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J Levin

Publications and source records attributed to J Levin.

At least 19 recordsLinked to original sources
PubMed2006

Factors associated with HIV sero-positivity in young, rural South African men.

OBJECTIVE: To describe factors associated with HIV infection in men aged 15-26 years. SETTING: Rural Eastern Cape Province, South Africa. SAMPLE: A total of 1277 sexually experienced Xhosa male volunteers from 70 villages participating in a cluster randomized controlled trial of an HIV behavioural intervention. Xhosas circumcise during manhood initiation rituals. DESIGN: Cross-sectional, analysis of the study's baseline interviews. MAIN MEASURE: HIV sero-status, sexual practices measured with an interviewer-administered questionnaire. RESULTS: About 2% of the men were HIV positive. A logistic regression model showed HIV positivity to be associated with age (OR 1.55; 95%CI 1.22-1.95), having made a woman pregnant (OR 2.93; 95% CI 1.28-6.68), having been circumcised (OR 0.40; 95% CI 0.16-0.98), and having had sex with a man (OR 3.61; 95% CI 1.0-13.0). CONCLUSIONS: Our findings provide further evidence to suggest that circumcision is protective. There was much heterosexual risk taking among men but only pregnancy (with its association with sexual frequency) predicted HIV sero-positivity. Although relatively rare, same-sex sexual experiences were a risk factor. Male-male sexual contact is rarely assessed in HIV research in Africa and almost never addressed in general HIV prevention programming. Our findings suggest that it should be given more attention.

Adolescent↗
PubMed2006

Factors associated with HIV sero-status in young rural South African women: connections between intimate partner violence and HIV.

BACKGROUND: This paper aims to describe factors associated with HIV sero-status in young, rural South African women and the relationship between intimate partner violence (IPV) and HIV. METHODS: A total of 1295 sexually active female volunteers, aged 15-26, from 70 villages were recruited to participate in a cluster randomized controlled trial of an HIV behavioural intervention. The main measures were HIV sero-status, and IPV and sexual practices measured using a questionnaire administered during baseline interviews. RESULTS: About 12.4% of women had HIV and 26.6% had experienced more than one episode of physical or sexual IPV. After adjusting for age, HIV infection was associated with having three or more past year partners [odds ratio (OR) 2.39; 95% confidence interval (95% CI) 1.48-3.85], sex in past 3 months (OR 3.33; 95% CI 1.87-5.94), a partner three or more years older (OR 1.69; 95% CI 1.16-2.48), and a more educated partner (OR 1.91; 95% CI 1.30-2.78). IPV was associated with HIV in two-way analyses (OR 1.56; 95% CI 1.08-2.23), but the effect was non-significant after adjusting for HIV risk behaviours. The experience of IPV was strongly associated with past year partner numbers, time of last sex, and partner's education; it was also marginally associated with partner age difference. Adverse experiences in childhood, including sexual abuse, increased the likelihood of having more past year partners (OR 1.43; 95% CI 1.21-1.69). CONCLUSIONS: IPV was strongly associated with most of the identified HIV risk factors. Our findings provide further evidence of links between IPV and HIV among women and the importance of joint prevention.

Adolescent↗
PubMed2006

A cluster randomized-controlled trial to determine the effectiveness of Stepping Stones in preventing HIV infections and promoting safer sexual behaviour amongst youth in the rural Eastern Cape, South Africa: trial design, methods and baseline findings.

OBJECTIVE: To describe the study design, methods and baseline findings of a behavioural intervention trial aimed at reducing HIV incidence. METHOD: A cluster randomized-controlled trial (RCT) conducted in 70 villages in rural South Africa. A behavioural intervention, Stepping Stones, was implemented in 35 communities in two workshops of 20 men and 20 women in each community who met for 17 sessions (50 h) over a period of 3-12 weeks. Individuals in the control arm communities attended a single session of about 3 h on HIV and safer sex. Impact assessment was conducted through two questionnaire and serological surveys at 12-month intervals. The primary outcome was HIV incidence and secondary measures included changes in knowledge, attitude and sexual behaviours. Qualitative research was also undertaken with 10 men and 10 women from two sites receiving the intervention (one rural and one urban) and five men and five women from one village in the control arm. They were interviewed individually three times prior to the workshops and then 9-12 months later. RESULTS: A total of 2776 participants (1409 intervention and 1367 control) were enrolled at baseline and had an interview, and HIV sero-status was established. HIV baseline prevalence rates in women were 9.8% in the intervention arm and 12.8% in the control arm. In men the prevalence was 1.7% in the intervention arm and 2.1% in the control arm. Demographic and behavioural characteristics were similar in the two arms. In the intervention groups 59.9% of participants attended more than 75% of the sessions. In the control group 66.3% attended the control session. CONCLUSION: This is the third RCT to be conducted in sub-Saharan Africa evaluating a behavioural intervention using HIV incidence as a primary outcome. It is of particular interest as the intervention in question is used in many developing countries. There is good baseline comparability between the study arms and the process data on the workshops suggested that the interventions were feasible and adequately implemented.

Adolescent↗
PubMed2005

Phase I study of 506U78 administered on a consecutive 5-day schedule in children and adults with refractory hematologic malignancies.

PURPOSE: A phase I study was conducted to determine the maximum-tolerated dose (MTD), toxicity profile, and pharmacokinetics of a novel purine nucleoside, nelarabine, a soluble prodrug of 9-beta-D-arabinosylguanine (araG; Nelarabine), in pediatric and adult patients with refractory hematologic malignancies. PATIENTS AND METHODS: Between April 1994 and April 1997, 93 patients with refractory hematologic malignancies were treated with one to 16 cycles of study drug. Nelarabine was administered daily, as a 1-hour intravenous infusion for 5 consecutive days, every 21 to 28 days. First-cycle pharmacokinetic data, including plasma nelarabine and araG levels, were obtained on all patients treated. Intracellular phosphorylation of araG was studied in samples of leukemic blasts from selected patients. RESULTS: The MTDs were defined at 60 mg/kg/dose and 40 mg/kg/dose daily x 5 days in children and adults, respectively. Dose-limiting toxicity (DLT) was neurologic in both children and adults. Myelosuppression and other significant organ toxicities did not occur. Pharmacokinetic parameters were similar in children and adults. Accumulation of araGTP in leukemic blasts was correlated with cytotoxic activity. The overall response rate was 31%. Major responses were seen in patients with T-cell malignancies, with 54% of patients with T-lineage acute lymphoblastic leukemia achieving a complete or partial response after one to two courses of drug. CONCLUSION: Nelarabine is a novel nucleoside with significant cytotoxic activity against malignant T cells. DLT is neurologic. Phase II and III trials in patients with T-cell malignancies are encouraged.

Adolescent↗
PubMed2004

Partial CD8+ T-cell depletion of allogeneic peripheral blood stem cell transplantation is insufficient to prevent graft-versus-host disease.

Prior studies suggest that depletion of CD8+ T cells from donor bone marrow or donor lymphocyte infusions can reduce graft-versus-host disease (GVHD) without compromising graft-versus-leukemia. We explored CD8 depletion in patients undergoing matched related donor (MRD, n=25) and unrelated donor (URD, n=16) peripheral blood stem cell transplantation following myeloablative conditioning with cyclophosphamide (60 mg/kg/day i.v. x 2) and total body irradiation (200 cGy x 7 fractions). Ex vivo incubation of mobilized donor peripheral blood cells with anti-CD8 antibody coated high-density microparticles removed 99% of CD8+ cells. The median number of CD8+ cells infused was 3.9 x 10(5) cells/kg (2.2 x 10(5) in MRD, and 8.1 x 10(5) in URD patients). Post transplant immune suppression included tacrolimus in the MRD cohort, and tacrolimus plus mini-methotrexate (5 mg/m2 days +1, 3, 6, 11) in the URD cohort. All 41 patients engrafted. Grade 2-4 acute GVHD incidence was 61% (44% MRD, 88% URD). Chronic GVHD incidence was 50% (48% MRD, 55% URD). Relapse incidence was 4.9%. Estimated event-free and overall survival rates were 65 and 63%, respectively, at 1 year and 56 and 57%, respectively, at 2 years. There was no correlation between CD8+ number and GVHD or survival. A 2-log depletion of CD8+ cells from PBSC is insufficient to prevent GVHD.

Adult↗
PubMed2004

Comparison of indoor air quality in electrified and un-electrified dwellings in rural South African villages.

UNLABELLED: A feasibility study was undertaken to assess the suitability of South African rural villages due to be electrified, for the purposes of undertaking a large-scale study of the impact of reductions in indoor air pollution on acute lower respiratory infections. As part of the feasibility study, quantitative assessments of indoor air pollution in non-electrified and electrified dwellings were performed. Concurrent measurements were made of levels of respirable particulate matter (RSP-stationary), and carbon monoxide (CO) (personal on children <18 months), as well as a stationary co-located with RSP) over a 24-h period in 52 un-electrified and 53 electrified dwellings. The proportion of dwellings with a detectable 24-h concentration of RSP was significantly higher in un-electrified (48.1%) than electrified dwellings (24.5%) (chi(2) = 6.30 on 1 d.f., P = 0.012). In addition a Kruskal-Wallis test (adjusted for ties) showed that the distribution of RSP differed between un-electrified and electrified areas (Kruskal-Wallis chi(2) = 8.20 on 1 d.f., P = 0.014). In those dwellings where some RSP was detected, the amount was on average higher in the un-electrified areas (mean 162 microg/m(3), median 107 microg/m(3)) than in the electrified areas (mean 77 microg/m(3), median 37.5 microg/m(3)). Stationary (kitchen CO) levels in un-electrified dwellings ranged from 0.36 to 20.95 p.p.m. However, in electrified dwellings, kitchen levels ranged from 0 to 11.8 p.p.m. When mean concentrations of CO were compared between electrified and un-electrified dwellings using a two-sample t-test (on log-transformed data), there was overwhelming evidence (P = 0.0004) that the mean level of log (CO) in the kitchen was higher in the un-electrified areas (1.25 vs. 0.69) and also overwhelming evidence (P < 0.0001) that the mean level of log (CO) on the child was higher in the un-electrified areas (0.83 vs. 0.34). Of importance in terms of both policy and for a potential future large-scale study, is that measurable significant differences in indoor pollutants between electrified and un-electrified dwellings during summer were found in spite of only partial transition to electricity use for cooking in electrified villages. PRACTICAL IMPLICATIONS: It is estimated that at least two-thirds of all households in the developing world are still primary dependent on biomass fuels and coal. This situation applies to 59% of rural households in South Africa. In the last decade a program of providing electricity to three million homes has been underway in South Africa. Among others this intervention aims to reduce exposure to pollutants from burning biomass fuels and reduce detrimental health effects, especially in young children. This study provides scientific evidence that electrified homes in South African villages have lower levels of air pollution (RSP and CO) relative to their non-electrified counterparts.

Air Pollution, Indoor↗
PubMed2004

Mapping of the prostate in endorectal coil-based MRI/MRSI and CT: a deformable registration and validation study.

The endorectal coil is being increasingly used in magnetic resonance imaging (MRI) and MR spectroscopic imaging (MRSI) to obtain anatomic and metabolic images of the prostate with high signal-to-noise ratio (SNR). In practice, however, the use of endorectal probe inevitably distorts the prostate and other soft tissue organs, making the analysis and the use of the acquired image data in treatment planning difficult. The purpose of this work is to develop a deformable image registration algorithm to map the MRI/MRSI information obtained using an endorectal probe onto CT images and to verify the accuracy of the registration by phantom and patient studies. A mapping procedure involved using a thin plate spline (TPS) transformation was implemented to establish voxel-to-voxel correspondence between a reference image and a floating image with deformation. An elastic phantom with a number of implanted fiducial markers was designed for the validation of the quality of the registration. Radiographic images of the phantom were obtained before and after a series of intentionally introduced distortions. After mapping the distorted phantom to the original one, the displacements of the implanted markers were measured with respect to their ideal positions and the mean error was calculated. In patient studies, CT images of three prostate patients were acquired, followed by 3 Tesla (3 T) MR images with a rigid endorectal coil. Registration quality was estimated by the centroid position displacement and image coincidence index (CI). Phantom and patient studies show that TPS-based registration has achieved significantly higher accuracy than the previously reported method based on a rigid-body transformation and scaling. The technique should be useful to map the MR spectroscopic dataset acquired with ER probe onto the treatment planning CT dataset to guide radiotherapy planning.

Algorithms↗
PubMed2004

Flexural properties of denture-base polymer reinforced with glass-fibre polysulphone composite.

The aim of this study was to determine the effect of glass-fibre composite reinforcement on the flexural strength and flexural modulus poly-methyl methacrylate (PMMA). Prefabricated electrical glass-fibre polysulphone composite rods (GF/PSu), 3mm in diameter, were incorporated in cylindrical, heat polymerizing PMMA specimens with diameters of 4, 5 and 6mm respectively (n = 10). These specimens were compared with PMMA control groups of similar dimension. A three point loading test was performed in air after storage of specimens in water at 37 degrees C for 8 weeks. The following variables were measured : Flexural Strength (FS) and Flexural Modulus (FM). The data were analyzed using one way analysis of variance (ANOVA). After testing, the fracture zone was evaluated using a scanning electron microscope (SEM). The glass-fibre reinforcement used in this study significantly enhanced both the FM and FS values of PMMA. This enhancement was, however, progressively reduced in relation to an increase in cross-sectional dimension of the specimens. SEM evaluation revealed delamination and fracture of the glass-fibres in the polymer matrix.

Adhesiveness↗
PubMed2003

Management of incomplete abortion in South African public hospitals.

OBJECTIVE: To describe the current management of incomplete abortion in South African public hospitals and to discuss the extent to which management is clinically appropriate. DESIGN: A multicentre, prospective descriptive study. SETTING: South African public hospitals that manage gynaecological emergencies. SAMPLE: Hospitals were selected using a stratified random sampling method. All women who presented to the above sampled hospitals with incomplete abortion during the three week data collection period in 2000 were included. METHODS: A data collection sheet was completed at the time of discharge for each woman admitted with a diagnosis of incomplete, complete, missed or inevitable abortion during the study period. Information gathered included demographic data, clinical signs and symptoms at admission, medical management, surgical management, anaestetic management, use of blood products and antibiotics and complications. Three clinical severity categories were used for the purpose of data analysis and interpretation. MAIN OUTCOME MEASURES: Detail of medical management, detail of surgical management, use of blood products and antibiotics, methods of analgesia and anaesthesia used, and use of abortifacients. RESULTS: There is a trend towards low cost technology such as the use of manual vacuum aspiration and sedation anaesthesia; however, this is mainly limited to the better resourced tertiary hospitals linked to academic units. The use of antibiotics and blood products has decreased but much of the use is inappropriate. The use of abortifacients does include some use of misoprostol but merely as an adjunct to surgical evacuation. CONCLUSIONS: The management of incomplete abortion remains a problem in South Africa, a low income country that is still managing a common clinical problem with costly interventions. The evidence of a trend towards low cost technology is promising, albeit limited to tertiary centres. This study has given us information as how to best address this problem. More training in low cost methods is needed, targeting in particular the district and regional hospitals, and reinforced by skills training focussed mainly on undergraduates and midwife post-abortion care programmes.

Abortifacient Agents↗
PubMed2002

A survey of blood lead levels among young Johannesburg school children.

Studies conducted around the world have established beyond doubt that elevated childhood blood lead levels may lead to detrimental health effects. Research has shown that certain groups of South African children are at particular risk of elevated blood lead levels. Johannesburg is the largest urban complex in southern Africa, with a population of around 3 million and extensive industrial and manufacturing activity. Among the challenges posed in the city are rapid urbanization, extensive poverty, and inequity. Little information on the blood lead distribution of Johannesburg children is available. This study was undertaken to determine blood lead levels among children living in three areas of Johannesburg: inner city suburbs and the low-income townships of Alexandra and Westbury to the north and west of the city center, respectively. The results indicated that blood lead levels ranged from 6 to 26 micro g/dL, with a mean level of 11.9 micro g /dL. The blood lead levels of 78% of children equaled or exceeded 10 micro g/dL, the current international action level. Maternal educational status, the presence of smokers in the home, and living in an informal dwelling were among the factors associated with elevated blood lead levels.

Child↗
PubMed2002

Oral eniluracil/5-fluorouracil in patients with inoperable hepatocellular carcinoma.

BACKGROUND: Conventional systemic chemotherapy currently available for patients with inoperable hepatocellular carcinoma is ineffective. The purpose of this study was to evaluate the safety and efficacy of eniluracil/5-fluorouracil (5-FU) in the treatment of patients with this highly refractory disease. PATIENTS AND METHODS: This multicenter, open-label study evaluated a 28-day oral regimen of 5-FU (1 mg/m2 twice daily) plus the dihydropyrimidine dehydrogenase inhibitor, eniluracil (10 mg/m2 twice daily), in patients with chemotherapy-naive or anthracycline-refractory inoperable hepatocellular carcinoma. RESULTS: A total of 36 patients enrolled into the study. No patient showed a confirmed partial or complete tumor response, although nine patients (25%) had a best response of stable disease. The median duration of progression-free survival was 9.6 weeks [95% confidence interval (CI) 9.1-10.6 weeks], and the median duration of overall survival was 32.7 weeks (95% CI 17.4-71.6 weeks). Eniluracil/5-FU was well tolerated. Diarrhea, the most frequent treatment-related non-hematological toxicity, occurred in 11 patients (31%). Hematological toxicities were infrequent and usually mild. CONCLUSIONS: Eniluracil/5-FU as a 28-day oral outpatient regimen is well tolerated by patients with inoperable hepatocellular carcinoma, although minimal activity was observed when given as monotherapy at the dose used in this study.

Administration, Oral↗
PubMed2001

Thrombocytopenic c-mpl(-/-) mice can produce a normal level of platelets after administration of 5-fluorouracil: the effect of age on the response.

Administration of 5-fluorouracil (5-FU) to mice results in a marked increase in the level of circulating platelets in 10 days. Mice lacking Mpl, the receptor for thrombopoietin (TPO), are thrombocytopenic. To gain insight into the mechanism by which 5-FU produces such a substantial stimulation of platelet production, this study investigated whether 5-FU (150 mg/kg) produced thrombocytosis in c-mpl(-/-) mice, thus establishing whether TPO was required for this response. A 5- to 6-fold increase in platelet levels in c-mpl(-/-) mice (to approximately 1000 x 10(9)/L) was observed on days 20 and 25 after 5-FU injection. Thus, at the peak of the response, c-mpl(-/-) mice had platelet levels comparable to those in normal mice. Administration of 5-FU also produced thrombocytosis in previously splenectomized c-mpl(-/-) mice. Comparison of the platelet response to 5-FU in young (6-12 weeks) and old (33-46 weeks) c-mpl(-/-) mice found that older mice produced a much more marked response than younger mice, with a mean maximum platelet level of approximately 1700 x 10(9)/L. To determine whether this increase in circulating platelets was preceded by an increase in hematopoietic progenitors, serial cultures of bone marrow and spleen were evaluated. A considerable increase in all colony types studied was observed on days 15 and 20 in spleens of c-mpl(-/-) mice, but no similar elevations were detected in bone marrow. These results indicate that c-mpl(-/-) mice can achieve a normal level of platelets after 5-FU injection, by means of a TPO-independent mechanism, and that they respond to 5-FU myelosuppression by producing large numbers of megakaryocytic, myeloid, and erythroid progenitors. (Blood. 2001;98:1019-1027)

Age Factors↗
PubMed2001

Rate coefficients and final states for the dissociative recombination of LiH+.

The dissociative recombination of LiH+ ions with low-energy electrons is observed at a storage ring and the final states are analyzed using fragment imaging and field ionization techniques. The rate coefficient is found to be larger than its estimated value used in astrophysical models. Mostly the highest energetically possible Rydberg states of the lithium atom are populated by the reaction, indicating a common trend for molecular recombination via the noncrossing mode.

Journal Article↗
PubMed2001

Two- and three-body kinematical correlation in the dissociative recombination of H(3)(+).

Fragmentation patterns for dissociative recombination of the triatomic hydrogen molecular ion H(3)(+) in the vibrational ground state have been measured using the storage ring technique and molecular fragment imaging. A broad distribution of vibrational states in the H(2) fragment after two-body dissociation and a large predominance of nearly linear momentum geometries after three-body dissociation are found. The fragmentation results are directly contrasted with Coulomb explosion imaging data on the initial H(3)(+) geometry, compared to existing wave-packet calculations, and considered in the light of a simple physical picture.

Journal Article↗
PubMed2001

Disease-modifying activity of SB 273005, an orally active, nonpeptide alphavbeta3 (vitronectin receptor) antagonist, in rat adjuvant-induced arthritis.

OBJECTIVE: To evaluate the effects of SB 273005, a potent, orally active nonpeptide antagonist of the integrin avbeta3 vitronectin receptor, on joint integrity in rats with adjuvant-induced arthritis (AIA). METHODS: Male Lewis rats with AIA were orally dosed either prophylactically (days 0-20) or therapeutically (days 10-20) with SB 273005. Efficacy was determined by measurement of paw inflammation, assessment of bone mineral density using dual-energy x-ray absorptiometry (DEXA), magnetic resonance imaging (MRI), and histologic evaluation. RESULTS: SB 273005 is a potent antagonist of the closely related integrins, avbeta3 (Ki = 1.2 nM) and alphavbeta5 (Ki = 0.3 nM). When SB 273005 was administered prophylactically to AIA rats twice per day, it inhibited paw edema at doses of 10, 30, and 60 mg/kg, by 40%, 50%, and 52%, respectively. Therapeutic administration twice daily was also effective, and a reduction in paw edema was observed at 30 mg/kg and 60 mg/kg of the antagonist (by 36% and 48%, respectively). SB 273005 was also effective when administered once per day, both prophylactically and therapeutically. Significant improvement in joint integrity in treated rats was shown using DEXA and MRI analyses. These findings were confirmed histologically, and significant protection of bone, cartilage, and soft tissue was observed within the joint. CONCLUSION: Symptoms of AIA in rats were significantly reduced by either prophylactic or therapeutic treatment with the alphavbeta3 antagonist, SB 273005. Measurements of paw inflammation and of bone, cartilage, and soft tissue structure indicated that this compound exerts a protective effect on joint integrity and thus appears to have disease-modifying properties.

Administration, Oral↗
PubMed2001

Genesis of clone size heterogeneity in megakaryocytic and other hemopoietic colonies: the stochastic model revisited.

OBJECTIVE: We previously showed that the distributions of the numbers of doublings (NbD) undergone by individual megakaryocyte progenitors before commitment to polyploidization are markedly skewed and can consistently be fitted to straight lines when plotted on semilogarithmic coordinates. The slope of such lines, which yields the probability of polyploidization per doubling, is made less steep by stimulators of megakaryocyte colony formation and is less steep in mixed erythroid-megakaryocyte than in pure megakaryocyte colonies. Therefore, megakaryocytopoiesis provides a unique model for the study of clonal heterogeneity in a hemopoietic lineage, which is the subject of this review. DATA SOURCES: Articles relevant to the interpretation of these data were selected from the authors' and public databases. DATA SYNTHESIS: Exponential NbD distributions were first explained by postulating that following the assembly of thrombopoiesis-specific regulators, megakaryocyte progenitors require only a single random event to arrest proliferation and commit to polyploidization. However, this stochastic model was refuted by data indicating that intrinsic properties of individual progenitors affect the NbD they achieve. We suggest that the unequal repartition of critical compounds (including receptors, signaling molecules, and gene regulators) inherent in the stem cell-progenitor transition causes a heritable heterogeneity in megakaryocyte progenitor responsiveness to polyploidization inducers. This model would be compatible with 1) the evidence for intraclonal synchronization in megakaryocyte and other hemopoietic clones generated by committed progenitors; 2) the low probability of polyploidization of the relatively insensitive bipotent megakaryocyte progenitors; and 3) the thesis that stimulators act in part by recruiting megakaryocyte progenitor cells endowed with lesser responsiveness to polyploidization inducers and higher proliferative potential. CONCLUSION: The responsiveness of individual megakaryocyte progenitors to polyploidization inducers may be a major determinant of the exponential shape of NbD distributions.

Animals↗
PubMed2001

Aluminium uptake and excretion in potroom workers of a new primary aluminium smelter during the construction stage.

The aim of this study was to define bio-accumulation and excretion patterns of aluminium in newly employed potroom workers as well as changes in ambient aluminium levels in the potrooms of a modern aluminium smelter during the plant construction stage and one year into full production. A study was carried out on 115 newly employed volunteer potroom workers at various intervals, over a total period of 36 months. Before commencement of employment a structured questionnaire was completed by all study participants and the first collection of blood and urine specimens took place. As none of the subjects had ever worked in the aluminium industry before, they also served as their own controls. Atomic absorption spectroscopy was used to measure the aluminium content in the biological fluids and the content of the metal in the ambient air of the potrooms. Significantly, the study found an early and marked biological response to inhalation of very low levels of airborne aluminium. After only 12 months, the mean concentration of aluminium in serum had almost doubled; thereafter it levelled off. A mixed model analysis did not find any differences in the concentrations of aluminium in the serum of the subjects since the variation between subjects at any given time was much smaller than the variation within subjects. This may be an indication of the pronounced effect of aluminium inhalation on the kinetics of this metal in the human body. Furthermore, urinary excretion of aluminium by the potroom workers showed a linear increase reaching a concentration of only 49 microg l(-1) at the 36 month stage, suggesting a slow rate of elimination.

Adult↗