Health effects of exposure to chlorination by-products in swimming pools

Concerns have been raised regarding the potential negative effects on human health of water disinfectants used in swimming pools. Among the disinfection options, the approaches using chlorine-based products have been typically preferred. Chlorine readily reacts with natural organic matter that are introduced in the water mainly through the bathers, leading to the formation of potentially harmful chlorination by-products (CBPs). The formation of CBPs is of particular concern since some have been epidemiologically associated with the development of various clinical manifestations. The higher the concentration of volatile CBPs in the water, the higher their concentration in the air above the pool, and different routes of exposure to chemicals in swimming pools (water ingestion, skin absorption, and inhalation) contribute to the individual exposome. Some CBPs may affect the respiratory and skin health of those who stay indoor for long periods, such as swimming instructors, pool staff, and competitive swimmers. Whether those who use chlorinated pools as customers, particularly children, may also be affected has been a matter of debate. In this article, we discuss the current evidence regarding the health effects of both acute and chronic exposures in different populations (work-related exposures, intensive sports, and recreational attendance) and identify the main recommendations and unmet needs for research in this area.     

Is there a relation between vitamin D,interleukin-17, and bone mineral density in patients with inflammatory bowel disease?

IntroductionIn inflammatory bowel diseases (IBD), osteopenia and osteoporosis constitute a significant medical problem. Cytokines, especially IL-17, play an important role in the pathogenesis of IBD and osteoporosis. Vitamin D is a regulator of bone metabolism, and helps maintain immune system homeostasis.Material and methodsThe research sample consisted of 208 persons: 83 patients (age 35 ±11.99 years) with Crohn’s disease (CD); 86 patients (age 39.58 ±14.74 years) with ulcerative colitis (UC); and 39 persons (age 30.74 ±8.63 years) in the control group (CG). Clinical data on bone mineral density of the lumbar spine (L2-L4), bone mineral density of the femoral neck (FN), and body mass index (BMI) were collected. 25OHD and IL-17 serum concentrations were also measured.ResultsBody mass index (kg/m²) results: in CD, 21.51 ±3.68; in UC, 23.31 ±4.38; and in CG, 24.57 ±3.45 (p < 0.01). Densitometry results for L2–L4 T-score SD: in CD –0.83 ±1.45; in UC –0.47 ±1.15; in CG 0.09 ±0.70. Densitometry results for FN T-score SD: in CD –0.62 ±1.26; in UC –0.29±1.17; in CG 0.41 ±1.03 25OHD (ng/ml) serum concentrations: in CD, 21.33±12.50; in UC, 22.04±9.56; in CG, 21.56±9.11 (ns). IL-17 (pg/ml) serum concentrations: in CD, 8.55±10.99; in UC, 11.67±12.97; in CG, 5.16±9.11 (ns).ConclusionsInflammatory bowel diseases patients and persons from the CG did not differ in vitamin D or IL-17 levels. Patients with a mild course of the disease had a higher vitamin D concentration and bone mineral density. In UC, higher vitamin D concentrations were associated with lower IL-17 concentrations. The IBD patients with a severe course of the disease had a lower body mass than those in the CG and the patients with a mild course of the disease.     

Time efficiency of direct anterior hip arthroplasty compared to postero-lateral approach in elderly patients

IntroductionPrimary arthroplasty of the hip joint is currently one of the most commonly performed procedures in orthopedics. In Poland we are observing significant changes in the age structure. With the prolonged life more and more elderly patients require musculoskeletal surgery to maintain comfortable and painless mobility. Reducing the duration of the procedure reduces the costs of anesthesiology, surgical and instrument teams, as well as the operating room technical team. The aim of the study was to compare the time required to perform hip joint arthroplasty by the direct anterior approach (DAA) with the postero-lateral approach (PLA) in our hospital.Material and methodsA retrospective analysis of 559 total and bipolar cemented and cementless hip replacement procedures based on two operative approaches – the minimally invasive DAA over the course of 2 years, and the standard PLA over the course of 3 years – was performed.ResultsStatistically significant differences were observed between the approaches used for cementless total arthroplasty with regard to the mean treatment times: 51.9 min for the 272 DAA cases, and 78.3 min for the 190 PLA cases (p < 0.0001). For the cementless hemi-arthroplasty procedure, the mean treatment times were 46.9 min in 36 patients for DAA, and 48.2 min for 61 patients for PLA (p = 0.57).ConclusionsMinimally invasive DAA significantly shortens the time of the procedure in elderly patients compared to PLA. Further study is needed to analyze other aspects of those two approaches.     

Mutations in SYNGAP1 Cause Intellectual Disability,Autism, and a Specific Form of Epilepsy by Inducing Haploinsufficiency

De novo mutations in SYNGAP1, which codes for a RAS/RAP GTP‐activating protein, cause nonsyndromic intellectual disability (NSID). All disease‐causing point mutations identified until now in SYNGAP1 are truncating, raising the possibility of an association between this type of mutations and NSID. Here, we report the identification of the first pathogenic missense mutations (c.1084T>C [p.W362R], c.1685C>T [p.P562L]) and three novel truncating mutations (c.283dupC [p.H95PfsX5], c.2212_2213del [p.S738X], and (c.2184del [p.N729TfsX31]) in SYNGAP1 in patients with NSID. A subset of these patients also showed ataxia, autism, and a specific form of generalized epilepsy that can be refractory to treatment. All of these mutations occurred de novo, except c.283dupC, which was inherited from a father who is a mosaic. Biolistic transfection of wild‐type SYNGAP1 in pyramidal cells from cortical organotypic cultures significantly reduced activity‐dependent phosphorylated extracellular signal‐regulated kinase (pERK) levels. In contrast, constructs expressing p.W362R, p.P562L, or the previously described p.R579X had no significant effect on pERK levels. These experiments suggest that the de novo missense mutations, p.R579X, and possibly all the other truncating mutations in SYNGAP1 result in a loss of its function. Moreover, our study confirms the involvement of SYNGAP1 in autism while providing novel insight into the epileptic manifestations associated with its disruption.     

Synonymous Mutations in RNASEH2A Create Cryptic Splice Sites Impairing RNase H2 Enzyme Function in Aicardi–Goutières Syndrome

Aicardi–Goutières syndrome is an inflammatory disorder resulting from mutations in TREX1, RNASEH2A/2B/2C, SAMHD1, or ADAR1. Here, we provide molecular, biochemical, and cellular evidence for the pathogenicity of two synonymous variants in RNASEH2A. Firstly, the c.69G>A (p.Val23Val) mutation causes the formation of a splice donor site within exon 1, resulting in an out of frame deletion at the end of exon 1, leading to reduced RNase H2 protein levels. The second mutation, c.75C>T (p.Arg25Arg), also introduces a splice donor site within exon 1, and the internal deletion of 18 amino acids. The truncated protein still forms a heterotrimeric RNase H2 complex, but lacks catalytic activity. However, as a likely result of leaky splicing, a small amount of full‐length active protein is apparently produced in an individual homozygous for this mutation. Recognition of the disease causing status of these variants allows for diagnostic testing in relevant families.     

Magnetic resonance imaging of wrist and finger joints in healthy subjects occasionally shows changes resembling erosions and synovitis as seen in rheumatoid arthritis

OBJECTIVE: To explore the presence of changes resembling rheumatoid arthritis erosions and synovitis in metacarpophalangeal (MCP) and wrist joints of healthy individuals on magnetic resonance imaging (MRI) and to compare the MRI findings with conventional radiographic, clinical, and biochemical findings. METHODS: Twenty-eight healthy individuals were studied. Contrast-enhanced MRI and conventional radiography of the dominant wrist and second through fifth MCP joints were performed, coupled with standard clinical assessments and biochemical analyses. MR images were evaluated according to the latest OMERACT (Outcome Measures in Rheumatology Clinical Trials) recommendations with respect to synovitis, erosions, and bone marrow edema. RESULTS: Conventional radiography revealed erosion-like changes in 1 of 224 MCP joint bones (0.4%) and in 1 of 420 wrist joint bones (0.2%). MRI depicted low-grade erosion-like changes in 5 of 224 MCP joint bones (2.2%) and in 7 of 420 wrist joint bones (1.7%), but postcontrast enhancement within the lesion was detected in only 8.3% of these. MRI depicted low-grade synovitis-like changes in 10 of 112 MCP joints (8.9%) and in 8 of 84 assessed wrist areas (9.5%), while only minimal early synovial enhancement was detected by dynamic MRI. Three subjects had elevated serum levels of C-reactive protein, and these subjects displayed 44.5% of the synovitis-like changes and 41.7% of the erosion-like changes. Bone marrow edema-like changes were not found in any joints. CONCLUSION: Changes resembling mild synovitis or small bone erosions are occasionally found in the MCP and wrist joints of healthy controls. Signs of synovitis on dynamic MRI, enhancement within bone erosion-like changes, and signs of bone marrow edema appear rarely or are absent in healthy controls. These signs may thus prove to be very specific in the distinction between arthritic and normal joints.     

Myocardial injury secondary to acute pulmonary embolism - a case report

A case of a 37-year-old male admitted to the hospital due to dyspnea and chest pain is presented. Electrocardiogram showed negative T waves in V1 and V2 as well as subtle ST segment elevation in all precordial leads. Cardiac enzymes were moderately elevated. The initial diagnosis was myocarditis or acute coronary syndrome, however, transthoracic echocardiography showed a marked right ventricular overload which suggested acute pulmonary embolism. The latter diagnosis was confirmed by transesophageal echocardiography which revealed thrombosis of both left and right pulmonary arteries. The patient received thrombolysis and anticoagulants, and his condition improved. He was discharged home and the course of a six-month follow-up was uneventful.     

Shaping Physiological Indices,Swimming Technique,and Their Influence on 200m Breaststroke Race in Young Swimmers

The aim of this study was to investigate somatic properties and physiological capacity, and analyze kinematic parameters in the 200 m breaststroke swimming race. Twenty-seven male swimmers participated in the study. They were 15.7±1.98 years old. Their average height was 1.80 ± 0.02 m and lean body mass (LBM) was 62.45 ± 8.29 kg. Physiological exercise capacity was measured in two separate 90 sec. all-out tests, one for the arms and second for legs. During the tests total work of arm cranking (TWAR) and cycling (TWLG) as well as peak of VO₂ for arm (VO_2peakAR) and leg (VO_2peakLG) were measured. The underwater swimmers body movements were recorded during the all-out swimming 200m breaststroke speed test using an underwater camera installed on a portable trolley. The swimming kinematic parameters and propulsive or non-propulsive movement phases of the arms and legs as well as average speed (V200), surface speed (V200surface) and swimming speed in turn zones (V200turns) were extracted. V200surface was significantly related to the percentage of leg propulsion and was shown to have large effect on VO_2peakLG in the Cohen analysis. V200turns depended significantly on the indicators of physiological performance and body structure: TWAR, VO_2peak LG and LBM, LBM, which in turn strongly determined the measured results of TWAR, TWLG, VO_2peakAR and VO_2peakLG. The V200turns and V200surface were strongly associated with V200, 0.92, p < 0.001 and 0.91, p < 0.001 respectively. In each lap of the 200m swimming there was an increased percentage of propulsion of limb movement observed simultaneously with a reduction in the gliding phase in the breaststroke cycles.

Key points

• This study investigated the influence of the selected indicators of somatic properties and physiological capacity as well kinematic and coordination parameters on breaststroke swimming.
• In this observations the body’s functional capacity have an important impact on achieving good breaststroke swimming results, the V₂₀₀ was moderately associated on VO₂peakLG, moreover, separate V₂₀₀turns depended with VO₂peakLG and on LBM and TWAR.
• The speed of surface breaststroke swimming - V₂₀₀surface similarly as V₂₀₀turns had a very strong influence on the end result of V_{200 ,} 0.91, p<0.001 and 0.92, p<0.001 respectively.
• The ability to swim fast on the surface (V₂₀₀surface) was positively and significantly associated with the percentage time of propulsion generation -LP in the breaststroke cycle.

Key words: Breaststroke swimming, physiological indices, lean body mass, kinematic indices