Morphometric variability of nicotinamide adenine dinucleotide phosphate diaphorase neurons in the primary sensory areas of the rat

Even though there is great regional variation in the distribution of inhibitory neurons in the mammalian isocortex, relatively little is known about their morphological differences across areal borders. To obtain a better understanding of particularities of inhibitory circuits in cortical areas that correspond to different sensory modalities, we investigated the morphometric differences of a subset of inhibitory neurons reactive to the enzyme nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) within the primary auditory (A1), somatosensory (S1), and visual (V1) areas of the rat. One hundred and twenty NADPH-d-reactive neurons from cortical layer IV (40 cells in each cortical area) were reconstructed using the Neurolucida system. We collected morphometric data on cell body area, dendritic field area, number of dendrites per branching order, total dendritic length, dendritic complexity (Sholl analysis), and fractal dimension. To characterize different cell groups based on morphology, we performed a cluster analysis based on the previously mentioned parameters and searched for correlations among these variables. Morphometric analysis of NADPH-d neurons allowed us to distinguish three groups of cells, corresponding to the three analyzed areas. S1 neurons have a higher morphological complexity than those found in both A1 and V1. The difference among these groups, based on cluster analysis, was mainly related to the size and complexity of dendritic branching. A principal component analysis (PCA) applied to the data showed that area of dendritic field and fractal dimension are the parameters mostly responsible for dataset variance among the three areas. Our results suggest that the nitrergic cortical circuitry of primary sensory areas of the rat is differentially specialized, probably reflecting peculiarities of both habit and behavior of the species.

Cardiovascular events in thyroid disease: a population based, prospective study

No consensus exists whether subclinical thyroid disease should be treated or just observed. Untreated overt thyroid disease is associated with increased risk of cardiovascular disease, and this study was conducted to assess the risk of cardiovascular events in subclinical thyroid disease. The population-based prospective study was conducted in Denmark. A total of 609 subjects from general practice aged 50 years or above with normal left ventricular function were examined. During a median of 5 years of follow-up, major cardiovascular events were documented. In subjects with abnormal TSH at baseline, information about potential thyroid treatment during follow-up was obtained from case reports and mailings. At baseline, 549 (90.7%) were euthyroid (TSH 0.40-4.00 mU/l), 31 (5.1%) were subclinical hypothyroid (TSH>4.00 mU/l), and 25 (4.1%) were subclinical hyperthyroid (TSH<0.40 mU/l). 1 overt hyperthyroid and 3 overt hypothyroid participants were excluded from the analyses. At baseline, the levels of NT-proBNP were inversely associated with the levels of TSH; the lower the levels of TSH, the higher the NT-proBNP concentration. During follow-up, 88 participants died, 81 had a major cardiovascular event, and 28 had a stroke. The incidence of stroke was increased among subjects with subclinical hyperthyroidism, HR 3.39 (95% CI 1.15-10.00, p=0.027) after adjusting for sex, age, and atrial fibrillation. Subclinical hypothyroidism was not related with any of the outcome measurements. Subclinical hyperthyroidism seems to be a risk factor of developing major cardiovascular events, especially stroke in older adults from the general population with normal left ventricular function.

Pharmacological inhibition of leukotriene biosynthesis: effects on the heart conductance

Leukotrienes are lipid mediators produced via 5-lipooxygenase pathway of arachidonic acid. At least two cysteinyl-leukotrienes receptors are highly expressed in the heart, including the conduction system. Coronary angiography or angioplasty is accompanied by release of cysteinyl leukotrienes into coronary circulation and into urine. We tested the hypothesis that inhibition of leukotrienes biosynthesis would affect the conductance system function. In a double-blind placebo controlled study, patients with stable angina undergoing elective coronary catheterization or angioplasty were randomly assigned to 48 hrs treatment with a 5-lipoxgenase inhibitor (n=54) or placebo (n=49). ECG Holter recording was carried out for 24 hrs before and after the procedure and urinary leukotriene E(4) measurements were done. Inhibition of 5-lipoxygenase caused 26% reduction of urinary leukotriene E(4), associated with: 1) decrease in heart rate by about 7%, 2) enhanced heart rate variability; 3) protection against depressions in atrioventricular conductance and ventricular repolarization induced by the procedure. No effects on either arrhythmias, or ECG patterns of ischemia were noted. We conclude that pharmacological inhibition of 5-lipoxygenase, shortly before percutaneous coronary intervention, reveals specific actions of leukotrienes on the heart rhythm. Inhibitors of 5-lipoxygenase might be of interest as a novel class of cardiac drugs affecting the conductive system.

Familial dysalbuminemic hyperthyroxinemia

A family with familial dysalbuminemic hyperthyroxinemia is described. The syndrome is inherited as an autosomal dominant trait and is characterized by marked elevation of serum thyroxine, due to increased binding of thyroxine to albumin, whereas serum triiodothyronine is normal. Serum free thyroxine is normal when measured with ultrafiltration or equilibrium dialysis, but artefactually high when measured with an analogue assay. The importance of the condition, which is harmless, lies in the misinterpretation of values with subsequent erroneous treatment of thyrotoxicosis. By using an ultrasensitive TSH method it is possible to discriminate between euthyroid and hyperthyroid patients and thereby to avoid incorrect diagnosis in subjects with euthyroid hyperthyroxinemia.

The influence of propranolol on the extrathyroidal metabolism of 3,3',5'-triiodothyronine (reverse T3)

The effect of propranolol 80 mg daily on the metabolism of 3,3',5'-triiodothyronine (reverse T3, rT3), 3,3',5'-triiodothyronine (T3) and thyroxine (T4) was studied by means of a non compartmental kinetic method in seven females with severe pretreatment hypothyroidism. The patients were maintained euthyroid on a constant L-T4 replacement therapy. Serum rT3 levels increased significantly during propranolol (p less than 0.02). This increase was explained by a decrease in metabolic clearance rate (MCR) (p less than 0.02), since the conversion rate from T4 and the distribution volume of rT3 were unchanged. By contrast the decreased serum levels of T3 were due to a significant decreased conversion from T4 (p less than 0.02) in spite of a decreased MCR. The results are compatible with the assumption of two different monodeiodinating enzymes, a 5-deiodinase responsible for the diodination of T4 to rT3 and a 5'-deiodinase responsible for the deiodination of T4 to T3.

Dietary supplementation with a specific combination of high protein, leucine, and fish oil improves muscle function and daily activity in tumour-bearing cachectic mice

Cancer cachexia is characterised by metabolic alterations leading to loss of adipose tissue and lean body mass and directly compromises physical performance and the quality of life of cancer patients. In a murine cancer cachectic model, the effects of dietary supplementation with a specific combination of high protein, leucine and fish oil on weight loss, muscle function and physical activity were investigated. Male CD2F1 mice, 6–7 weeks old, were divided into body weight-matched groups: (1) control, (2) tumour-bearing, and (3) tumour-bearing receiving experimental diets. Tumours were induced by s.c. inoculation with murine colon adenocarcinoma (C26) cells. Food intake, body mass, tumour size and 24 h-activity were monitored. Then, 20 days after tumour/vehicle inoculation, the animals were killed and muscle function was tested ex vivo. Tumour-bearing mice showed reduced carcass, muscle and fat mass compared with controls. EDL muscle performance and total daily activity were impaired in the tumour-bearing mice. Addition of single nutrients resulted in no or modest effects. However, supplementation of the diet with the all-in combination of high protein, leucine and fish oil significantly reduced loss of carcass, muscle and fat mass (loss in mass 45, 52 and 65% of TB-con, respectively (P<0.02)) and improved muscle performance (loss of max force reduced to 55–64% of TB-con (P<0.05)). Moreover, total daily activity normalised after intervention with the specific nutritional combination (50% of the reduction in activity of TB-con (P<0.05)). In conclusion, a nutritional combination of high protein, leucine and fish oil reduced cachectic symptoms and improved functional performance in cancer cachectic mice. Comparison of the nutritional combination with its individual modules revealed additive effects of the single components provided.

N-terminal-pro-B-type natriuretic peptide during pharmacological heart rate reduction in hyperthyroidism

We hypothesized that elevated N-terminal-pro-B-type natriuretic peptide levels in hyperthyroidism are mainly driven by increased metabolism due to excess thyroid hormones. Therefore, serum levels of N-terminal-pro-B-type natriuretic peptide were studied during reduced cardiac work load by means of pharmacologically induced heart rate reduction in untreated hyperthyroidism. We designed a noncontrolled interventional study. Eighteen women with newly diagnosed hyperthyroidism were evaluated (including an echocardiography) before and after pharmacological heart rate reduction with 360 mg verapamil daily for 6 days. Before treatment, N-terminal-pro-B-type natriuretic peptide was independently associated with thyroid function (free triiodothyronine-index, r=0.64, p=0.001) and the hemoglobin concentration (r=-0.36, p=0.031). The verapamil treatment induced a decrease in parameters reflecting cardiac function; resting heart rate [from mean 97 to 80 beats per min (17.5%), p<0.001] and mean arterial pressure (8.5%, p=0.001). Median N-terminal-pro-B-type natriuretic peptide increased insignificantly from 224 to 240 pg/ml (p=0.31). Thyrotrotrophin levels were totally suppressed (<0.001 mU/l), free thyroxine-index decreased from median 319 to 315 arbitrary units (p=0.039) and free triiodothyronine-index increased from 8.6 to 9.9 arbitrary units (p=0.010). No changes in echocardiographic parameters were observed. A decrease in resting heart rate in untreated hyperthyroidism due to verapamil treatment did not result in decreasing N-terminal-pro-B-type natriuretic peptide levels. Thus elevated N-terminal-pro-B-type natriuretic peptide in hyperthyroidism seems mainly a result of high metabolism due to excess thyroid hormones rather than increased cardiac work load.

A specific mixture of short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides induces a beneficial immunoglobulin profile in infants at high risk for allergy

BACKGROUND

It has been suggested that human breast milk oligosaccharides play a role in the development of the immune system in infants, and may consequently inhibit the onset of allergy. A specific prebiotic mixture of short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides (GOS/FOS) has been shown to reduce the incidence of atopic dermatitis (AD) at 6 months of age in infants at risk for allergy.

AIM OF THE STUDY

This study was aimed to analyze the effect of GOS/FOS on the immune response in these infants.

METHODS

In a double-blind randomized placebo-controlled study, infants received a hypoallergenic whey formula with either 8 g/l GOS/FOS in a 9 : 1 ratio (IMMUNOFORTIS) or 8 g/l maltodextrine (placebo) for 6 months. At 3 months of age, children were vaccinated with Hexavac against a.o. diphteria, tetanus, polio (DTP). At 6 months of age, plasma samples were collected from 84 infants (verum group n = 41, placebo group n = 43). Levels of total immunoglobulins (Ig) and of cow's milk protein (CMP-) and DTP-specific Ig were measured.

RESULTS

GOS/FOS supplementation led to a significant reduction in the plasma level of total IgE, IgG1, IgG2 and IgG3, whereas no effect on IgG4 was observed. CMP-specific IgG1 was significantly decreased. DTP-specific Ig levels were not affected.

CONCLUSIONS

This study shows that GOS/FOS supplementation induces a beneficial antibody profile. GOS/FOS reduces the total Ig response and modulates the immune response towards CMP, while leaving the response to vaccination intact. This suggests that oral GOS/FOS supplementation is a safe method to restrain the atopic march.

Beneficial immune modulatory effects of a specific nutritional combination in a murine model for cancer cachexia

The majority of patients with advanced cancer are recognised by impaired immune competence influenced by several factors, including the type and stage of the tumour and the presence of cachexia. Recently, a specific nutritional combination containing fish oil, specific oligosaccharide mixture, high protein content and leucine has been developed aimed to support the immune system of cancer patients in order to reduce the frequency and severity of (infectious) complications. In a recently modified animal model cachexia is induced by inoculation of C26 tumour cells in mice. In a pre-cachectic state, no effect was observed on contact hypersensitivity, a validated in vivo method to measure Th1-mediated immune function, after adding the individual nutritional ingredients to the diet of tumour-bearing mice. However, the complete mixture resulted in significantly improved Th1 immunity. Moreover, in a cachectic state, the complete mixture reduced plasma levels of pro-inflammatory cytokines and beneficially affected ex vivo immune function. Accordingly, the combination of the nutritional ingredients is required to obtain a synergistic effect, leading to a reduced inflammatory state and improved immune competence. From this, it can be concluded that the specific nutritional combination has potential as immune-supporting nutritional intervention to reduce the risk of (infectious) complications in cancer patients.

The multicomponent phytopharmaceutical SKI306X inhibits in vitro cartilage degradation and the production of inflammatory mediators

Clinical studies have demonstrated that SKI306X, a purified preparation of three medicinal plants, relieves joint pain and improves functionality in osteoarthritis patients. To study the biological action of SKI306X, bovine cartilage explants and human peripheral blood mononuclear cells (PBMC) were stimulated with IL-1 beta and lipopolysaccharide (LPS) respectively, in the presence or absence of SKI306X and its individual composites. All tested compounds inhibited dose-dependently IL-1 beta-induced proteoglycan release and nitric oxide production by cartilage, indicating cartilage protective activity. SKI306X and two of its compounds inhibited PGE(2), TNF-alpha and IL-1 beta production by LPS-stimulated PBMC, indicating anti-inflammatory activity. These results demonstrate that the biological effect of SKI306X is at least bipartite: (1) cartilage protective and (2) anti-inflammatory. The observed anti-inflammatory effects may provide an explanation for the outcome of the clinical studies. Long-term clinical trails are necessary to elucidate whether the in vitro cartilage protective activity results in disease-modifying effects.

Defining leukemia stem cells in MLL-translocated leukemias: implications for novel therapeutic strategies

Hematological malignancies and probably many other tumors are dependent on highly proliferating and self-renewing cancer stem cells. An important question in the development of novel, less toxic antileukemic strategies specifically targeting leukemia stem cells is how closely leukemia stem cells are related to normal hematopoietic stem cells. It has been recently demonstrated that leukemia stem cells can be derived from different stages in normal hematopoiesis and have unique phenotypic and genetic features. Introduction of Mixed-lineage leukemia ( MLL)-fusion oncoproteins, frequently found in infant leukemias and therapy-related leukemias, into differentiated hematopoietic progenitor cells results in the generation of leukemias with a high frequency of leukemia stem cells. The progenitor-derived leukemia stem cells ectopically express a limited stem cell program while maintaining the global identity of differentiated myeloid cells. Development of therapeutic strategies that specifically target the leukemia stem cell program while sparing normal hematopoietic stem cells may represent a novel therapeutic approach in human leukemias with high efficacy yet less side effects.

Natural female mating rate maximizes hatchling size in a marine invertebrate

1. Males and females often differ in their optimal mating rates, resulting potentially in conflicts over remating. In species with separate sexes, females typically have a lower optimal mating rate than males, and can regulate contacts with males accordingly. The realized mating rate may therefore be closer to the female's optimum. In simultaneous hermaphrodites, however, it has been suggested that the intraindividual optimization between 'male' and 'female' interests generates more 'male'-driven mating rates. 2. In order to assess the consequences of variation in mating rate on 'female' reproductive output, we exposed the simultaneously hermaphroditic sea slug Chelidonura sandrana to four mating rate regimes and recorded the effects on a variety of fitness components. 3. In focal 'females', we found (i) a slight but significant linear decrease in fecundity with mating rate, whereas (ii) maternal investment in egg capsule volume peaked at an intermediate mating rate. 4. Combining the observed fecundity cost with the apparent benefits of larger offspring size suggests that total female fitness is maximized at an intermediate mating rate. With the latter being close to the natural mating rate of C. sandrana in the field, our findings challenge the assumption of 'male'-driven mating systems in simultaneous hermaphrodites. 5. Our study provides experimental evidence for various mathematical models in which female fitness is maximized at intermediate mating rates.