Do central terminals of intact myelinated primary afferents sprout into the superficial dorsal horn of rat spinal cord after injury to a neighboring peripheral nerve?

In order to investigate whether normal myelinated primary afferent axons sprout into the territories of adjacent injured peripheral nerve fibers in the superficial dorsal horn of the spinal cord, adult rats underwent either sectioning of the saphenous or femoral nerves on one side, or else unilateral denervation of the skin of the posterior thigh. Two weeks later cholera toxin B subunit (CTb), which is normally transported selectively by myelinated somatic primary afferents, was injected into the ipsilateral (intact) sciatic nerve. The relationship between CTb, vasoactive intestinal peptide (VIP), and binding of Bandeiraea simplicifolia isolectin B4 (IB4) was then examined in the ipsilateral dorsal horn of the second to fifth lumbar spinal segments (L2-L5).

Change in blood lead concentration up to 1 year after a gunshot wound with a retained bullet.

The authors studied the time course and prevalence of elevated blood lead concentrations and associated injury- and patient-specific factors during the first year following gunshot injury. They determined blood lead levels at mean time points of 0.3, 3.

Association between essential tremor and blood lead concentration.

Lead is a ubiquitous toxicant that causes tremor and cerebellar damage. Essential tremor (ET) is a highly prevalent neurologic disease associated with cerebellar involvement. Although environmental toxicants may play a role in ET etiology and their identification is a critical step in disease prevention, these toxicants have received little attention.

Lack of evidence for sprouting of Abeta afferents into the superficial laminas of the spinal cord dorsal horn after nerve section.

The central arborizations of large myelinated cutaneous afferents normally extend as far dorsally as the ventral part of lamina II in rat spinal cord. Woolf et al. (1992) reported that after nerve injury some of these afferents sprouted into lamina I and the dorsal part of lamina II, and it has been suggested that this could contribute to allodynia associated with neuropathic pain.

Associations of renal function with polymorphisms in the delta-aminolevulinic acid dehydratase, vitamin D receptor, and nitric oxide synthase genes in Korean lead workers.

We analyzed data from 798 lead workers to determine whether polymorphisms in the genes encoding delta-aminolevulinic acid dehydratase (ALAD), endothelial nitric oxide synthase (eNOS), and the vitamin D receptor (VDR) were associated with or modified relations of lead exposure and dose measures with renal outcomes. Lead exposure was assessed with job duration, blood lead, dimercaptosuccinic acid (DMSA)-chelatable lead, and tibia lead. Renal function was assessed with blood urea nitrogen (BUN), serum creatinine, measured creatinine clearance, calculated creatinine clearance and urinary N-acetyl-beta-D-glucosaminidase (NAG), and retinol-binding protein.

Calculating the uncertainty in lead concentration for in vivo bone lead x-ray fluorescence.

A revised mathematical treatment of the calibration line intercept has been published for in vivo bone lead measurements using 109Cd-based K-shell x-ray fluorescence. The revised calibration line treatment prompts changes, presented herein, to the method for calculating the measurement uncertainty.

The relationship between blood lead, bone lead and child intelligence.

We report associations between serial measures of blood lead and intelligence in children age 10-12 years, half heavily exposed to lead from the prenatal period onward, and half relatively unexposed. For a subsample, we examine bone lead-IQ associations, comparing them with bone lead associations. Both blood and bone lead levels were associated with intelligence decrements, small relative to the contribution of social factors.

Elevated blood lead resulting from maxillofacial gunshot injuries with lead ingestion.

Purpose: The purpose of this study was to identify the contribution of ingested lead particles to elevated blood lead concentrations in victims of gunshot injury to the maxillofacial region.

Patients And Methods: As part of a larger study of the effects of retained lead bullets on blood lead, a retrospective review of study findings was completed on 5 of 8 patients who sustained injuries to the maxillofacial region. These 5 patients were recruited into the larger study within 11 days of injury and showed a penetration path for the projectile that engaged the upper aerodigestive tract.

The longitudinal association of lead with blood pressure.

Background: Several investigators have reported an association of blood lead or bone lead with increased blood pressure and hypertension, but questions remain concerning whether these effects are acute or chronic in nature.

Methods: In this longitudinal study, we evaluated the relation of lead, measured in blood and tibia, to changes in blood pressure between 1994 and 1998. We studied 496 current and former employees of a chemical-manufacturing facility in the eastern United States who had previous occupational exposure to inorganic and organic lead.

Corrections to "How to calculate lead concentration and concentration uncertainty in XRF in vivo bone lead analysis" by Kondrashov and Rothenberg.

Kondrashov and Rothenberg (Appl. Radiat. Isot.

Increases in hypertension and blood pressure during pregnancy with increased bone lead levels.

Prior studies have revealed associations of current lead exposure (blood lead) and past lead exposure (bone lead) with risks of hypertension and elevated blood pressure. The authors examined the effects of blood and bone lead on hypertension and elevated blood pressure in the third trimester and postpartum among 1,006 women enrolled in Los Angeles prenatal care clinics between 1995 and 2001. The authors measured bone lead concentration by K-shell x-ray fluorescence in the tibia (mean = 8.

L-shell x-ray fluorescence measurements of lead in bone: accuracy and precision.

This study aimed to quantify the accuracy and precision of a method for in vivo measurements of lead in bone using L-shell x-ray fluorescence (LXRF), the former via comparison with independent measurements of lead in bone obtained using electrothermal atomic absorption spectrometry (AAS) following acid digestion. Using LXRF. the lead content of adult human cadaver tibiae was measured, both as intact legs and as dissected tibiae with overlying tissue removed, the latter at several proximal-distal locations.

Projection neurons in lamina I of rat spinal cord with the neurokinin 1 receptor are selectively innervated by substance p-containing afferents and respond to noxious stimulation.

Lamina I of the spinal cord is densely innervated by nociceptive primary afferents, many of which contain substance P. It contains numerous projection neurons: the majority of these respond to noxious stimuli, however some are activated by cooling. In the rat, approximately 80% of the projection neurons express the neurokinin 1 (NK1) receptor, on which substance P acts, and most cells with this receptor are activated by noxious stimuli.

ApoE genotype, past adult lead exposure, and neurobehavioral function.

Our objective in this study was to determine if the known relation between tibia bone lead levels and neurobehavioral test scores are influenced by the apolipoprotein E (ApoE) genotype. We collected data on 20 neurobehavioral tests in 529 former organolead workers who had an average of 16 years since last occupational exposure to lead. We used linear regression to model the relations between each of 20 neurobehavioral test scores and tibia lead, a binary variable for ApoE genotype (i.

Measurements of lead in human tibiae. A comparison between K-shell x-ray fluorescence and electrothermal atomic absorption spectrometry.

The aim of this study was to validate 109Cd-based K-shell x-ray fluorescence measurements against atomic absorption spectrometry (AAS) measurements of core and surface tibia lead. The lead content of nine adult human cadaver tibiae was measured using 109Cd-based K-shell x-ray fluorescence (XRF) spectrometry and the results compared to measurements obtained using electrothermal atomization atomic absorption spectrometry following acid digestion. Each tibia was divided into nine cross-sectional segments, which were further separated into tibia core and surface samples for the AAS analytical measurements.

L-shell x-ray fluorescence measurements of lead in bone: system development.

This paper reports on the development of an L-shell x-ray fluorescence (XRF) bone lead measurement system. A secondary target gave greater lead x-ray peak signal-to-background ratios than partially plane polarized XRF. Filtration did not improve the lead x-ray peak signal-to-background ratio: the gains in spectrum quality were outweighed by the losses caused by attenuation.

L-shell x-ray fluorescence measurements of lead in bone: theoretical considerations.

This paper reviews several theoretical considerations pertinent to the use of lead L-shell x-rays for the in vivo measurement of lead in bone: the method of correcting for attenuation, the contributions to the measurement uncertainty, interferences, the depth of bone sampled and the signal strength. Both the predicted bone lead concentration and the measurement uncertainty therein are influenced by the choice of linear attenuation coefficient with which to correct for overlying tissue. Measurement uncertainty is also influenced by inter-individual variability in body composition, methodological uncertainty in the ultrasound measurement of overlying tissue thickness and discrepancy between the site of LXRF and the site of ultrasound measurement.