First Early Cambrian Radiolaria

Radiolarian skeletons are known from a limestone concretion collected from a black shale succession and from black cherts of the Yangtze Platform, China. Both occurrences are of earliest Cambrian age. The findings, reported in this paper, represent the oldest known fossil Radiolaria. Their spherical skeletons display a morphology typical of spherical radiolarians from Ordovician and younger faunas. This occurrence of radiolarians with radial symmetry and, most probably, a planktonic lifestyle can now be traced back into the earliest Cambrian. Thus, radiolarians have been part of the early oceanic plankton and likely played a significant role in the silica cycle of the oceans along with siliceous sponges.

Siliceous microfossils and biosiliceous sedimentation in the lowermost Cambrian of China

Clay-rich and siliceous sedimentary rocks of earliest Cambrian age on the Yangtze Platform, China, contain abundant siliceous microfossils. The black cherts and black shales in this sequence, of earliest Cambrian age, contain sponge spicules (both macroscleres and microscleres), derived from lithistid demosponges and hexactinellids. These spicule associations are useful for biostratigraphic correlation, and indicate that Porifera played an important role in the geochemical cycling of silica at the beginning of the Phanerozoic. Phosphatic microfossils also contributed to the deep-sea ecology of this region during the earliest Cambrian.

Dolly for dinner? Assessing commercial and regulatory trends in cloned livestock

As cloning technologies become more widely established, will products enter the food chain sooner than regulatory agencies and the public might be prepared for?

The contribution of neurotrophins to the pathogenesis of allergic asthma

The neurotrophins nerve growth factor, brain-derived neurotrophic factor, NT-3 (neurotrophin 3) and NT-4 are known for regulating neuron development, function and survival. Beyond this, neurotrophins were found to exert multiple effects on non-neuronal cells such as immune cells, smooth muscle and epithelial cells. In allergic asthma, airway inflammation, airway obstruction, AHR (airway hyperresponsiveness) and airway remodelling are characteristic features, indicating an intensive interaction between neuronal, structural and immune cells in the lung. In allergic asthma patients, elevated neurotrophin levels in the blood and locally in the lung are commonly observed. Additionally, structural cells of the lung and immune cells, present in the lung during airway inflammation, were shown to be capable of neurotrophin production. A functional relationship between neurotrophins and the main features of asthma was revealed, as airway obstruction, airway inflammation, AHR and airway remodelling were all shown to be stimulated by neurotrophins. The aim of the present review is to provide an overview of neurotrophin sources and target cells in the lung, concerning their possible role as mediators between structural cells, immune cells and neurons, connecting the different features of allergic asthma.

Neuro-immune interaction in allergic asthma: role of neurotrophins

The nature of persistent airway hyperreactivity and chronic inflammation in asthma remains unclear. It has been suggested that bi-directional neuro-immune interaction plays an important role in the pathogenesis of this disease, leading to enhanced airway narrowing after contact with unspecific stimuli, as well as infiltration, activation and degranulation of several immune cell subtypes. Important mediators in neuro-immune cross-talk are neurotrophins, which are produced by cells at the site of inflammation. In addition to modulating the function of several leucocyte subsets, they play an important role in the synthesis of neuropeptides by sensory nerve cells. Neuropeptides have been shown to cause smooth-muscle contraction and, in addition, modulate the production of pro-inflammatory molecules by leucocytes. The aim of the present review is to provide an overview of the molecular mechanisms by which neurotrophins and neuropeptides are involved in neuro-immune cross-talk in allergic asthma.

Allergic airway inflammation induces tachykinin peptides expression in vagal sensory neurons innervating mouse airways

BACKGROUND

Allergic airway inflammation has been shown to induce pro-inflammatory neuropeptides such as tachykinin peptides substance P (SP) and neurokinin A (NKA) together with related peptide like calcitonin gene-related peptide (CGRP) in nodose sensory neurons innervating guinea-pig airways.

OBJECTIVE

The present study was designed to examine the effects of allergen sensitization and challenge on the SP/NKA expression in the jugular-nodose ganglion neurons innervating the murine airways.

METHODS

Using retrograde neuronal tracing technique in combination with double-labelling immunohistochemistry, the expression of SP/NKA was investigated in a murine model of allergic airway inflammation.

RESULTS

Allergic airway inflammation was found to induce the expression of SP/NKA (13.2+/-1.43% vs. 5.8+/-0.37%, P<0.01) in large-diameter (>20 microm) vagal sensory neurons retrograde labelled with Fast blue dye from the main stem bronchi.

CONCLUSION

Based on the induction of tachykinins in airway-specific large-sized jugular-nodose ganglia neurons by allergic airway inflammation, the present study suggests that allergen sensitization and challenge may lead to de novo induction of tachykinins in neurons. This may partly contribute to the pathogenesis of airways diseases such as allergic airway inflammation.

The role of charged amphipathic helices in the structure and function of surfactant protein B

Surfactant protein B (SP-B) is essential for normal lung surfactant function. Theoretical models predict that the disulfide cross-linked, N- and C-terminal domains of SP-B fold as charged amphipathic helices, and suggest that these adjacent helices participate in critical surfactant activities. This hypothesis is tested using a disulfide-linked construct (Mini-B) based on the primary sequences of the N- and C-terminal domains. Consistent with theoretical predictions of the full-length protein, both isotope-enhanced Fourier transform infrared (FTIR) spectroscopy and molecular modeling confirm the presence of charged amphipathic alpha-helices in Mini-B. Similar to that observed with native SP-B, Mini-B in model surfactant lipid mixtures exhibits marked in vitro activity, with spread films showing near-zero minimum surface tensions during cycling using captive bubble surfactometry. In vivo, Mini-B shows oxygenation and dynamic compliance that compare favorably with that of full-length SP-B. Mini-B variants (i.e. reduced disulfides or cationic residues replaced by uncharged residues) or Mini-B fragments (i.e. unlinked N- and C-terminal domains) produced greatly attenuated in vivo and in vitro surfactant properties. Hence, the combination of structure and charge for the amphipathic alpha-helical N- and C-terminal domains are key to SP-B function.

Density of dendritic cells in the human tracheal mucosa is age dependent and site specific

BACKGROUND

The mucosal immune system undergoes extensive changes in early childhood in response to environmental stimuli. Dendritic cells (DC) play a major role in the development of the immune system. However, few data exist on the influence of continuous environmental stimulation on the distribution and phenotype of human airway DC.

METHODS

Human tissue samples are mostly paraffin embedded which limits the use of several antibodies, and respiratory tissue for cryopreservation is difficult to obtain. Human frozen post mortem tracheal tissue was therefore used for this study. Only samples with epithelial adherence to the basement membrane were included (n = 34). Immunohistochemical staining and sequential overlay immunofluorescence were performed with DC-SIGN and a panel of leucocyte markers co-expressed by DC.

RESULTS

DC detected in the human tracheal mucosa using DC-SIGN correlated with the expression of HLA-DR, co-stimulatory and adhesion molecules. Higher cell densities were found at the ventral tracheal site of patients older than 1 year than in infants in the first year of life.

CONCLUSION

The increasing population of mucosal DC with age could reflect immunological maturation.

Identification of the semaphorin receptor PLXNA2 as a candidate for susceptibility to schizophrenia

The discovery of genetic factors that contribute to schizophrenia susceptibility is a key challenge in understanding the etiology of this disease. Here, we report the identification of a novel schizophrenia candidate gene on chromosome 1q32, plexin A2 (PLXNA2), in a genome-wide association study using 320 patients with schizophrenia of European descent and 325 matched controls. Over 25,000 single-nucleotide polymorphisms (SNPs) located within approximately 14,000 genes were tested. Out of 62 markers found to be associated with disease status, the most consistent finding was observed for a candidate locus on chromosome 1q32. The marker SNP rs752016 showed suggestive association with schizophrenia (odds ratio (OR) = 1.49, P = 0.006). This result was confirmed in an independent case-control sample of European Americans (combined OR = 1.38, P = 0.035) and similar genetic effects were observed in smaller subsets of Latin Americans (OR = 1.26) and Asian Americans (OR = 1.37). Supporting evidence was also obtained from two family-based collections, one of which reached statistical significance (OR = 2.2, P = 0.02). High-density SNP mapping showed that the region of association spans approximately 60 kb of the PLXNA2 gene. Eight out of 14 SNPs genotyped showed statistically significant differences between cases and controls. These results are in accordance with previous genetic findings that identified chromosome 1q32 as a candidate region for schizophrenia. PLXNA2 is a member of the transmembrane semaphorin receptor family that is involved in axonal guidance during development and may modulate neuronal plasticity and regeneration. The PLXNA2 ligand semaphorin 3A has been shown to be upregulated in the cerebellum of individuals with schizophrenia. These observations, together with the genetic results, make PLXNA2 a likely candidate for the 1q32 schizophrenia susceptibility locus.

Comparison of non-invasive measures of cholinergic and allergic airway responsiveness in rats

AIM

Non-invasive analysis of tidal expiratory flow parameters such as Tme/TE (time needed to reach peak expiratory flow divided by total expiratory time) or midexpiratory tidal flow (EF50) has been shown useful for phenotypic characterization of lung function in humans and animal models. In this study, we aimed to compare the utility of two non-invasive measures, EF50 and Tme/TE, to monitor bronchoconstriction to inhaled cholinergic and allergic challenges in Brown-Norway rats.

METHODS

Non-invasive measurements of Tme/TE and EF50 were paralleled by invasive recordings of Tme/TE, EF50 and pulmonary conductance (GL).

RESULTS

First, dose-response studies with acetylcholine were performed in naive rats, showing that EF50 better than Tme/TE reflected the dose-related changes as observed with the classical invasive outcome parameter GL. The subsequent determination of allergen-specific early airway responsiveness (EAR) showed that ovalbumin-sensitized and -challenged rats exhibited airway inflammation and allergen-specific EAR. Again, EF50 was more sensitive than Tme/TE in detecting the allergen-specific EAR recorded with invasive and non-invasive lung function methods and agreed well with classical GL measurements.

CONCLUSION

We conclude that non-invasive assessment of EF50 is significantly superior to Tme/TE and serves as a suitable and valid tool for phenotypic screening of cholinergic and allergic airway responsiveness in rats.

Structured Diabetes Therapy and Education Improves the Outcome of Patients with Insulin Treated Diabetes Mellitus

AIMS/HYPOTHESIS

JEVIN (Jena's St. Vincent Trial) is a prospective, 10 year follow-up, population-based survey of all insulin treated patients with type 1 and type 2 diabetes mellitus aged 16 to 60 years and living in the city of Jena (100,000 inhabitants), Thuringia, Germany. It aims to show the effects of implementation of the St. Vincent Declaration and to evaluate the effect of recent changes in the health care system and new treatment strategies.

PATIENTS AND METHODS

190 patients (83% of the target population), 244 patients (90%) and 261 patients (90%) were studied in 1989/90, 1994/95 and 1999/2000, respectively.

RESULTS

Up to 1994/95, the HbA1c of patients with type 1 diabetes mellitus increased (1994/95: 8.50+/-1.80% versus 1989/90: 7.83+/-1.60%, p=0.002). For patients with type 2 diabetes mellitus, it remained constant (9.01+/-2.06% versus 9.17+/-1.60%, n. s.). During the period from 1994/95 to 1999/2000, there was a substantial improvement in the relative HbA1c of both, patients with type 1 (7.62+/-1.55%, p<0.0001), and with type 2 diabetes (7.57+/-1.29%, p<0.0001). Up to 1999/2000, 87.7% of the patients with type 1 (1989/90: 0%, 1994/95: 73.2%) and 96.6% of the patients with type 2 diabetes (1989/90: 0%, 1994/95: 89.7%) participated in TTP's. The incidence of acute and the prevalence of long-term complications remained constant.

CONCLUSIONS

Results of the population-based, prospective trial to optimise patients' quality of diabetic control suggest: For patients with insulin treated type 2 diabetes mellitus, excellent treatment can be available by primary care physicians interested, educated and highly engaged in diabetes therapy. Moreover, structured diabetes therapy consisting of treatment and teaching programmes, regular self-monitoring, patients' insulin dose adjustment and patients' empowerment, should be offered to all patients with diabetes mellitus.

Evaluation of Selective Caries Removal by a Fluorescence Feedback-Controlled Er:YAG Laser in vitro

AIM

To establish a fluorescence threshold level that could guide a therapeutic Er:YAG laser through a caries lesion to determine a therapeutic endpoint of caries removal.

MATERIALS AND METHODS

A total of 65 extracted human teeth, 35 with dentine caries and 30 healthy, were used for this study. An Er:YAG laser system that emitted at a wavelength of 2.94 microm was used. The laser was equipped with a laser fluorescence feedback system, excitation wavelength 655 nm, to control the irradiation by the Er:YAG laser. The evaluated threshold levels of the fluorescence feedback system were 3, 7, 8, 10, 12, 15 and 20. After treatment the teeth were prepared for histological staining according to the method of Brown and Brenn for the identification of bacteria. The specimens were subjected to a quantitative evaluation of residual bacteria on the treated dentine surface. In addition, the internal fluorescence of dentine and potential fluorescence changes of dentine after laser irradiation were evaluated.

RESULTS

About 80% of the irradiated dentine surface showed residual bacteria with threshold levels of 20, 15, 12, and 10. Residual bacteria were not found with threshold levels of 7 and 3. The study revealed a significant increase in dentine fluorescence after laser irradiation.

CONCLUSION

The results of the present in vitro study indicate that a fluorescence threshold level of 7 or 8 units can guide an Er:YAG laser to a complete removal of carious dentine.

[Alopecia totalis, hypotension and erectile dysfunction in a 34 year old patient. Difficult clarification of a common cause]

The occurrence of both autoimmune endocrinopathies and endocrinopathies caused by other reasons is called polyglandular autoimmune syndrome (PAS-syndrome). In a 34 years old man with weakness, weight loss and erectile dysfunction we found low cortisol caused by an autoimmune adrenalitis and low testosterone caused by a hypophysitis with impaired gonadotropin secretion. Thyroid autoantibodies and islet cell autoantibodies without any hormone deficiencies were further signs of a broad endocrine autoimmune syndrome. In the following 11 years the patient developed three autoimmune disorders: paradrenal glandular insufficiency, hypogonadism caused by hypophysitis, Diabetes mellitus type 1. In the same time several non endocrine autoimmune diseases became manifest: alopecia totalis, vitiligo, retrobulbar neuritis and keratoconjunctivitis.

Risk of malignancies in patients with insulin-treated diabetes mellitus: results of a population-based trial with 10-year follow-up (JEVIN)

BACKGROUND

Studies involving diabetes mellitus and malignancies show contradictory results: Many of them have found incidences of malignancies that are comparable or lower, other studies have found higher rates than those of non-diabetic subjects. Hence, the goal of the present trial was to study the possible association between diabetes mellitus and the incidence of malignancies and its outcome in a selection-free population over a longer period of time. -

PATIENTS AND METHODS

All the patients (n=291) who participated in the JEVIN (Jena's St. Vincent)- trial (a prospective, 10 year follow-up, population-based intervention survey of all insulin-treated patients with type 1 and type 2 diabetes mellitus aged 16 to 60 years and living in the city of Jena [about 100,000 inhabitants], Thuringia, Germany) were assessed. The baseline examination took place in 1989/90, follow-up examinations were performed in 1994/95 and 1999/2000. -

RESULTS

Up to 1999/2000, 2 patients with type 1 and 5 patients with insulin-treated type 2 diabetes mellitus developed a malignancy (incidence 0.0241). The most frequent malignancies were cancer of the colon and rectum (3 of 291 patients, incidence 0.0103). Comparing these data with the incidence of carcinoma of the colon and rectum reported by the Robert-Koch-Institute of Germany (incidence 0.0012) diabetic patients showed a 9.9-fold increased risk (p=0.042). There were no significant differences regarding incidence of total malignancies or carcinoma of the breast, the lung, renal cells or gonads. Correlation and multivariate analyses revealed no associations between the development of malignancies and patients' outcome and diabetes duration, the duration of insulin therapy, insulin dosage, the quality of diabetes control or the presence of diabetes-related long-term complications. -

CONCLUSIONS

Conclusive to other data derived from selected cohorts, population-based the JEVIN-trial demonstrate an increased incidence of malignancies of the colon and rectum in insulin-treated patients with diabetes mellitus. However, for further confirmation of these interesting results more studies in larger populations over longer periods of time are necessary to explain the heterogeneous findings in patients with diabetes mellitus of an increased incidence for some cancer entities, but not for others. Knowledge of these mechanisms should have important implications for the direction of strategies to prevent the development of malignancies, or to enhance ability to make an earlier diagnosis and more effective therapies.

Perinatal Morbidity in Women with Undiagnosed Gestational Diabetes in Northern Thuringia in Germany

INTRODUCTION

Undiagnosed gestational diabetes mellitus (GDM) is associated with severe perinatal complications.

PATIENTS AND METHODS

Out of 970 women, infant and maternal morbidity was assessed in 114 mother-children-pairs with an infant birth weight over the 90th percentile (Voigt et al., 1996). It was the aim of this retrospective study to assess the number of mothers with undiagnosed GDM, who have born a macrosomic child.

RESULTS

The macrosomia rate in newborns was 12 % in this study excluding macrosomic infants of mothers with preexisting diabetes mellitus. Maternal data: Age 28.3 +/- 5.3 years, adipositas (body-mass-index > 30 kg/m) in 42.1 % vs. 30.4 % in the peer group (p < 0.02), increase in weight > 15 kg during pregnancy in 57.9 % of the mothers who have given birth to a macrosomic child vs. 30.9 % in the peer group (p < 0.0001), family history of diabetes mellitus (28.0 % vs. 11.3 % in the peer group, p = 0.006), preeclampsia in 8.8 % vs. 2.7 % in the peer group (p = 0.002), cervical insufficiency in 2.6 % vs. 0.4 % in the peer group (p = 0.02). After delivery HbA1c was elevated in 38.6 % of the women having born macrosomic infant (mean HbA1c: 5.0 % +/- 0.5). Infant data: neonatal jaundice 16.7 % vs. 4.5 % in the peer group, p < 0.0001. There were no statistically significant differences concerning perinatal condition and malformations. Neonatal hypoglycaemia occurred in 9.6 % of the macrosomic infants. Cord blood insulin levels were significantly elevated in comparison to the peer group of mothers without metabolic disorders and having born eutroph infants (8.4 mU/l [3.0 - 100.0] vs. 5.3 mU/l [3.0 - 30.7], p = 0.01). 11.4 % of all macrosomic infants had cord blood insulin levels above the normal range.

CONCLUSION

More than one third of the mothers having born one or more macrosomic infants had an impairment of glucose metabolism immediately after birth. The elevated prevalence of preeclampsia in this group confirms the relationship of hypertension and impaired glucose metabolism during pregnancy. The detection of hyperinsulinaemia, postnatal hypoglycaemia, elevated prevalence of neonatal jaundice with need of further therapy and diabetic fetopathy in macrosomic infants of mothers, whose metabolism was not monitored during pregnancy, pinpoint the need for a diagnostic screening for GDM.