Evaluation of the Impact of Exposure To Heat and to By-Products of Combustion on the Health of Firefighters.

Firefighters are often exposed to high temperatures and by-products of combustion, which can affect their health. In this study, we assessed the impact of acute exposure of firefighters in fire simulators. Twenty male firefighters were exposed to fire simulators, and observed in four phases: pre-exposure (group 0, control) and after the end of the first (group 1), second (group 2), and fourth (group 3) weeks of training. Blood samples were collected and dosed to evaluate the response of the immune, inflammatory (C-reactive protein, IL6, and IL10), and endocrine systems (cortisone, total testosterone, free testosterone, SHBG, bioavailable testosterone, TSH, and free T4). In groups 0, 1, and 3, a thermographic evaluation was also carried out to study the temperature and body heat flow of the participants. Regarding the inflammatory process, an increase in C-reactive protein and a reduction in IL-10 were observed. With respect to hormonal markers, an increase in cortisol and reduced levels of free T4 and bioavailable testosterone were found after exposure, with recovery of testosterone levels in the final week of training. Thermoregulatory adaptation of the organism has been associated with changes in heat flow in the organism in people subjected to extreme temperatures, with emphasis on the performance of the lower limbs. Our findings demonstrate an inflammatory response with hormonal changes after exposure to fire and an adaptive response of thermal balance, which could aid understanding of the physiology of the human body in extreme situations.

Les sapeurs-pompiers (SP) sont régulièrement exposés à la chaleur et aux produits de combustion, qui peuvent avoir un retentissement sur leur santé. Nous avons évalué l'effet d'une exposition aiguë de 22 SP (tous des hommes) à incendie simulé grâce à la répétition à 4 reprises d'une même batterie d'examens (avant- T0, et à la fin des 1ère -T1 2ème - T2 et 3ème - T3 semaines d'entraînement). Des paramètres sanguins relatifs à l'inflammation et l'immunité (CRP, IL6, IL10) ainsi qu'au système endocrinien (cortisol, testostérones totale, libre et biodisponible, SHBG, TSH et T4 libre) étaient prélevés à chaque évaluation. Une étude thermographique, évaluant la température corporelle et le flux thermique corporel était réalisée à T0, T1 et T3. On constatait une augmentation de la CRP et une baisse de IL10. On observait une augmentation de la cortisolémie ainsi qu'une baisse de thyroxine libre et testostérone biodisponible, cette dernière se normalisant à T3. L'adaptation corporelle à la chaleur se traduit par une augmentation du flux thermique, en particulier aux membres inférieurs. Nous observons donc des réponses inflammatoire comme endocrinienne et une adaptation de la thermorégulation en cas d'exposition à un incendie, constatations pouvant contribuer à la compréhension de la physiologie humaine en situations extrêmes.

Arthroscopic single-row repair of massive potentially irreparable postero-superior cuff tear.

PURPOSE: We retrospectively evaluated the results of complete repair of massive potentially irreparable postero-superior tears in a consecutive cohort of patients. With the increasing and widespread use of superior capsular reconstruction, a complete repair of the superior cuff, also if not functional, may be a valuable option for irreparable cuff lesions. METHODS: A consecutive case series of massive potentially irreparable postero-superior cuff tears that underwent complete repair was included in the study. Irreparability of cuff tear was defined when on preoperative MRI images, a positive tangent sign, a Goutallier 3-4 stage of fatty infiltration, and an absent acromion-humeral distance were present. A single-row complete repair was performed using triple-loaded titanium suture anchors. Operative time was recorded, as well as intra- and postoperative complications. Patients were followed for 12 months post-op; they were clinically evaluated with the use of constant score (CS) and subjective shoulder value (SSV) at 3, 6, and 12 months; a 12-month postoperative ultrasound evaluation was obtained. RESULTS: Thirty-two patients satisfying the inclusion criteria were enrolled. The mean age was 52 years (range 41-58). The repair was completed with a mean use of 2.4 triple-loaded suture anchors (range 2-4); the mean operative time was 70 min (range 45-90). The mean preoperative CS was 55 (range 45-75, SD 17), while the SSV was 40 (range 30-70, SD 22). At the final follow-up, the mean CS and SSV were 72 (range 62-85, SD 8) and 80 (range 60-90, SD 10) (p < 0.001 with respect to the preoperative scores), respectively. At the final follow-up, sonography showed a complete healing of the cuff in 20 cases (62.5%). No intra-operative complications occurred; at the final follow-up, five patients (15, 6%) were not satisfied of the results and asked for revision surgery. CONCLUSIONS: The complete repair of massive potentially irreparable rotator cuff tear in patients younger than 60 years old yielded good results at a short-term follow-up, with a sonographic re-tear rate of about 20%. Even if it is logical to consider a tendon with severe fatty degeneration as non-functional, the superior soft tissue reconstruction we achieved may have at least the same results of a superior capsular reconstruction, with obvious lower costs. LEVEL OF EVIDENCE: Level 4, case series with no comparison group.

Shoulder adhesive capsulitis and hypercholesterolemia: role of APO A1 lipoprotein polymorphism on etiology and severity.

PURPOSE: Relationship between shoulder adhesive capsulitis (AC) and hypercholesterolemia is known. The connecting link might be represented by the correlation between HDL and transforming growth factor beta (TGF-ß): normally, HDLs stimulate TGF-ß expression; the latter is employed in the development of fibrous tissue. We assess whether the presence of the Apo-A1-G75A-polymorphism, which is correlated to an enhanced HDL function, could be a risk factor for the genesis and severity of AC. METHODS: Peripheral blood samples of 27 patients [7M; 20F, mean age 54.81 (41-65)] with AC and hypercholesterolemia were submitted to polymerase chain reaction in order to evaluate the Apo-A1-G75A-polymorphism. Genome database was used as control. Two categories were obtained according to AC severity: type I (active forward flexion ≥ 100°) and type II (< 100°). Data were submitted to statistics. RESULTS: The prevalence of Apo-A1-G75A-polymorphism in the studied group and in the control group was 22.2% (10AG; 1AA; 16GG) and 19% (OR 1.22, IC 0.59-2.53, p > 0.05), respectively. Patients with type I and II capsulitis were 11 [flexion 148.0° (range 100°-165°)] and 16 [flexion 82.5° (range 50°-95°)], respectively. The prevalence of Apo-A1-G75A in type I was 18.1% (2AG; 9GG) and in type II was 56.3% (8GA; 1AA; 7GG), respectively (RR 1.87, IC 1.005-3.482, p < 0.05). CONCLUSIONS: Apo-A1-G75A-polymorphism is not necessary for the genesis, but it is a risk factor for severity of AC. LEVEL OF EVIDENCE: III.

Adhesive capsulitis of the shoulder: pain intensity and distribution.

PURPOSE: Papers regarding adhesive capsulitis (AC) of the shoulder focused on etiology, epidemiology, diagnosis, and treatment; until now, information on shoulder pain characteristics is still scarce. Our aim was to analyze pain intensity and distribution in patients with AC. METHODS: The study group was composed of 278 (133M-145F) consecutive patients with AC. After diagnosis, shoulder pain distribution was assessed through an upper limb pain map and pain intensity through a visual analog scale. Patients were distinguished on the basis of gender, age, time elapsed from onset of symptoms, and severity of functional limitation. Data were submitted to statistical analysis. RESULTS: Intensity of shoulder pain caused by AC was higher in females (p < 0.05); it did not vary with the side and between patient younger and older than 55 years. Patients whose pain arose from more than 3 months suffered a lower intensity of shoulder pain. Furthermore, pain intensity was higher in the most severe form of AC (active forward flexion < 60°) (p < 0.05). Pain was localized predominantly on the anterior aspect of the shoulder (dermatomes C5-C6) and rarely extended beyond the distal third of the arm. No differences were found in pain distribution between male and female, between patients with pain from less or more than 3 months and between different levels of AC severity (p > 0.05). CONCLUSION: Shoulder pain due to AC may be influenced by gender and severity of functional limitation. AC pain distribution principally involves anterior aspect of the shoulder with downward extension of the arm until its distal third. LEVELS OF EVIDENCE: Level IV.

Sleep quality and disturbances in patients with different-sized rotator cuff tear.

INTRODUCTION: The literature is unanimous in saying that shoulder pain, due to rotator cuff tear (RCT), may be mostly at night; to our knowledge, this statement is not supported by scientific evidence. Our aim was to investigate sleep quality and disturbances in patient with RCT and in a control group. MATERIALS AND METHODS: A case-control design study was used. We enrolled 324 consecutive patients (Group A) (156M-168F, mean age ± SD: 64.94 ± 6.97; range 47-74) who underwent arthroscopic rotator cuff repair. Tear size was determined intraoperatively. The control group (Group B) included 184 subjects (80M-104F, mean age ± SD = 63.34 ± 6.26; range 44-75) with no RCT. All participants were submitted to two standardized self-reported questionnaires evaluating sleep quality and disturbances: the Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESS). Data were submitted to statistics. RESULTS: We found no significant differences between the two groups according to both PSQI (Group A: 5.22 ± 2.59; Group B: 5.21 ± 2.39) and ESS (Group A: 2.59 ± 2.54; Group B: 5.76 ± 2.63), p > 0.05. Patients with small tears had average PSQI and ESS higher than patients with large and massive lesions (p < 0.005). Pearson's test showed that tear severity was negatively correlated with both sleep latency (r 2 = -0.35, ß = 0.069, p < 0.005) and sleep disturbances (r 2 = -0.65, ß = 0.053, p < 0.001). CONCLUSIONS: RCT is only one of the responsible causes for sleep disturbance in middle-aged and elderly subjects. Patients with small tears have a poorer sleep quality with respect to those with a more severe tear; particularly, they not only take more time to fall asleep, but also have a more disturbed sleep compared to patients with large and massive tears. LEVEL OF EVIDENCE: III.

Acromioclavicular joint cyst in ASA 3-4 patients.Whether and how quickly it recurs after aspiration and steroid injection.

We observed the clinical course, in the short-medium term, of patients with voluminous type II acromio-clavicular (AC) joint cyst who underwent aspiration and steroid injection regarded as the only possible treatment to avoid possible skin complications. Four patients (7.4% of cases described in literature) (3F-1M ; mean age 83 years, range : 78-87 years) with a voluminous ( > 7 cm) oval, no mobile, no fluctuant cyst overlying the AC joint, were retrospectively observed. The patients, judged by the anesthesiologist as ASA 3-4 patients, were merely submitted to cyst aspiration and steroid injection. The content of the cyst was microscopically analysed. All patients were clinically evaluated on the day of aspiration and after 14-30 days and after 1 year. Shoulder function and pain intensity were analysed with Constant score and VAS. We were able to aspirate 80-150 ml of amorphous joint fluid. At the first follow-up, all patients had a recurrence of the cyst, a lower grade of tension of the skin overlying the cyst and also a very little decreasing of pain intensity. After a month from aspiration, the cysts of the 4 patients had the same size as that present before aspiration. The range of motion, the average value of VAS and Constant were similar to those recorded before aspiration. In no case signs of infection or draining sinus occurred. Aspiration is a useless practice. However it is still a motive for discussion if the reduced suffering of the skin overlying the cyst after the aspiration has avoided, or simply postponed, an imminent complication.

Does immobilization position after arthroscopic rotator cuff repair impact work quality or comfort?

PURPOSE: The purpose of this study was to quantify subjective discomfort and decrease in working performance in patients submitted to arthroscopic rotator cuff repair. METHODS: We enrolled 101 asymptomatic administrative employees (mean age 55). Subjects were asked to write a text using Microsoft Word and to make a table using Microsoft Excel, with and without shoulder braces which kept the right shoulder in neutral (brace A) and internal rotation (brace B). Total time needed to complete the tests and number of mistakes committed were annotated. Furthermore, a questionnaire to assess the subjective and interpersonal discomfort caused by the braces was compiled. Data were submitted to statistical analysis. RESULTS: When any brace is worn, both times and mistakes are higher than those registered without brace (p < 0.02). Both times and mistakes are higher for brace B in comparison with brace A (p < 0.02). Subjects wearing brace B had a severe/very severe discomfort degree three times higher than that registered in subjects wearing brace A. Finally, 91 % of subjects preferred brace A to brace B. DISCUSSION: If the choice of the brace is not supported by biological or clinical advantages, we recommend to use the brace that keeps the arm at the side, since it ensures better working performance and lower discomfort. It also received the greatest satisfaction of the respondents. LEVEL OF EVIDENCE: IV.

Arginine L-alpha-ketoglutarate, methylsulfonylmethane, hydrolyzed type I collagen and bromelain in rotator cuff tear repair: a prospective randomized study.

OBJECTIVE: Arthroscopic rotator cuff repair generally provides satisfactory result, in terms of decreasing shoulder pain, resulting in improvement in range of motion. Unfortunately, imaging studies have shown that after surgical repair re-rupture rate is potentially high. Literature data indicate that each of the components present in a commercial supplement sold in Italy as Tenosan * (arginine L-alpha-ketoglutarate, methylsulfonylmethane, hydrolyzed type I collagen and bromelain) have a potential role in tendon healing and mitigating the pain due to tendonitis. We evaluated the clinical and MRI results of rotator cuff repair with and without the employment of this oral supplement in patients with a large, postero-superior rotator cuff tear (RCT). RESEARCH DESIGN AND METHODS: We enrolled 90 consecutive patients who had a large, postero-superior RCT. All the lesions were managed with an arthroscopic repair. Patients were randomized and treated either with (Group I) or without (Group II) the supplement. The primary outcomes were the difference between the pre- and post-operative Constant score and repair integrity assessed by MRI according to Sugaya's classification. The secondary outcome was the pre- and post-operative Simple Shoulder Test. RESULTS: No statistically significant differences were identified between the two groups for each considered variable, except for shoulder pain (follow-up: 6 months) and repair integrity (final follow-up). Intensity of shoulder pain was lower in the Group I patients (p < 0.001). Analogously, in Group I, the percentage of patients with a better repair integrity result was significantly higher than Group II. CONCLUSION: The use of the supplement for 3 months after cuff repair decreases shoulder post-operative pain and leads to a slight improvement in repair integrity. This improvement does not seem to correlate with an better objective functional outcome. However, these effects could facilitate and abbreviate the post-operative rehabilitation program and reduce re-rupture rate. The main limitations of this study are the relative short follow-up period and small number of patients studied.

Cultured chondrocytes produce injectable tissue-engineered cartilage in hydrogel polymer.

The purpose of this study was to determine if chondrocytes cultured through several subcultures at very low plating density would produce new cartilage matrix after being reimplanted in vivo with or without a hydrogel polymer scaffold. Chondrocytes were initially plated in low-density monolayer culture, grown to confluence, and passaged four times. After each passage cells were suspended in purified porcine fibrinogen and injected into the subcutaneous space of nude mice while simultaneously polymerizing with thrombin to reach a final concentration of 40 million cells/cc. Controls were made by injecting fresh, uncultured cells with fibrin polymer and by injecting the cultured cells in saline (without polymer). All samples were harvested at 6 weeks. When injected in polymer, both fresh cells and cells that had undergone only one passage in culture produced cartilaginous nodules. Cultured cells did not produce cartilage, regardless of length of time spent in culture, when injected without polymer. Cartilage was also not recovered from samples with cells kept in culture for longer than one passage, even when provided with a polymer matrix. All samples harvested were subjected to histological analysis and assayed for total DNA, glycosaminoglycan (GAG), and type II collagen. There was histological evidence of cartilage in the groups that used fresh cells and cultured cells suspended in fibrin polymer that only underwent one passage. No other group contained areas that would be consistent with cartilage histologically. All experimental samples had a higher percent of DNA than native swine cartilage, and there was no statistical difference between the DNA content of the groups containing cultured or fresh cells in fibrin polymer. Whereas the GAG content of native cartilage was 8.39% of dry weight and fresh cells in fibrin polymer was 12.85%, cultured cells in fibrin polymer never exceded the 2.48% noted from first passage cells. In conclusion, this study demonstrates that porcine chondrocytes that have been cultured in monolayer for one passage will produce cartilage in vivo when suspended in fibrin polymer.

Adhesion of tissue-engineered cartilate to native cartilage.

Reconstruction of cartilaginous defects to correct both craniofacial deformities and joint surface irregularities remains a challenging and controversial clinical problem. It has been shown that tissue-engineered cartilage can be produced in a nude mouse model. Before tissue-engineered cartilage is used clinically to fill in joint defects or to reconstruct auricular or nasal cartilaginous defects, it is important to determine whether it will integrate with or adhere to the adjacent native cartilage at the recipient site. The purpose of this study was to determine whether tissue-engineered cartilage would adhere to adjacent cartilage in vivo. Tissue-engineered cartilage was produced using a fibrin glue polymer (80 mg/cc purified porcine fibrinogen polymerized with 50 U/cc bovine thrombin) mixed with fresh swine articular chondrocytes. The polymer/chondrocyte mixture was sandwiched between two 6-mm-diameter discs of fresh articular cartilage. These constructs were surgically inserted into a subcutaneous pocket on the backs of nude mice (n = 15). The constructs were harvested 6 weeks later and assessed histologically, biomechanically, and by electron microscopy. Control samples consisted of cartilage discs held together by fibrin glue alone (no chondrocytes) (n = 10). Histologic evaluation of the experimental constructs revealed a layer of neocartilage between the two native cartilage discs. The neocartilage appeared to fill all irregularities along the surface of the cartilage discs. Safranin-O and toluidine blue staining indicated the presence of glycosaminoglycans and collagen, respectively. Control samples showed no evidence of neocartilage formation. Electron microscopy of the neocartilage revealed the formation of collagen fibers similar in appearance to the normal cartilage matrix in the adjacent native cartilage discs. The interface between the neocartilage and the native cartilage demonstrated neocartilage matrix directly adjacent to the normal cartilage matrix without any gaps or intervening capsule. The mechanical properties of the experimental constructs, as calculated from stress-strain curves, differed significantly from those of the control samples. The mean modulus for the experimental group was 0.74 +/- 0.22 MPa, which was 3.5 times greater than that of the control group (p < 0.0002). The mean tensile strength of the experimental group was 0.064 +/- 0.024 MPa, which was 62.6 times greater than that of the control group (p < 0.0002). The mean failure strain of the experimental group was 0.16 +/- 0.061 percent, which was 4.3 times greater than that of the control group (p < 0.0002). Finally, the mean fracture energy of the experimental group was 0.00049 +/- 0.00032 J, which was 15.6 times greater than that of the control group. Failure occurred in all cases at the interface between neocartilage and native cartilage. This study demonstrated that tissue-engineered cartilage produced using a fibrin-based polymer does adhere to adjacent native cartilage and can be used to join two separate pieces of cartilage in the nude mouse model. Cartilage pieces joined in this way can withstand forces significantly greater than those tolerated by cartilage samplesjoined only by fibrin glue.

Injectable tissue-engineered cartilage using a fibrin glue polymer.

The purpose of this study was to demonstrate the feasibility of using a fibrin glue polymer to produce injectable tissue-engineered cartilage and to determine the optimal fibrinogen and chondrocyte concentrations required to produce solid, homogeneous cartilage. The most favorable fibrinogen concentration was determined by measuring the rate of degradation of fibrin glue using varying concentrations of purified porcine fibrinogen. The fibrinogen was mixed with thrombin (50 U/cc in 40 mM calcium chloride) to produce fibrin glue. Swine chondrocytes were then suspended in the fibrinogen before the addition of thrombin. The chondrocyte/polymer constructs were injected into the subcutaneous tissue of nude mice using chondrocyte concentrations of 10, 25, and 40 million chondrocytes/cc of polymer (0.4-cc injections). At 6 and 12 weeks, the neocartilage was harvested and analyzed by histology, mass, glycosaminoglycan content, DNA content, and collagen type II content. Control groups consisted of nude mice injected with fibrin glue alone (without chondrocytes) and a separate group injected with chondrocytes suspended in saline only (40 million cells/cc in saline; 0.4-cc injections). The fibrinogen concentration with the most favorable rate of degradation was 80 mg/cc. Histologic analysis of the neocartilage showed solid, homogeneous cartilage when using 40 million chondrocytes/cc, both at 6 and 12 weeks. The 10 and 25 million chondrocytes/cc samples showed areas of cartilage separated by areas of remnant fibrin glue. The mass of the samples ranged from 0.07 to 0.12 g at 6 weeks and decreased only slightly by week 12. The glycosaminoglycan content ranged from 2.3 to 9.4 percent for all samples; normal cartilage controls had a content of 7.0 percent. DNA content ranged from 0.63 to 1.4 percent for all samples, with normal pig cartilage having a mean DNA content of 0.285 percent. The samples of fibrin glue alone produced no cartilage, and the chondrocytes alone produced neocartilage samples with a significantly smaller mass (0.47 g at 6 weeks and 0.46 g at 12 weeks) when compared with all samples produced from chondrocytes suspended in fibrin glue (p < 0.03). Gel electrophoreses demonstrated the presence of type II collagen in all sample groups. This study demonstrates that fibrin glue is a suitable polymer for the formation of injectable tissue-engineered cartilage in the nude mouse model. Forty million chondrocytes per cc yielded the best quality cartilage at 6 and 12 weeks when analyzed by histology and content of DNA, glycosaminoglycan, and type II collagen.

Transdermal photopolymerized adhesive for seroma prevention.

The purpose of this study was to determine whether or not a synthetic photopolymerized tissue adhesive (polyethylene oxide hydrogel) is useful in seroma prevention using a well established rat mastectomy seroma model. Twenty-three Sprague-Dawley rats received mastectomies. The rats were randomly assigned to either the control group (n = 13) or the experimental group (n = 10). The control animals received 0.2 cc of saline into the wound before closure. The experimental group received either 0.2 cc (n = 5) or 0.4 cc (n = 5) of the polyethylene oxide polymer into their wounds before closure. The experimental animals were placed under an ultraviolet A lamp for 3 minutes to polymerize the adhesive. On postoperative day seven, the resultant seromas were quantified, and wound tissues were harvested for histologic evaluation. The rats in the control group had a mean seroma volume of 3.25 cc (SD = 2.41), whereas the rats treated with polymer had a mean seroma volume of 0.37 cc (SD = 0.51). A Student's t test was performed showing a statistically significant difference between the control and experimental groups (p < 0.005). The volume of polymer used (0.2 cc versus 0.4 cc) did not significantly impact the volume of the resultant seromas. This study demonstrates that photopolymerizable polyethylene oxide hydrogels can be used as a tissue adhesive and that such an adhesive significantly reduces seroma formation in the rat mastectomy model.