Natural moisturising factor constituents in South African nursing students.

BACKGROUND: The majority of South African healthcare workers are Black Africans with dark-pigmented skin. Studies on how the markers of skin barrier function and natural moisturising factor (NMF) compare between dark and light-pigmented skin are limited. Quantifying NMF in a nursing student population during their practical training at university may provide valuable insight into their potential susceptibility to skin conditions associated with low NMF. OBJECTIVES: The objectives of this study were to quantify and compare NMF content of Black African, Mixed Race and White nursing students from their dominant dorsal hand. METHODS: Forty-nine White, 32 Black African and 5 Mixed Race nursing students participated in this study. Tape strip samples were collected from the participants' dominant dorsal hand and NMF content was measured, including histidine (HIS), pyrrolidone carboxylic acid (PCA), trans-urocanic acid (t-UCA) and cis-urocanic acid (c-UCA), as well as cytokines interleukin-1 alpha (IL-1α) and interleukin-1 receptor antagonist (IL-1RA). RESULTS: No statistically significant differences in PCA, t-UCA, c-UCA, IL-1α or IL-1RA were found between Black African and White nursing students. HIS was significantly (p = 0.001) higher in White nursing students when compared to Black African students. The ratio of tot-UCA/HIS was significantly higher in Black Africans (p = 0.0002) when compared to White nursing students. CONCLUSION: No significant differences were established in NMF content between White and Black African nursing students, other than HIS which was significantly higher in White students than in Black African students. Different HIS levels between the racial groups suggest variation in histidase activity which may be related to skin pH and pigmentation. This finding may suggest that nursing students at the beginning of their careers may have similar susceptibility to skin diseases related to NMF.

Safety of dual antiplatelet therapy using aspirin and low-dose Prasugrel with platelet reactivity testing in flow diverter treatment of intracranial aneurysms.

BACKGROUND: Dual antiplatelet therapy (DAPT) is standard care for intracranial stenting to prevent thrombotic complications. Clopidogrel resistance has resulted in patients receiving newer P2Y12 inhibitors like Prasugrel, which may reduce thrombotic complications but could increase haemorrhagic complications. This study, utilising platelet reactivity testing, compared thrombotic and haemorrhagic complications associated with Clopidogrel or 20 mg Prasugrel loading in patients treated with flow diverters (FD) for intracranial aneurysms. METHODS: We retrospectively analysed prospectively collected data from 225 consecutive FD procedures. All patients received aspirin. 147 cases received Clopidogrel and 82 received Prasugrel. All patients had VerifyNow testing before the procedure. RESULTS: P2Y12 non-responders were significantly more likely to have thrombotic complications than responders and hyper-responders (7% vs. 2%, p = 0.01). Low-dose Prasugrel resulted in a significantly lower rate of non-responders when compared with Clopidogrel (7% vs. 25%, p < 0.01). We found no statistically significant difference in rates of haemorrhage between the Clopidogrel and Prasugrel groups (2.4% vs. 3.9%, p = 0.47). There were 12 complications (≤7 days) in the Clopidogrel group versus 6 in the Prasugrel group (9% vs. 7.8%, respectively, p = 0.91) and a non-significant reduction in thrombotic complications in the Prasugrel group (5.2% vs. 3.9%, p = 0.88). No significant difference was shown in long-term complications between the groups (p = 0.33). CONCLUSION: These results support the use of platelet reactivity testing and the safety of low-dose Prasugrel for FD treatment of intracranial aneurysms.

In vitro skin permeation of potassium hexachloroplatinate and a comparison with potassium tetrachloroplatinate.

Halogenated platinum salts are known respiratory sensitizers in the workplace, and occupational exposure to platinum via the respiratory system and skin has been reported. The aim of this study was to compare the permeability and skin retention of potassium hexachloroplatinate to previously published data of potassium tetrachloroplatinate. Experiments were performed using female Caucasian skin and Franz diffusion cells with the application of 0.3 mg Pt/mL in the donor solution for 24-h. After 8-h of exposure, 1.87 ng/cm2 of Pt was detected in the receptor solution with exposure to potassium hexachloroplatinate, whereas 0.47 ng/cm2 was detected with exposure to potassium tetrachloroplatinate. After 24-h of exposure the Pt retention in the skin was 1861.60 ng/cm2 and 1486.32 ng/cm2 with exposure to potassium hexa- and tetrachloroplatinate respectively. The faster rate of Pt permeation from exposure to potassium hexachloroplatinate was confirmed by the flux and permeability coefficient values. The results indicate a higher permeability and skin retention of Pt when exposed to potassium hexachloroplatinate, confirming a higher risk associated with occupational exposure to this platinum compound relative to potassium tetrachloroplatinate.

Skin and respiratory exposure to soluble lead, cobalt, nickel, copper, arsenic and silver at two South African precious metals refineries.

OBJECTIVES: Precious metals refinery workers are exposed to soluble platinum group metals (PGMs) during PGM-refining but may also be exposed to hazardous non-PGMs (Pb, Co, Ni, Cu, As and Ag) still present in the matte following base metals refining. The aim of this article was to report the skin and respiratory exposure of workers to soluble non-PGMs during PGM-refining. METHODS: Skin and respiratory exposure (of 40 workers at two precious metals refineries) were measured simultaneously over two consecutive shifts. Skin exposure was measured on the palm, wrist, neck and forehead using Ghostwipes™ and respiratory exposure was measured using the MDHS method 46/2 during which soluble metals were extracted using 0.07 M HCl and mechanical agitation, followed by ICP-MS analysis. RESULTS: The geometric means (GM) of average skin exposure to individual soluble metals on all anatomical areas was found in the order Cu (0.018 µg/cm2) > Ni (0.016 µg/cm2) > Pb (0.008 µg/cm2) > Ag (0.006 µg/cm2) > As (0.004 µg/cm2) > Co (0.0008 µg/cm2) with the palm being the highest exposed anatomical area. The order of the GM respiratory exposure was Pb (0.224 µg/m3) > Ag (0.201 µg/m3) > Cu (0.159 µg/m3) > As (0.079 µg/m3) > Ni (0.034 µg/m3) > Co (0.016 µg/m3) with exposure to As exceeding the South African occupational exposure limit (20 µg/m3) during concentrate handling (max 66.174 µg/m3). CONCLUSIONS: Workers were exposed to a mixture of toxic PGM and non-PGMs via the skin and inhalation. Exposure to these metals could lead to the development of diseases, such as contact dermatitis, occupational allergy, or occupational cancer. Non-PGMs must be included in hazardous chemical risk assessments and control strategies implemented at precious metals refineries.

WEB vs coiling in ruptured aneurysms: A propensity score matched comparison of safety and efficacy.

BACKGROUND: We aim to compare the safety and efficacy of WEB with coiling for acutely ruptured aneurysms.METHODS: All consecutive ruptured aneurysms with width suitable for WEB (2-10 mm) treated over 5 years (1/1/2015 to 31/12/2019) were included. We recorded WFNS, Fisher grade, patient demographics and aneurysm characteristics (size, location, D/W and aspect ratio, lobulation). Primary endpoints were mRS status at 3 months, aneurysm occlusion on latest available imaging follow-up, retreatment rate and procedural complications. We applied propensity score matching using aneurysm morphology (size, D/N ratio, ASPECT ratio and lobulation) to optimise matching for WEB versus coil comparison and minimise the effects of confounding. RESULT: A total of 493 patients were identified, 97 treated with the WEB device. 1:1 propensity score matching was used to establish a matched group of 97 patients treated with coiling. The WEB arm showed 3% procedural complication rate, with no haemorrhagic complications and use of adjunctive device in 4%. Satisfactory occlusion on follow-up (mean 14 months) was 79%, with 19% retreatment rate. The coil arm had 8% complication rate, with use of an adjunctive device in 52% of cases (balloon 44%, stent 8%). Satisfactory occlusion on follow-up (mean 22 months) was 90%, with 8% retreatment rate. CONCLUSION: Treatment of ruptured wide-necked bifurcation aneurysms with WEB has a lower complication rate than coiling with high rate of satisfactory occlusion. However, there was a higher retreatment rate when compared with patients treated with coiling. An adjunct device (balloon or stent), was used in over 50% of aneurysms in the coiling group.

Personal Solar Ultraviolet Radiation Exposure of Farmworkers: Seasonal and Anatomical Differences Suggest Prevention Measures Are Required.

INTRODUCTION: Farmworkers are at risk of excess exposure to solar ultraviolet radiation (UVR) during their work activities, especially if they work in geographical areas with high ambient solar UVR levels such as in South Africa. Excess exposure to solar UVR may lead to several negative health effects such as certain cataracts and skin cancer. This study evaluated personal solar UVR exposure of a group of farmworkers to determine if they were at risk of health-related problems due to excess solar UVR exposure. METHODS: Polysulphone film (PSF) badges were placed on the shoulder, arm, and top of the head of outdoor and indoor farmworkers on a macadamia nut and avocado farm in the Limpopo province for the duration of their daily work shift to evaluate their total daily solar UVR exposure. Sixteen days were assessed for each of the three, high solar UVR seasons, i.e. autumn, spring, and summer. RESULTS: During autumn, farmworkers' arms received the highest solar UVR exposures (geometric mean (GM) = 7.8 SED, where 1 standard erythemal dose (SED) = 100 J/m2, 95% CI 6.1-9.8 SED) while the highest exposures were on the top of the head during spring (GM = 11.6 SED, 95% CI 7.3-17.4 SED) and summer (GM = 13.9, 95% CI 10.4-17.9 SED). Statistically significant differences in solar UVR exposure were found between the body sites during spring and summer but not autumn. CONCLUSIONS: The relatively high daily solar UVR exposure levels of farmworkers suggest this occupational group is at risk of excess solar UVR exposure and preventive measures with awareness information to safeguard health is necessary for employers and employees.

Effectiveness of Personal Protective Equipment in Reducing Skin Exposure to Soluble Platinum.

OBJECTIVES: Various forms of personal protective equipment (PPE), including disposable coveralls and gloves, are used to help reduce skin exposure to soluble platinum in precious metals refineries. We aimed to investigate the effectiveness of PPE in reducing workers' skin exposure to soluble platinum. METHODS: Thirty precious metals refinery workers were divided into two groups according to their use of PPE and related procedures. Group A (n = 13) used disposable coveralls worn over standard overalls along with long-sleeved rubber gloves, while Group B (n = 17) used standard overalls only and surgical nitrile gloves. The skin (palm, wrist, neck, and forehead) and respiratory exposure of these groups to soluble platinum were concurrently measured (using Ghostwipes™ and MDHS 46/2, respectively) along with their urinary platinum excretion. RESULTS: Both groups of workers experienced comparable geometric mean (GM) respiratory exposure to soluble platinum (Group A = 0.744 µg m-3 versus Group B = 0.711 µg m-3) (P = 0.789), but significantly lower skin exposure (average of all measured anatomical areas) was found for Group A (Group A = 0.005 µg cm-2 versus Group B = 0.033 µg cm-2) (P = 0.018). Significantly lower skin exposure was measured on the palm (P = 0.017), wrist (P = 0.017), forehead (P = 0.027) of Group A workers compared with Group B. No significant difference was found for the urinary platinum excretion of the two groups (Group A GM = 0.208 µg g-1 creatinine versus Group B GM = 0.361 µg g-1 creatinine) (P = 0.273). CONCLUSIONS: The use of disposable coveralls and long-sleeved rubber gloves, along with strict usage procedures, proved effective in reducing precious metals refinery workers' skin exposure to soluble platinum.

Skin and respiratory exposure to platinum group metals at two South African precious metals refineries.

OBJECTIVE: Platinum Group Metals (PGMs) are mined and refined together and have the potential to elicit adverse respiratory and skin health effects. The aim of this study was to investigate the simultaneous skin and respiratory exposure of precious metals refinery workers to all six soluble PGMs. METHODS: The simultaneous skin and respiratory exposure to soluble PGMs of forty workers at two precious metals refineries were measured over two consecutive work shifts using Ghostwipes™ and Methods for the Determination of Hazardous Substances method 46/2. Skin exposure was measured on the palm, wrist, neck, and forehead of workers. RESULTS: The highest geometric mean (GM) skin exposure (average of palm, wrist, neck and forehead) was found for soluble Pt (0.008 µg/cm2) [95% confidence interval (CI) 0.005-0.013], followed, in order, by Rh, Ir, Pd, Ru, and Os. Significantly higher concentrations of soluble PGMs were found on the palm and wrist compared to the neck and forehead (p < 0.0001). The highest GM respiratory exposure was found for soluble Pd (0.342 µg/m3 [95% CI 0.163-0.718]) followed, in order, by Pt, Rh, Ru, Ir, and Os. Skin exposure to all soluble PGMs was positively correlated with respiratory exposure (r = 0.466-0.702). CONCLUSION: This is the first study to report skin exposure to all six soluble PGMs. Precious metals refinery workers were exposed to quantifiable concentrations of soluble PGMs via both the skin and inhalation. Exposure via both routes occurred together and control measures should be aimed at reducing both skin and respiratory exposure.

Low Use of Ocular Sun Protection among Agricultural Workers in South Africa: Need for Further Research.

Although ocular diseases related to solar ultraviolet radiation exposure have a high prevalence in Africa, little is known about the occupational use of ocular photoprotective measures on the continent. In a survey of South Africa farmworkers on a farm in the Limpopo Province, we analyzed factors related to ocular sun protection including use of different types of hats and sunglasses in relation to age, gender and duration of agricultural employment. Majority of participants (80%) never wore sunglasses while 23% never wore a hat when working. More male workers used measures to protect their eyes than female workers. The type of hat most worn was a cap although broad-brimmed hats provide more effective photoprotection. The need for awareness campaigns that focus on the importance of using photoprotective measures in both an agricultural and South Africa contexts was identified.

Subjective and objective skin colour of a farmworker group in the Limpopo Province, South Africa.

BACKGROUND: Farmworkers in the Limpopo Province, South Africa, are at risk of excessive exposure to solar ultraviolet radiation (sUVR) due to both their work and the sUVR environment in the geographic area. However, the natural protection provided by this group's skin against sUVR has not been quantified. The aim of this study was to evaluate the subjective and objective skin colour of a group of farmworkers in order to classify the natural photoprotection provided by melanin and to evaluate the different measurement methods. MATERIALS AND METHODS: Skin colour was established by using the subjective Fitzpatrick skin phototype system (FST) questionnaire and two objective methods, namely the individual typology angle (ITA°) and melanin index (MI). A total of 71 farmworkers participated in the study. RESULTS: Black Africans tended to perceive their skin to be lighter than objectively measured, potentially due to cultural factors. The constitutive skin colour of most farmworkers was objectively classified in the FST V/brown group. Significant differences were found between the ITA° and MI of sun-exposed (constitutive) and non-sun-exposed (facultative) skin in Black African and White farmworkers. A strong correlation was found between ITA° and MI on different anatomical positions indicating both methods are appropriate to determine skin colour in deeply pigmented skin. CONCLUSION: The evaluation of skin colour with the use of both subjective and objective methods may be used to design an effective photoprotection programme for farmworkers in the Limpopo Province.

Endocrine profiling in patients with Fanconi anemia, homozygous for a FANCG founder mutation.

BACKGROUND: Fanconi anemia (FA) is phenotypically diverse, hereditary condition associated with bone marrow failure, multiple physical abnormalities, and an increased susceptibility to the development of malignancies. Less recognized manifestations of FA include endocrine abnormalities. International discourse has highlighted that these abnormalities are widespread among children and adults with FA. To date there has been no systematic study that has evaluated the endocrine abnormalities in a cohort of patients with FA, homozygous for a founder mutation (c.637_643del (p.Tyr213Lysfs*6)) in FANCG. The objectives of the study were to evaluate endocrine gland function in patients with FA of a single FA genotype, and to determine the frequency and nature of endocrine abnormalities in this group. METHODS: Cross-sectional, descriptive study of 24 South African patients of African ancestry with FA (homozygous for a FANCG founder mutation). Outcomes measured included growth, pubertal status, growth hormone axis screening, thyroid gland function, glucose and insulin metabolism and bone age (BA). RESULTS: Endocrine dysfunction was present in 70.8% (17 of 24), including abnormal insulin-like growth factor 1 (IGF-1)/insulin-like growth factor-binding protein 3 (IGFBP-3) in 25.0% (6 of 24), insulin resistance in 41.7% (10 of 24), abnormal thyroid function in 16.7% (4 of 24) and short stature in 45.8% (11 of 24). No abnormalities of glucose metabolism were identified. Abnormal pubertal status was seen in three males (12.5%). Abnormal BAs were present in 34.8% (8 of 23). CONCLUSION: Endocrine abnormalities occur at a high frequency in patients with FA, homozygous for a FANCG founder mutation, similar to other FA cohorts. Our data are specific to FA patients with a single genotype, and therefore provide the first genotype-phenotype information on endocrine abnormalities in South African patients, homozygous for a FANCG founder mutation. Recommendations regarding endocrine screening in this patient subgroup are made, including, but not limited to, baseline testing of thyroid function, fasted insulin and glucose, and IGF-1 and IGFBP-3.

Measurement of transepidermal water loss, stratum corneum hydration and skin surface pH in occupational settings: A review.

BACKGROUND: The skin provides a permeable barrier which may be impaired in occupational settings. Transepidermal water loss (TEWL), stratum corneum hydration (SCH) and skin surface pH (SSpH) have been used in occupational settings to predict early onset of occupational skin diseases, to measure the effectiveness of prevention strategies for occupational skin diseases, and to assess skin condition during exposure. The aim was to compare the findings, identify shortcomings in the methodology and data reporting and furthermore, to make recommendations for future studies. MATERIALS AND METHODS: A literature study was conducted on studies published before December 2018 to provide a review on the measurement of TEWL, SCH and SSpH in occupational settings. RESULTS: TEWL, SCH and SSpH were previously measured in a wide variety of industries. Results between studies were highly variable, due to different study designs and different anatomical positions measured. Not all of the measurement conditions were reported and variations in study objectives led to data being reported and interpreted differently for most studies. CONCLUSION: Incomplete reporting of methodology hinders comparison of bioengineering measurements. No bioengineering method has been proven useful as a predictive tool for occupational skin diseases, however, it is useful in the acute assessment of skin condition. It is recommended that future studies on TEWL, SCH and SSpH adhere to guidelines for occupational settings as far as possible to enable comparison between studies.

Mortality and cardiovascular and respiratory morbidity in individuals with impaired FEV1 (PURE): an international, community-based cohort study.

BACKGROUND: The associations between the extent of forced expiratory volume in 1 s (FEV1) impairment and mortality, incident cardiovascular disease, and respiratory hospitalisations are unclear, and how these associations might vary across populations is unknown. METHODS: In this international, community-based cohort study, we prospectively enrolled adults aged 35-70 years who had no intention of moving residences for 4 years from rural and urban communities across 17 countries. A portable spirometer was used to assess FEV1. FEV1 values were standardised within countries for height, age, and sex, and expressed as a percentage of the country-specific predicted FEV1 value (FEV1%). FEV1% was categorised as no impairment (FEV1% ≥0 SD from country-specific mean), mild impairment (FEV1% <0 SD to -1 SD), moderate impairment (FEV1% <-1 SD to -2 SDs), and severe impairment (FEV1% <-2 SDs [ie, clinically abnormal range]). Follow-up was done every 3 years to collect information on mortality, cardiovascular disease outcomes (including myocardial infarction, stroke, sudden death, or congestive heart failure), and respiratory hospitalisations (from chronic obstructive pulmonary disease, asthma, pneumonia, tuberculosis, or other pulmonary conditions). Fully adjusted hazard ratios (HRs) were calculated by multilevel Cox regression. FINDINGS: Among 126 359 adults with acceptable spirometry data available, during a median 7·8 years (IQR 5·6-9·5) of follow-up, 5488 (4·3%) deaths, 5734 (4·5%) cardiovascular disease events, and 1948 (1·5%) respiratory hospitalisation events occurred. Relative to the no impairment group, mild to severe FEV1% impairments were associated with graded increases in mortality (HR 1·27 [95% CI 1·18-1·36] for mild, 1·74 [1·60-1·90] for moderate, and 2·54 [2·26-2·86] for severe impairment), cardiovascular disease (1·18 [1·10-1·26], 1·39 [1·28-1·51], 2·02 [1·75-2·32]), and respiratory hospitalisation (1·39 [1·24-1·56], 2·02 [1·75-2·32], 2·97 [2·45-3·60]), and this pattern persisted in subgroup analyses considering country income level and various baseline risk factors. Population-attributable risk for mortality (adjusted for age, sex, and country income) from mildly to moderately reduced FEV1% (24·7% [22·2-27·2]) was larger than that from severely reduced FEV1% (3·7% [2·1-5·2]) and from tobacco use (19·7% [17·2-22·3]), previous cardiovascular disease (5·5% [4·5-6·5]), and hypertension (17·1% [14·6-19·6]). Population-attributable risk for cardiovascular disease from mildly to moderately reduced FEV1 was 17·3% (14·8-19·7), second only to the contribution of hypertension (30·1% [27·6-32·5]). INTERPRETATION: FEV1 is an independent and generalisable predictor of mortality, cardiovascular disease, and respiratory hospitalisation, even across the clinically normal range (mild to moderate impairment). FUNDING: Population Health Research Institute, the Canadian Institutes of Health Research, Heart and Stroke Foundation of Ontario, Ontario Ministry of Health and Long-Term Care, AstraZeneca, Sanofi-Aventis, Boehringer Ingelheim, Servier, and GlaxoSmithKline, Novartis, and King Pharma. Additional funders are listed in the appendix.

Urinary excretion of platinum (Pt) following skin and respiratory exposure to soluble Pt at South African precious metals refineries.

Adverse respiratory and skin health effects have been associated with occupational exposure to soluble platinum (Pt). However, the relationship between skin exposure and urinary Pt excretion has not yet been investigated. In this study we examined the relationship between skin and respiratory exposure to soluble Pt and urinary Pt excretion at two South African precious metals refineries. The skin and respiratory exposure to soluble Pt as well as the urinary Pt excretion of forty precious metals refinery workers was assessed simultaneously using Ghostwipes™, Methods for the Determination of Hazardous Substances method 46/2 and spot urine tests, respectively. The geometric mean for skin exposure to soluble Pt on four anatomical positions (palm, wrist, neck and forehead) was 0.008 µg/cm2 [95% confidence interval (CI): 0.005-0.013 µg/cm2], while the geometric mean for respiratory exposure was 0.301 µg/m3 (95%CI: 0.151-0.601 µg/m3) and the geometric mean for urinary Pt excretion was 0.212 µg/g creatinine (95%CI: 0.169-0.265 µg/g creatinine). Partial correlations identified significant positive correlations between skin exposure, respiratory exposure and urinary Pt excretion (r = 0.580 to 0.754). Skin and respiratory exposures to soluble Pt were both positively correlated with urinary Pt excretion, and both exposure routes should be considered when investigating occupational exposure to soluble Pt.

Correlation between the severity of myelopathy and cervical morphometric parameters on dynamic magnetic resonance imaging.

BACKGROUND: To compare morphometric factors of cervical spine in the cervical stenosis on dynamic and static magnetic resonance imaging. To analyse the relationship between the severity of myelopathy and morphometric parameters. METHODS: Patients with cervical canal stenosis scanned with MRI in neutral (N), flexion (F) and extension (E) positions were retrospectively reviewed. All cases were evaluated in Nurick and Muhle grades. Following parameters were measured: anterior and posterior length of the cervical cord (aLCC, pLCC), mid-cord distance (L value), cervical cord angle (CCA), cervical lordosis, spine/cord (S/C) angle ratio, spinal cord (SC) area, cerebrospinal fluid (CSF) area, and CSF reserve ratio (CSF/CSF plus SC). Univariate multiple regression for Nurick grade as dependent factor was used. RESULTS: Sixty-three patients and 34 men, with the mean age of 58.2 ± 11 years, were analysed. Significant differences were found for pLCC, SC area, C lordosis and CCA. The difference between F and E for C lordosis angle was 42.80° ± 14.4 and for CC angle 30.42° ± 9.6. The mean S/C angle ratio was calculated for 1.4 ± 1.3. Nurick grade positively correlated with age (p = 0.041) and S/C angle ratio (p = 0.011), negatively with SC area (p = 0.006) and flexion-extension difference of L value (0.004). CONCLUSIONS: Severity of myelopathy correlates with age, spinal cord area on extension and reduced mobility of spinal cord. An association between spine/cervical cord angle mismatch and Nurick grade was found.

Urinary excretion of platinum from South African precious metals refinery workers.

BACKGROUND: Urinary platinum (Pt) excretion is a reliable biomarker for occupational Pt exposure and has been previously reported for precious metals refinery workers in Europe but not for South Africa, the world's largest producer of Pt. OBJECTIVE: This study aimed to quantify the urinary Pt excretion of South African precious metals refinery workers. METHODS: Spot urine samples were collected from 40 workers (directly and indirectly exposed to Pt) at two South African precious metals refineries on three consecutive mornings prior to their shifts. Urine samples were analysed for Pt using inductively coupled plasma-mass spectrometry and were corrected for creatinine content. RESULTS: The urinary Pt excretion of workers did not differ significantly between sampling days. Urinary Pt excretions ranged from <0.1 to 3.0 µg Pt/g creatinine with a geometric mean of 0.21 µg Pt/g creatinine (95% CI 0.17 to 0.26 µg Pt/g creatinine). The work area (P=0.0006; η2=0.567) and the number of years workers were employed at the refineries (P=0.003; η2=0.261) influenced their urinary Pt excretion according to effect size analyses. Directly exposed workers had significantly higher urinary Pt excretion compared with indirectly exposed workers (P=0.007). CONCLUSION: The urinary Pt excretion of South African precious metals refinery workers reported in this study is comparable with that of seven other studies conducted in precious metals refineries and automotive catalyst plants in Europe. The Pt body burden of workers is predominantly determined by their work area, years of employment in the refineries and whether they are directly or indirectly exposed to Pt.

Cervical Spine and Cord Angle Mismatch in the Pathogenesis of Myelopathy.

BACKGROUND: Cervical myelopathy is a complex pathology and dynamic compression of the tethered cervical cord, which may be responsible for clinical symptoms. METHODS: Patients with cervical canal stenosis who had magnetic resonance imaging in flexion and extension positions were retrospectively reviewed. All cases were evaluated in Nurick grade. The cervical parameters-cervical cord (CC) angle, cervical lordosis, and spine/cord (S/C) angle ratio-were measured on the magnetic resonance imaging. Mean values of these parameters were compared between nonmyelopathic (Nurick grade 0) and myelopathic groups (Nurick grades 1-5). A multinomial ordinal logistic regression was used to predict outcome for Nurick grade using the CC angle, the cervical lordosis angle, and the S/C angle ratio as independent variables. RESULTS: A total of 65 patients (35 men) with the mean age of 58.6 ± 11.4 years were analyzed. A comparison of means between Nurick grade 0 against each of myelopathic grades 1-5 revealed significant differences only for the S/C angle ratio. A cumulative comparison between nonmyelopathic and myelopathic grades for the S/C angle ratio showed significant difference of 0.29 (1.16 ± 0.5 vs. 1.45 ± 0.6, respectively; P < 0.05). Cumulative comparison for the CC angle difference in flexion and extension lordosis did not show substantial differences. The S/C angle ratio was the only significant parameter in the prediction of the Nurick grade with an odds ratio of 2.63 (95% confidence interval 2.11-2.79). CONCLUSIONS: A positive correlation between Nurick grade and cervical spine and cord angle mismatch was found.

Analysis of Morphometric Parameters in Cervical Canal Stenosis on Neutral and Dynamic Magnetic Resonance Imaging.

OBJECTIVE: A dynamic compression injury of the cervical spinal cord (SC) is widely accepted in the pathophysiology of cervical myelopathy. Flexion/extension magnetic resonance imaging (MRI) provides information on the dynamic cervical injury. We sought to compare morphometric parameters on neutral and flexion/extension MRI in cervical spondylotic myelopathy. METHODS: Patients with cervical canal stenosis who had MRI in neutral, flexion, and extension positions were reviewed retrospectively. A morphometric comparison of following parameters at compression level was performed: SC area, cerebrospinal fluid (CSF) area, and CSF reserve ratio (CSF/CSF plus SC). Patients were classified according to the presence of high signal (HS) in SC, and predictors of HS were calculated by the use of logistic regression analysis. RESULTS: In total, 55 patients, 26 men, with mean age of 57 ± 13 were analyzed. Significant difference was found in mean CSF reserve ratio between flexion and extension (0.47 ± 0.18 vs. 0.40 ± 0.21, P < 0.05). SC area was significantly smaller in flexion (58.8 ± 13.3 mm2) than in both neutral (66.9 ± 22.3 mm2) and extension (68.3 ± 19.1 mm2). HS was found in 22 cases, and predictors of HS were smaller SC area on extension (odds ratio 1.46; 95% confidence interval 1.07-1.84) and smaller CSF plus SC area on flexion (OR 1.32; 95% confidence interval 1.06-1.45). Cut-off values on the receiver operating characteristic curve were 55 mm2 for SC and 99 mm2 for CSF plus SC area. CONCLUSIONS: Application of dynamic MRI in cervical stenosis reveals significant differences of both SC and CSF reserve ratio in flexion/extension and neutral positions. Patients with smaller SC area in extension and smaller CSF plus SC area in flexion have greater risk of HS on MRI.

Occupational Respiratory Exposure to Platinum Group Metals: A Review and Recommendations.

Platinum group metals (PGMs) is a group of metals that include platinum, palladium, rhodium, ruthenium, iridium, and osmium. Occupational respiratory exposure to platinum has been reported since 1945, but studies investigating occupational exposure to palladium, rhodium, ruthenium, iridium, and osmium are scarce. This review provides a summation of the information available on the respiratory exposure to PGMs in various industrial settings, methods used to assess exposure, and the possible adverse health effects resulting from occupational exposure to PGMs. Of these effects, respiratory sensitization caused by soluble PGMs is of most importance. Metallic PGMs have not been shown to cause allergic reactions. This review reiterates that occupational respiratory exposure to PGMs is dependent on the type of industry where exposure takes place, the chemical form (soluble or insoluble) of the PGMs present in the workplace air, and the tasks performed by workers in the specific work areas. Sensitization to soluble platinum is associated with the degree of exposure to soluble platinum compounds, and the highest concentrations of soluble PGMs in workplace air have been reported for precious metals refineries where personal exposures frequently exceed the occupational exposure limit for soluble platinum (2 µg/m3). Additionally, this review emphasizes that personal exposure monitoring is preferred over area monitoring when assessing workers' exposure to PGMs. The legislation applicable to occupational exposure to PGMs is also discussed, and it is highlighted that the occupational exposure limit for soluble platinum has remained unchanged, in most countries, since 1970 and that too few countries have classified PGM compounds as respiratory or skin sensitizers. Finally, recommendations are made to ensure that future investigations are comparable in terms of the type of exposure monitoring (personal or area) conducted, the type of tasks included in the exposure monitoring program, and the format in which results are reported.