Optically Detected Magnetic Resonance of Porphyrin Complexes in the Bacterium Rhodopseudomonas sphaeroides

By ODMR in zero-field the porphyrins of the BChl-biosynthesis in whole cells of Rhodopseudomonas sphaeroides R-26 are investigated. In the optical emission spectrum 11 pigments could be identified using ODM R in combination with emission and excitation spectroscopy. The properties of these pigments were analyzed in respect to their interactions with the surrounding molecules. An energy transfer from the triplet state of Zn-protoporphyrin to the antenna pigm ent singlet system was proved by DE-ODMR. The wavelength dependence of the zfs param eters within the individual emission band is explained by a model of selective spin-orbit-coupling. In the case of the precursors chlorophyllide a and pheophorbide a, for example, we could show that the pigments are bound to proteins via a hydrogen bond to the ketocarbonylgroup of ring V and that porphyrins with a central Mg-atom have an additional bond via a Fifth ligand of the Mg

Synthese und Kristallstruktur von 7-Azaindolato-Silber, einem dimeren Ag(I)-Komplex mit kurzem Ag-Ag-Abstand

[Ag(C7H5N2)]2 is obtained by the slow addition of a tetrahydrofuran (thf) solution of AgClO4 to a solution of Na(C7H5N2) in thf. The slightly yellow compound crystallizes in the monoclinic space group P21/n with the lattice constants a = 554.5(1) pm, b = 954.6(2) pm, c = 1196.5(3) pm, β = 99.67(2)°. The structure consists of centrosymmetric, planar, dimeric complexes with ligand disorder in the crystal. The N atoms coordinate the Ag+ ions nearly linearly (N-Ag-N = 168°, Ag-N = 213 pm). The Ag+ ions in the dimeric unit have a short distance of 284 pm. The complexes are linked by weak intermolecular η2-Ag-C interactions to chains.

Octachalcogen Cations Te8 2+, Se8 2+, and Mixed (Te8-xSex)8 2+ Stabilized by Chlorometallates of Bi, Zr, and Hf: Synthesis and Crystal Structures of Se8[Bi4Cl14] and E8[MCl6] (E = Se, Te; M = Zr, Hf)

The title compounds were obtained by the reaction of elemental chalcogens E (E = Se, Te) with the respective tetrachlorides ECl4 and the Lewis acidic metal halides ZrCl4, HfCl4, and BiCl3. An alternative way, particularly for the preparation of mixed Se/Te-species, is the enlargement of smaller cationic rings in E4MCl6] (M = Zr, Hf) by adding the respective complementary chalcogen. All reactions were carried out in sealed, evacuated glass ampoules at temperatures between 120 °C and 220 °C, and yielded black crystals of Se8[Bi4Cl14], (Te5.0Se3.0)[HfCl6], (Te5.3 Se2.7)[ZrCl6], (Te6.5Se1.5)[ZrCl6] and Te8[HfCl6], which have been identified by crystal structure analyses. All five compounds contain eight-membered chalcogen rings in an endo-exo-conformation which are isostructural to the known octachalcogen dications E8 2+ (E = S, Se, Te). While in (Te5 .0Se3.0)[HfCl6], (Te5.3Se2 .7 )[ZrCl6], (Te6 .5Se1.5 )[ZrCl6] and Te8[HfCl6] the molecular polycations are surrounded by discrete, octahedral [MCl6]2- counterions, Se4[Bi4Cl14] contains a two-dimensional polymeric anion ([Bi4Cl14]2-)n built of a variety of vertex and edge-sharing BiClx-polyhedra (x = 6, 7). The Bi-Cl bond lengths are spread over a wide range between 250 and 350 pm.

Die Reaktion von MoCl4mit TeCl4: Synthese und Struktur von Tris(trichlorotelluronium)hexachloromolybdat(IV)-chlorid,([TeCl3]+)3[MoCl6]2-(Cl-) / The Reaction of MoCl4 with TeCl4: Synthesis and Crystal Structure of Tris(trichlorotelluronium)Hexachloromolybdate(IV)Chloride,([TeCl3]+)3[MoCl6]2-[Cl-]

Red crystals of (TeCl3)3MoCl6(Cl) are obtained by reacting MoCl4 with TeCl4 in a 1:3 molar ratio in a sealed evacuated ampoule at 170°. The crystal structure determination (orthorhombic, space group Cmc21, a = 1541.6(2), b = 1268.1(1), c = 1180.6(1) pm) shows the presence of trigonal-pyramidal [TeCl3]+ ions, octahedral [MoCI6]2- ions, and isolated Cl- ions. The ions are linked by long Te-Cl bridges resulting in distorted TeCl6 octahedra. The octahedra are connected by joint edges and corners to zig-zag chains running along the polar c axis.

Synthese und Kristallstruktur von (TeCl3)2MoCl6 und β-(TeCl3)2ReCl6 / Synthesis and Crystal Structure of (TeCl3)2MoCl6 and β-(TeCl3)2ReCl6

Single crystals of (TeCl3)2MoCl6 and β-(TeCl3)2ReCl6 are obtained by the reactions of TeCl4 with MoCl4 at 195 °C and of TeCl4 / Te with ReCl5 at 150 °C, respectively. The com pounds form dark-red moisture sensitive crystals. The crystal structure determinations show, that both crystallize isotypically ( rhombohedral, space group R3̄, (TeCl3)2MoCl6: a = 1116,9(1), c = 3539,5(5) pm. 1966 unique reflections for 69 parameters, final R = 0.058; β-(TeCl3)2 ReCl6: a = 1113,3(3), c = 3546(2) pm. 1653 unique reflections for 70 parameters, final R = 0.034). The structures consist of octahedral MCl6 2- anions (with M=Mo,Re) and pyramidal TeCl3+ cations. The ions are interconnected through long Te-Cl bridges (291,1- 295,6 pm) to give distorted TeCl6 octahedra. MCl6 and TeCl6 units are connected via edges and corners, resulting in a complex layer structure with layers parallel to the ab-plane. In the previously reported a-form of (TeCl3)2ReCl6, only connections via corners are observed.

A pathogenic progranulin mutation and C9orf72 repeat expansion in a family with frontotemporal dementia

AIMS

Frontotemporal lobar degeneration (FTLD) is a progressive neurodegenerative disease and is the second most common form of young onset dementia after Alzheimer's disease (AD). An autosomal dominant pattern of inheritance is present in around 25-50% of FTLD cases indicating a strong genetic component. Major pathogenic mutations of FTLD have been demonstrated independently in the progranulin (GRN) gene and the C9orf72 hexanucleotide expansion repeat. In this study we present a family that have been identified as carrying both a GRN Cys31fs mutation and the C9orf72 hexanucleotide expansion repeat.

METHODS

In the present study we describe the clinical and genetic details of family members and pathological features of two family members that have come to post-mortem.

RESULTS

The mean age at disease onset was 57 years (48-61 years) and mean duration 4 years (2-7 years). The most common presenting syndrome was behavioural variant frontotemporal dementia. Brain imaging from available cases showed a symmetrical pattern of atrophy particularly affecting the frontal and temporal lobes. Pathologically two cases were classified as FTLD-TDP type A with TDP-43 positive inclusions, with additional p62-positive 'star-like' inclusions found in the hippocampal formation and cerebellum.

CONCLUSIONS

The type and distribution of the pathological lesions in these two cases were in keeping with FTLD cases carrying only the C9orf72 hexanucleotide repeat. However the driving force of the pathological process may be either pathogenic mutation or a combination of both converging on a singular mechanism.

Association of interleukin-1 gene variations with moderate to severe chronic periodontitis in multiple ethnicities

Background and Objective

Genetic markers associated with disease are often non-functional and generally tag one or more functional “causative” variants in linkage disequilibrium. Markers may not show tight linkage to the causative variants across multiple ethnicities due to evolutionary divergence, and therefore may not be informative across different population groups. Validated markers of disease suggest causative variants exist in the gene and, if the causative variants can be identified, it is reasonable to hypothesize that such variants will be informative across diverse populations. The aim of this study was to test that hypothesis using functional Interleukin-1 (IL-1) gene variations across multiple ethnic populations to replace the non-functional markers originally associated with chronic adult periodontitis in Caucasians.

Material and Methods

Adult chronic periodontitis cases and controls from four ethnic groups (Caucasians, African Americans, Hispanics and Asians) were recruited in the USA, Chile and China. Genotypes of IL1B gene single nucleotide polymorphisms (SNPs), including three functional SNPs (rs16944, rs1143623, rs4848306) in the promoter and one intronic SNP (rs1143633), were determined using a single base extension method or TaqMan 5′ nuclease assay. Logistic regression and other statistical analyses were used to examine the association between moderate to severe periodontitis and IL1B gene variations, including SNPs, haplotypes and composite genotypes. Genotype patterns associated with disease in the discovery study were then evaluated in independent validation studies.

Results

Significant associations were identified in the discovery study, consisting of Caucasians and African Americans, between moderate to severe adult chronic periodontitis and functional variations in the IL1B gene, including a pattern of four IL1B SNPs (OR = 1.87, p < 0.0001). The association between the disease and this IL1B composite genotype pattern was validated in two additional studies consisting of Hispanics (OR = 1.95, p = 0.04) or Asians (OR = 3.27, p = 0.01). A meta-analysis of the three populations supported the association between the IL-1 genotype pattern and moderate to severe periodontitis (OR 1.95; p < 0.001). Our analysis also demonstrated that IL1B gene variations had added value to conventional risk factors in predicting chronic periodontitis.

Conclusion

This study validated the influence of IL-1 genetic factors on the severity of chronic periodontitis in four different ethnicities.

C9orf72 expansions are the most common genetic cause of Huntington disease phenocopies

OBJECTIVE

In many cases where Huntington disease (HD) is suspected, the genetic test for HD is negative: these are known as HD phenocopies. A repeat expansion in the C9orf72 gene has recently been identified as a major cause of familial and sporadic frontotemporal lobar degeneration and amyotrophic lateral sclerosis. Our objective was to determine whether this mutation causes HD phenocopies.

METHODS

A cohort of 514 HD phenocopy patients were analyzed for the C9orf72 expansion using repeat primed PCR. In cases where the expansion was found, Southern hybridization was performed to determine expansion size. Clinical case notes were reviewed to determine the phenotype of expansion-positive cases.

RESULTS

Ten subjects (1.95%) had the expansion, making it the most common identified genetic cause of HD phenocopy presentations. The size of expansion was not significantly different from that associated with other clinical presentations of C9orf72 expanded cases. The C9orf72 expansion-positive subjects were characterized by the presence of movement disorders, including dystonia, chorea, myoclonus, tremor, and rigidity. Furthermore, the age at onset in this cohort was lower than previously reported for subjects with the C9orf72 expansion and included one case with pediatric onset.

DISCUSSION

This study extends the known phenotype of the C9orf72 expansion in both age at onset and movement disorder symptoms. We propose a revised clinico-genetic algorithm for the investigation of HD phenocopy patients based on these data.

A novel prion disease associated with diarrhea and autonomic neuropathy

BACKGROUND

Human prion diseases, although variable in clinicopathological phenotype, generally present as neurologic or neuropsychiatric conditions associated with rapid multifocal central nervous system degeneration that is usually dominated by dementia and cerebellar ataxia. Approximately 15% of cases of recognized prion disease are inherited and associated with coding mutations in the gene encoding prion protein (PRNP). The availability of genetic diagnosis has led to a progressive broadening of the recognized spectrum of disease.

METHODS

We used longitudinal clinical assessments over a period of 20 years at one hospital combined with genealogical, neuropsychological, neurophysiological, neuroimaging, pathological, molecular genetic, and biochemical studies, as well as studies of animal transmission, to characterize a novel prion disease in a large British kindred. We studied 6 of 11 affected family members in detail, along with autopsy or biopsy samples obtained from 5 family members.

RESULTS

We identified a PRNP Y163X truncation mutation and describe a distinct and consistent phenotype of chronic diarrhea with autonomic failure and a length-dependent axonal, predominantly sensory, peripheral polyneuropathy with an onset in early adulthood. Cognitive decline and seizures occurred when the patients were in their 40s or 50s. The deposition of prion protein amyloid was seen throughout peripheral organs, including the bowel and peripheral nerves. Neuropathological examination during end-stage disease showed the deposition of prion protein in the form of frequent cortical amyloid plaques, cerebral amyloid angiopathy, and tauopathy. A unique pattern of abnormal prion protein fragments was seen in brain tissue. Transmission studies in laboratory mice were negative.

CONCLUSIONS

Abnormal forms of prion protein that were found in multiple peripheral tissues were associated with diarrhea, autonomic failure, and neuropathy. (Funded by the U.K. Medical Research Council and others.).

Prevalent abnormal prion protein in human appendixes after bovine spongiform encephalopathy epizootic: large scale survey

OBJECTIVES

To carry out a further survey of archived appendix samples to understand better the differences between existing estimates of the prevalence of subclinical infection with prions after the bovine spongiform encephalopathy epizootic and to see whether a broader birth cohort was affected, and to understand better the implications for the management of blood and blood products and for the handling of surgical instruments.

DESIGN

Irreversibly unlinked and anonymised large scale survey of archived appendix samples.

SETTING

Archived appendix samples from the pathology departments of 41 UK hospitals participating in the earlier survey, and additional hospitals in regions with lower levels of participation in that survey.

SAMPLE

32,441 archived appendix samples fixed in formalin and embedded in paraffin and tested for the presence of abnormal prion protein (PrP).

RESULTS

Of the 32,441 appendix samples 16 were positive for abnormal PrP, indicating an overall prevalence of 493 per million population (95% confidence interval 282 to 801 per million). The prevalence in those born in 1941-60 (733 per million, 269 to 1596 per million) did not differ significantly from those born between 1961 and 1985 (412 per million, 198 to 758 per million) and was similar in both sexes and across the three broad geographical areas sampled. Genetic testing of the positive specimens for the genotype at PRNP codon 129 revealed a high proportion that were valine homozygous compared with the frequency in the normal population, and in stark contrast with confirmed clinical cases of vCJD, all of which were methionine homozygous at PRNP codon 129.

CONCLUSIONS

This study corroborates previous studies and suggests a high prevalence of infection with abnormal PrP, indicating vCJD carrier status in the population compared with the 177 vCJD cases to date. These findings have important implications for the management of blood and blood products and for the handling of surgical instruments.

Homozygosity for the C9orf72 GGGGCC repeat expansion in frontotemporal dementia

An expanded hexanucleotide repeat in the C9orf72 gene is the most common genetic cause of frontotemporal dementia and amyotrophic lateral sclerosis (c9FTD/ALS). We now report the first description of a homozygous patient and compare it to a series of heterozygous cases. The patient developed early-onset frontotemporal dementia without additional features. Neuropathological analysis showed c9FTD/ALS characteristics, with abundant p62-positive inclusions in the frontal and temporal cortices, hippocampus and cerebellum, as well as less abundant TDP-43-positive inclusions. Overall, the clinical and pathological features were severe, but did not fall outside the usual disease spectrum. Quantification of C9orf72 transcript levels in post-mortem brain demonstrated expression of all known C9orf72 transcript variants, but at a reduced level. The pathogenic mechanisms by which the hexanucleotide repeat expansion causes disease are unclear and both gain- and loss-of-function mechanisms may play a role. Our data support a gain-of-function mechanism as pure homozygous loss of function would be expected to lead to a more severe, or completely different clinical phenotype to the one described here, which falls within the usual range. Our findings have implications for genetic counselling, highlighting the need to use genetic tests that distinguish C9orf72 homozygosity.

Adjuvant therapy after resection of brain metastases. Frameless image-guided LINAC-based radiosurgery and stereotactic hypofractionated radiotherapy

BACKGROUND

Tumor bed stereotactic radiosurgery (SRS) after resection of brain metastases is a new strategy to delay or avoid whole-brain irradiation (WBRT) and its associated toxicities. This retrospective study analyzes results of frameless image-guided linear accelerator (LINAC)-based SRS and stereotactic hypofractionated radiotherapy (SHRT) as adjuvant treatment without WBRT.

MATERIALS AND METHODS

Between March 2009 and February 2012, 44 resection cavities in 42 patients were treated with SRS (23 cavities) or SHRT (21 cavities). All treatments were delivered using a stereotactic LINAC. All cavities were expanded by ≥ 2 mm in all directions to create the clinical target volume (CTV).

RESULTS

The median planning target volume (PTV) for SRS was 11.1 cm(3). The median dose prescribed to the PTV margin for SRS was 17 Gy. Median PTV for SHRT was 22.3 cm(3). The fractionation schemes applied were: 4 fractions of 6 Gy (5 patients), 6 fractions of 4 Gy (6 patients) and 10 fractions of 4 Gy (10 patients). Median follow-up was 9.6 months. Local control (LC) rates after 6 and 12 months were 91 and 77 %, respectively. No statistically significant differences in LC rates between SRS and SHRT treatments were observed. Distant brain control (DBC) rates at 6 and 12 months were 61 and 33 %, respectively. Overall survival (OS) at 6 and 12 months was 87 and 63.5 %, respectively, with a median OS of 15.9 months. One patient treated by SRS showed symptoms of radionecrosis, which was confirmed histologically.

CONCLUSION

Frameless image-guided LINAC-based adjuvant SRS and SHRT are effective and well tolerated local treatment strategies after resection of brain metastases in patients with oligometastatic disease.

Neurally adjusted ventilatory assist in non-invasive ventilation

This manuscript describes the motivation for developing neurally adjusted ventilatory assist (NAVA) and its subsequent use with a non-invasive interface. The challenges with conventional, pneumatically controlled non-invasive modes are briefly described, followed by a mini-review on the upper airways and the diaphragm electrical activity (EAdi) signal. The bulk of the review focuses on the importance and use of monitoring the EAdi during non-invasive ventilation, and a report of the recent experimental and clinical findings with NAVA during non-invasive ventilation. In summary, non-invasive NAVA provides a truly synchronized mode of non-invasive ventilation, both in time and in level of assist. Along with EAdi monitoring, NAVA can increase the confidence to treat respiratory failure non-invasively.

Outbreak of listerosis due to imported cooked ham, Switzerland 2011

From 24 April to 31 July 2011, nine cases of listeriosis were registered in the cantons of Aargau, Basel-Land and Zurich, Switzerland. In six of the cases, infection with Listeria monocytogenes was laboratory confirmed, while three remained suspected cases. The suspected cases were family members of confirmed cases with identical or similar symptoms. All confirmed cases were infected with a L. monocytogenes strain belonging to serovar 1/2a: all had an indistinguishable pulsotype by pulsed-field gel electrophoresis (PFGE). The same strain was detected in samples of cooked ham that were on sale from a particular retailer. Two samples of ham tested contained 470 and 4,800 colony-forming units (CFU) L. monocytogenes per gram respectively. Data of shopper cards from two confirmed cases could be evaluated: both cases had purchased the contaminated ham. The outbreak initiated a product recall and alert actions at national and European level, through the Rapid Alert System for Food and Feed (RASFF). Following the RASFF alert, the company producing the contaminated ham was inspected by the responsible authorities. Their investigations showed that the ham was not contaminated in the production plant, but in the premises of a company to which slicing and packing was outsourced.

Outbreak of listerosis due to imported cooked ham, Switzerland 2011

From 24 April to 31 July 2011, nine cases of listeriosis were registered in the cantons of Aargau, Basel-Land and Zurich, Switzerland. In six of the cases, infection with Listeria monocytogenes was laboratory confirmed, while three remained suspected cases. The suspected cases were family members of confirmed cases with identical or similar symptoms. All confirmed cases were infected with a L. monocytogenes strain belonging to serovar 1/2a: all had an indistinguishable pulsotype by pulsed-field gel electrophoresis (PFGE). The same strain was detected in samples of cooked ham that were on sale from a particular retailer. Two samples of ham tested contained 470 and 4,800 colony-forming units (CFU) L. monocytogenes per gram respectively. Data of shopper cards from two confirmed cases could be evaluated: both cases had purchased the contaminated ham. The outbreak initiated a product recall and alert actions at national and European level, through the Rapid Alert System for Food and Feed (RASFF). Following the RASFF alert, the company producing the contaminated ham was inspected by the responsible authorities. Their investigations showed that the ham was not contaminated in the production plant, but in the premises of a company to which slicing and packing was outsourced.