Detection of macaque perforin expression and release by flow cytometry, immunohistochemistry, ELISA, and ELISpot

Simian immunodeficiency virus (SIV)-infection in macaques provides an important animal model for human immunodeficiency virus-1 (HIV-1) infection. The involvement of perforin (PFN), released by cytotoxic cells to mediate killing of virus-infected cells, has been difficult to assess in this experimental model due to a lack of reagents. We therefore evaluated monoclonal antibodies (mAbs) Pf-80, Pf-164 and Pf-344, previously raised against human PFN, for cross-reactivity with macaque PFN. Mabs Pf-164 and Pf-344 reacted with intracellular PFN in peripheral blood mononuclear cells (PBMC) from cynomolgus and rhesus macaques by flow cytometry and stained PFN in rhesus lymphoid tissue by immunohistochemistry (IHC). Moreover, PFN capture enzyme-linked immunosorbent (ELISA) and enzyme-linked immunospot (ELISpot) assays utilizing mAbs Pf-164/Pf-80 for capture and mAb Pf-344 for detection were used to quantify PFN release by mitogen-stimulated cynomolgus and rhesus PBMC. The PFN ELISpot was further used to quantify antigen-specific CD8+ T cells by ex vivo stimulation of PBMC from cynomolgus macaques immunized against SIV/HIV-1. These macaque PFN-reactive mAbs and immunoassays will be valuable new tools for investigation of cytotoxic T lymphocyte (CTL) responses in non-human primate models of infectious diseases as well as for vaccine development.     

Assessment of intermittent trichloroethylene exposure in vapor degreasing.

To validate various sampling strategies in assessment of trichloroethylene (TCE) exposure, urine and air samples were obtained from 29 metal workers involved in vapor degreasing. Urinary trichloroacetic acid and trichloroethanol were useful metabolites to estimate TCE exposure on a group basis, but the predictive value of a single urine sample was low when related to the air concentration. With intermittent TCE exposure, the best information is obtained by analyzing both metabolites.     

Heavy lifting during pregnancy--a hazard to the fetus? A prospective study

The influence of heavy lifting during pregnancy on gestational age, birthweight and the risk of fetal death (spontaneous abortion or stillbirth) was investigated in a prospective study of 3906 occupationally active women. Information on exposure was collected at the women's first contact with the antenatal care centres in Orebro County from October 1980 to June 1983. Logistic and linear regression were used to analyse the data, allowing for several non-occupational factors in the models. Women who reported heavy lifting did not have in general more unfavourable outcomes than other women, although the risk estimates varied between different occupational categories. Lifting of weights greater than or equal to 12 kg more than 50 times per week increased the risk of pre-term birth (less than 37 weeks of gestation--odds ratio 1.7), but only among women who stopped working before the 32nd week of pregnancy. Unfavourable outcomes were more common among those who reported chemical exposure during pregnancy. The preventive routines and regulations in Sweden may have helped to reduce possible risks from heavy lifting during pregnancy.     

Long-term follow up of workers exposed to solvents.

Long term occupational exposure to organic solvents may cause adverse effects to the central nervous system. This collaborative study between six Swedish departments of occupational medicine examines the overall prognosis in terms of working capacity, symptoms, and psychometric test performance for individuals occupationally exposed to organic solvents. After re-analyses of the data from an initial clinical investigation of 111 men, the subjects were divided into two subgroups: one group of 65 with symptoms but no impairment on the tests and one group of 46 with toxic encephalopathy (symptoms and test impairment). At least five years after the initial examination the subjects were asked to attend a re-examination that included a structured medical interview and a psychometric investigation. The results indicate that effects on the central nervous system persist even when exposure has ceased. In the group of 46 more men had stopped working and were receiving sickness or early retirement pensions. This group also had reduced activity levels with regard to everyday life, leisure activities, and education or training and more neuropsychiatric symptoms. There was no support for the view that a solvent induced toxic encephalopathy is a progressive disease comparable with presenile dementia such as Alzheimer's disease or Pick's disease. If a worker was removed from exposure when he presented symptoms without signs of impairment in intellectual function recovery was seen in most cases.     

Erratum

Gunvor Gard and Sigrid Tibaek want it to be known that in the following two publications Sigrid Tibaek has an affiliation to both Department of Geriatrics and Rheumatology, Copenhagen University Hospital, Glostrup, Denmark and Department of Health Sciences, Division of Physiotherapy, Lund University, Lund, Sweden.     

Glucose metabolism during leg exercise in man

Arterial concentrations and net substrate exchange across the leg and splanchnic vascular bed were determined for glucose, lactate, pyruvate, and glycerol in healthy postabsorptive subjects at rest and during 40 min of exercise on a bicycle ergometer at work intensities of 400, 800, and 1200 kg-m/min.Rising arterial glucose levels and small decreases in plasma insulin concentrations were found during heavy exercise. Significant arterial-femoral venous differences for glucose were demonstrated both at rest and during exercise, their magnitude increasing with work intensity as well as duration of the exercise performed. Estimated glucose uptake by the leg increased 7-fold after 40 min of light exercise and 10- to 20-fold at moderate to heavy exercise. Blood glucose uptake could at this time account for 28-37% of total substrate oxidation by leg muscle and 75-89% of the estimated carbohydrate oxidation.Splanchnic glucose production increased progressively during exercise reaching levels 3 to 5-fold above resting values at the heavy work loads. Close agreement was observed between estimates of total glucose turnover during exercise based on leg glucose uptake and splanchnic glucose production. Hepatic gluconeogenesis-estimated from splanchnic removal of lactate, pyruvate, glycerol, and glycogenic amino acids-could supply a maximum of 25% of the resting hepatic glucose production but could account for only 6-11% of splanchnic glucose production after 40 min of moderate to heavy exercise.IT IS CONCLUDED THAT: (a) blood glucose becomes an increasingly important substrate for muscle oxidation during prolonged exercise of this type: (b) peripheral glucose utilization increases in exercise despite a reduction in circulating insulin levels: (c) increased hepatic output of glucose, primarily by means of augmented glycogenolysis, contributes to blood glucose homeostasis in exercise and provides an important source of substrate for exercising muscle.     

Prediction of outcomes of secondary alveolar bone grafting in children born with unilateral cleft lip and palate

The aim of this cross-sectional clinical outcome study using retrospective data capture of treatment histories was to examine the characteristics of children born with unilateral cleft lip and palate (UCLP) in the United Kingdom (UK) who were not grafted at the appropriate age or who had an unsuccessful secondary alveolar bone graft. The subjects were born with complete non-syndromic UCLP between 1.4.82 and 31.3.84 and were aged between 12.0 years and 14.7 years at the time of data collection under the care of 48 cleft teams. The success of secondary alveolar bone grafting was assessed using a modification of the Bergland index. There were no independent predictors for unmet bone grafting need. The outcome of secondary alveolar bone grafting was assessed for 164 subjects; 90 (55%) had a successful first graft. Non-Caucasian (P = 0.037) and increasing age at grafting (P = 0.007) were risk factors for poor outcome. After adjustment for other risk factors, increased age at grafting was independently associated with having a seriously deficient or failed graft (OR = 1.03; 95% CI 1.01-1.06 P = 0.036). All the non-Caucasians in this sample had an unsatisfactory graft. Increasing age in months at grafting and ethnicity are predictors for poor outcome of secondary alveolar bone grafting in children born with UCLP in the UK.     

Long term changes in health complaints after removal of amalgam restorations

Objective: Concerns over adverse effects of mercury released from dental amalgam sometimes lead patients to request removal of their amalgam restorations. Several studies report improvement of subjective health after removal of amalgam restorations, but the mechanisms are unclear. The aim of this paper is to present data on long term changes in intensity of health complaints after amalgam removal in a group of patients with health complaints self-attributed to dental amalgam. Data from the five years follow-up in a clinical trial are presented and related to potential determinants of change.

Materials and methods: Patients previously referred to a specialty unit for health complaints attributed to amalgam restorations were included in the study. The 20 participants who were allocated to the treatment group had all amalgam restorations removed and replaced with other dental restorative materials. Intensity of health complaints was calculated from questionnaire data and personality variables were measured by MMPI-2.

Results: At the follow-up five years after the amalgam removal was completed, intensity of general health complaints was significantly reduced (p=.001), but the symptom load was still high. The reduction was significantly correlated with concentration of mercury in urine at pre-treatment. There were no significant correlations with personality variables.

Conclusions: Removal of amalgam restorations was followed by a long term reduction of general health complaints, which was associated with mercury concentration in urine before amalgam removal. Additional studies are needed to confirm the potential mechanisms for the observed reduction.