Vagus nerve stimulation in pediatric epileptic syndromes

Vagal nerve stimulation (VNS) has shown promising results in various cohorts of non-surgical refractory epilepsy in adults and children. However studies report a significant delay between implantation and clinical response. We describe a cohort of 28 children and adolescents prospectively followed, classified by epileptic syndromes and treated with VNS using a 6-week rapid ramping protocol between January 2000 and March 2005. Our cohort showed favorable outcome within 6 months which was sustained at 24 months: 68% (19/28) showing >or=50% reduction in seizure frequency, including 14% (4/28) who became seizure-free. VNS was particularly efficacious in children with cryptogenic generalized and partial epilepsies. Although adverse events occurred in 68% (19/28) of patients, most were transient. In conclusion, rapid ramping is associated with an early and lasting response in most children but with a slightly higher side-effect rate.

The acute phase response in the rodent

In the rodent, the general response to acute inflammation and tissue damage is characterized by a complex rearrangement in the pattern of concentrations of proteins in the plasma leading to an increase in the sedimentation rate of erythrocytes, an increase in leukocyte concentration in the bloodstream, and a decrease in the hematocrit. Body temperature changes only slightly or not at all. The reasons for the change in plasma concentrations of proteins are changes in their rates of synthesis in the liver. Degradation of plasma proteins is not affected. The details of the acute phase response evolved in the interaction of species with their environment. Therefore, it is not surprising to find differences in the details of the acute phase response among species. For example, alpha 2-macroglobulin is a strongly positive acute phase reactant in the rat, but not in the mouse; C-reactive protein is a strongly positive acute phase protein in the mouse, but is not found in the rat. An inducible acute phase cysteine proteinase inhibitor system, which has evolved from a primordial kininogen gene, has been observed so far only in the rat. The changes in the synthesis rates of acute phase proteins during inflammation are closely reflected by corresponding changes in intracellular mRNA levels. In the liver, the capacity to induce the acute phase pattern of synthesis and secretion of plasma proteins probably develops around birth. Changes in mRNA levels are brought about by changes in transcription rates or by changes in mRNA stability. Kinetics of mRNA changes during the acute phase response differ for individual proteins. The main signal compound for eliciting the acute phase response in liver seems to be interleukin-6/interferon-beta 2/hepatocyte stimulating factor, whereas interleukin-1 leads to typical acute phase changes in mRNA levels only for alpha 1-acid glycoprotein, albumin, and transthyretin. Plasma protein genes are expressed in various extrahepatic tissues, such as the choroid plexus, the yolk sac, the placenta, the seminal vesicles, and other sites. All these tissues are involved in maintaining protein homeostasis in associated extracellular compartments by synthesis and secretion of proteins. Synthesis and secretion of plasma proteins in paracompartmental organs other than the liver is not influenced by the acute phase stimuli.

The bile acid deoxycholic acid has a non-linear dose response for DNA damage and possibly NF-kappaB activation in oesophageal cells, with a mechanism of action involving ROS

Deoxycholic acid (DCA) is a secondary bile acid implicated in various cancers of the gastrointestinal (GI) tract. In oesophageal adenocarcinoma, DCA is believed to contribute to carcinogenesis during reflux where stomach contents enter the lower oesophagus. It is imperative that we understand the mechanisms whereby oesophageal carcinogens function in order that therapeutic options may be developed. We have previously shown that DCA can damage chromosomes and does so through its generation of reactive oxygen species (ROS). We show here, after detailed experiments, that DCA appears to have a non-linear dose response for DNA damage. DCA induces DNA damage (as measured by the micronucleus assay) at doses of 100 microM and higher in oesophageal OE33 cells, but fails to induce such DNA damage below this cut-off dose. We also show that in terms of NF-kappaB activation (as measured by up-regulation of two NF-kappaB target genes) by DCA, a similar dose response is observed. This dose-response data may be important clinically as DCA exposure to the oesophagus may be used as a way to identify the 10% of Barrett's oesophagus patients currently progressing to cancer from the 90% of patients who do not progress. Only quantitative studies measuring DCA concentrations in refluxates correlated with histological progression will answer this question. We further show here that ROS are behind DCAs ability to activate NF-kappaB as antioxidants (epigallocatechin gallate, resveratrol and vitamin C) abrogate DCAs ability to up-regulate NF-kappaB-controlled genes. In conclusion, low doses of DCA appear to be less biologically significant in vitro. If this were to be confirmed in vivo, it might suggest that reflux patients with low DCA concentrations may be at a lower risk of cancer progression compared to patients with high levels of DCA in their refluxate. Either way, antioxidant supplementation may possibly help prevent the deleterious effects of DCA in the whole GI tract.

Evaluation of a psycho-educational group programme for family caregivers in home-based palliative care

BACKGROUND

Family caregivers are often responsible for providing significant support to relatives who require palliative care at home. However, evidence suggests that family caregivers have limited information, resources or support to prepare them for such a role. Furthermore, family caregiving can be associated with negative physical, financial and psychosocial outcomes.

PURPOSE

This project sought to examine the utility of a group family caregiver psycho-educational programme focused on preparing primary family caregivers for the role of supporting a relative with advanced cancer at home.

METHOD

The education programme consisted of three consecutive weekly sessions presented in a group format, conducted at six home-based palliative care services across metropolitan and regional Victoria (Australia). Participating caregivers were required to complete a set of self-report questionnaires measuring caregiver competence, preparedness, optimism, rewards, social support, burden and information needs, at three time points: commencement of the programme (T1), upon completion (T2) and 2 weeks later (T3). Caregivers were also asked to report on the relevance, acceptability and content of the programme, as well as any barriers to access.

RESULTS

Sixteen education programmes were conducted, with 74 caregivers attending the first session. Forty-four caregivers completed all three data collection sets. Following the intervention, a significant positive effect was found for the following outcomes: preparedness for the caring role, caregiving competence, caregiving rewards and having information needs met from T1 to T2. These improvements were maintained at follow-up (T3). Feedback on the individual sessions and entire programme was favourable and the overwhelming majority of participants reported that the programme had a positive impact on their lives.

CONCLUSIONS

This study demonstrated that a group education programme to prepare family caregivers for the role of supporting a dying relative at home was accessible, applicable and effective.

Mitochondrial DNA variation in Karkar Islanders

We analyzed 375 base pairs (bp) of the first hypervariable region (HVS-I) of the mitochondrial DNA (mtDNA) control region and intergenic COII/tRNALys 9-bp deletion from 47 Karkar Islanders (north coast of Papua New Guinea) belonging to the Waskia Papuan language group. To address questions concerning the origin and evolution of this population we compared the Karkar mtDNA haplotypes and haplogroups to those of neighbouring East Asians and Oceanic populations. The results of the phylogeographic analysis show grouping in three different clusters of the Karkar Islander mtDNA lineages: one group of lineages derives from the first Pleistocene settlers of New Guinea-Island Melanesia, a second set derives from more recent arrivals of Austronesian speaking populations, and the third contains lineages specific to the Karkar Islanders, but still rooted to Austronesian and New Guinea-Island Melanesia populations. Our results suggest (i) the absence of a strong association between language and mtDNA variation and, (ii) reveal that the mtDNA haplogroups F1a1, M7b1 and E1a, which probably originated in Island Southeast Asia and may be considered signatures of Austronesian population movements, are preserved in the Karkar Islanders but absent in other New Guinea-Island Melanesian populations. These findings indicate that the Karkar Papuan speakers retained a certain degree of their own genetic uniqueness and a high genetic diversity. We present a hypothesis based on archaeological, linguistic and environmental datasets to argue for a succession of (partial) depopulation and repopulation and expansion events, under conditions of structured interaction, which may explain the variability expressed in the Karkar mtDNA.

Management of diabetes mellitus and hospital-related hyperglycemia in patients of a medical ICU, with the use of two "down-to-earth" protocols: a feasibility study

OBJECTIVE

Optimal control of blood glucose in the ICU has been shown to significantly decrease mortality and morbidity of severely ill patients. The purpose of the present project was to develop and implement undemanding, "down-to-earth" protocols, enabling tight glucose control in critically ill patients, in the setting of a city hospital ICU with limited personnel and facilities.

RESEARCH DESIGN AND METHODS

From January 2003 to January 2006, a total of 745 patients (3197 patient-days) were treated for hyperglycemia in our medical ICU. On July 2003 two different intensive insulin therapy protocols were implemented: A protocol of continuous intravenous insulin, including specific algorithms for calculation of initial insulin bolus, initial infusion rate and further adjustment plan, was used for patients with compromised peripheral tissue perfusion. For patients with stable circulation, a protocol of subcutaneous intensive insulin therapy, including a formula for calculation of daily insulin dosage in previously non-insulin-treated diabetics, was adopted. 134 patients were treated during the run-in phase of the project and 539 patients were treated during the main treatment phase. 72 patients treated for hyperglycemia in our ICU prior to the implementation of the two protocols (from January 2003 to July 2003) served as controls.

RESULTS

After the implementation of the two protocols, a marked overall increase of normoglycemic blood glucose values (64.7% vs. 48.5%, P<0.001), a decrease of manifest hyperglycemias (6.4% vs. 17.4%, P<0.001) and an increase in hypoglycemic events (1.8% vs. 0.7%, P<0.001) was observed. Seven cases of severe hypoglycemia requiring glucose infusion were observed during the main treatment phase (0.3%). No hypoglycemia-associated deaths occurred.

CONCLUSIONS

The combined implementation of the two protocols presents a simple, safe and effective way of pursuing normoglycemia in critically ill patients.

Meta analysis: Cancer risk in Barrett's oesophagus

BACKGROUND

Risk of cancer in Barrett's oesophagus is reported to vary between studies and also between countries, where the studies were conducted as per several systematic reviews. Cancer incidence has implications on surveillance strategies.

AIM

To perform a meta-analysis to determine the incidence of oesophageal cancer in Barrett's oesophagus.

METHODS

Articles retrieved by MEDLINE search (English language, 1966-2004). Studies had to necessarily include verified Barrett's oesophagus surveillance patients, documented follow-up and cancer identified as the outcome measure. A random effects model of meta-analysis was chosen and results were expressed as mean (95% CI).

RESULTS

Forty-one articles selected for conventional Barrett's oesophagus (length >3 cm); eight included short segment Barrett's oesophagus (one additional article including only short segment Barrett's oesophagus). Cancer incidence was 7/1000 (6-9) person-years duration of follow-up (pyd), with no detectable geographical variation [UK 7/1000 (4-12) pyd, USA 7/1000 (5-9) pyd and Europe 8/1000 (5-12) pyd]. Cancer incidence in the UK was 10/1000 (7-14), when two large studies were excluded. Cancer incidence in SSBO was 6/1000 (3-12) pyd. When short segment Barrett's oesophagus compared to conventional Barrett's oesophagus, there was a trend towards reduced cancer risk [OR 0.55, (95% CI: 0.19-1.6), P = 0.25].

CONCLUSION

We found no geographical variations in Barrett's oesophagus cancer risk, but observed a trend towards reduced cancer risk in short segment Barrett's oesophagus. There is a time trend of decreasing cancer incidence.

The effect of fish and omega-3 LCPUFA intake on low birth weight in Indian pregnant women

BACKGROUND

Inadequate consumption of fish could be a risk factor for low birth weight (LBW). This study assessed fish intake and omega-3 LCPUFA intake and status for their association with LBW in a cohort of urban, south Indian pregnant women.

SUBJECTS/METHODS

In a prospective cohort study, data on maternal fish intake and omega-3 LCPUFA intake and status of 676 women were obtained at baseline (first trimester), the second and third trimesters of pregnancy. Infant birth weight was measured immediately following hospital delivery. The dropout rate was 7.6%.

RESULTS

Fifty-six percent of the study women consumed fish with low daily median intakes (3.4, 4.1 and 3.8 g day(-1) at the three trimesters, respectively). Consequently, the median intakes of EPA and DHA during pregnancy were also low at 2.1 and 10.1 mg day(-1), respectively. EPA and DHA intakes were associated with their status in erythrocyte membrane phospholipids during pregnancy (r=0.40 and 0.36, r=0.34 and 0.32 and r=0.37 and 0.41, at the three trimesters, respectively, all P<0.001). Women who did not eat fish during the third trimester had a significantly higher risk of LBW (OR: 2.49, P=0.019). Similarly, low EPA intake during the third trimester had an association with a higher risk of LBW (OR: 2.75, P=0.011).

CONCLUSIONS

Among low fish-eating pregnant women, fish intake in the third trimester was closely associated with birth weight. Supplementation with omega-3 LCPUFA during pregnancy may have important implications for fetal development in India.

Polyamine analogues bind human serum albumin

Polyamine analogues show antitumor activity in experimental models, and their ability to alter activity of cytotoxic chemotherapeutic agents in breast cancer is well documented. Association of polyamines with nucleic acids and protein is included in their mechanism of action. The aim of this study was to examine the interaction of human serum albumin (HSA) with several polyamine analogues, such as 1,11-diamino-4,8-diazaundecane (333), 3,7,11,15-tetrazaheptadecane.4HCl (BE-333), and 3,7,11,15,19-pentazahenicosane.5HCl (BE-3333), in aqueous solution at physiological conditions using a constant protein concentration and various polyamine contents (microM to mM). FTIR, UV-visible, and CD spectroscopic methods were used to determine the polyamine binding mode and the effects of polyamine complexation on protein stability and secondary structure. Structural analysis showed that polyamines bind nonspecifically (H-bonding) via polypeptide polar groups with binding constants of K333 = 9.30 x 10(3) M(-1), KBE-333 = 5.63 x 10(2) M(-1), and KBE-3333 = 3.66 x 10(2) M(-1). The protein secondary structure showed major alterations with a reduction of alpha-helix from 55% (free protein) to 43-50% and an increase of beta-sheet from 17% (free protein) to 29-36% in the 333, BE-333, and BE-3333 complexes, indicating partial protein unfolding upon polyamine interaction. HSA structure was less perturbed by polyamine analogues compared to those of the biogenic polyamines.

Long-term effects of infliximab on bone and cartilage turnover markers in patients with rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is associated with systemic bone loss, subchondral bone erosion and cartilage degradation under the control of pro-inflammatory cytokines, including tumour necrosis factor alpha (TNFalpha). Therefore, we tested the hypothesis that administration of infliximab, an anti-TNFalpha drug in the treatment of RA, would modulate systemic and local bone resorption and reduce cartilage degradation.

METHODS

We performed a prospective study of a multicentric cohort of 48 women, mean (SD) age 54.2 (12.1) years old, with severe RA for 11.4 (7.8) years, who started infliximab after failure of other disease-modifying antirheumatic drugs. At baseline and 6, 22 and 54 weeks after initiating Infliximab therapy we measured the following biochemical markers: pro-collagen serum type I N-terminal propeptide (PINP), a marker of bone formation; serum C-terminal cross-linked telopeptide of type I collagen (CTX-I), a marker of cathepsin K-mediated bone collagen degradation believed to reflect systemic bone resorption; serum C-terminal cross-linked telopeptide of type I collagen (ICTP), an index of matrix metalloprotease (MMP) mediated type I collagen degradation reflecting preferential joint metabolism; and urinary CTX-II a biochemical markers of cartilage degradation. Total hip and lumbar spine bone mineral density (BMD) was assessed at baseline, and after 6 and 12 months by dual-energy x-ray absorptiometry (DXA). No patient received bisphosphonates while 77% were under oral glucocorticoids.

RESULTS

BMD remained stable over 1 year. Serum CTX-I levels rapidly decreased by 19% and 28% at week 6 and week 22, respectively (analysis of variance (ANOVA) p = 0.032) values returning to pre-treatment level at week 54. By contrast, ICTP levels progressively declined with a maximal 25% decrease at week 54 (ANOVA p = 0.028). By contrast, PINP levels remained stable over time, which led to a 30 to 40% improvement in bone remodelling balance, as assessed by the ratios PINP/CTX and PINP/ICTP (p<0.05). There was no significant change of urinary CTX-II in the whole population, but a slight decrease (ANOVA p = 0.041) in those with pre-treatment levels above the upper limit of normal range.

CONCLUSIONS

In summary, the improvement in the formation/resorption marker ratio suggests beneficial systemic and local bone effects of infliximab in patients with RA.

Meta-analysis: cancer risk of low-grade dysplasia in chronic ulcerative colitis

BACKGROUND

The cancer risk of low-grade dysplasia (LGD) in chronic ulcerative colitis is variable and its management remain contentious.

AIM

To determine the risk of cancer or any advanced lesion once LGD is diagnosed.

METHODS

A MEDLINE, EMBASE and Pub Med search was conducted using the key words 'surveillance', 'colorectal cancer', 'low-grade dysplasia' and 'ulcerative colitis'. A random effects model of meta-analysis was used.

RESULTS

Twenty surveillance studies had 508 flat LGD or LGD with dysplasia-associated lesion or mass. An average of 4.3 colonoscopies was performed/patient post-LGD diagnosis (range: 3-7.6). An average of 18 biopsies taken per colonoscopy (range: 9-24) detected 73 advanced lesions (cancer or high-grade dysplasia) pre-operatively. The cancer incidence was 14 of 1000 (95% CI: 5.0-34) person years duration (pyd) and the incidence of any advanced lesion was 30 of 1000 pyd (95% CI: 12-76). When LGD is detected on surveillance there is a ninefold risk of developing cancer (OR: 9.0, 95% CI: 4.0-20.5) and 12-fold risk of developing any advanced lesion (OR: 11.9, 95% CI: 5.2-27).

CONCLUSIONS

The risk of developing cancer in patients with LGD is high. These estimates are valuable for decision-making when LGD is encountered on surveillance.

Preliminary results of carotid artery stenting in a non-academic hospital

INTRODUCTION

A review of our experience with CAS in a non-academic hospital is presented.

MATERIALS AND METHODS

A consecutive series of 18 CAS-interventions between 2003 and 2005 is studied retrospectively. Indication, medical history, preoperative carotid imaging, operative technique and results were studied for each patient.

RESULTS

CAS was used 12 times in men and six (33.3%) times in women between 2003 and 2005. Five (27.8%) symptomatic stenoses, 12 (66.6%) asymptomatic stenoses and one (5.6%) arterio-venous fistula were treated. One permanent postoperative ipsilateral ischaemic neurologic deficit occurred (5.6%). The mean duration of hospital stay was 4.9 days (range : 2-9 days).

CONCLUSIONS

Our study shows that CAS is feasible in non-academic hospital settings, with acceptable early results. Participating in larger studies should confirm our results.

Anthropometry and body composition of south Indian babies at birth

OBJECTIVES

To assess the consequences on body composition of increasing birth weight in Indian babies in relation to reported values in Western babies, and to assess the relationship between maternal and neonatal anthropometry and body composition.

DESIGN

Prospective observational study.

SETTING

Bangalore City, India.

SUBJECTS

A total of 712 women were recruited at 12.5+/-3.1 weeks of gestation (mean+/-standard deviation, SD) and followed up until delivery; 14.5% were lost to follow-up. Maternal body weight, height, mid upper-arm circumference and skinfold thicknesses were measured at recruitment. Weight and body composition of the baby (skinfold thicknesses, mid upper-arm circumference, derived arm fat index and arm muscle index; AFI and AMI, respectively) were measured at birth in hospital.

RESULTS

The mean+/-SD birth weight of all newborns was 2.80+/-0.44 kg. Birth weight was significantly related to the triceps and subscapular skinfold thickness of the baby. In a small number of babies with large birth weight for gestational age, there was a relatively higher normalised AFI relative to AMI than for babies with lower or appropriate birth weight for gestational age. Maternal height and fat-free mass were significantly associated with the baby's length at birth.

CONCLUSIONS

Skinfold thicknesses in Indian babies were similar to those reported in a Western population with comparable birth weights, and the relationship of AFI to birth weight appeared to be steeper in Indian babies. Thus, measures to increase birth weight in Indian babies should take into account possible adverse consequences on body composition. There were no significant relationships between maternal anthropometry and body composition at birth on multivariate analysis, except for sum of the baby's skinfold thicknesses and maternal fat-free mass (P<0.02).

Preserved Bone Health in Adolescent Elite Rhythmic Gymnasts despite Hypoleptinemia

BACKGROUND/AIMS

Leptin is linked to hormonal disturbances occurring in anorexia and positively linked with bone mineral density. The aim of this study was to determine whether hypoleptinemia occurring in rhythmic gymnasts may affect bone health.

METHOD

Leptin, insulin, cortisol, IGF1 levels and bone markers were determined in 36 rhythmic gymnasts (EG) and 20 controls (C). Body composition, BMD at the whole body (WBBMD), lumbar spine (LSBMD) and bone ultrasound properties (SOS, BUA) were measured.

RESULTS

The rhythmic gymnasts had lower fat mass and leptin level than the controls. There was no difference for IGF1, cortisol and insulin levels. Bone turnover rate was higher in elite gymnasts. The uncoupling index showed that remodeling favored the bone formation. LSBMD, WBBMD, SOS and BUA were higher in elite gymnasts after adjustment for fat mass. Leptin correlated positively with fat mass and negatively with physical activity.

CONCLUSION

High impact training is able to counterbalance bone effects usually encountered in hormonally disturbed subjects. Our results suggest that hypoleptinaemia might be related to direct osteogenic effects and indirect hormonal mechanisms including preservation of IGF and cortisol levels.

Efficacy and safety of leflunomide alone and in combination with methotrexate in the treatment of refractory rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis patients who develop refractoriness are left with no alternatives other than leflunomide and costly biological response modifiers. Leflunomide, though effective, was associated with adverse events and has not been extensively studied in the Indian population.

AIMS

Determination of safety and efficacy of leflunomide alone and if not useful, in combination with methotrexate in patients refractory to conventional disease-modifying agents.

SETTING AND DESIGN

Open labeled clinical trial with leflunomide [100 mg, OD x 3 days followed by 20 mg, OD x 6 months], if no improvement at three months, combined with methotrexate [5-7.5 mg, OD x 3 months] at a tertiary care hospital.

MATERIALS AND METHODS

The primary endpoint in the improvement in EULAR criteria and secondary endpoints were patient and physician global evaluation, incidence of remission and biochemical and clinical adverse events.

STATISTICAL ANALYSIS

Chi square test or Fisher's exact test and parametric and non-parametric repeat measure ANOVA were used for analysis.

RESULTS

Among 84 patients who were included in the study, leflunomide showed improvement and remission in 52 [62%] and 6 [7%] in six months, by intention to treat analysis. Adverse events were observed in 15, discontinuation in 5 and 24 dropped out. With combination in 11 patients, there was improvement and remission in nine [91%] and one [9%] after three months. Adverse events were observed in six and one discontinued.

CONCLUSIONS

If regular monitoring of hepatic function and hematological parameters are performed, leflunomide is an effective and safe drug in the Indian population in resistant rheumatoid arthritis patients, especially if used alone.

[Risk factors for hepatitis C virus transmission to Health Care Workers after occupational exposure: a European case-control study]

BACKGROUND

Factors that influence the risk for HCV infection after occupational exposure to hepatitis C virus (HCV) have not yet been determined. The objective of this study was to assess potential risk factors for Hepatitis C seroconversion after occupational exposure to HCV.

METHODS

We conducted a European matched case-control study from 01/01/1991 through 31/12/ 2002. Cases were Health Care Workers (HCWs) who were HCV seronegative at the time of exposure, sustained a documented exposure to HCV, and present documented HCV seroconversion temporally associated with the exposure. Controls-HCWs had a documented exposure to HCV, were HCV seronegative at the time of exposure, and remained so at least 6 months later. Controls were matched to cases for the center and the time period of the exposure occurrence.

RESULTS

60 cases and 204 controls were included. All cases were exposed to HCV-infected materials through percutaneous injuries. Those for whom information was available (61.6%) were exposed to viremic source patients. Multivariate conditional logistic regression analysis, in which HCV viral load was not introduced because of missing values, identified needle placed in the source patient's vein or artery (Odds Ratio [OR]=100.1; 95% Confidence Interval [CI]=7.3-1365.7), deep injury (OR=155.2; 95%CI=7.1-3417.2), and HCW's gender (M vs. F: OR=3.1; 95%CI=1.0-10.0) as risk factors for HCV infection. In univariate unmatched analysis the risk of HCV transmission was increased 11-fold (C195%=1.1-114.1) in HCWs exposed to sources with a viral load>6 log10 copies/mL when compared to sources with a HCV viral load<4 log10 copies/mL.

CONCLUSION

The risk of HCV transmission after percutaneous exposure increases with a larger volume of blood, and, a higher titer of HCV in the source patient's blood. The role of HCW's gender need to be further investigated. The results of this study have important implications for counselling and follow-up of HCWs after exposure.

Research strategies for safety evaluation of nanomaterials, part VII: evaluating consumer exposure to nanoscale materials

Considerable media attention has recently been given to novel applications for products that contain nanoscale materials. These products could have utility in several industries that market consumer products, including textiles, sporting equipment, cosmetics, consumer electronics, and household cleaners. Some of the purported benefits of these products include improved performance, convenience, lower cost, as well as other desirable features, when compared to the conventional products that do not contain nanoscale materials. Although there are numerous likely consumer advantages from products containing nanoscale materials, there is very little information available regarding consumer exposure to the nanoscale materials in these products or any associated risks from these exposures. This paper seeks to review a limited subset of products that contain nanoscale materials, assess the available data for evaluating the consumer exposures and potential hazards associated with these products, and discuss the capacity of U.S. regulatory agencies to address the potential risks associated with these products.

Two mutations in the HSN2 gene explain the high prevalence of HSAN2 in French Canadians

BACKGROUND

Hereditary sensory and autonomic neuropathy type 2 (HSAN2; MIM 201300) is a rare recessive neuropathy typically diagnosed in the first decade. The 1973 study of a French Canadian family led to the definition of HSAN2.

OBJECTIVES

To demonstrate that the apparent higher prevalence of HSAN2 in Quebec is due to the presence of two HSN2 mutations and that carriers of different mutations appear to have a similar phenotype.

METHODS

Through attending physicians, the authors recruited French Canadian patients with HSAN2. Exclusion of linkage to the known HSAN loci and linkage to the HSAN2 was performed using standard methods. Sequencing of the HSN2 gene was used to uncover the causal mutations.

RESULTS

A large cluster of HSAN2 patients comprising 16 affected individuals belonging to 13 families was identified. The mode of inheritance is clearly autosomal recessive. All patients originated from southern Quebec, and 75% are from the Lanaudière region. Whereas linkage to the HSAN1, 3, and 4 loci was excluded, linkage to the 12p13.33 HSAN2 locus was confirmed. Sequencing of the HSN2 gene uncovered two French Canadian mutations and a novel nonsense mutation in a patient of Lebanese origin, all predicted to lead to truncations of the HSN2 protein. The comparison of clinical variables between patients with different genotypes does not suggest any difference in phenotype.

CONCLUSIONS

Two founder mutations are responsible for the apparently higher prevalence of HSAN2 in French Canadians. Genotype-phenotype correlation does not suggest any significant clinical variability.

Risk factors for hepatitis C virus transmission to health care workers after occupational exposure: a European case-control study

BACKGROUND

Additional studies are required to identify risk factors for hepatitis C virus (HCV) transmission to health care workers after occupational exposure to HCV.

METHODS

We conducted a matched case-control study in 5 European countries from 1 January 1991 through 31 December 2002. Case patients were health care workers who experienced seroconversion after percutaneous or mucocutaneous exposure to HCV. Control subjects were HCV-exposed health care workers who did not experience seroconversion and were matched with case patients for center and period of exposure.

RESULTS

Sixty case patients and 204 control subjects were included in the study. All case patients were exposed to HCV-infected fluids through percutaneous injuries. The 37 case patients for whom information was available were exposed to viremic source patients. As risk factors for HCV infection, multivariate analysis identified needle placement in a source patient's vein or artery (odds ratio [OR], 100.1; 95% confidence interval [CI], 7.3-1365.7), deep injury (OR, 155.2; 95% CI, 7.1-3417.2), and sex of the health care worker (OR for male vs. female, 3.1; 95% CI, 1.0-10.0). Source patient HCV load was not introduced in the multivariate model. In unmatched univariate analysis, the risk of HCV transmission increased 11-fold for health care workers exposed to source patients with a viral load >6 log(10) copies/mL (95% CI, 1.1-114.1), compared with exposures to source patients with a viral load < or =4 log10 copies/mL.

CONCLUSION

In this study, HCV occupational transmission was found to occur after percutaneous exposures. The risk of HCV transmission after percutaneous exposure increased with deep injuries and procedures involving hollow-bore needle placement in the source patient's vein or artery. These results highlight the need for widespread adoption of needlestick-prevention devices in health care settings, together with other preventive measures.

European recommendations for the management of healthcare workers occupationally exposed to hepatitis B virus and hepatitis C virus

Exposure prevention is the primary strategy to reduce the risk of occupational bloodborne pathogen infections in healthcare workers (HCW). HCWs should be made aware of the medicolegal and clinical relevance of reporting an exposure, and have ready access to expert consultants to receive appropriate counselling, treatment and follow-up. Vaccination against hepatitis B virus (HBV), and demonstration of immunisation before employment are strongly recommended. HCWs with postvaccinal anti-HBs levels, 1-2 months after vaccine completion, &gt;10 mIU/mL are considered as responders. Responders are protected against HBV infection: booster doses of vaccine or periodic antibody concentration testing are not recommended. Alternative strategies to overcome non-response should be adopted. Isolated anti-HBc positive HCWs should be tested for anti-HBc IgM and HBV-DNA: if negative, anti-HBs response to vaccination can distinguish between infection (anti-HBs &gt;50 mUI/ml 30 days after 1st vaccination: anamnestic response) and false positive results(anti-HBs &gt;10 mUI/ml 30 days after 3rd vaccination: primary response); true positive subjects have resistance to re-infection. and do not need vaccination The management of an occupational exposure to HBV differs according to the susceptibility of the exposed HCW and the serostatus of the source. When indicated, post-exposure prophylaxis with HBV vaccine, hepatitis B immunoglobulin or both must be started as soon as possible (within 1-7 days). In the absence of prophylaxis against hepatitis C virus (HCV) infection, follow-up management of HCV exposures depends on whether antiviral treatment during the acute phase is chosen. Test the HCW for HCV-Ab at baseline and after 6 months; up to 12 for HIV-HCV co-infected sources. If treatment is recommended, perform ALT (amino alanine transferase) activity at baseline and monthly for 4 months after exposure, and qualitative HCV-RNA when an increase is detected.

European recommendations for the management of healthcare workers occupationally exposed to hepatitis B virus and hepatitis C virus

Exposure prevention is the primary strategy to reduce the risk of occupational bloodborne pathogen infections in healthcare workers (HCW). HCWs should be made aware of the medicolegal and clinical relevance of reporting an exposure, and have ready access to expert consultants to receive appropriate counselling, treatment and follow-up. Vaccination against hepatitis B virus (HBV), and demonstration of immunisation before employment are strongly recommended. HCWs with postvaccinal anti-HBs levels, 1-2 months after vaccine completion, >or=10 mIU/mL are considered as responders. Responders are protected against HBV infection: booster doses of vaccine or periodic antibody concentration testing are not recommended. Alternative strategies to overcome non-response should be adopted. Isolated anti-HBc positive HCWs should be tested for anti-HBc IgM and HBV-DNA: if negative, anti-HBs response to vaccination can distinguish between infection (anti-HBs >or=50 mUI/ml 30 days after 1st vaccination: anamnestic response) and false positive results(anti-HBs >or=10 mUI/ml 30 days after 3rd vaccination: primary response); true positive subjects have resistance to re-infection. and do not need vaccination The management of an occupational exposure to HBV differs according to the susceptibility of the exposed HCW and the serostatus of the source. When indicated, post-exposure prophylaxis with HBV vaccine, hepatitis B immunoglobulin or both must be started as soon as possible (within 1-7 days). In the absence of prophylaxis against hepatitis C virus (HCV) infection, follow-up management of HCV exposures depends on whether antiviral treatment during the acute phase is chosen. Test the HCW for HCV-Ab at baseline and after 6 months; up to 12 for HIV-HCV co-infected sources. If treatment is recommended, perform ALT (amino alanine transferase) activity at baseline and monthly for 4 months after exposure, and qualitative HCV-RNA when an increase is detected.

Conformational dynamics of estrogen receptors alpha and beta as revealed by intrinsic tryptophan fluorescence and circular dichroism

Estrogen receptors (ER alpha and ER beta) are ligand-activated nuclear receptors that mediate the action of estrogens. These receptors activate transcription by similar mechanism(s), although the overall amino acid sequence identity is only 47%. In order to compare the structural and conformational features of ER alpha and ER beta, we monitored their intrinsic tryptophan fluorescence during thermal unfolding. The 50% unfolding temperatures (T(M)) of ER alpha and ER beta were 39+/-1 and 40+/-2 degrees C, respectively. Estradiol had no significant effect on the T(M) of ER alpha or ER beta. In contrast, binding of the estrogen-response element increased the T(M) of ER alpha and ER beta by 10 degrees C. Thermal unfolding of estradiol-bound ER alpha and ligand-free ER beta showed two-step transitions, with the formation of intermediates that were stable between 36-48 and 34-42 degrees C, respectively. We confirmed the presence of intermediate states during thermal unfolding by circular dichroism spectroscopy. Atomic force microscopy showed that the ER beta intermediate consisted of discrete globular particles, whereas the ER alpha intermediate showed a speckled appearance, with sparse well-defined particles. Fluorescence-quenching studies showed the presence of two classes of tryptophan in unliganded ER alpha and ER beta. Binding of estradiol to ER beta exposed its tryptophans, whereas estradiol reduced the accessibility of the tryptophans of ER alpha. Our results illustrate the differential effects of ligands on the unfolding of ER alpha and ER beta, and identify partially unfolded intermediates. Differences in the conformational flexibility and stability of ER alpha and ER beta may represent functional differences of ligand-bound ERs in recruiting coactivator proteins and initiating transcription.

Are we increasing serious maternal morbidity by postponing termination of pregnancy in severe pre-eclampsia/eclampsia?

The objective of this study was to evaluate the impact of admission--delivery interval on maternal morbidity in patients with severe pre-eclampsia/eclampsia. This was a retrospective study, which involved review of case sheets of 188 women (admitted to St John's Medical College Hospital during the year 2000--2001 with the above diagnosis). The incidence of severe pre-eclampsia and eclampsia was 5.18% (188/3,627) with 119 primigravida and 69 multigravida. The incidence of serious maternal complications in the post partum period was 17% (11/68) in the category of women who delivered within 12 hours of admission compared with 40.6% (28/69) in the 12--48-h category and 60.8% (31/51) in the>48-h category. The incidence of serious maternal complications in the subset with HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome was 33.4% (7/21) in the<or=12-h category compared with 90.9% (20/22)in the>12-h. We concluded that termination of pregnancy within 12 hours of admission in severe pre-eclampsia/eclampsia especially in patients with HELLP syndrome helps to prevent avoidable serious maternal morbidity.

[Incidents of blood donation]

In France, more than two million blood donations are needed for transfusion each year. The rules and requirements for blood donors selection are strict and aim to protect the donors' health as well as the patients'security. However, the review of the literature shows that adverse effects of blood withdrawal occur quite frequently. They can be classified in immediate or delayed events, or local (hematoma, nerve injury, arterial puncture injury, allergy, veinitis, thrombosis) and general reactions (vasovagal reaction, citrate toxicity, cardiovascular failure, allergy to ethylene oxide, adverse effects of drugs used for some types of donation). This article reviews the principal adverse events described in the literature and concludes with the necessity to set up hemovigilance for donors, as defined in directive 2002/98/EC of the European parliament and of the council.

Practice variability in the management of infrarenal arterial stenoses in seven Belgian hospitals

This multicentre retrospective study describes the variation of therapeutic options, treatment outcomes and costs for treating infrarenal arterial stenoses as observed in daily practice in 1997-99 in seven Belgian hospitals. Data were obtained from clinical record review and from the sickness fund claims database, and included preoperative functional state, presence of acute ischaemia, diabetes and polyvascular disease, state of the lower-leg run-off arteries, anatomical site and type of lesion, type of treatment, result at 30 days and up to 4 years. A total of 442 episodes were studied, but most analyses dealt with a subgroup of 240 lesions in the common iliac up to the superficial femoral artery. The proportion of surgical treatments (as compared to an endovascular or mixed approach) varied from 15% to 81% between the hospitals. In univariate survival analysis, relapse or failure rates at 4 years ranged from 5% for the common iliac artery to 35% for the superficial femoral artery. Polyvascular disease, a poor run-off, multiple stenoses and chronic occlusion were significant risk factors; age and diabetes were not. In the multivariate (stratified Cox regression) analysis, only a location in the superficial femoral artery and a poor preoperative clinical stage were significant risk factors, but type of therapeutic approach was not. The total average cost of treatment was 5300 Euro, of which 15% was contributed by the patient. Surgery was associated with longer stays (median at 12 days) than endovascular treatments (median 2 d), and was 1.9 times more expensive. In conclusion, the results of the present study suggest that a multidisciplinary approach, orienting the patient to the most appropriate therapeutic pathway could increase both the quality and the cost-effectiveness of the care. In many clinical situations, the endovascular approach appears to offer similar long-term results as surgery, but at a substantially lower cost, both for the patient and for society, especially when performed in a (semi-)ambulatory radiology setting.

Practice variability in the management of subrenal arterial stenoses in seven Belgian hospitals

This multicentre retrospective study describes the variation of therapeutic options, treatment outcomes and costs for treating subrenal arterial stenoses as observed in daily practice in 1997-99 in seven Belgian hospitals. Data were obtained from clinical record review and from the sickness fund claims database, and included preoperative functional state, presence of acute ischaemia, diabetes and polyvascular disease, state of the lower-leg run-off arteries, anatomical site and type of lesion, type of treatment, result at 30 days and up to 4 years. A total of 442 episodes were studied, but most analyses dealt with a subgroup of 240 lesions in the common iliac up to the superficial femoral artery. The proportion of surgical treatments (as compared to an endovascular or mixed approach) varied from 15% to 81% between the hospitals. In univariate patency analysis, relapse or failure rates at 4 years ranged from 5% for the common iliac artery to 35% for the superficial femoral artery. Polyvascular disease, a poor run-off, multiple stenoses and chronic occlusion were significant risk factors; age and diabetes were not. In the multivariate (stratified Cox regression) analysis, only a location in the superficial femoral artery and a poor preoperative clinical stage were significant risk factors, but type of therapeutic approach was not. The total average cost of treatment was 5,300 Euros, of which 15% was contributed by the patient. Surgery was associated with longer stays (median at 12 days) than endovascular treatments (median 2 days), and was 1.9 times more expensive. In conclusion, the results of the present study suggest that a multidisciplinary approach, orienting the patient to the most appropriate therapeutic pathway, could increase both the quality and the cost-effectiveness of the care.

High-grade dysplasia in Barrett's oesophagus: natural history and review of clinical practice

BACKGROUND

Management of high-grade dysplasia in Barrett's oesophagus is controversial: surgery carries an appreciable morbidity/mortality, high-grade dysplasia may not progress to cancer and endoscopic ablation is an emerging option.

AIM

To review Barrett's oesophagus-related high-grade dysplasia management and outcome over a 10-year period.

METHODS

This was a retrospective case note review of 36 patients identified from a pathology database.

RESULTS

There were 31 men of mean age 67 years. Endoscopic surveillance identified nine. Median follow-up was 21 months. Seven patients had no further intervention because of age/comorbidity. The other 29 had repeat endoscopic biopsies, nine showing cancer (six oesophagectomized). Of the 20 remaining patients with persisting high-grade dysplasia, eight had surgery (histology showed cancer in six), seven continued endoscopic surveillance (high-grade dysplasia regressed in four) and five had 'curative' argon ablation. An intensive biopsy protocol was not followed in 55% of endoscopies. Prevalent cancers occurred in 44% with an annual incidence of 5% over 5 years. All cause mortality was 39% (14 of 36, eight of 14 from cancer).

CONCLUSIONS

Management of high-grade dysplasia was not uniform. Unsuspected cancer was common in high-grade dysplasia patients undergoing surgery but 13% regressed under surveillance. High-grade dysplasia patients have a high mortality but 43% did not die from cancer.

Community outreach for untreated schizophrenia in rural India: a follow-up study of symptoms, disability, family burden and costs

BACKGROUND

In resource-poor countries, there remains an alarming treatment gap for people with schizophrenia, particularly those living in rural areas. Decentralization of mental health services, including community-based outreach programmes, represents one obvious strategy for bringing appropriate care to these communities. This study set out to assess the costs and effects of such a programme in rural Karnataka in India.

METHOD

Eight rural communities were visited by an outreach team, who identified cases of drug-naive or currently untreated schizophrenia. Recruited cases were provided with appropriate psychotropic medication and psychosocial support, and after obtaining informed consent were assessed every 3 months over one and a half years on symptomatology, disability, family burden, resource use and costs. A repeated-measures analysis was carried out to test for significant change in these outcome measures over this period.

RESULTS

A total of 100 cases of untreated schizophrenia were recruited, of whom 28% had never received antipsychotic medication and the remaining 72% had not been on medication for the past 6 months. Summary scores for psychotic symptoms, disability and family burden were all reduced significantly, with particular improvement observed at the first follow-up assessment. Increases in treatment and community outreach costs over the follow-up period were accompanied by reductions in the costs of informal-care sector visits and family care-giving time.

CONCLUSIONS

Efforts to organize community-based care such as outreach services for people with schizophrenia living in more remote areas of resource-constrained countries can bring substantial benefits to patients and families alike.

Tolerance and short term efficacy of rituximab in 43 patients with systemic autoimmune diseases

OBJECTIVE

To assess the tolerance and efficacy of rituximab in patients with various autoimmune diseases seen in daily rheumatological practice.

METHODS

866 rheumatology and internal medicine practitioners were contacted by e-mail to obtain the files of patients treated with rituximab for systemic autoimmune diseases. Patients with lymphoma were analysed if the evolution of the autoimmune disease could be evaluated.

RESULTS

In all, 43 of 49 cases could be analysed, including 14 with rheumatoid arthritis (RA), 13 with systemic lupus erythematosus (SLE), six with primary Sjogren's syndrome (pSS), five with systemic vasculitis, and five with other autoimmune diseases. Rituximab was prescribed for lymphoma in two patients with RA and two with pSS. In the 39 other cases, rituximab was given because of the refractory character of the autoimmune disease. The mean follow up period was 8.3 months (range 2 to 26). There were 11 adverse events in 10 patients and treatment had to be discontinued in six. Efficacy was observed in 30 patients (70%): RA 11, SLE 9, pSS 5, vasculitis 2, antisynthetase syndromes 2, sarcoidosis 1. The mean decrease in corticosteroid intake was 9.5 mg/d (range 0 to 50) in responders. Seven patients experienced relapse after mean 8.1 months (5 to 15). Three patients died because of refractory autoimmune disease.

CONCLUSIONS

Despite absence of marketing authorisation, rituximab is used to treat various refractory autoimmune diseases in daily rheumatological practice. This study showed good tolerance and short term clinical efficacy, with marked corticosteroid reduction in patients with SLE, pSS, vasculitis, and polymyositis.

Proposed recommendations for the management of HIV post-exposure prophylaxis after sexual, injecting drug or other exposures in Europe

Post-exposure prophylaxis (PEP) is the standard of care for a healthcare worker (HCW) accidentally exposed to an HIV infected source person (occupational exposure), but this is not the case for non-occupational exposures. Very few national guidelines exist for the management of non-occupational exposures to HIV in Europe, contrarily to the occupational ones. The administration of non-occupational post-exposure prophylaxis (NONOPEP) for HIV may be justified by: a biological plausibility, the effectiveness of PEP in animal studies and occupational exposures in humans, efficacy in the prevention of mother to child HIV transmission, and cost effectiveness studies. These evidences, the similar risk of HIV transmission for certain non-occupational exposures to occupational ones, and the conflicting information about attitudes and practices among physicians on NONOPEP led to the proposal of these European recommendations. Participant members of the European project on HIV NONOPEP, funded by the European Commission, and acknowledged as experts in bloodborne pathogen transmission and prevention, met from December 2000 to December 2002 at three formal meetings and a two day workshop for a literature review on risk exposure assessment and the development of the European recommendations for the management of HIV NONOPEP. NONOPEP is recommended in unprotected receptive anal sex and needle or syringe exchange when the source person is known as HIV positive or from a population group with high HIV prevalence. Any combination of drugs available for HIV infected patients can be used as PEP and the simplest and least toxic regimens are to be preferred. PEP should be given within 72 hours from the time of exposure, starting as early as possible and lasting four weeks. All patients should receive medical evaluation including HIV antibody tests, drug toxicity monitoring and counseling periodically for at least 6 months after the exposure. NONOPEP seems to be a both feasible and frequent clinical practice in Europe. Recommendations for its management have been achieved by consensus, but some remain controversial, and they should be updated periodically. NONOPEP should never be considered as a primary prevention strategy and the final decision for prescription must be made on the basis of the patient-physician relationship. Finally, a surveillance system for these cases will be useful to monitor NONOPEP practices in Europe.

Proposed recommendations for the management of HIV post-exposure prophylaxis after sexual, injecting drug or other exposures in Europe

Post-exposure prophylaxis (PEP) is the standard of care for a healthcare worker (HCW) accidentally exposed to an HIV infected source person (occupational exposure), but this is not the case for non-occupational exposures. Very few national guidelines exist for the management of non-occupational exposures to HIV in Europe, contrarily to the occupational ones. The administration of non-occupational post-exposure prophylaxis (NONOPEP) for HIV may be justified by: a biological plausibility, the effectiveness of PEP in animal studies and occupational exposures in humans, efficacy in the prevention of mother to child HIV transmission, and cost effectiveness studies. These evidences, the similar risk of HIV transmission for certain non-occupational exposures to occupational ones, and the conflicting information about attitudes and practices among physicians on NONOPEP led to the proposal of these European recommendations. Participant members of the European project on HIV NONOPEP, funded by the European Commission, and acknowledged as experts in bloodborne pathogen transmission and prevention, met from December 2000 to December 2002 at three formal meetings and a two day workshop for a literature review on risk exposure assessment and the development of the European recommendations for the management of HIV NONOPEP. NONOPEP is recommended in unprotected receptive anal sex and needle or syringe exchange when the source person is known as HIV positive or from a population group with high HIV prevalence. Any combination of drugs available for HIV infected patients can be used as PEP and the simplest and least toxic regimens are to be preferred. PEP should be given within 72 hours from the time of exposure, starting as early as possible and lasting four weeks. All patients should receive medical evaluation including HIV antibody tests, drug toxicity monitoring and counseling periodically for at least 6 months after the exposure. NONOPEP seems to be a both feasible and frequent clinical practice in Europe. Recommendations for its management have been achieved by consensus, but some remain controversial, and they should be updated periodically. NONOPEP should never be considered as a primary prevention strategy and the final decision for prescription must be made on the basis of the patient-physician relationship. Finally, a surveillance system for these cases will be useful to monitor NONOPEP practices in Europe.

Étude comparative entre technique isocinétique et kinésithérapie classique chez le lombalgique chronique. Résultats préliminaires

OBJECTIVE

To determine if the use of an isokinetic device for trunk exercise is more effective than standard physiotherapy in promoting motor disinhibition for patients with chronic low back pain.

POPULATION

chronic low back pain outpatients who are treated in a Rheumatology or PM & R unit within an academic hospital.

METHODOLOGY

This is a prospective, controlled, randomized study, with two groups of treatment: one treated with isokinetic techniques and the other with standard physiotherapy, six sessions for each treatment during 2 weeks. Outcome measures include pain (VSA), trunk mobility (Schöber index, distance from fingers to floor), muscle extensibility and muscle strength (Biering-Sorensen and Shirado-Ito test), and functional capacity (Quebec scale).

RESULTS

Seventeen subjects were enrolled. The results suggest that both isokinetic exercise and physiotherapy result in improved range of motion, extensibility, muscle strength, and pain, without any significant superiority of one technique over the other. However, each technique has specific advantage.

DISCUSSION

Despite methodologic limitations, this study shows that isokinetic exercise is not better than physiotherapy in reversing motor inhibition in chronic low back pain. Our results are consistent with those of other studies in the literature, with regard to the absence of established overall superiority of one exercise technique or program over the other in this population, and with regard to partial benefits of specific exercise techniques.

CONCLUSION

The non-specific benefit of one technique indicates that further studies are needed to evaluate the benefit of combining exercise techniques in chronic low back pain, in order to address the multiple factors involved in this pathology.

Progestins initiate adverse events of menopausal estrogen therapy

OBJECTIVE

Recent report, particularly the Women's Health Initiative, demonstrated that hormone therapy with combined estrogen plus progestin increased the incidence of heart attacks, stroke, blood clots, breast cancer and dementia in women over 65 years old. We investigated the role of synthetic progestins in initiating the adverse events associated with estrogen therapy.

METHODS

We used a fluorescence imaging technique, which allows video microscopic recordings of blood flow, blood vessel morphology and activities of various blood cells in a live animal. The acute peripheral and cerebrovascular responses were measured following intraperitoneal (5 or 10 mg) or intravenous (10 or 100 microg) administration of progesterone, synthetic progestins (medroxyprogesterone acetate and norethindrone) or estrogens (conjugated equine estrogens and 17 beta-estradiol).

RESULTS

In both peripheral and cerebral vasculature, synthetic progestins caused endothelial disruption, accumulation of monocytes in the vessel wall, platelet activation and clot formation, which are early events in atherosclerosis, inflammation and thrombosis. Natural progesterone or estrogens did not show such toxicity.

CONCLUSION

The risk associate with combined estrogen plus progestin therapy may be a consequence of vascular actions of progestins. Using progestins with minimal vascular toxicity may lead to safer estrogen preparations for menopausal women.

Measurement of TG synthesis and turnover in vivo by 2H2O incorporation into the glycerol moiety and application of MIDA

A method is presented for measurement of triglyceride (TG) synthesis that can be applied to slow-turnover lipids. The glycerol moiety of TG is labeled from 2H2O, and mass isotopomer distribution analysis (MIDA) is applied. Mice and rats were given 4-8% 2H2O in drinking water; TG-glycerol was isolated from adipose and liver during < or =12-wk of 2H2O labeling. Mass isotopomer abundances in the glycerol moiety of TG were measured by GC-MS. The combinatorial pattern of isotopomers revealed the number of H atoms in glycerol incorporating label from 2H2O (n) to be 3.8-4.0 of a possible 5 for adipose tissue and 4.6-4.8 for liver TG. Hepatic TG-glycerol in fact reached 97% predicted maximal value of label incorporation (4.4-4.6 x body 2H2O enrichment), indicating near-complete replacement of the liver TG pool. Label incorporation into adipose tissue revealed turnover of mesenteric TG to be faster (k = 0.21 day-1) than other depots (k = 0.04-0.06 day-1) in mice. TG isolated from subcutaneous depots of growing adult rats plateaued at 85-90% of calculated maximal values at 12 wk (k = 0.05 day-1), excluding significant dilution by unlabeled alpha-glycerol phosphate. Turnover of plasma TG, modeled from 2H incorporation over 60 min, was 0.06 min-1 (half-life 11.5 min). In summary, use of 2H2O labeling with MIDA of TG-glycerol allows measurement of new alpha-glycerol phosphate-derived TG synthesis and turnover. The hypothesis that mesenteric TG is more lipolytically active than other depots, previously difficult to prove by isotope dilution techniques, was confirmed by this label incorporation approach.

Enhanced two-photon biosensing with double-clad photonic crystal fibers

A double-clad photonic crystal fiber was used to improve detection efficiency over a standard single-mode fiber in a two-photon fluorescence detection scheme in which the dye was excited and the fluorescence was detected back through the same fiber.