, respectively) was assessed by measuring compound muscle action potential amplitudes and latencies that follow supramaximal peroneal and tibial nerve stimulation. Results showed higher amplitudes in anterior tibialis muscle, induced by "native" peroneal (vs. tibial) stimulation in four of five animals, and higher amplitudes in interosseous muscles after "native" tibial (vs. peroneal) stimulation in all cases examined. Preparations in which bridges between proximal and distal nerve stumps were bridged with unbranched tubes showed random patterns of muscle innervation. The results suggest that if allowed to express "specificity" at the level of nerve trunk transection, regenerating mammalian peripheral axons can grow into, and form functional connection with, native (vs. foreign) muscle groups. This finding has possible clinical significance.     

ESWL: stone-free efficacy based upon stone size and location

Summary Extracorporeal shock wave lithotripsy was used for the treatment of 1060 patients or 1128 kidneys with solitary stones. There were 528 pelvic stones, 82 upper caliceal stones, 120 middle caliceal stones and 398 lower caliceal stones. These groups were divided into two subgroups of large (>15 mm) and small (15 mm) stones. A total of 1232 treatments were carried out (1.16/patient or 1.09/kidney) and 91% of the patients underwent a single treatment. Auxiliary procedures were required in 5% of the patients and the complication rate was 3%. Overall, 74% of the patients were stone-free after 3 months of follow-up. Of the 26% with residual stones, 18% had sand (2 mm fragments) or match-heads (4 mm), 6% had fragments (5 mm) and 2% had no fragmentation at all. A stone-free result occurred in approximately 87% with small pelvic and upper caliceal stones, whereas large stones in these locations became stone-free in approximately 70% of cases. Both large and small stones in the lower half of the kidney (mid and lower calices) become stone-free less frequently (to a statistically significant degree) than do similar stones located in the pelvis or upper calices.     

Receptor binding and growth-promoting activity of insulin-like growth factor-I in a bovine mammary epithelial cell line (MAC-T3).

Insulin-like growth factor-I (IGF-I) has been known to be mitogenic to a variety of cell types, although a growth-regulatory role for IGF-I on bovine mammary epithelial cells has not been fully investigated. In the present study, we examined the receptor binding of IGF-I and its effect on growth in a bovine mammary epithelial cell line (MAC-T3). Specific receptors for IGF-I were detected on cultured bovine mammary epithelial cells. Competitive binding revealed that half-maximal inhibition of 125I-labelled IGF-I binding by IGF-I was approximately 3 micrograms/l. Dissociation rate constant of the IGF-I receptor was 3.10 +/- 0.06 nmol/l (S.E.M.) with a receptor site concentration of 366 +/- 8 fmol/mg protein for the average of three experiments. IGF-I exerted a positive mitogenic effect on MAC-T3 cells according to both direct DNA assay and thymidine incorporation assay. Moreover, the mitogenic effect of IGF-I on MAC-T3 cells was enhanced by the addition of fetal calf serum in the culture media. The present results suggest that the bovine mammary epithelial cell line (MAC-T3) provides a useful model system with which to study the biological actions of insulin-like growth factors on the bovine mammary secretory tissue in vitro.     

PROPHYLACTIC VS. SYMPTOMATIC THIRD MOLAR REMOVAL: EFFECTS ON PATIENT POSTOPERATIVE MORBIDITY

PurposeThe present study aimed to assess differences in postoperative morbidity between prophylactic and symptomatic third molar removals, and to assess the effect of age on the recovery of the patient.MethodsPatients admitted for third molar removal were prospectively followed up four times during treatment in context of the M3BE study. Data were collected through pre-, peri and postoperative surveys (days 3 and 10). Uni- and multivariable logistic regression was used to assess the probability of postoperative symptoms of discomfort on day 3 and day 10 according to several patient- and surgery-related predictive factors (age, gender, indication for removal, method of extraction, anesthesia and number of extracted maxillary and/or mandibular third molars).ResultsIn total, 6010 patients with a mean age of 25.2 (± 11.2) underwent 6347 surgeries to have 15,357 third molars removed. Frequently observed symptoms of postoperative discomfort were pain, trismus and swelling, all of which were transient in nature with steep decreases from postoperative days 3 to 10. Increasing age was associated with an enhanced risk of persistent pain, trismus and swelling and a significantly higher risk of iatrogenic injury to the inferior alveolar nerve. Symptomatic indications for removal were more common in patients over age 25 years, but these pre-existing pathologies did not compromise the postoperative recovery process. Other factors related to postoperative morbidity were female gender, intraoperative osteotomy and the number of extractions.ConclusionThe results of this study suggest that there are convincing patient- and surgery-related factors that favor timely third molar removal, preferably before the age of 25, especially in order to avoid persistent morbidity and nerve complications.     

Early imaging signs of the use of antiresorptive medication and MRONJ: a systematic review

Objective

The main aim is to identify, by means of different imaging modalities, the early bone changes in patients “at risk” and in stage 0 MRONJ.

Materials and methods

A search of the literature was performed on PubMed, Embase, Web of Science, and Cochrane Library databases, until June 9, 2020. No language or year restrictions were applied. Screening of the articles, data collection, and qualitative analysis was done. The Newcastle-Ottawa Scale (NOS) was used for observational studies, and the Systematic Review Centre for Laboratory Animal Experimentation’s (SYRCLE) risk of bias tool for the animal studies.

Results

A total of 1188 articles were found, from which 47 were considered eligible, whereas 42 were suitable for the qualitative analysis. They correspond to 39 human studies and 8 animal studies. Radiographic findings such as bone sclerosis, osteolytic areas, thickening of lamina dura, persisting alveolar socket, periapical radiolucency, thicker mandibular cortex, widening of the periodontal ligament space, periodontal bone loss, and enhancement of the mandibular canal were identified as early bone changes due to antiresorptive therapy. All those findings were also reported later in Stage 0 patients.

Conclusion

The main limitations of these results are the lack of prospective data and comparisons groups; therefore, careful interpretation should be made. It is a fact that radiographic findings are present in antiresorptive-treated patients, but the precise timepoint of occurrence, their relation to the posology, and potential risk to develop MRONJ are not clear.

Clinical relevance

The importance of a baseline radiographic diagnosis for antiresorptive-treated patients.