Flexible robotic teleoperation architecture for intelligent oil fields

Teleoperation virtual platforms allow people to send their skills and capacities into machines located in either relative close (few meters away) or far (different continents) locations. With the use of lightweight protocols, people can remotely control the actions and movements of robots so they can avoid physical interaction with dangerous or risky places. Oil and gas well-pads stations are working zones considered hazardous due to the various chemical substances used in their daily processes. This characteristic makes these places the perfect candidates for the implementation of teleoperation solutions in order to reduce the direct interaction of humans with different chemicals and risky situations. The following investigation focuses on the development of a base teleoperation scheme to perform inspection and maintenance tasks in the inside one of these hydrocarbon facilities. The proposed system aims to generate an easily scalable teleoperation solution using distributed control schemes and a lightweight communication protocol to remotely manipulate a KUKA mobile manipulator. As the first stage of this investigation, the main result focuses on the development of the generic control and communication functions that allow the physical testing of the system using a KUKA YouBOT mobile manipulator and the help of a qualified operator of the station.

State-of-the-art of waste wood supply chain in Germany and selected European countries

According to the statistic office of the European Union (Eurostat), Germany is the main producer of waste wood in Europe followed by France, United Kingdom, Italy and Finland. Based on the characteristics of the waste wood, it can be classified in four (4) categories: A I, A II, A III and A IV. This paper focuses in the A I waste wood since is the only category able to be used directly for both material and energy purposes without a previously pre-treatment. Currently, most of this waste wood is used for direct energy production due to the previous government legislation that promoted its use directly in incineration facilities. However, the newest Renewable Energy Act (EEG 2017) may promote the cascade-use of A I waste wood prior to be intended for energy purposes. Nonetheless, the government incentives to the energy sector is not the only bottleneck that the use of A I waste wood as raw material in the wood-based industry has to overcome. The peak availability, collection logistics (collection centers and transportation) and recycling facility location are some of the parameters that must be considered in order to design the "best" supply chain network for A I waste wood. This work presents a detailed description of the effect of the hierarchical strategic decision in the proper design of the waste wood supply chain. Additionally, the global picture of waste wood recycling in different European countries (UK, Italy and Finland) is briefly presented.

18F-FDG-PET SUV AS A PROGNOSTIC MARKER OF INCREASING SIZE IN THYROID CANCER TUMORS

OBJECTIVE

Positron emission tomography/computed tomography (PET/CT) scans with 2-[fluorine-18] fluoro-2-deoxy-D-glucose (¹⁸F-FDG) are used in high-risk thyroid cancer patients to identify metastasis. The prognostic significance of increases in standardized uptake values (SUVs) has not been clearly defined. This pilot study investigated the correlation between SUV increases and subsequent changes in individual lesion size.

METHODS

A retrospective chart review of patients with histologically confirmed thyroid cancer who were monitored with serial ¹⁸F-FDG-PET/CT scans from 2008 to 2013 was performed. Forty-seven patients were selected for analysis. A mixed-effects statistical model was used after data normalization.

RESULTS

For a 10% increase in SUV, a 6% increase in tumor area was observed (P<.0001). Analysis on cube root-transformed data from serial scans was significant in 4 of 5 groups: scans 1 to 2 (P = .0001), scans 2 to 3 (P = .0005), scans 3 to 4 (P = .008), scans 4 to 5 (P = .66), and overall (P<.0001). After exclusion of outliers, for a 10% increase in SUV, the expected percentage increases in area on subsequent scans were found to be 3.4% (P = .0006), 2.6% (P = .005), 4% (P = .074), and 4.1% (P = .27) for the second, third, fourth, and fifth scans, respectively. The association was similarly significant in cases with a ≥25% increase in SUV. Secondary analysis showed a significant association of SUV with thyroglobulin (Tg) level (P = .035) but not with thyroid-stimulating hormone (TSH) level (P = .85).

CONCLUSIONS

A significant positive correlation was noted between the increase in lesional SUV and subsequent increase in lesion area. An increase in lesional SUV in subsequent scans may portend tumor growth and could prompt consideration for earlier or more aggressive intervention.

ABBREVIATIONS

DTC = differentiated thyroid cancer EORTC = European Organization for Research and Treatment of Cancer ¹⁸F-FDG = 2-[fluorine-18] fluoro-2-deoxy-D-glucose FNA = fine-needle aspiration MTC = medullary thyroid cancer PET/CT = positron emission tomography/computed tomography PVE = partial volume effect RAI = radioactive iodine SUV = standardized uptake value Tg = thyroglobulin TSH = thyroid-stimulating hormone.

Cold Water Immersion is Acutely Detrimental but Increases Performance Post-12 h in Rugby Players

We evaluated the effectiveness of cold water immersion on recovery of performance (i. e., the ability of repetitively performing a physical test) in rugby players acutely and 12 h later. 8 male rugby union players (23±4.7 years; 176.9±4.5 cm; 87.5±8.6 kg) performed a rugby-specific exercise protocol (40 min) followed by recovery strategies: cold water immersion (8.9±0.6°C; 9 min with 1 min out of water, repeated twice) or control (players remained seated for 20 min) in a random order. The players underwent performance tests (countermovement and 30 s continuous jumps and agility T) at 4 time points: at baseline, immediately after rugby-specific exercise, post-recovery strategies and 12 h later. The performance of the agility and countermovement jump test were not different between cold water immersion and control immediately post rugby-specific exercises and 12 h thereafter. However, the 30 s continuous jump test performance decreased immediately but increased 12 h later after cold water immersion compared with control. Perception of recovery was better in the cold water immersion group compared with controls post 12 h exercise. Cold water immersion improves 30 s continuous jump performance, total quality recovery and seems to be an easy and practical tool for coaches and players, especially during congested periods of the season when fast recovery (~12 h) for the following activity is essential.

Selective Allosteric Inhibition of MMP9 Is Efficacious in Preclinical Models of Ulcerative Colitis and Colorectal Cancer

Expression of matrix metalloproteinase 9 (MMP9) is elevated in a variety of inflammatory and oncology indications, including ulcerative colitis and colorectal cancer. MMP9 is a downstream effector and an upstream mediator of pathways involved in growth and inflammation, and has long been viewed as a promising therapeutic target. However, previous efforts to target matrix metalloproteinases (MMPs), including MMP9, have utilized broad-spectrum or semi-selective inhibitors. While some of these drugs showed signs of efficacy in patients, all MMP-targeted inhibitors have been hampered by dose-limiting toxicity or insufficient clinical benefit, likely due to their lack of specificity. Here, we show that selective inhibition of MMP9 did not induce musculoskeletal syndrome (a characteristic toxicity of pan-MMP inhibitors) in a rat model, but did reduce disease severity in a dextran sodium sulfate-induced mouse model of ulcerative colitis. We also found that MMP9 inhibition decreased tumor growth and metastases incidence in a surgical orthotopic xenograft model of colorectal carcinoma, and that inhibition of either tumor- or stroma-derived MMP9 was sufficient to reduce primary tumor growth. Collectively, these data suggest that selective MMP9 inhibition is a promising therapeutic strategy for treatment of inflammatory and oncology indications in which MMP9 is upregulated and is associated with disease pathology, such as ulcerative colitis and colorectal cancer. In addition, we report the development of a potent and highly selective allosteric MMP9 inhibitor, the humanized monoclonal antibody GS-5745, which can be used to evaluate the therapeutic potential of MMP9 inhibition in patients.

Detecting drawdowns masked by environmental stresses with water-level models

Detecting and quantifying small drawdown at observation wells distant from the pumping well greatly expands the characterized aquifer volume. However, this detection is often obscured by water level fluctuations such as barometric and tidal effects. A reliable analytical approach for distinguishing drawdown from nonpumping water-level fluctuations is presented and tested here. Drawdown is distinguished by analytically simulating all pumping and nonpumping water-level stresses simultaneously during the period of record. Pumping signals are generated with Theis models, where the pumping schedule is translated into water-level change with the Theis solution. This approach closely matched drawdowns simulated with a complex three-dimensional, hypothetical model and reasonably estimated drawdowns from an aquifer test conducted in a complex hydrogeologic system. Pumping-induced changes generated with a numerical model and analytical Theis model agreed (RMS as low as 0.007 m) in cases where pumping signals traveled more than 1 km across confining units and fault structures. Maximum drawdowns of about 0.05 m were analytically estimated from field investigations where environmental fluctuations approached 0.2 m during the analysis period.

A novel method for the purification of low soluble recombinant C-type lectin proteins

Snake venoms contain a complex mixture of many biological molecules including proteins. The purification of recombinant proteins is a key step in studying their function and structure with affinity chromatography as the common method used in their purification. In bacterial expression systems, hydrophobic recombinant proteins are usually precipitated into inclusion bodies, and contaminants are typically associated with tagged proteins after purification. The purpose of this study was to develop a procedure to purify hydrophobic recombinant proteins without an affinity tag. Snake venom mature C-type lectin-like proteins (CLPs) with a tag were cloned, expressed, and purified by repeated sonication and wash steps. The effects of the signal peptide on the expression and solubility of the recombinant protein were investigated. The CLPs in washed inclusion bodies were solubilized and refolded by dialysis. The CLPs without a tag were successfully purified with a yield 38 times higher than the traditional method, and inhibited blood platelet aggregation with an IC(50) of 100.57 μM in whole blood. This novel procedure is a rapid, and inexpensive method to purify functional recombinant hydrophobic CLPs from snake venoms useful in the development of drug therapies.

Convergence of the mammalian target of rapamycin complex 1- and glycogen synthase kinase 3-β-signaling pathways regulates the innate inflammatory response

The PI3K pathway and its regulation of mammalian target of rapamycin complex 1 (mTORC1) and glycogen synthase kinase 3 (GSK3) play pivotal roles in controlling inflammation. In this article, we show that mTORC1 and GSK3-β converge and that the capacity of mTORC1 to affect the inflammatory response is due to the inactivation of GSK3-β. Inhibition of mTORC1 attenuated GSK3 phosphorylation and increased its kinase activity. Immunoprecipitation and in vitro kinase assays demonstrated that GSK3-β associated with a downstream target of mTORC1, p85S6K, and phosphorylated GSK3-β. Inhibition of S6K1 abrogated the phosphorylation of GSK3-β while increasing and decreasing the levels of IL-12 and IL-10, respectively, in LPS-stimulated monocytes. In contrast, the direct inhibition of GSK3 attenuated the capacity of S6K1 inhibition to influence the levels of IL-10 and IL-12 produced by LPS-stimulated cells. At the transcriptional level, mTORC1 inhibition reduced the DNA binding of CREB and this effect was reversed by GSK3 inhibition. As a result, mTORC1 inhibition increased the levels of NF-κB p65 associated with CREB-binding protein. Inhibition of NF-κB p65 attenuated rapamycin's ability to influence the levels of pro- or anti-inflammatory cytokine production in monocytes stimulated with LPS. These studies identify the molecular mechanism by which mTORC1 affects GSK3 and show that mTORC1 inhibition regulates pro- and anti-inflammatory cytokine production via its capacity to inactivate GSK3.

The role of glycogen synthase kinase 3 in regulating IFN-β-mediated IL-10 production

The ability of IFN-β to induce IL-10 production from innate immune cells is important for its anti-inflammatory properties and is believed to contribute to its therapeutic value in treating multiple sclerosis patients. In this study, we identified that IFN-β stimulates IL-10 production by activating the JAK1- and PI3K-signaling pathways. JAK1 activity was required for IFN-β to activate PI3K and Akt1 that resulted in repression of glycogen synthase kinase 3 (GSK3)-β activity. IFN-β-mediated suppression of GSK3-β promoted IL-10, because IL-10 production by IFN-β-stimulated dendritic cells (DC) expressing an active GSK3-β knockin was severely reduced, whereas pharmacological or genetic inhibition of GSK3-β augmented IL-10 production. IFN-β increased the phosphorylated levels of CREB and STAT3 but only CREB levels were affected by PI3K. Also, a knockdown in CREB, but not STAT3, affected the capacity of IFN-β to induce IL-10 from DC. IL-10 production by IFN-β-stimulated DC was shown to suppress IFN-γ and IL-17 production by myelin oligodendrocyte glycoprotein-specific CD4(+) T cells, and this IL-10-dependent anti-inflammatory effect was enhanced by directly targeting GSK3 in DC. These findings highlight how IFN-β induces IL-10 production and the importance that IL-10 plays in its anti-inflammatory properties, as well as identify a therapeutic target that could be used to increase the IL-10-dependent anti-inflammatory properties of IFN-β.

Primary cutaneous adenoid cystic carcinoma in the United States: incidence, survival, and associated cancers, 1976 to 2005

BACKGROUND

Primary cutaneous adenoid cystic carcinoma (PCACC) is a rare appendageal tumor of uncertain origin. Details on epidemiologic features of PCACC are sparse and largely based on clinical reports.

OBJECTIVE

We sought to develop an understanding of PCACC incidence, survival, and associated cancers using population-based data.

METHODS

We used the Surveillance, Epidemiology, and End Results program to calculate age-adjusted incidence rates (IRs), IR ratios, 95% confidence intervals, standardized incidence ratios (SIRs), and 5-year relative survival of PCACC diagnosed during 1976 to 2005.

RESULTS

In a population of 723,174,580 person-years, the overall PCACC IR was 0.23 per 1 million person-years (n = 152), with similar IRs among male and female patients (IR = 0.24). Most cases of PCACC presented at a localized stage and arose on the face/head/neck. Among 122 of the 2-month survivors of PCACC and more than 2.4 million 2-month cancer survivors, risk of associated cancers overall was not significantly increased (SIR = 1.17 [n = 24] and SIR = 1.43 [n = 16], respectively). However, PCACC was associated with significantly increased risks of subsequent lymphohematopoietic (n = 6; SIR = 3.70) and thyroid (n = 2; SIR = 15.25) cancers, whereas the converse associations were not observed. Five-year relative survival was excellent (96.1%; n = 122) with more favorable survival noted for PCACC involving the face/head/neck than the trunk.

LIMITATIONS

A pathologic review of reported cases was not undertaken.

CONCLUSION

PCACC is a rare appendageal tumor that affects male and female individuals equally, primarily presents at localized stage, predominates in the face/head/neck, and is associated with favorable survival. Immunosuppression does not appear to contribute to the development of PCACC, and the observed associated cancer patterns will need to be confirmed in larger studies.

c-jun controls the ability of IL-12 to induce IL-10 production from human memory CD4+ T cells

IL-12p70 is an immunoregulatory cytokine that has been shown to induce IL-10 production from CD4+ T cells, yet the underlying cellular mechanisms controlling this process are poorly understood. In the present study, we demonstrate that IL-12p70 induces IL-10 production from human memory CD4+ T cells via a PI3K-dependent signaling mechanism. Specifically, stimulation of human memory CD4+ T cells in the presence of IL-12p70 lead to increased PI3K activity and the subsequent phosphorylation and inactivation of the downstream constitutively active serine/threonine kinase, glycogen synthase kinase-3beta (GSK3beta). Inhibition of PI3K prevented the inactivation of GSK3beta by IL-12p70, as well as the subsequent ability of IL-12p70 to augment IL-10 levels by memory CD4+ T cells. Moreover, ectopic expression of a constitutively active form of GSK3beta abrogated the ability of IL-12p70 to increase IL-10 production by TCR-stimulated CD4+ T cells. In contrast, direct inhibition of GSK3 mimicked the effect of IL-12p70 on IL-10 production by memory CD4+ T cells. Analysis of downstream transcription factors identified that the ability of IL-12p70 to inactivate GSK3beta lead to increased levels of c-jun. The ability of IL-12p70 to inactivate GSK3beta and induce c-jun levels was required for IL-12 to augment IL-10 production by human memory CD4+ T cells, since small interfering RNA-mediated gene silencing of c-jun abrogated this process. These studies identify the cellular mechanism by which IL-12 induces IL-10 production from human memory CD4+ T cells.

Porphyromonas gingivalis induce apoptosis in human gingival epithelial cells through a gingipain-dependent mechanism

BACKGROUND

The oral pathogen Porphyromonas gingivalis has been shown to modulate apoptosis in different cell types, but its effect on epithelial cells remains unclear.

RESULTS

We demonstrate that primary human gingival epithelial cells (HGECs) challenged with live P. gingivalis for 24 hours exhibit apoptosis, and we characterize this by M30 epitope detection, caspase-3 activity, DNA fragmentation and Annexin-V staining. Live bacteria strongly upregulated intrinsic and extrinsic apoptotic pathways. Pro-apoptotic molecules such as caspase-3, -8, -9, Bid and Bax were upregulated after 24 hours. The anti-apoptotic Bcl-2 was also upregulated, but this was not sufficient to ensure cell survival. The main P. gingivalis proteases arginine and lysine gingipains are necessary and sufficient to induce host cell apoptosis. Thus, live P. gingivalis can invoke gingival epithelial cell apoptosis in a time and dose dependent manner with significant apoptosis occurring between 12 and 24 hours of challenge via a gingipain-dependent mechanism.

CONCLUSION

The present study provides evidence that live, but not heat-killed, P. gingivalis can induce apoptosis after 24 hours of challenge in primary human gingival epithelial cells. Either arginine or lysine gingipains are necessary and sufficient factors in P. gingivalis elicited apoptosis.

Skin metastases from lung cancer

Cutaneous metastases from the lung are rare but must be ruled out in patients with suspicious skin lesions and history of smoking or lung cancer. All histological types of lung cancer may metastasize to the skin and clinical lesions are variable. The percentage of patients with lung cancer that develop cutaneous metastases ranges from 1 to 12 percent. In 20-60 percent of cases the skin lesions present before or synchronously with the diagnosis of the primary tumor. Skin lesions are often described as nodular, mobile or fixed, hard or flexible, single or multiple, and painless. Histologically, cutaneous metastases from the lung are frequently moderately or poorly differentiated. IHC markers that may be useful in these cases are anti-thyroid transcription factor (TTF) and CK7/20. Treatment of solitary cutaneous metastases usually includes surgery alone or combined with chemotherapy, and/or radiation. If multiple cutaneous lesions or internal metastases exist, chemotherapy is the primary option. Cutaneous metastases and their primaries in the lung are usually incurable and suggest an unfortunate prognosis. Poor prognostic indicators include non-resectable or small-cell primary tumors, multiple cutaneous metastases, or other distant metastases. Mean survival is usually about 5-6 months.

GSK3 β Regulates the mTOR -mediated inflammatory response in TLR-stimulated innate immune cells (135.55)

The tuberous sclerosis complex-mammalian target of rapamycin (TSC-mTOR) pathway has been shown to play a critical role in regulating the inflammatory response. Here we identity the downstream signaling molecules within this pathway that are responsible for differentially controlling pro- and anti- inflammatory cytokines production by TLR-stimulated innate immune cells. Utilizing a kinase screen, we demonstrate that inhibition of mTOR by rapamycin or siRNA-mediated gene silencing results in the loss of GSK3-β (Ser 9) phosphorylation and subsequently increases its kinase activity. The ability of rapamycin to inhibit the TSC-mTOR pathway and thus augment pro-inflammatory cytokines while concurrently suppressing the anti-inflammatory cytokine IL-10 was shown to be dependent on its regulation of GSK3-beta activity. Analysis of downstream kinases of mTOR identified that p70S6K was responsible for the ability of the TSC-mTOR pathway to control GSK3 activity. mTOR inhibition in vivo induced a potent adaptive and innate inflammatory response that was abrogated by preventing rapamycin from increasing GSK3 activity. These findings identify the molecular mechanism by which the TSC-mTOR pathway regulates the host inflammatory response.

Toll-like receptor-mediated production of IL-1Ra is negatively regulated by GSK3 via the MAPK ERK1/2

IL-1 receptor antagonist (IL-1Ra), a natural inhibitor of IL-1beta, has been shown to regulate the progression of a variety of inflammatory diseases. Although experimental studies and clinical trials have demonstrated the importance of IL-1Ra in chronic inflammatory diseases, the cellular mechanisms responsible for regulating the endogenous production of IL-1Ra by innate immune cells are currently unresolved. In the present study, we identify that glycogen-synthase kinase 3 (GSK3) regulates the production of the anti-inflammatory cytokine IL-1Ra via its ability to regulate the MAPK ERK1/2 in TLR-stimulated cells. Elucidation of the cell-signaling pathway by which GSK3 controlled ERK activity demonstrated that GSK3 inhibition resulted in an abrogation in the levels of the inhibitory residue serine 71 on Rac1 and increased the ability of Rac1 to interact with and activate p21-activated protein kinase. siRNA-mediated knockdown of Rac1 attenuated the ability of GSK3 inhibition to augment phospho-ERK1/2 levels in LPS-stimulated immune cells. Moreover, inhibiting the ability of GSK3 to augment ERK1/2 activity abrogated enhanced IL-1Ra production by GSK3-inhibited cells. Our findings identify that GSK3 negatively regulates the levels of IL-1Ra produced by LPS-stimulated innate immune cells.

Antigenic experience dictates functional role of glycogen synthase kinase-3 in human CD4+ T cell responses

Signals induced by the TCR and CD28 costimulatory pathway have been shown to lead to the inactivation of the constitutively active enzyme, glycogen synthase kinase-3 (GSK3), which has been implicated in the regulation of IL-2 and T cell proliferation. However, it is unknown whether GSK3 plays a similar role in naive and memory CD4(+) T cell responses. Here we demonstrate a divergence in the dependency on the inactivation of GSK3 in the proliferative responses of human naive and memory CD4(+) T cells. We find that although CD28 costimulation increases the frequency of phospho-GSK3 inactivation in TCR-stimulated naive and memory CD4(+) T cells, memory cells are less reliant on GSK3 inactivation for their proliferative responses. Rather we find that GSK3beta plays a previously unrecognized role in the selective regulation of the IL-10 recall response by human memory CD4(+) T cells. Furthermore, GSK3beta-inactivated memory CD4(+) T cells acquired the capacity to suppress the bystander proliferation of CD4(+) T cells in an IL-10-dependent, cell contact-independent manner. Our findings reveal a dichotomy present in the function of GSK3 in distinct human CD4(+) T cell populations.

IFN-beta production by TLR4-stimulated innate immune cells is negatively regulated by GSK3-beta

TLR 4 stimulation of innate immune cells induces a MyD88-independent signaling pathway that leads to the production of IFN-beta. In this study, we demonstrate glycogen synthase kinase 3-beta (GSK3-beta) plays a fundamental role in this process. Suppression of GSK3-beta activity by either pharmacological inhibition, small interfering RNA-mediated gene silencing, or ectopic expression of a kinase-dead GSK3-beta mutant enhanced IFN-beta production by TLR4-stimulated macrophages. Conversely, ectopic expression of a constitutively active GSK3-beta mutant severely attenuated IFN-beta production. GSK3-beta was found to negatively control the cellular levels of the transcription factor c-Jun and its nuclear association with ATF-2. Small interfering RNA-mediated knockdown of c-Jun levels abrogated the ability of GSK3-beta inhibition to augment IFN-beta, demonstrating that the ability of GSK3 to control IFN-beta production was due to its ability to regulate c-Jun levels. The ability of GSK3 inhibition to control IFN-beta production was confirmed in vivo as mice treated with a GSK3 inhibitor exhibited enhanced systemic levels of IFN-beta upon LPS challenge. These findings identify a novel regulatory pathway controlling IFN-beta production by TLR4-stimulated innate immune cells.

Are birth weight and maternal smoking during pregnancy associated with malnutrition and excess weight among school age children?

In the late 1980's child malnutrition was still prevalent in Brazil, and child obesity was beginning to rise in the richest regions of the country. To assess the extent of the nutritional transition during the period and the influence of birth weight and maternal smoking on the nutritional condition of schoolchildren, we estimated the prevalence of excess weight and malnutrition in a cohort of Brazilian schoolchildren from 1987 to 1989. We calculated the body mass index (BMI) of 8- to 10-year-old schoolchildren born in Ribeirão Preto in 1978/79. We considered children with a BMI <5th percentile (P5) to be malnourished, children with P5 > or = BMI<P85 to be thin and normal, and children with BMI > or = P85 to be overweight. We evaluated the association of these nutritional disorders with birth factors (infant weight, sex, preterm delivery, number of pregnancies, maternal smoking during pregnancy, marital status, and schooling) and type of school using nominal logistic regression. A total of 2797 schoolchildren were evaluated. There was a significant prevalence of malnutrition (9.5%) and excess weight already tended to increase (15.7%), while 6.4% of the children were obese. Excess weight was more prevalent among children attending private schools (odds ratio, OR = 2.27) and firstborn children (OR = 1.69). Maternal smoking during pregnancy protected against malnutrition (OR = 0.56), while children with lower birth weight were at higher risk for malnutrition (OR = 4.23). We conclude that a nutritional transition was under way while malnutrition was still present, but excess weight and related factors were already emerging.

Neurturin enhances the recovery of erectile function following bilateral cavernous nerve crush injury in the rat

Background

The molecular mechanisms responsible for the survival and preservation of function for adult parasympathetic ganglion neurons following injury remain incompletely understood. However, advances in the neurobiology of growth factors, neural development, and prevention of cell death have led to a surge of clinical interest for protective and regenerative neuromodulatory strategies, as surgical therapies for prostate, bladder, and colorectal cancers often result in neuronal axotomy and debilitating loss of sexual function or continence. In vitro studies have identified neurturin, a glial cell line-derived neurotrophic factor, as a neuromodulator for pelvic cholinergic neurons. We present the first in vivo report of the effects of neurturin upon the recovery of erectile function following bilateral cavernous nerve crush injury in the rat.

Methods

In these experiments, groups (n = 8 each) consisted of uninjured controls and animals treated with injection of albumin (blinded crush control group), extended release neurotrophin-4 or neurturin to the site of cavernous nerve crush injury (100 μg per animal). After 5 weeks, recovery of erectile function (treatment effect) was assessed by cavernous nerve electrostimulation and peak aortic pressures were measured. Investigators were unblinded to specific treatments after statistical analyses were completed.

Results

Erectile dysfunction was not observed in the sham group (mean maximal intracavernous pressure [ICP] increase of 117.5 ± 7.3 cmH₂O), whereas nerve injury and albumin treatment (control) produced a significant reduction in ICP elevation of 40.0 ± 6.3 cmH₂O. Neurturin facilitated the preservation of erectile function, with an ICP increase of 55% at 62.0 ± 9.2 cmH₂O (p < 0.05 vs control). Extended release neurotrophin-4 did not significantly enhance recovery of erectile function with an ICP change of 46.9 ± 9.6. Peak aortic blood pressures did not differ between groups. No significant pre- and post-treatment weight differences were observed between control, neurotrophin-4 and neurturin cohorts. All animals tolerated the five-week treatment course.

Conclusion

Treatment with neurturin at the site of cavernous nerve crush injury facilitates recovery of erectile function. Results support further investigation of neurturin as a neuroprotective and/or neuroregenerative agent facilitating functional recovery after cavernous or other pelvic autonomic nerve injuries.

(18)F-FDG PET hemispheric cerebral hypometabolic activity: patient motion artifact

A 51-y-old man underwent (18)F-FDG PET for disease restaging of non-Hodgkin's lymphoma. Initial attenuation correction images demonstrated unilateral hemispheric cerebral hypometabolic activity. The remainder of the scan was otherwise unremarkable. Non-attenuation correction images demonstrated a patient motion artifact attributable to lateral movement of the patient's head during image acquisition. Subsequent repeat (18)F-FDG PET showed normal cerebral cortical activity.

Prevalence and risk factors for work related asthma in young adults

OBJECTIVES

To investigate the prevalence and predictors of work related asthma in young adults from the general population.

METHODS

A total of 1922 subjects randomly selected from a birth cohort 1978/79 in Brazil, aged 23-25 years, completed a respiratory symptoms questionnaire based on the European Community Respiratory Health Survey, and underwent spirometry, bronchial challenge test with methacholine, and skin prick test. For subjects presenting with bronchial hyperresponsiveness, workplace exposure and its relationship with symptoms were assessed by a specific questionnaire and individualised job description to define cases of work related asthma.

RESULTS

The prevalence of work related asthma was 4.2% (81 cases): 1.5% (29 cases) were classified as aggravated asthma and 2.7% (52 cases) as occupational asthma. Work related asthma was associated with atopy and education. Lower educational level (1-8 years of schooling) was associated with work related asthma (odds ratio 7.06, 95% CI 3.25 to 15.33). There was no association between work related asthma and smoking, gender, or symptoms of rhinitis.

CONCLUSION

The prevalence of work related asthma was high (4.2%), and was associated with low schooling, probably because of low socioeconomic level. The disease may therefore be a consequence of poverty.

Charcot-Marie-Tooth disease and related hereditary polyneuropathies: molecular diagnostics determine aspects of medical management

PURPOSE

An evidence-based approach was used to determine the frequency distribution of genes contributing to the Charcot-Marie-Tooth (CMT) disease phenotype.

METHODS

We performed a combined analysis of 11 population-based studies from various ethnic backgrounds to generate an evidence-based testing scheme. To estimate the relative frequencies of the responsible genes for which population-based studies are not available, we used our cohort of clinically classified patients with CMT and related neuropathies collected before the availability of genetic testing.

RESULTS

Similar mutation frequencies were detected in the various studies, revealing a uniform distribution of pathogenic mutations. In CMT1 70% of patients harbor the CMT1A duplication, followed by GJB1 mutations at 8.8%. MPZ and PMP22 mutations are less common, identified on average in 2.9% and 1.5% of patients, respectively. Other genes not tested in population-based studies contribute to less than 1% of disease individually. In CMT2 MFN2 mutations are the most common, although population-based studies are not yet available.

CONCLUSION

CMT represents a heterogeneous group of disorders at the molecular level. Nevertheless, testing for the CMT1A duplication (i.e., duplication of PMP22) alone yields an accurate molecular diagnosis in approximately half of all patients. If one further specifies the clinical type (demyelinating vs. axonal), the yield of detecting a molecular defect increases to 75% to 80% in the demyelinating or CMT1 group with a screening test that evaluates for CMT1A duplication/hereditary neuropathy with liability to pressure palsies deletion and GJB1 point mutations.

What can adaptive optics do for a scanning laser ophthalmoscope ?

By compensating for the aberrations in the eye that cause blur, the adaptive optics scanning laser ophthalmoscope (AOSLO) yields high-magnification, high-resolution, real-time images of the living human retina. Features as small as single cone photoreceptors can be resolved, single leukocytes are recorded in real time as they pass through the smallest retinal capillaries, and the optical sectioning capability can be used to visualize independent layers of the retinal tissue ranging from the nerve fiber layer, through the blood vessels to the photoreceptors. The use of AO technology not only enhances the breadth of applications of conventional SLOs, but it facilitates a host of new applications. Here we provide an overview of AOSLO performance and its applications, including two clinical examples. Finally, we preview two novel applications; one where the AOSLO is used to present AO-corrected stimuli directly onto the retina while simultaneously recording their exact retinal position, and a second application where AOSLO videos are used to provide very precise, high-frequency measures of eye movements.

Reduction of Brown Fat 2-Deoxy-2-[F-18]fluoro-d-glucose Uptake by Controlling Environmental Temperature Prior to Positron Emission Tomography Scan

Brown fat uptake of 2-deoxy-2-[F-18]fluoro-D: -glucose (FDG) on a positron emission tomography (PET) scan limits the ability to assess for cancer. Drugs such as benzodiazepine, propranolol, and reserpine have been proposed to reduce this uptake, but the studies have been either small clinical or preclinical trials. As an alternative, we evaluated the effect of controlling the patient's environmental temperature on brown fat uptake of FDG.

METHOD

From January 1, 2002 to November 30, 2004, patients were identified who had (1) a pattern of FDG uptake in the neck/paravertebral areas suggestive of brown fat, (2) a repeat FDG-PET scan after control of the patient's environmental temperature, and (3) no evidence of cancer in the neck/paravertebral areas by other diagnostic methods. For the follow-up PET scan, all patients wore warm clothing and avoided exposure to cold air during their transit to our facility. After arrival, patients were kept in a separate temperature-controlled room (at least 75 degrees F) for 15 minutes to two hours before FDG injection as well as during the uptake phase. Four physicians blindly and retrospectively assessed the FDG uptake in the neck and paravertebral regions on all initial and temperature-controlled PET scans by visually grading the radioactivity on a semiquantitative scale (0 = background, 1+ = background but <liver, 2+ = equal to liver, 3+ >liver). The changes in maximal SUVs were determined in the left and right neck region. Data were evaluated using a two-tail t-test.

RESULTS

Ten patients met the above criteria. The median age was 32 years with a range of 11-58 years. In comparing the semiquantitative uptake and the SUVs of FDG in the neck and paravertebral areas on the initial PET scan to the temperature-controlled PET scan, the mean decrease and the standard deviation of the decrease demonstrated a statistically significant decrease in with P values range from <0.02 to <0.001.

CONCLUSION

Controlling the patient's environmental temperature prior to the dosing and during the uptake phase can significantly reduce FDG uptake in brown fat in the neck and paravertebral areas. Further studies are warranted to determine the most effective protocol to control the patient's environmental temperature in order to minimize brown fat uptake.

Micro Photo Detector Fabricated of Ferroelectric-Metal Heterostructure

The anomalous photovoltaic effect (APE) in ferroelectric thin films has been utilized for the development of an optical micro-detector active in the visible range (from 350 to 800 nm). La-doped Pb(Zr,Ti)O(3) (PLZT) ferroelectric films epitaxially grown on Pt(001)/Mg(001) substrate were fabricated into micro-detector arrays and characterized as to their optical response. The Au/PLZT/Pt/MgO device was self-polarized in the as-deposited form with the polarization vector perpendicular to film surface. The heterostructure photovoltage response ranged from 100 to 200 mV, and the photocurrent was ~30 nA/cm(2) for devices of ~250 μm diameter under illumination of 100 mW/cm(2) at wavelengths from 400 to 580 nm. Such micro-detectors can be used for optical sensors in MEMS devices as well as for electrical stimulators of biological cells.

Dendritic Cells in Human Thymus and Periphery Display a Proinsulin Epitope in a Transcription-Dependent, Capture-Independent Fashion

The natural expression of tissue-specific genes in the thymus, e.g., insulin, is critical for self-tolerance. The transcription of tissue-specific genes is ascribed to peripheral Ag-expressing (PAE) cells, which discordant studies identified as thymic epithelial cells (TEC) or CD11c+ dendritic cells (DC). We hypothesized that, consistent with APC function, PAE-DC should constitutively display multiple self-epitopes on their surface. If recognized by Abs, such epitopes could help identify PAE cells to further define their distribution, nature, and function. We report that selected Abs reacted with self-epitopes, including a proinsulin epitope, on the surface of CD11c+ cells. We find that Proins+ CD11c+ PAE cells exist in human thymus, spleen, and also circulate in blood. Human thymic Proins+ cells appear as mature DC but express CD8alpha, CD20, CD123, and CD14; peripheral Proins+ cells appear as immature DC. However, DC derived in vitro from human peripheral blood monocytes include Proins+ cells that uniquely differentiate and mature into thymic-like PAE-DC. Critically, we demonstrate that human Proins+ CD11c+ cells transcribe the insulin gene in thymus, spleen, and blood. Likewise, we show that mouse thymic and peripheral CD11c+ cells transcribe the insulin gene and display the proinsulin epitope; moreover, by using knockout mice, we show that the display of this epitope depends upon insulin gene transcription and is independent of Ag capturing. Thus, we propose that PAE cells include functionally distinct DC displaying self-epitopes through a novel, transcription-dependent mechanism. These cells might play a role in promoting self-tolerance, not only in the thymus but also in the periphery.

Benzodiazepine-resistant "brown fat" pattern in positron emission tomography: two case reports of resolution with temperature control

PURPOSE

Supraclavicular uptake of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) on positron emission tomography (PET) scan is attributed to lymph node, muscle, or brown fat activity. Differentiation between physiological or pathological etiologies is necessary. Benzodiazepine premedication to reduce physiological uptake has been attempted with variable success. A relationship between brown-fat FDG uptake and cold temperature has also been established. To our knowledge, no case reports or studies have been published to demonstrate whether controlling the temperature can alter the physiological uptake in these regions.

PROCEDURES

Two teenage female patients with these patterns on PET scans performed with oral benzodiazepine administration underwent repeat imaging with temperature-controlled environment settings.

RESULTS

Resolution of supraclavicular FDG uptake with temperature control in two patients in whom benzodiazepine had no prior effect.

CONCLUSION

Although the exact mechanism remains unknown, we propose that the control of temperature reduces the metabolism of glucose by brown fat. Further studies are warranted to confirm the above observations, and, if confirmed, to determine the most efficient and effective use of temperature control to minimize supraclavicular and axillary FDG uptake.

Role of B7 costimulatory molecules in mediating systemic and mucosal antibody responses to attenuated Salmonella enterica serovar Typhimurium and its cloned antigen

The purpose of the present study was to evaluate the ability of an attenuated Salmonella enterica serovar Typhimurium vaccine strain to up-regulate B7-1 and B7-2 on antigen-presenting cells and to examine the functional roles these costimulatory molecules play in mediating immune responses to Salmonella and to an expressed cloned antigen, the saliva-binding region (SBR) of antigen I/II. In vitro stimulation of B cells (B220+), macrophages (CD11b+), and dendritic cells (CD11c+) with S. enterica serovar Typhimurium induced an up-regulation of B7-2 and, especially, B7-1 expression. The in vivo functional roles of B7-1, B7-2, and B7-1/2 were evaluated in BALB/c wild-type and B7-1, B7-2, and B7-1/2 knockout (KO) mice following intranasal immunization with the Salmonella expressing the cloned SBR. Differential requirements for B7-1 and B7-2 were observed upon primary and secondary immunizations. Compared to wild-type controls, B7-1 and B7-2 KO mice had reduced mucosal and systemic anti-Salmonella antibody responses after a single immunization, while only B7-1 KO mice exhibited suppressed anti-Salmonella antibody responses following the second immunization. Mucosal and systemic antibody responses to SBR were reduced following the primary immunization, whereas a compensatory role for either B7-1 or B7-2 was observed after the second immunization. B7-1/2 double KO mice failed to induce detectable levels of mucosal or systemic immunoglobulin A (IgA) or IgG antibody responses to either Salmonella or SBR. These findings demonstrate that B7-1 and B7-2 can play distinct as well as redundant roles for mediating mucosal and systemic antibody responses, which are likely dependent upon the nature of the antigen.

Molecular mechanisms, diagnosis, and rational approaches to management of and therapy for Charcot-Marie-Tooth disease and related peripheral neuropathies

During the last decade, 18 genes and 11 additional loci harboring candidate genes have been associated with Charcot-Marie-Tooth disease (CMT) and related peripheral neuropathies. Ten of these 18 genes have been identified in the last 2 years. This phenomenal pace of CMT gene discovery has fomented an unprecedented explosion of information regarding peripheral nerve biology and its pathologic manifestations in CMT. This review integrates molecular genetics with the clinical phenotypes and provides a flowchart for molecular-based diagnostics. In addition, we discuss rational approaches to molecular therapeutics, including novel biologic molecules (eg, small interfering ribonucleic acid [siRNA], antisense RNA, and ribozymes) that potentially could be used as drugs in the future. These may be applicable in attempts to normalize gene expression in cases of CMT type 1A, wherein a 1.5 Mb genomic duplication causes an increase in gene dosage that is associated with the majority of CMT cases. Aggresome formation by the PMP22 gene product, the disease-associated gene in the duplication cases, could thus be avoided. We also discuss alternative therapeutics, in light of other neurodegenerative disorders, to disrupt such aggresomes. Finally, we review rational therapeutic approaches, including the use of antioxidants such as vitamin E, coenzyme Q10, or lipoic acid to relax potential oxidative stress in peripheral nerves, for CMT management.

Molecular Mechanisms, Diagnosis, and Rational Approaches to Management of and Therapy for Charcot-Marie-Tooth Disease and Related Peripheral Neuropathies

During the last decade, 18 genes and 11 additional loci harboring candidate genes have been associated with Charcot-Marie-Tooth disease (CMT) and related peripheral neuropathies. Ten of these 18 genes have been identified in the last 2 years. This phenomenal pace of CMT gene discovery has fomented an unprecedented explosion of information regarding peripheral nerve biology and its pathologic manifestations in CMT. This review integrates molecular genetics with the clinical phenotypes and provides a flowchart for molecular-based diagnostics. In addition, we discuss rational approaches to molecular therapeutics, including novel biologic molecules (eg, small interfering ribonucleic acid [siRNA], antisense RNA, and ribozymes) that potentially could be used as drugs in the future. These may be applicable in attempts to normalize gene expression in cases of CMT type 1A, wherein a 1.5 Mb genomic duplication causes an increase in gene dosage that is associated with the majority of CMT cases. Aggresome formation by the PMP22 gene product, the disease-associated gene in the duplication cases, could thus be avoided. We also discuss alternative therapeutics, in light of other neurodegenerative disorders, to disrupt such aggresomes. Finally, we review rational therapeutic approaches, including the use of antioxidants such as vitamin E, coenzyme Q10, or lipoic acid to relax potential oxidative stress in peripheral nerves, for CMT management.

Human KIR sequences 2003

We have compiled the nucleotide sequences and their amino acid translations from a total of 89 Killer Immunoglobulin-like Receptor (KIR) alleles, derived from 17 different KIR genes. The alignments use the KIR3DL2*001 allele as a reference sequence. Each of the KIR sequences included in these alignments has been checked and where discrepancies have arisen between reported sequences, the original authors have been contacted where possible, and necessary amendments to published sequences have been incorporated into this alignment. Future sequencing may identify errors in this list and we would welcome any evidence that helps to maintain the accuracy of this compilation.

Bethlem myopathy in a black creole pedigree

OBJECTIVES

To analyze the clinical and molecular features of a distinctive muscular dystrophy in a family of black Creole descent.

METHODS

We clinically characterized a four-generation pedigree and performed linkage analysis for all relevant autosomal-dominant muscular dystrophies.

RESULTS

Affected family members had minor neurologic dissimilarities from previously reported Bethlem myopathy pedigrees and a high incidence of keloid formation. Multipoint linkage analysis traced the family's disease to the region of the collagen genes COL6A1-COL6A2.

CONCLUSIONS

We report that Bethlem myopathy was linked to the collagen VIA1-2 region on chromosome 21q22.3 in a black Creole family. This is the first report of molecular-proven Bethlem myopathy in a family of either Creole or African-American descent. Although the correlation of Bethlem myopathy and keloids was not statistically significant, the possible connection between these two abnormalities raises the possibility of a common pathophysiological link involving collage VIA.

Bone and In-111 octreotide imaging in oncogenic osteomalacia: a case report

Osteoporosis associated with aging is considered the most common cause of bone mineral loss. Osteomalacia, abnormal bone loss with excess osteoid formation, is another cause. A 46-year-old man was examined for chronic hip and lower extremity pain that had not been relieved by nonsteroidal anti-inflammatory drugs or steroids. A bone scan revealed multiple foci of activity. The serum calcium level was normal, but phosphorus values were low. These results did not correspond with the indications for typical hyperparathyroid disease, so another cause was sought. An In-111 octreotide scan showed a focus in the right humeral head. At surgery, a phosphaturic tumor of mesenchymal origin was partially resected. Oncogenic osteomalacia is related to secretion of a phosphaturic material from a fibroblast growth factor.

Charcot-Marie-Tooth disease type 1A: molecular mechanisms of gene dosage and point mutation underlying a common inherited peripheral neuropathy

Charcot-Marie-Tooth disease type 1A is a demyelinating, inherited peripheral neuropathy which is associated with a DNA duplication in chromosome 17p11.2-p12 in over 70% of patients with CMT1A. The CMT1A duplication is not detected cytogenetically, and constitutes a tandem duplication of a 1.5-Mb region of DNA flanked by homologous sequences designated as CMT1A-REP. Detection of the CMT1A duplication by molecular methods is a valuable diagnostic test for the majority of CMT1A cases. This duplication mutation shows stable inheritance through multiple generations, and may also arise as a new mutation in sporadic patients. The CMT1A duplication leads to the disease phenotype apparently through increased dosage of a gene(s) within the duplicated segment. A disease gene associated with CMT1A has been identified in the form of PMP22, which maps within the CMT1A duplication region, and encodes a myelin protein of the peripheral nerve. Point mutations in the PMP22 gene have been identified in CMT1A patients, including one case of a new mutation in PMP22 which coincided with the onset of the disease. Thus, two alternative molecular mechanisms are responsible for CMT1A: DNA duplication leading to increased gene dosage, and point mutation of the PMP22 gene.

Charcot-Marie-Tooth disease and related neuropathies: mutation distribution and genotype-phenotype correlation

Charcot-Marie-Tooth disease (CMT) is a genetically heterogeneous disorder that has been associated with alterations of several proteins: peripheral myelin protein 22, myelin protein zero, connexin 32, early growth response factor 2, periaxin, myotubularin related protein 2, N-myc downstream regulated gene 1 product, neurofilament light chain, and kinesin 1B. To determine the frequency of mutations in these genes among patients with CMT or a related peripheral neuropathy, we identified 153 unrelated patients who enrolled prior to the availability of clinical testing, 79 had a 17p12 duplication (CMT1A duplication), 11 a connexin 32 mutation, 5 a myelin protein zero mutation, 5 a peripheral myelin protein 22 mutation, 1 an early growth response factor 2 mutation, 1 a periaxin mutation, 0 a myotubularin related protein 2 mutation, 1 a neurofilament light chain mutation, and 50 had no identifiable mutation; the N-myc downstream regulated gene 1 and the kinesin 1B gene were not screened for mutations. In the process of screening the above cohort of patients as well as other patients for CMT-causative mutations, we identified several previously unreported mutant alleles: two for connexin 32, three for myelin protein zero, and two for peripheral myelin protein 22. The peripheral myelin protein 22 mutation W28R was associated with CMT1 and profound deafness. One patient with a CMT2 clinical phenotype had three myelin protein zero mutations (I89N+V92M+I162M). Because one-third of the mutations we report arose de novo and thereby caused chronic sporadic neuropathy, we conclude that molecular diagnosis is a necessary adjunct for clinical diagnosis and management of inherited and sporadic neuropathy.

Massive muscle cell degeneration in the early stage of merosin-deficient congenital muscular dystrophy

Primary merosin-deficient congenital muscular dystrophy (CMD) is a severe form of congenital muscular disorder which is caused by mutations in the laminin alpha2 chain gene (LAMA2). The disease is characterized by marked dystrophic changes in skeletal muscles during early infancy, while little is known about the pathological process of the muscle fiber degeneration. Here, we report the immunohistochemical analysis of skeletal muscle in ten patients with primary merosin-deficient CMD using a panel of molecular markers for skeletal muscle proteins, cellular necrosis, and apoptosis. In the youngest patient (a 52 day old baby), prominent massive muscle cell degeneration occurred in association with the deposition of the C5-9 complement membrane attack complex (MAC). Most of the MAC-positive muscle fibers showed a severely deranged immunoreaction to dystrophin, dystroglycans, and other sarcolemmal proteins. In addition, we found scattered positive signals for apoptosis. Similar but milder changes were also observed in six other patients younger than 1 year. In the patients older than 3 years, muscle fibers positive for MAC and apoptotic signals were barely detectable. These findings imply that massive muscle fiber degeneration occurs in the very early stage of merosin-deficient CMD and may contribute to the severe dystrophic changes in muscle from early infancy.

Typing of human papillomavirus by pyrosequencing

The possibility of using a new bioluminometric DNA sequencing technique, called pyrosequencing, for typing of human papillomaviruses (HPV) was investigated. A blinded pyrosequencing test was performed on an HPV test panel of 67 GP5+/GP6+ PCR-derived amplification products. The 67 clinical DNA samples were sequenced up to 25 bases and sequences were searched using BLAST. All of the samples were correctly genotyped by pyrosequencing and the results were unequivocally in accordance with the results obtained from conventional DNA sequencing. Pyrosequencing was found to be a fast and efficient tool for identifying individual HPV types. Furthermore, pyrosequencing has the capability of determining novel HPV types as well as HPV sequence variants harboring mutation(s). The method is robust and well suited for large-scale programs.

Periaxin mutations cause recessive Dejerine-Sottas neuropathy

The periaxin gene (PRX) encodes two PDZ-domain proteins, L- and S-periaxin, that are required for maintenance of peripheral nerve myelin. Prx(-/-) mice develop a severe demyelinating peripheral neuropathy, despite apparently normal initial formation of myelin sheaths. We hypothesized that mutations in PRX could cause human peripheral myelinopathies. In accordance with this, we identified three unrelated Dejerine-Sottas neuropathy patients with recessive PRX mutations-two with compound heterozygous nonsense and frameshift mutations, and one with a homozygous frameshift mutation. We mapped PRX to 19q13.13-13.2, a region recently associated with a severe autosomal recessive demyelinating neuropathy in a Lebanese family (Delague et al. 2000) and syntenic to the location of Prx on murine chromosome 7 (Gillespie et al. 1997).

Periaxin mutations cause recessive Dejerine-Sottas neuropathy

The periaxin gene (PRX) encodes two PDZ-domain proteins, L- and S-periaxin, that are required for maintenance of peripheral nerve myelin. Prx(-/-) mice develop a severe demyelinating peripheral neuropathy, despite apparently normal initial formation of myelin sheaths. We hypothesized that mutations in PRX could cause human peripheral myelinopathies. In accordance with this, we identified three unrelated Dejerine-Sottas neuropathy patients with recessive PRX mutations-two with compound heterozygous nonsense and frameshift mutations, and one with a homozygous frameshift mutation. We mapped PRX to 19q13.13-13.2, a region recently associated with a severe autosomal recessive demyelinating neuropathy in a Lebanese family (Delague et al. 2000) and syntenic to the location of Prx on murine chromosome 7 (Gillespie et al. 1997).