The role of leptin in the respiratory system: an overview

Since its cloning in 1994, leptin has emerged in the literature as a pleiotropic hormone whose actions extend from immune system homeostasis to reproduction and angiogenesis. Recent investigations have identified the lung as a leptin responsive and producing organ, while extensive research has been published concerning the role of leptin in the respiratory system. Animal studies have provided evidence indicating that leptin is a stimulant of ventilation, whereas researchers have proposed an important role for leptin in lung maturation and development. Studies further suggest a significant impact of leptin on specific respiratory diseases, including obstructive sleep apnoea-hypopnoea syndrome, asthma, COPD and lung cancer. However, as new investigations are under way, the picture is becoming more complex. The scope of this review is to decode the existing data concerning the actions of leptin in the lung and provide a detailed description of leptin's involvement in the most common disorders of the respiratory system

Interaction of smooth muscle calponin and desmin

AbstractInteraction of smooth-muscle calponin and desmin was analyzed by means of ultracentrifugation, fluorescent spectroscopy and affinity chromatography. At low and intermediate ionic strength (30–50 mM NaCl) calponin is cosedimented with desmin with an apparent dissociation constant 3–15 μM and stoichiometry of 1 calponin/4–6 desmin. Calmodulin decreases the quantity of calponin bound to desmin. Increase of ionic strength up to 150 mM weakens calponin-desmin interaction, but even at this ionic strength part of calponin remains bound to desmin. Calponin increases the rate and extent of fluorescence quenching induced by polymerization of 5-iodoacetamidofluorescein-labeled desmin. Affinity chromatography data indicate that desmin-binding sites are located in the N-terminal 22 kDa fragment of calponin. Since calponin interacts with desmin with an affinity comparable with that of, e.g., tropomyosin and myosin we suppose that calponin-desmin interaction may be important for cytoskeleton organization

Displacement of the Posterior Horn of the Lateral Meniscus into Posterolateral Compartment: An Unusual Injury Pattern

We report a case of acute ACL injury with an unusual lateral meniscal tear pattern. The entire posterior horn of the lateral meniscus was avulsed from its attachments while remaining in continuity with the body of the meniscus. It was displaced posteriorly and laterally to the popliteus tendon so that it was not immediately visible at the time of arthroscopy. This type of displacement of the posterior horn of the lateral meniscus is difficult to identify at arthroscopy and has not previously been described in the literature to our knowledge. We recommend to surgeons who encounter an absent posterior horn of the lateral meniscus to consider this injury pattern

Repair of isolated horizontal meniscal tears with all-inside suture materials using the overlock method: outcome study with a minimum 2-year follow-up

BACKGROUND: This study aimed to consider the use of a meniscal repair in patients in order to close the horizontal cleavage extending up to the avascular zone. The hypothesis was to examine the clinical and arthroscopic outcomes following meniscal repair of degenerative horizontal cleavage tears with new-generation all-inside suture materials using the overlock method. METHODS: We retrospectively reviewed a consecutive series of 55 patients which had a horizontal pattern, and finally, 27 patients with a horizontal tear only which required no additional intra-articular surgical intervention were included in the study. Arthroscopic meniscal repair was performed using the overlock method. Functional outcomes were evaluated using Lysholm knee scoring scale, Cincinnati scores, subjective International Knee Documentation Committee (IKDC) criteria and Tegner activity scale. Assessment of meniscal healing was evaluated clinically by the presence of meniscal signs. The preoperative and postoperative MRIs were examined. RESULTS: The mean follow-up period was 29 months (range, 24–38). The mean Lysholm score improved significantly from 59.5 ± 12.4 points preoperatively to 90.0 ± 4.7 points postoperatively (P < 0.0001). The Cincinnati score increased from 14.8 ± 5.3 to 26.9 ± 1.6 (P < 0.0001). The Tegner activity score increased from 3.7 ± 1.4 to 6.4 ± 1.6 (P < 0.0001). The mean IKDC subjective score also improved significantly from 48.5 ± 9.8 preoperatively to 90.4 ± 5.0 postoperatively (P < 0.0001). CONCLUSION: Meniscal repair of degenerative horizontal tears using the overlock method resulted in improved Lysholm and IKDC subjective scores. With careful selection of the patients and the horizontal meniscus tears, the success of the meniscus repairs increases. Repair can be recommended for all horizontal meniscus tears which can be repaired arthroscopically

Epidemiology of meniscal injuries in US high school athletes between 2007 and 2013

PURPOSE: Knowledge of epidemiologic trends of meniscal injuries in young active populations is limited. Better awareness of injury patterns is a first step to lowering injury rates. Our hypothesis was that meniscal injuries in high school athletes would vary by gender, sport, and type of exposure. METHODS: During 2007–2013, a large nationally disperse sample of US high schools reported athlete exposure and injury data for 22 sports by having certified athletic trainers complete an internet-based data collection tool. RESULTS: 1,082 meniscal injuries were reported during 21,088,365 athlete-exposures for an overall injury rate of 5.1 per 100,000 athlete exposures. The overall rate of injury was higher in competition (11.9) than practice (2.7) (RR = 4.4; 95% CI, 3.9–5.0), and 12/19 sports showed significantly higher injury rates in competition compared to practice. Of all injuries, 68.0% occurred in boys, yet among the gender-comparable sports of soccer, basketball, track and field, lacrosse, and baseball/softball injury rates were higher for girls than boys (5.5 and 2.5, respectively, RR = 2.2; 95% CI, 1.8–2.7). Contact injury represented the most common mechanism (55.9%). Surgery was performed for the majority of injuries (63.8%), and 54.0% of athletes had associated intra-articular knee pathology. CONCLUSIONS: Meniscal injury patterns among high school athletes vary by gender, sport, and type of exposure. Overall rates are higher for boys, but this is driven by football; however in gender-comparable sports girls may be at higher risk for meniscal injury. Our study is clinically relevant because recognition of distinct differences in these injury patterns will help drive evidence-based, targeted injury prevention strategies and efforts. LEVEL OF EVIDENCE: Level II