In vivo characterization of progestins with reduced non-genomic activity in vitro

Postmenopausal women that still have an uterus and suffer from hot flushes are treated with combinations of estrogens and progestins. Whereas estrogens are indispensable for treating postmenopausal symptoms, progestins are added to counteract the proliferative activity of estrogens on uterine epithelial cells. However, in the mammary gland, progestins, given together with estrogens, stimulate the proliferation of mammary epithelial cells. Therefore, progestins with reduced proliferative activity in the mammary gland would be of advantage for hormone therapy of postmenopausal women. In order to identify progestins with better tissue-selectivity, we exploited the activation of different signal transduction pathways by the classical progesterone receptor. We demonstrated that progestins with reduced non-genomic versus genomic activity in vitro show a better dissociation of uterine versus mammary gland effects in vivo than medroxyprogesterone acetate (MPA), a synthetic progestin that is widely used in hormone therapy.

Outbreak of norovirus illness associated with a swimming pool

On 3 February 2004, the Vermont Department of Health received reports of acute gastroenteritis in persons who had recently visited a swimming facility. A retrospective cohort study was conducted among persons attending the facility between 30 January and 2 February. Fifty-three of 189 (28%) persons interviewed developed vomiting or diarrhoea within 72 h after visiting the facility. Five specimens tested positive for norovirus and three specimen sequences were identical. Entering the smaller of the two pools at the facility was significantly associated with illness (RR 5.67, 95% CI 1.5-22.0, P=0.012). The investigation identified several maintenance system failures: chlorine equipment failure, poorly trained operators, inadequate maintenance checks, failure to alert management, and insufficient record keeping. This study demonstrates the vulnerability of recreational water to norovirus contamination, even in the absence of any obvious vomiting or faecal accident. Our findings also suggest that norovirus is not as resistant to chlorine as previously reported in experimental studies. Appropriate regulations and enforcement, with adequate staff training, are necessary to ensure recreational water safety.

Parallel high-resolution confocal Raman SEM analysis of inorganic and organic bone matrix constituents

In many multi-disciplinary fields of science, such as tissue engineering, where material and biological sciences are combined, there is a need for a tool that combines ultrastructural and chemical data analysis in a non-destructive manner at high resolution. We show that a combination of confocal Raman spectroscopy (CRS) and scanning electron microscopy (SEM) can be used for such analysis. Studies of atomic composition can be done by X-ray microanalysis in SEM, but this is only possible for atomic numbers greater than five and does not reveal molecular identity. Raman spectroscopy, however, can provide information on molecular composition and identity by detection of wavelength shifts caused by molecular vibrations. In this study, CRS-SEM revealed that early in vitro-formed bone extracellular matrix (ECM) produced by rat osteoprogenitor cells resembles mature bone chemically. We gained insight into the structure and chemical composition of the ECM, which was composed of mainly mineralized collagen type I fibres and areas of dense carbonated calcium phosphate related to the collagen fibre density, as revealed by Raman imaging of SEM samples. We found that CRS-SEM allows the study of specimens in a non-destructive manner and provides high-resolution structural and chemical information about inorganic and organic constituents by parallel measurements on the same sample.

[Secondary dyslipoproteinema in liver disease]

By far the most common dyslipoproteinema in patients with liver disease is hypertriglyceridemia with decreased HDL cholesterol occurring in fatty liver diseases. Since these latter frequently occur in patients with a metabolic syndrome, it must be assumed that lipid metabolism disorder is associated with a pronounced atherogenic effect. This means that--in contrast to cholestatic liver disease--treatment is almost always indicated. General therapeutic measures (weight reduction, optimization of blood sugar) are to the fore. As medication, metformin, fibrates and insulin sensitizers may be considered since, apart from improving glucose metabolism and hypertriglyceridemia, they also have a direct hepatic effect. It must, however, be noted that the available study data are not yet satisfactory, so that an individual decision must be made as to whether medical treatment of a lipid metabolism disorder makes good lipidological sense and is hepatologically justified.

MHC Class II–Mediated Antigen Presentation by Alloreactive Rat CD4+ T Cells Does Not Induce Regulatory Properties

Activated CD4+ T cells have the capacity to express major histocompatibility complex (MHC) class II molecules and to present processed antigens to T cells. Because the role of MHC class II positive T cells in allograft rejection is unknown, the purpose of this study was to investigate their function as antigen-presenting cells (APCs) in the allogeneic immune response. For this, alloreactive CD4+ T cells were induced in Lewis rats by immunization with the allogeneic peptide P1. The P1-specific T cells are involved in the rejection of allografts from Wistar Furth rats. With monoclonal antibodies specific for the alphabeta T-cell receptor (clone R73) and MHC class II molecules (clone Ox6), the presence of antigen-specific T cells, with and without expression of MHC class II molecules, was demonstrated. Concerning their ability to bind these antibodies they were characterized as R73(pos), Ox6(pos) and R73(pos), Ox6(neg), respectively. The R73(pos), Ox6(pos) T cells loaded with P1 were indeed very effective in restimulating R73(pos), Ox6(neg) T cells but not vice versa. Further on, R73(pos), Ox6(pos) T cells, but not R73(pos), Ox6(neg) T cells, were able to activate naïve allogeneic T cells demonstrating their capacity to express co-stimulatory molecules. In addition, specific mRNA for CD86, MHC class II, and CIITA, the master regulator of MHC class II expression, were detectable in the R73(pos), Ox6(pos) T cells only. In conclusion, the R73(pos), Ox6(pos) T cells act as professional APCs with the possible biological capability of amplifying the local immune response to the allograft.

Increase in adiponectin levels during pioglitazone therapy in relation to glucose control, insulin resistance as well as ghrelin and resistin levels

Glitazones increase the secretion of the adipocyte-derived hormone adiponectin. Furthermore, the gastric signal peptide ghrelin is known to suppress adiponectin expression in adipocyte cell culture models. It is not known whether the increase in adiponectin during glitazone therapy is due to a suppression of ghrelin levels, a decrease of resistin concentrations or an amelioration of glucose control. In 10 patients (age 71+/-9 yr, body mass index 29.9+/-3.6 kg/m(2), HbA1c 6.9+/-0.5%) with Type 2 diabetes, who had already been treated with sulfonylureas, we additionally initiated a pioglitazone therapy (30 mg/day) for 12 weeks. To investigate the pioglitazone effect independently of blood glucose, glycosylated hemoglobin (HbA1c) was kept unchanged by reducing the daily dose of sulfonylurea if necessary. Ghrelin concentration [radioimmunoassay (RIA), Phoenix Pharmaceuticals, Mountain View, CA, USA], adiponectin levels [enzyme-linked immunosorbent assay (ELISA), Biovendor, Heidelberg, Germany] as well as resistin concentrations (ELISA, Linco Research, St. Charles, MO, USA) were measured before and after pioglitazone. Glucose control remained unchanged within the 12-week pioglitazone therapy (HbA1c 6.9+/-0.5% before vs 6.8+/-0.6% after pioglitazone) while body weight increased from 86.6+/-9.2 to 88.0+/-9.4 kg (p<0.05), and insulin concentration decreased from 19.6+/-5.7 to 10.1+/-1.6 microU/ml (p<0.05). Adiponectin concentration increased in all patients from 7.70+/-2.47 to 23.33+/-8.28 microg/ml (p<0.01), while resistin concentrations tended to decrease (by 15%; p=0.059). However, ghrelin remained unchanged during therapy. No correlations were observed either between ghrelin, resistin, insulin and adiponectin, or between body weight and hormone plasma levels. The increase in adiponectin levels during pioglitazone therapy seems to be at least partly independent of blood glucose and insulin concentration as well as of ghrelin levels, and it was not associated with a decrease in resistin concentrations.

Novel Mutation (Gly280Ala) in the ATP-Binding Domain of Glycerol Kinase Causes Severe Hyperglycerolemia

Glycerol kinase deficiency is a rarely diagnosed X-linked recessive disorder which occurs as a complex form together with the adrenal hypoplasia congenita (AHC) or with Duchenne muscular dystrophy (DMD) or as an isolated form either symptomatic or asymptomatic. We report the case of a male adult who had pseudo-hypertriglyceridemia (falsely elevated triglycerides of 552 mg/dl) refractory to lipid-lowering therapy for more than 15 years. Further investigations revealed an isolated, asymptomatic glycerol kinase deficiency. Using polymerase chain reaction and direct DNA sequencing, a novel missense mutation Gly280Ala in the Xp21.3 glycerol kinase gene was found. Comparison between human and E.coli glycerol kinase showed that the mutation affects a highly conserved amino acid in an ATP-binding domain in the active centre. This mutation is assumed to destabilize a hydrogen bond between ligand and enzyme resulting in a reduced activity of glycerol kinase and therefore in hyperglycerolemia.

Use of a systems-based approach to an environmental health assessment for a waterborne disease outbreak investigation at a snowmobile lodge in Wyoming

Investigations into disease outbreaks generally incorporate an epidemiologic investigation, laboratory analysis, and an environmental health assessment. This last component is designed to discover connections between factors in the environment and the outbreak, but is often limited, either by time and resources, or the expertise of the personnel included in outbreak investigation teams. A waterborne Norovirus outbreak investigation in Sheridan County, Wyoming, in 2001 provides an excellent example of the importance of including an in-depth, systems-based environmental health assessment in outbreak investigations. The epidemiologic component of this investigation identified the water supply of a snowmobile lodge in the Bighorn Mountains as the source of the outbreak, a result that was confirmed by laboratory analysis. Including a systems-based environmental health assessment in this investigation also helped to uncover the underlying environmental factors that led to contamination of the water supply. Those factors included an onsite wastewater disposal system that was overloaded by increased use and not well suited to local soil and geologic conditions and a drinking water system with no treatment or disinfection. In addition, heavy precipitation and increased pumping of wells to satisfy higher demands probably facilitated the contamination of the drinking water wells by causing greater movement of wastewater through the soil and underlying bedrock. By focusing on these links between factors in the environment and adverse health outcomes, the systems-based environmental health assessment also helped to highlight prevention strategies for avoiding recurrences.

Postprandial ghrelin release in anorectic patients before and after weight gain

The appetite-modulating hormone ghrelin transmits changes in food intake to the central nervous system. In patients with anorexia nervosa, weight gain reduces elevated fasting ghrelin levels to normal, however, less is known about the effects on postprandial ghrelin levels. In 20 female anorectic in-patients (25.6 +/- 1.0 years; body mass index (BMI) 15.1 +/- 0.3 kg/m2) a standardized test with 250 ml fluid meal (250 kcal: 9.4 g protein, 34.4 g carbohydrates, and 8.3 g fat) was performed at three different times (at admission, after partial weight gain of at least 2 kg, and at discharge) and compared to healthy controls (n = 6; BMI 21.1 +/- 0.7 kg/m2). Plasma ghrelin levels were measured preprandially as well as 20 and 60 min postprandially by a commercially available radioimmunoassay (Phoenix Pharmaceuticals, USA). At admission plasma ghrelin levels significantly decreased postprandially (from 871.9 +/- 124 to 620.3 +/- 80 pg/ml 60 min after meal; P < 0.005). After partial weight gain (2.8 +/- 0.1 kg; BMI 16.1 +/- 0.3 kg/m2) postprandial ghrelin concentrations decreased from 597.0 +/- 79 to 414.7 +/- 39 pg/ml (P < 0.0001), at discharge (weight gain: 7.6 +/- 0.5 kg; BMI 17.9 +/- 0.4 kg/m2) from 570.4 +/- 78 to 395.4 +/- 44 pg/ml (P < 0.0001). Mean postprandial ghrelin decrease was not significantly different between the three tests (29, 25, and 26%, respectively) or to controls (20%). In anorectic patients mean postprandial ghrelin decrease did not change during weight gain. These findings indicate that in anorexia nervosa the suppression of ghrelin release by acute changes of energy balance (feeding) is not disturbed and that it is independent from chronic changes in energy balance (weight gain).

Construction and evaluation of cDNA libraries for large-scale expressed sequence tag sequencing in wheat (Triticum aestivum L.)

A total of 37 original cDNA libraries and 9 derivative libraries enriched for rare sequences were produced from Chinese Spring wheat (Triticum aestivum L.), five other hexaploid wheat genotypes (Cheyenne, Brevor, TAM W101, BH1146, Butte 86), tetraploid durum wheat (T. turgidum L.), diploid wheat (T. monococcum L.), and two other diploid members of the grass tribe Triticeae (Aegilops speltoides Tausch and Secale cereale L.). The emphasis in the choice of plant materials for library construction was reproductive development subjected to environmental factors that ultimately affect grain quality and yield, but roots and other tissues were also included. Partial cDNA expressed sequence tags (ESTs) were examined by various measures to assess the quality of these libraries. All ESTs were processed to remove cloning system sequences and contaminants and then assembled using CAP3. Following these processing steps, this assembly yielded 101,107 sequences derived from 89,043 clones, which defined 16,740 contigs and 33,213 singletons, a total of 49,953 "unigenes." Analysis of the distribution of these unigenes among the libraries led to the conclusion that the enrichment methods were effective in reducing the most abundant unigenes and to the observation that the most diverse libraries were from tissues exposed to environmental stresses including heat, drought, salinity, or low temperature.

Combined AFM and confocal fluorescence microscope for applications in bio-nanotechnology

We present a custom-designed atomic force fluorescence microscope (AFFM), which can perform simultaneous optical and topographic measurements with single molecule sensitivity throughout the whole visible to near-infrared spectral region. Integration of atomic force microscopy (AFM) and confocal fluorescence microscopy combines the high-resolution topographical imaging of AFM with the reliable (bio)-chemical identification capability of optical methods. The AFFM is equipped with a spectrograph enabling combined topographic and fluorescence spectral imaging, which significantly enhances discrimination of spectroscopically distinct objects. The modular design allows easy switching between different modes of operation such as tip-scanning, sample-scanning or mechanical manipulation, all of which are combined with synchronous optical detection. We demonstrate that coupling the AFM with the fluorescence microscope does not compromise its ability to image with a high spatial resolution. Examples of several modes of operation of the AFFM are shown using two-dimensional crystals and membranes containing light-harvesting complexes from the photosynthetic bacterium Rhodobacter sphaeroides.

Effect of Pioglitazone on Lipids in Well Controlled Patients with Diabetes Mellitus Type 2 - Results of a Pilot Study

INTRODUCTION

Patients with diabetes mellitus type 2 are characterized by a typical dyslipoproteinemia. Improvement in glucose control usually also ameliorates this dyslipoproteinemia. It is unclear whether different antidiabetic strategies differ in their effects on the lipid profile. Particularly, it is unknown whether glitazones improve lipid values independently of their effects on glucose metabolism.

METHODS

Ten patients well controlled on sulfonylureas (HbA1c 6.9 +/- 0.5 %) with diabetic dyslipoproteinemia were treated with additional pioglitazone (30 mg/d) for 3 months. Every 4 weeks the sulfonylurea dose was adjusted to keep HbA1c and fasting glucose constant. Before and after 3 months of pioglitazone therapy lipid metabolism was determined in detail (cholesterol, triglyceride, LDL-cholesterol, HDL-cholesterol, VLDL-cholesterol, VLDL-triglycerides, lipoprotein(a), LDL-subtype distribution by isopycnic density gradient ultracentrifugation).

RESULTS

Although glucose control remained unchanged (HbA1c 6.9 +/- 0.5 % vs. 6.8 +/- 0.6 %; fasting glucose concentration 7.7 +/- 1.1 vs. 7.3 +/- 1.3 mmol/l) we observed a significant reduction in triglyceride concentration (1.9 +/- 0.6 vs. 1.4 +/- 0.5 mmol/l, - 26 %, p < 0.01), a significant increase in HDL-cholesterol concentration (1.2 +/- 0.2 vs. 1.4 +/- 0.2 mmol/l, + 14 %, p < 0.05), a significant decrease in LDL/HDL-ratio (3.03 +/- 0.77 vs. 2.51 +/- 0.61, - 24 %, p < 0.05) and non-significant improvements in total cholesterol, LDL-cholesterol, VLDL-triglycerides, and VLDL-cholesterol concentrations. The LDL-subtype profile improved (significant reduction [- 20 %] in small dense LDL).

CONCLUSIONS

This pilot study indicates that at comparable fasting glucose concentration and at comparable HbA1c value pioglitazone is superior to sulfonylureas concerning the improvement of diabetic dyslipoproteinemia. Whether this relates to indirect effects (improvement in insulin sensitivity) or direct effects (stimulation of PPARalpha) remains to be determined.

Effects of ezetimibe on plasma lipoproteins in severely hypercholesterolemic patients treated with regular LDL-apheresis and statins

Ezetimibe, a cholesterol absorption inhibitor, can be combined with statins to lower LDL-cholesterol. We evaluated additional ezetimibe (10 mg/day) in a placebo-controlled, double blind, randomized cross-over study in 20 patients (age 56+/-9 years, m:f 10:10, BMI 27.5+/-4.0 kg/m(2)) suffering from severe hypercholesterolemia and CHD who were treated by statins and regular LDL-apheresis. Lipoproteins (cholesterol, triglycerides, LDL-cholesterol, HDL-cholesterol, VLDL-cholesterol, VLDL-triglycerides, lipoprotein(a)) were determined twice (before and during ezetimibe/placebo, each given for 5 weeks), dietary behaviour was analyzed once (3-days-protocol) during each treatment period. During ezetimibe the mean (+/-S.D.) preapheresis LDL-cholesterol concentration decreased from 159+/-26 mg/dl (4.11+/-0.67 mmol/l) to 133+/-28 mg/dl (3.44+/-0.72 mmol/l) (-16+/-11%, P<0.0001, Wilcoxon test) and the postapheresis LDL-cholesterol from 51+/-9 mg/dl (1.32+/-0.23 mmol/l) to 43+/-8 mg/dl (1.11+/-0.21 mmol/l) (-14+/-25%, P<0.05), while there was no significant change during placebo. Mean VLDL-cholesterol fell by 18+/-71% (P<0.05) during ezetimibe and was not significantly changed by placebo (+19+/-70%). Furthermore, during ezetimibe less plasma volume was treated (3725+/-1560 versus 3870+/-1549 ml, P<0.05). Ezetimibe had no effect on pre- and postapheresis triglyceride, HDL-cholesterol and lipoprotein(a) levels. The effect of ezetimibe was independent of the statin dose. Dietary behaviour did not change and no side effects were observed. Thus, in patients with severe LDL-hypercholesterolemia and CHD the addition of ezetimibe to intensive lipid lowering therapy (statins and LDL-apheresis) resulted in a further, clinically significant decrease of LDL-cholesterol.

In vivo metabolism of LDL subfractions in patients with heterozygous FH on statin therapy

LDL can be subfractionated into buoyant (1.020-1.029 g/ml(-1)), intermediate (1.030-1.040 g/ml(-1)), and dense (1.041-1.066 g/ml(-1)) LDLs. We studied the rebound of these LDL-subfractions after LDL apheresis in seven patients with heterozygous familial hypercholesterolemia (FH) regularly treated by apheresis (58 +/- 9 years, LDL-cholesterol = 342 +/- 87 mg/dl(-1), triglycerides = 109 +/- 39 mg/dl(-1)) and high-dose statins. Apolipoprotein B (apoB) concentrations were measured in LDL subfractions immediately after and on days 1, 2, 3, 5, and 7 after apheresis. Compartmental models were developed to test three hypotheses: 1) that dense LDLs are derived from the delipidation of buoyant and intermediate LDLs (model A); 2) that dense LDLs are generated directly from LDL-precursors (model B); or 3) that a model combining both pathways (model C) is necessary to describe the metabolism of dense LDLs. In all models, it was assumed that apoB production and fractional catabolic rate (FCR) did not change with apheresis. Apheresis decreased buoyant, intermediate, and dense LDL-apoB by 60 +/- 12%, 67 +/- 5%, and 69 +/- 11%, respectively. Models B and C, but not model A, described the rebound data. The model with the greatest biological plausibility (model C) was used to estimate metabolic parameters. FCR was 1.05 +/- 0.86 d(-1), 0.48 +/- 0.11 d(-1), and 0.69 +/- 0.24 d(-1) for buoyant, intermediate, and dense LDLs, respectively. Dense LDL production was 17.3 +/- 0.2 mg/kg(-1)/d(-1), 58% of which was derived directly from LDL precursors (VLDL, IDL, or direct secretion), while 42% was derived from buoyant and intermediate LDLs. Thus, our data indicate that in statin-treated patients with heterozygous FH dense LDLs originate from two sources. Whether this is also valid in other metabolic situations (with predominant small, dense LDLs) remains to be determined.

Immunogenicity of parathyroid allografts in the rat: immunosuppressive dosages effective in passenger leukocyte-rich small bowel transplants are not effective in parathyroid gland transplants with few passenger leukocytes

BACKGROUND AND AIMS

The passenger leukocytes harboured within an allograft induce a massive allo-immune response that leads to allograft rejection if not countered by immunosuppression. We compared the response to short-term immunosuppression of parathyroid gland transplants possessing few passenger leukocytes with that of passenger leukocyte-rich small bowel transplants.

METHODS

Heterotopic parathyroid and orthotopic small bowel transplantation was performed in a Wistar Furth-to-Lewis rat strain combination. Immunosuppression with cyclosporine A (CsA) was administered in different dosages for 14 days. Dysfunctional allografts were examined immunohistologically.

RESULTS

CsA more effectively suppressed the immune response provoked by immunogenic small bowel grafts than that induced by less-immunogenic parathyroid grafts. Immunosuppression with 20 mg/kg per day induced long-term survival in the small bowel (165+/-21 days) but not in the parathyroid (28+/-3 days). All rejected grafts featured massive cellular infiltration by activated T cells as a sign of immune rejection.

CONCLUSION

Immunosuppressive dosages effective in passenger leukocyte-rich small bowel transplants were not as effective in parathyroid gland transplants harbouring few passenger leukocytes. In spite of the paucity of passenger leukocytes in parathyroid grafts it is more difficult to control by immunosuppression the immune response to them than that to the passenger leukocyte-rich small bowel.

Nonresonant Raman imaging of protein distribution in single human cells

A confocal Raman microscope is used to study the protein distribution inside biological cells. It is shown that high quality Raman imaging of the protein distribution can be obtained using confocal nonresonant Raman imaging (lambda(exc) = 647.1 nm). The results are shown for two different human cell types. Perpheral blood lymphocytes are used as an example of the fully maturated cells with a low level of nuclear transcription. Human eye lens epithelial cells are used as an example of cells with a high level of nuclear activity. The protein distribution in both cell types is completely different. The nuclear distribution of the protein largely varies in the peripheral blood lymphocyte cells, while proteins are more homogenously distributed over the nuclear space in the eye lens epithelial cells. The imaging time is approximately 20 min for a field of view of 10 x 10 microm(2). The size of the sampling volume is 1.4 fL using a full width at half-maximum criterion along the z axis and a 1/e(2) criterion in the xy plane. The results presented here indicate that Raman imaging is particularly of interest in the study of cellular processes, like phagocytosis, apoptosis, chromatin compaction, and cellular differentiation, which are accompanied by relatively large-scale redistributions of the materials.

Orientation effects in waveguide resonance Raman spectroscopy of monolayers

In this paper we study the effect of molecular orientation on the observed Raman spectra in waveguide Raman spectroscopy. Depolarization ratios differ from those in 'normal' Raman spectroscopy due to the polarization properties of the guiding modes that excite the Raman scattering. Waveguide Raman spectra of submonolayers of cytochrome c and NiOEP were recorded using different polarization settings. The observed depolarization ratios strongly deviate from those obtained in bulk Raman spectra. Using the derived equations for the depolarization ratios, the preferred orientation angle of the molecules can be obtained from the observed depolarization ratios. From these results we first conclude that high-quality spectra of sub-monolayers can be obtained using waveguide Raman spectroscopy and secondly, that these spectra can be used to determine the preferred orientation of the molecule with respect to the waveguide surface.