Position statement for adult and paediatric spirometry in South Africa: 2022 update.

Spirometry is required as part of the comprehensive evaluation of both adult and paediatric individuals with suspected or confirmed respiratory diseases and occupational assessments. It is used in the categorisation of impairment, grading of severity, assessment of potential progression and response to interventions. Guidelines for spirometry in South Africa are required to improve the quality, standardisation and usefulness in local respiratory practice. The broad principles of spirometry have remained largely unchanged from previous versions of the South African Spirometry Guidelines; however, minor adjustments have been incorporated from more comprehensive international guidelines, including adoption of the Global Lung Function Initiative 2012 (GLI 2012) spirometry reference equations for the South African population. All equipment should have proof of validation regarding resolution and consistency of the system. Daily calibration must be performed, and equipment quality control processes adhered to. It is important to have standard operating procedures to ensure consistency and quality and, additionally, strict infection control as highlighted during the COVID-19 pandemic. Adequate spirometry relies on a competent, trained operator, accurate equipment, standardised operating procedures, quality control and patient co-operation. All manoeuvres must be performed strictly according to guidelines, and strict quality assurance methods should be in place, including acceptability criteria (for any given effort) and repeatability (between efforts). Results must be categorised and graded according to current guidelines, taking into consideration the indication for the test.

6-Hydroxymelatonin protects against quinolinic-acid-induced oxidative neurotoxicity in the rat hippocampus.

Melatonin, a naturally occurring chemical mediator, although assigned a diverse range of functions, has attracted interest because of its ability to function as a free radical scavenger. Its major hepatic metabolite and photoproduct, 6-hydroxymelatonin (6-OHM), also shares this property. Since singlet oxygen and quinolinic acid (QUIN) are critically involved in the pathology of neurotoxicity, the objective of this study was to investigate the ability of 6-OHM to scavenge singlet oxygen and evaluate its ability to scavenge superoxide anions and reduce QUIN-induced neurotoxicity in the hippocampus in-vivo. The results show that 6-OHM is an efficient inhibitor of singlet oxygen formation as indicated by the rate constants and quantum yields reported for 6-OHM and zinc phthalocyanine (ZnPc), respectively. 6-OHM, appears to reduce QUIN-induced superoxide anion generation in the hippocampus, which provides some evidence of the neuroprotective effects of 6-OHM.

Melatonin generates singlet oxygen on laser irradiation but acts as a quencher when irradiated by lamp photolysis.

Melatonin, a naturally occurring chemical mediator, although assigned a diverse range of functions, has attracted interest in recent years because of its ability to function as a free radical scavenger. Because of the implications of singlet oxygen in neurotoxicity, the objective of the study was to investigate the ability of melatonin to quench singlet oxygen generated using laser irradiation or lamp photolysis. The results show that melatonin produces radicals upon laser irradiation while the lamp photolysis studies show that melatonin is able to scavenge singlet oxygen produced by naphthalene. While melatonin is a free radical scavenger under biological conditions, it acts as a generator of singlet oxygen and or radicals (as PhiDelta is 1.41) when irradiated with laser light, implying that it has the potential to be used in photodynamic therapy in the destruction of tumors.

Polyaspartamides as water-soluble drug carriers. Part 1: Antineoplastic activity of ferrocene-containing polyaspartamide conjugates.

BACKGROUND: Numerous detrimental side effects and/or lack of water-solubility of anticancer drugs often prove dose-limiting in chemotherapy. Water-soluble polymeric drug carriers may overcome/minimise many of these limitations. MATERIALS AND METHODS: Aspartic acid polymers to which ferrocene-containing antineoplastic agents are covalently bound, were tested for cytotoxicity against murine EMT-6 cancer cells. Cell survival was measured by means of the colorometric 3-(4,5-dimethylthiazol-2-yl)-diphenyltertrazolium bromide assay. RESULTS: The 90% lethal dosage of pure 3-ferrocenylbutanoic acid is 452 microg/mL LD90 for the polymeric derivative, expressed in terms of 3-ferrocenylbutanoic acid content, is only 65 microg/ml. A polymer structural effect in drug activity was evident: longer side chains linking drugs to polymer backbones enhanced drug activity. Drug activity is also enhanced if drug modifications (to enable drug anchoring) resulted in a lower ferrocenyl reduction potential. CONCLUSIONS: The effectivity of antineoplastic drugs may be enhanced by covalently anchoring them on suitable biodegradable water-soluble polymeric drug carriers.

Comparison of a new desktop spirometer (Diagnosa) with a laboratory spirometer.

BACKGROUND: The Diagnosa is a fully integrated system, able to determine spirometry, ECG, blood pressure and body composition. Real time data can be transferred via Internet to a remote receiving center. OBJECTIVES: The aim of this study was to perform biological testing of the spirometry component in subjects with normal and pathological pulmonary function. METHODS: A group of 45 patients (mean age 43.3 years, 30 males) was tested on both the Diagnosa and the standard Jaeger Masterlab spirometer according to the guidelines of the American Thoracic Society. Three subgroups of 15 subjects each (normal spirometry, obstructive and restrictive airflow limitation) were selected. RESULTS: All measurements performed with the Diagnosa (FVC, FIVC, FEV(1), PEF, FEF(25), FEF(50), FEF(75)) correlated closely (r = 0.92-0.99) with those performed with the Jaeger spirometer and showed good limits of agreement (the largest difference between the two devices being 0.2 liter for FEV(1)). Analysis of the 3 subgroups showed no difference for any parameters compared to the overall group. Electronic transfer of all data was successful. CONCLUSIONS: The Diagnosa spirometer is comparable to a standard laboratory spirometer and can be used reliably for telemedicine purposes.