Human exposure to diesel exhaust induces CYP1A1 expression and AhR activation without a coordinated antioxidant response.

BACKGROUND: Diesel exhaust (DE) induces neutrophilia and lymphocytosis in experimentally exposed humans. These responses occur in parallel to nuclear migration of NF-κB and c-Jun, activation of mitogen activated protein kinases and increased production of inflammatory mediators. There remains uncertainty regarding the impact of DE on endogenous antioxidant and xenobiotic defences, mediated by nuclear factor erythroid 2-related factor 2 (Nrf2) and the aryl hydrocarbon receptor (AhR) respectively, and the extent to which cellular antioxidant adaptations protect against the adverse effects of DE. METHODS: Using immunohistochemistry we investigated the nuclear localization of Nrf2 and AhR in the epithelium of endobronchial mucosal biopsies from healthy subjects six-hours post exposure to DE (PM10, 300 µg/m3) versus post-filtered air in a randomized double blind study, as a marker of activation. Cytoplasmic expression of cytochrome P450s, family 1, subfamily A, polypeptide 1 (CYP1A1) and subfamily B, Polypeptide 1 (CYP1B1) were examined to confirm AhR activation; with the expression of aldo-keto reductases (AKR1A1, AKR1C1 and AKR1C3), epoxide hydrolase and NAD(P)H dehydrogenase quinone 1 (NQO1) also quantified. Inflammatory and oxidative stress markers were examined to contextualize the responses observed. RESULTS: DE exposure caused an influx of neutrophils to the bronchial airway surface (p = 0.013), as well as increased bronchial submucosal neutrophil (p < 0.001), lymphocyte (p = 0.007) and mast cell (p = 0.002) numbers. In addition, DE exposure enhanced the nuclear translocation of the AhR and increased the CYP1A1 expression in the bronchial epithelium (p = 0.001 and p = 0.028, respectively). Nuclear translocation of AhR was also increased in the submucosal leukocytes (p < 0.001). Epithelial nuclear AhR expression was negatively associated with bronchial submucosal CD3 numbers post DE (r = -0.706, p = 0.002). In contrast, DE did not increase nuclear translocation of Nrf2 and was associated with decreased NQO1 in bronchial epithelial cells (p = 0.02), without affecting CYP1B1, aldo-keto reductases, or epoxide hydrolase protein expression. CONCLUSION: These in vivo human data confirm earlier cell and animal-based observations of the induction of the AhR and CYP1A1 by diesel exhaust. The induction of phase I xenobiotic response occurred in the absence of the induction of antioxidant or phase II xenobiotic defences at the investigated time point 6 h post-exposures. This suggests DE-associated compounds, such as polycyclic aromatic hydrocarbons (PAHs), may induce acute inflammation and alter detoxification enzymes without concomitant protective cellular adaptations in human airways.

Documented higher burden of advanced and very advanced HIV disease among patients, especially men, accessing healthcare in a rapidly growing economic and industrial hub in South Africa: A call to action.

BACKGROUND: Lephalale Municipality in Limpopo Province, South Africa, has seen significant economic and industrial development owing to expansion of the coal mining and power generation sectors. This development has coincided with substantial population growth of 65% between 2001 and 2016, attributable to largely (migrant) males living in the area who, overall, outnumbered females by ~121:100. The local HIV prevalence is reported to be higher than national rates. OBJECTIVES: Anonymised National Health Laboratory Service CD4+ data were used to document increasing laboratory services workload and to establish the burden of advanced (CD4+ count <200 cells/µL) and very advanced (<100 cells/µL) HIV disease among adult patients accessing public healthcare in Lephalale between 2006 and 2015. METHODS: A cross-sectional design was used to analyse CD4+ laboratory data. CD4+ outcomes were categorised by volumes of tests, year, health facility type, age categories (15 - 19, 20 - 24, 25 - 29, 30 - 34, 35 - 39, 40 - 44, 45 - 49 and >49 years), CD4+ test range (≤50, 51 - 100, 101 - 200, 201 - 350, 351 - 500 and ≥501 cells/µL) and gender. Median CD4+ counts were calculated. RESULTS: Extracted Lephalale data comprised 57 490 CD4+ results, with a mean patient age of 34 years. Considerably fewer male than female patients had CD4+ counts reported (male/female ratio 0.45:1). CD4+ test volumes showed a five-fold escalation over the study period, increasing from 1 458 tests in 2006 to 8 239 in 2015. A considerable burden of advanced and very advanced HIV disease (exceeding 50% of all cases) was noted in 2006/2007; by 2015 the proportion had fallen, but was still high at 27%. The overall median CD4+ count in 2006 (192 cells/µL) confirmed a high burden of advanced disease, with modest improvement to 289 cells/µL by 2015. Between 2006 and 2015, the median CD4+ count for females increased from 204 to 405 cells/µL, while that for males increased from 126 to 285 cells/µL. Age analysis further revealed that men aged <20 years or >25 years, and specifically those aged 30 - 45 years, had up to 44% more advanced HIV disease. CONCLUSIONS: Lower median CD4+ counts and a dramatic increase in volumes of CD4+ tests performed from 2007 onwards revealed a high burden of advanced and very advanced HIV disease in patients accessing care in Lephalale. Viewed together with Statistics South Africa census documentation of a disproportionately high number of males compared with females living in the area, these figures suggest that improved systems are urgently needed to encourage and accommodate access to HIV care for male (migrant worker) patients living and working in emerging industrial centres.

Prostate cancer age-standardised incidence increase between 2006 and 2016 in Gauteng Province, South Africa: A laboratory data-based analysis.

BACKGROUND: Prostate cancer (PCa) is the leading male neoplasm in South Africa (SA) and is the second most frequently diagnosed cancer among men globally. Age-specific incidence rates (ASIRs) vary by up to 189-fold globally, with an ASIR of 68.0 per 100 000 in 2018 in SA. OBJECTIVES: To describe PCa among men undergoing prostate biopsy in Gauteng Province, SA. METHODS: We undertook a retrospective descriptive study using prostate biopsy data collected from the National Health Laboratory Service (NHLS) database between 2006 and 2016. We extracted the Systematized Nomenclature of Medicine (SNOMED) clinical terms morphology and topography codes to assign histological findings using the International Classification of Diseases for Oncology. PCa was defined as adenocarcinoma with a reported Gleason Score (GS). The new grade group (GG) based on the GS is defined as follows; (i) GG1 for a GS ≤6; (ii) GG2 for a GS of 3 + 4 = 7 ; (iii) GG3 for a GS of 4 + 3 = 7; (iv) GG4 for a GS of 8; and (v) GG5 for a GS ≥9. Higher-grade disease was defined as GG4 and GG5 (GS ≥8), in line with local guidelines. We reported associations of PCa with a GS ≥7 with age and race and used provincial and world standard population data to determine annual ASIRs. RESULTS: We identified 22 937 biopsies referred to the NHLS between 2006 and 2016. Of the 6 448 biopsies (39%) with a PCa finding for black Africans, 46% were diagnosed with high-risk PCa compared with 36 - 40% for other race groups (p<0.0001). Black Africans were more likely than whites to have GG4 or GG5 PCa (odds ratio 1.45; 95% confidence interval 1.27 - 1.67). The ASIR increased from 44.9 per 100 000 in 2006 to 57.3 per 100 000 in 2016. CONCLUSIONS: Black African men were significantly more likely to present with PCa with a GS ≥8 (GG4 and GG5) compared with the other racial groups in Gauteng. The ASIR increased dramatically during the study period, perhaps as a result of increased screening and awareness. There is a need for additional research to better understand why black African men present with higher-grade disease.

Using Big Data Techniques to Improve Prostate Cancer Reporting in the Gauteng Province, South Africa.

Prostate cancer (PCa) data is of public health importance in South Africa. Biopsy data is recorded as semi-structured narrative text that is not easily analysed. Our study reports a pilot study that applied predictive analytics and text mining techniques to extract prognostic information that guides patient management. In particular, the Gleason score (GS) reported in a number of formats were extracted successfully. Our study reports that predominantly older men were diagnosed with PCa reporting a high-risk GS (8-10). Where cell differentiation was reported, 64% of biopsies reported poor differentiation. The approaches demonstrated in our study should be extended to a larger dataset to assess whether it has the potential to scale up to the national level.

Piloting a national laboratory electronic programme status reporting system in Ekurhuleni health district, South Africa.

BACKGROUND: The National Health Laboratory Service (NHLS) performs ~4 million CD4 tests per annum for the public health sector at 61 CD4 testing laboratories across South Africa. Currently, CD4 laboratory data captured do not differentiate between antiretroviral treatment (ART) and pre-ART care. METHODS: A cross-sectional study was undertaken to evaluate a redesigned Comprehensive Care, Management and Treatment of HIV and AIDS (CCMT) request form, incorporating a two-tick collection procedure linking the CD4 test request to patient CCMT programme status. Field testing was undertaken at three health facilities, where healthcare personnel were required to capture whether the CD4 count requested was a 'first-ever CD4', 'CD4 taken previously, not yet in ART care' or 'in ART care'. All data were extracted from the NHLS Corporate Data Warehouse and analysed using Microsoft Excel and Stata-12. RESULTS: A substantial increase in the number of request forms with a CCMT programme status (28.1% v. 84.4%) was reported pre- and post-implementation. Post-implementation data (N=1 004) revealed that 30.8% patients were ART naive ('first-ever CD4'), with 7.4% 'not yet on ART' (median CD4 counts of 150 and 328 cells/µL, respectively). Patients on ART comprised 61.9% of the study group (median CD4 count ~346 cells/µL). Sixty percent of patients were aged between 30 and 44 years, and females predominated (male/female ratio 0.7:1). CONCLUSIONS: A simple modification to the CCMT request form can successfully facilitate collection of programme status. For national implementation, it would be advantageous to have a unique patient identifier to further enhance laboratory-based programmatic monitoring and evaluation.

Implementation of a new 'community' laboratory CD4 service in a rural health district in South Africa extends laboratory services and substantially improves local reporting turnaround time.

BACKGROUND: The CD4 integrated service delivery model (ITSDM) provides for reasonable access to pathology services across South Africa (SA) by offering three new service tiers that extend services into remote, under-serviced areas. ITSDM identified Pixley ka Seme as such an under-serviced district. OBJECTIVE: To address the poor service delivery in this area, a new ITSDM community (tier 3) laboratory was established in De Aar, SA. Laboratory performance and turnaround time (TAT) were monitored post implementation to assess the impact on local service delivery. METHODS: Using the National Health Laboratory Service Corporate Data Warehouse, CD4 data were extracted for the period April 2012-July 2013 (n=11,964). Total mean TAT (in hours) was calculated and pre-analytical and analytical components assessed. Ongoing testing volumes, as well as external quality assessment performance across ten trials, were used to indicate post-implementation success. Data were analysed using Stata 12. RESULTS: Prior to the implementation of CD4 testing at De Aar, the total mean TAT was 20.5 hours. This fell to 8.2 hours post implementation, predominantly as a result of a lower pre-analytical mean TAT reducing from a mean of 18.9 to 1.8 hours. The analytical testing TAT remained unchanged after implementation and monthly test volumes increased by up to 20%. External quality assessment indicated adequate performance. Although subjective, questionnaires sent to facilities reported improved service delivery. CONCLUSION: Establishing CD4 testing in a remote community laboratory substantially reduces overall TAT. Additional community CD4 laboratories should be established in under-serviced areas, especially where laboratory infrastructure is already in place.

Do children with a specific reading disability have a general serial-ordering deficit?

Two experiments are described in which reading disabled subjects and their normal controls were tested for their ability to abstract sequential regularities from a noisy background. Subjects were presented with an adaptation of the repeated digits task of Hebb (1961) and its spatial analogue the Corsi Blocks (Milner, B. Br. Med. Bull. 27, 272-277, 1971). Normal subjects had a digit span significantly better than their block span and also significantly better than that of the disabled readers. This suggested that normal subjects have better defined "storage filters" for digits or a specific advantage in the construction of 'transitory filters' for verbal material. There were no differences between groups on block span. On the repeated digit sequences normal readers abstracted a relatively stable "storage filter" in the first five recurrent trials whereas the disabled readers showed no discrimination until the last five recurrent trials. On the repeated blocks task the disabled group performed as well as normal readers. Taken together this date gives strong evidence for a specific deficit in verbal serial organization in disabled readers but does not support a general deficit in serial organization.

CD4+ T cell enumeration in HIV infection with limited resources.

The incidence of human immunodeficiency virus (HIV) infection continues to increase in South Africa. Limited resources are available for diagnosis and management of the disease and the development of affordable strategies is required. Absolute CD4 counts are used locally predominantly to monitor disease progression and institute prophylaxis against opportunistic infections. A dramatic increase in demand for CD4 counts prompted an investigation for a more cost-effective flow cytometry method than those currently recommended by the Centers for Disease Control (CDC). CD4 counts generated by two different single tube methods using CD3/CD4/CD8 [1(3)] and CD4 [1(1)] antibodies, respectively, were compared to the CDC recommended 6 tube 2 colour panel [6(2)]. Whole blood analysis using the Coulter Multi-Q-Prep system and an Epics XL Flow Cytometer (Coulter, Hialeah, FL) was performed for each of the three methods. Random samples from HIV positive adult patients were compared. A mean difference in the absolute CD4 counts of less than 10x10(6)/l was generated by both of the alternative panels when compared with the 6(2) panel. The precision of the three methods is comparable. In reagents alone, the 1(3) and 1(1) methods represent a cost saving of 76% and 93%, respectively, over the 6(2) method. The 1(3) and 1(1) panels would permit more affordable CD4 counts to be determined by the gold standard methodology of flow cytometry with no clinically significant sacrifices in accuracy or precision.

Affordable CD4+ T cell counts by flow cytometry. II. The use of fixed whole blood in resource-poor settings.

We tested the feasibility and precision of affordable CD4+ T cell counting in resource-poor settings using a recently standardised fixative, TransFix in whole blood (WB) by flow cytometry (FCM). The precision of the assays was established under optimal conditions for single-platform FCM such as the volumetric CytoronAbsolute and the bead-based FACSCan. Fresh WB samples from HIV-seropositive and seronegative patients were tested in Tanzania and South Africa, fixed and sent to the UK for reanalysis 7 days later. Correlation, bias and limits of agreements were analysed by linear regression and the Bland-Altman test. Absolute CD4+ T cell counts remained stable for at least 10 days when TransFix was added to WB in 1:10 dilution at 20-25 degrees C, and for 7 days when added in 1:10 or 1:5 dilution to samples stored to mimic 'tropical' conditions at 37 degrees C. Higher temperatures such as 42 degrees C were tolerated for only short periods since the recovery had decreased to 63% by day 3. The reproducibility of lymphocyte subset analysis remained unchanged by TransFix with coefficient of variations <6% for all T cell subsets. Absolute CD4+ T cell counts and CD4+ T cell % values on fixed samples in the UK showed a high correlation with the results using fresh samples in Tanzania (r=0.993 and 0.969, respectively) and with the samples handled in Johannesburg (r=0.991 and 0.981) with minimal bias. Primary CD4 gating using only a single CD4 antibody also remained accurate in TransFixed samples (r=0.999). Thus, TransFix permits optimal fixation and transport of WB samples in the developing world for FCM to local regional laboratories and for quality assurance in international centres. When used together with inexpensive primary CD4 gating, TransFix will allow reliable and affordable CD4+ T cell counting by FCM in resource-poor settings.

Melatonin has no effect on the growth, morphology or cell cycle of human breast cancer (MCF-7), cervical cancer (HeLa), osteosarcoma (MG-63) or lymphoblastoid (TK6) cells.

Melatonin was previously shown to inhibit proliferation of MCF-7 human breast cancer cells. In this study the effect of melatonin on MCF-7 cells was further examined, while human cervical carcinoma (HeLa), osteosarcoma (MG-63) and lymphoblastoid (TK6) cells were tested for the first time. Haemocytometer counts, DNA content, flow cytometry and indirect immunofluorescence for nucleolar proteins, actin and beta-tubulin showed no differences in the growth, cell cycle or morphology between melatonin-exposed and control cells. The direct antiproliferative effect of melatonin thus seems to be confined to a melatonin-responsive subclone of MCF-7 cells and not applicable to the majority of cancer cells.

CD10 antigen density in childhood common acute lymphoblastic leukaemia: comparisons of race and sex.

During the 25 month period from July 1989 until August 1991, 58 children with FAB defined acute lymphoblastic leukaemia (ALL) were referred for immunophenotypic analysis. Of these, 42 children with a common/pre-B phenotype (CD19/CD10-positive) were studied specifically to assess CD10 antigen density. A pattern of segregation was found between males and females and between black and white children. Black males, who are the worst prognostic group, had the lowest CD10 density, while white females, known to constitute the best prognostic group, had significantly higher CD10 antigen density than the other groups. Black females and white males occupied intermediate positions with respect to CD10 antigen density. A two way analysis of variance showed that although sex had contributed significantly to this variation (p = 0.0038), the contribution of race was marginal (p = 0.0530). It is hypothesized that low CD10 antigen density patterns in males and in Blacks could be causally related to poor prognosis.

The use of ischemic nerve block procedures in the investigation of the sensory control of movements.

In this study the ischemic nerve block (INB) technique is investigated as a procedure for blocking afferent information in the study of the sensory control of movements. A movement replication task is used. The results suggest that the elbow, wrist and metacarpal-phalangeal joints are at three different stages of sensory information loss or reduction. With the index finger, replications of joint position are not made in the correct direction significantly greater than chance. Error is also largest for the finger. The elbow joint appears to be least affected by the block. Motor impairment under the block is also investigated and the results show that there is a marked decrement in the force exerted in flexion and extension of the index finger, wrist and elbow joints after sensory drop-out. This finding indicates that there is substantial motor impairment of movements distal to the block. The limitations of the INB technique as a procedure for investigating the control of movement under conditions of sensory loss are discussed.

Response amendments during manual aiming movements to double-step targets.

The present paper reports a double-step analysis of a discrete aiming movement. A second target step was presented during the trajectory of the response to an initial step and represented an artificially induced movement error signal. Two stimulus patterns involving steps in the same direction (an undershoot error signal) and opposite direction (an overshoot error signal) to the initial step were examined. Moreover, in a random error condition the subject had no advance information regarding the direction of the error. In a deliberate error condition the subject knew in advance whether any subsequent error would be an undershoot or overshoot. Response parameters were considered as a function of the interstep interval which was randomly varied across trials. In terms of movement time, the standard deviations and a constant amendments score of double-step trials, subjects could respond more appropriately and effectively to a deliberate rather than a random error, and an undershoot error rather than an overshoot error. These results are discussed in terms of a mixed-mode of visuo-spatial error updating and related to the generalized motor program hypothesis.

The latency of aiming movements.

The latency of movements requiring successively more and more precision was investigated in three simple reaction time experiments. The movements involved a horizontal arm sweep aimed at small circular targets. The results failed to provide strong support for the hypothesis that movements, and hence motor programs, requiring greater precision had longer latencies. The results are discussed in terms of a neural organization hypothesis, relating change in response complexity to the spatial and temporal structure of the motor program.

Serial organization and timing in a motor skill.

The temporal and serial organization (or timing) of responses in motor skill was investigated in a repetitive motor task, resisted hand cranking. Both positional timing and serial timing were analyzed using strain-gauge techniques and were related to the performance of the preferred and non-preferred hands. The results demonstrated the superiority of the preferred hand on the serial timing criteria and supported the hypothesis that skilled performance is characterized by more effective temporal structuring of the components of the response.

Latency and response complexity.

Two experiments were conducted in which the latency of movement responses of varying complexity was investigated. The complexity of an arm sweep movement was varied by (a) increasing the extent of movement from 6 in. to 18 in., (b) reversing the movement, and (c) by making two or three pauses in an on-going movement. The results only partially supported the hypothesis that the latency of a response is related to the complexity of the movement pattern. Specifically RT was longer when the response involved significant changes in the temporal organization of the movement pattern.

Effector organization and "gradation" of effort.

It is proposed that an aspect of the effector organization process is the gradation of the response. Gradation was investigated in a hand cranking task by using strain-gauge and electromyographic recording techniques. Criteria of gradation were related to (a) the impulsive force at a particular point in the cycle of movement, (b) an index of the work done per unit of time, (c) the degree of muscle activity in each of the 6 muscles analyzed, and (d) an index of muscle activity based on the pen deflection of an EMG record. Further, two criteria of the organization of the force were employed - the force range and the consistency of the force range. None of the criteria of gradation was closely related to speed of performance, but the organizational criteria showed a trend toward being related to speed. The implications of these findings are discussed.

Response complexity and the latency of different movement patterns.

Two series of experiments are described in which RT of responses of varying complexity is investigated. Complexity of arm movements was manipulated in terms of (a) the amount of force exerted in resisted movements, (b) the distance moved by the limb and the direction of movement, using reversing or continuing movements, and (c) the combining of the arms in reversing and continuing movements. Simple and two-choice RT situations were used. As response complexity increased in terms of the number of sets of response units that have to be organized into a spatio-temporal sequence, the latency correspondingly increased. However latency was not affected by changes in the amount of force exerted, or in simple reversal movements. The implications of these results are discussed.

The effects of changes in direction, load, and amplitude of movement on gradation of effort.

Gradation of a response is a form of amplification control which determines that the response as a whole is appropriately graded in effort. The present study is an investigation of the effects of changes in resistance to cranking, amplitude of movement, and direction of movement on the gradation of the response in hand cranking. Criteria of gradation were derived from strain gauge and EMG records. A modification in gradation occurred principally when the resistance to movement changed appreciably. The findings are discussed in terms of one basic pattern of organization that is used, despite variations in task conditions.

Programming precision in repetitive tapping.

The present paper reports an experiment using the Fitts' tapping paradigm. It is concerned with a comparison of movement times and accuracy during blind and visual repetitive tapping. A blind condition was used to investigate rapid aiming movements under motor program control, whilst visual aiming was used to assess the role of visual feedback for control purposes. Subjects in the blind conditions were able to replicate the amplitude specifications of the task, whereas effective target width was constant for a set amplitude and did not reflect specified target width. Subjects, furthermore, responded more rapidly when tapping blind. These results are discussed in terms of the magnitude of forces being attempted as a result of performing a set amplitude, and the role of visual feedback.