Ca(4)IrO(6), Ca(3)MgIrO(6) and Ca(3)ZnIrO(6)

Single crystals of tetracalcium iridium hexaoxide, Ca(4)IrO(6), tricalcium magnesium iridium hexaoxide, Ca(3)MgIrO(6), and tricalcium zinc iridium hexaoxide, Ca(3)ZnIrO(6), were prepared via high-temperature flux growth and structurally characterized by single-crystal X-ray diffraction. The three compounds are isostructural and adopt the K(4)CdCl(6) structure type, comprised of chains of alternating face-shared [CaO(6)], [MgO(6)] or [ZnO(6)] trigonal prisms and [IrO(6)] octahedra, surrounded by columns of Ca(2+) ions.

Missing a therapeutic window of opportunity: an audit of patients attending a tertiary teaching hospital with potentially osteoporotic hip and wrist fractures

OBJECTIVE

To establish the rate of and the predictors for performance of a bone mineral density (BMD) test and the treatment of osteoporosis in an at-risk cohort of patients attending a tertiary teaching hospital with fracture possibly related to osteoporosis.

METHODS

A list of all patients between ages 40 and 85 who had been admitted to a tertiary teaching hospital in the last 18 mo with hip fracture or seen in the accident and emergency department with a wrist fracture over the last 30 mo was obtained from computer records; those patients were invited to participate in the audit. In a followup telephone questionnaire, they were queried about potential risk factors for osteoporosis and subsequent fracture, the performance of a BMD test, any information received on osteoporosis and the source of this information, and the prescription of any treatment for osteoporosis.

RESULTS

In total, 218 patients were included in the audit from a potential 374 eligible patients. The majority were female (78%), with hip and wrist fractures in 42% and 58%, respectively; 32% subsequently had BMD measured and 39% were offered treatment for osteoporosis. Ninety-four percent of patients had heard of osteoporosis, with the major source of information being the media (83%) and friends (23%), with little information from the medical profession (34%). The major predictors for a patient to have a subsequent BMD test were female sex (OR 3.4, 95% CI 1.3-9.9), history of a previous fracture after the age of 50 (OR 2.3, 95% CI 1.0-5.6), family history of osteoporosis (OR 3.5, 95% CI 1.3-9.5), or the use of concurrent medications with a potential to cause osteoporosis (OR 2.5, 95% CI 1.1-5.8). The main predictors of treatment for osteoporosis being offered were age (risk increased by 1.04 for every year of life), abnormal result on the BMD test (OR 19, 95% CI 6-60), history of fracture after the age of 50 (OR 2.6, 95% CI 1.1-6.7), and a history of fracture with minimal trauma (OR 2.6, 95% CI 1.1-4.2). There was a range of treatments offered, with calcium supplementation alone accounting for 60% of treatments.

CONCLUSION

Osteoporosis was overlooked by medical practitioners responsible for the care of this at-risk patient cohort, with little evidence of the medical profession offering information, further investigation, or treatment of patients who presented with a probable osteoporotic fracture of the hip or wrist. This suggests that greater education of the accident and emergency and orthopedic medical staff as well as the general public is required concerning this opportunity to investigate and treat symptomatic osteoporosis.

The POU domain transcription factor Brn-3a protects cortical neurons from apoptosis

We have demonstrated previously that exogenously expressed Brn-3a is capable of protecting neurons of the peripheral nervous system against apoptosis. In these previous studies Brn-3a showed a degree of neuronal sub-type specificity, in that while it could promote survival in NGF-dependent sensory neurons, no effect was observed in NGF-dependent neurons of the sympathetic nervous system. In this report, we show that Brn-3a delivered using a herpes simplex virus is capable of protecting cultures of rat cerebrocortical neurons of the central nervous system against two types of cell death stimuli, including glutamate neurotoxicity. Hence the protective effect of Brn-3a is not confined to neurons of the peripheral nervous system but can also occur in neurons of the CNS.

Observation of a large magnetic anisotropy in the new 2H-perovskite related oxide Ba8CoRh6O21: magnetic measurements on aligned single crystals

Single crystals of Ba8CoRh6O21, grown out of a potassium carbonate flux, were characterized by single-crystal X-ray diffraction and magnetic measurements. X-ray data were collected in a superspace group approach and solved using the JANA2000 software package. Ba8CoRh6O21 represents the first example of a structurally characterized m = 5, n = 3 member of the A3n+3mA'nB3m+nO9m+6n family of 2H hexagonal perovskite related oxides and contains chains consisting of six consecutive RhO6 octahedra followed by one distorted CoO6 trigonal prism. Magnetic measurements were carried out on large aligned single crystals, and a very large magnetic anisotropy in the magnetic susceptibility, persisting up to room temperature, was observed.

Self-assembly of a bis-urea macrocycle into a columnar nanotube

A bis-urea macrocycle 1 was synthesized and shown to form extended nanotubular columns by X-ray crystallography.

Crystal growth, structure determination and magnetism of a new hexagonal rhodate: Ba9Rh8O24

Single crystals of Ba9Rh8O24, grown from a molten potassium carbonate flux, crystallize in the spacegroup R3c with lattice parameters of a = 10.0899(4) and c = 41.462(2) A. Magnetic measurements on oriented single crystals reveal the existence of magnetic anisotropy.

Successful treatment of rheumatoid arthritis is associated with a reduction in synovial membrane cytokines and cell adhesion molecule expression

OBJECTIVE

To investigate the change in synovial membrane cytokine content and cell adhesion molecule expression in sequential biopsies from the same knee joint of patients with rheumatoid arthritis, before and following anti-rheumatic drug treatment and to assess the relationship of these changes with clinical responses to the drug treatment.

METHODS

A selected group of patients with rheumatoid arthritis, some of whom had achieved a disease remission based on American College of Rheumatology (ACR) criteria, were included in this study. Sequential synovial biopsies obtained before and throughout the treatment period were studied by immunohistochemical labelling techniques for the cellular content, production of a range of pro- and anti-inflammatory cytokines and the expression of cell adhesion molecules. The staining was quantitated using computer-assisted digital image analysis.

RESULTS

There was a decrease in tumour necrosis factor-alpha (TNFalpha) and interleukin-1beta (IL-1beta) production in the synovial membrane lining and sublining of all patients who responded to treatment. The changes in IL-1 receptor antagonist production were variable. Paradoxically, there was a trend to decreased synovial membrane production of the anti-inflammatory cytokines, IL-10 and transforming growth factor-beta (TGFbeta), while IL-4 was not detectable in any of the synovial membrane biopsies. A significant reduction in the density and total amount of E-selectin expression in the synovial membrane was seen. Similarly, intercellular adhesion molecule-1 (ICAM-1) expression in the lining and sublining was decreased in those patients who had a significant clinical response to drug treatment or attained disease remission. There were no consistent or significant changes seen in the expression of other cell adhesion molecules in the synovial membranes of these patients.

CONCLUSIONS

Successful drug treatment of rheumatoid arthritis patients is characterized at the synovial membrane level by a decrease in TNFalpha, IL-10 and TGFbeta production. Some (E-selectin and ICAM-1) but not all (P-selectin, VCAM-1, PECAM-1) cell adhesion molecules are modulated in patients who respond clinically to drug treatment. E-selectin and ICAM-1 may be important targets for the development of future drug treatments for rheumatoid arthritis.

Love and the commitment problem in romantic relations and friendship

On the basis of the proposition that love promotes commitment, the authors predicted that love would motivate approach, have a distinct signal, and correlate with commitment-enhancing processes when relationships are threatened. The authors studied romantic partners and adolescent opposite-sex friends during interactions that elicited love and threatened the bond. As expected, the experience of love correlated with approach-related states (desire, sympathy). Providing evidence for a nonverbal display of love, four affiliation cues (head nods, Duchenne smiles, gesticulation, forward leans) correlated with self-reports and partner estimates of love. Finally, the experience and display of love correlated with commitment-enhancing processes (e.g., constructive conflict resolution, perceived trust) when the relationship was threatened. Discussion focused on love, positive emotion, and relationships.

Echocardiographic follow-up study of the Ross procedure in older versus younger patients

OBJECTIVES

This study was designed to determine echocardiographic follow-up results of the Ross procedure in older adult patients with aortic valve disease.

BACKGROUND

The excellent long-term results of the Ross procedure from several institutions have indicated that the pulmonary autograft may be the best available substitute for the diseased aortic valve in children and adolescents. The advantages of this operation include optimal hemodynamics and elimination of thromboembolic complications. These features may benefit older adult patients as well.

METHODS

We reviewed data from 49 consecutive patients who had a Ross procedure between 1991 and 1996. Preoperative and postoperative Doppler echocardiographic studies were available for 44 patients (22 men, 22 women; mean [+/-SD] age 36 +/- 14 years) who were grouped into <40 (n = 25) and > or =40 years old (n = 19). Measurements included left ventricular diastolic volume (LVDV), mass, and ejection fraction (EF); a peak pressure gradient across autograft in the aortic position and homograft in the pulmonary position; and valvular regurgitation.

RESULTS

The mean length of echocardiographic follow-up was 36 +/- 16 months. Postoperatively, there was a reduction in LVDV and left ventricular mass in both age groups: 153 +/- 99 mL to 111 +/- 72 mL (P =.015) and 210 +/- 93 g to 152 +/- 54 g (P =.002) for younger patients, 174 +/- 115 mL to 126 +/- 43 mL (P =.17) and 233 +/- 71 g to 215 +/- 65 g (P =.19) for older patients. No significant change in EF was noted in the younger age group. However, in the older age group a significant decrease to EF <25% was found in 2 patients 1 year after surgery. Moderate autograft regurgitation was also detected in 2 patients: 1 in each age group. Pressure gradients across the autograft remained within the normal range in both age groups. Two younger patients had severe homograft stenosis with peak gradients of 100 and 62 mm Hg. The older patients did not demonstrate homograft dysfunction.

CONCLUSIONS

The Ross procedure can be performed in selected older adults with aortic valve disease and provides durable valves in both aortic and pulmonic positions for at least 3 years after surgery but may result in less favorable left ventricular remodeling compared with that in the younger patients. Further follow-up will be necessary to determine the long-term outcome of the Ross procedure in this older adult patient population.

Effects of mycorrhizae on growth and demography of tallgrass prairie forbs

The effects of arbuscular mycorrhizal (AM) symbiosis on ramet and genet densities, vegetative growth rates, and flowering of three forb species were studied in native tallgrass prairie in northeastern Kansas. Mycorrhizal activity was experimentally suppressed for six growing seasons on replicate plots in an annually burned and an infrequently burned watershed with the fungicide benomyl. Benomyl reduced mycorrhizal root colonization to an average of 4.2%, approximately a two-thirds reduction relative to controls (13.7% colonization). Mycorrhizae influenced the population structure of these forbs. Although mycorrhizal suppression had no long-term effect on genet densities and no effect on ramet survivorship throughout the growing season, the number of ramets per individual was significantly increased such that ramet densities of all three species were approximately doubled in response to long-term mycorrhizal suppression. Effects of mycorrhizae on ramet growth and reproduction varied among species. Ramet growth rates, biomass, and flowering of Salvia azurea were greater in plots with active mycorrhizal symbiosis, whereas mycorrhizae reduced ramet growth rates and biomass of Artemesia ludoviciana. Aster sericeus ramet growth rates and biomass were unaffected by the fungicide applications, but its flowering was reduced.The pattern of responses of these three species to mycorrhizae differed considerably between the two sites of contrasting fire regime, indicating that the interaction of fire-induced shifts in resource availability and mycorrhizal symbiosis together modulates plant responses and the intensity and patterns of interspecific competition between and among tallgrass prairie grass and forb species. Further, the results indicate that effects of mycorrhizae on community structure are a result of interspecific differences in the balance between direct positive effects of the symbiosis on host plant performance and indirect negative effects mediated through altered competitive interactions.

Organometallic dehydro[14] annulenes containing Vollhardt's cyclobutadiene: are CpCo-complexed cyclobutadienes more aromatic then benzene?

Pd-catalyzed coupling of 1,2-diethynyl-3,4-(bistrimethylsilyl)cyclobutadienecyclopentadienylcobalt to a series of 1-iodo-2-(trimethylsilylethynyl)benzenes and 1-chloro-4-trimethylsilylbut-1-ene-3-yne is followed by desilylation with potassium carbonate. Cu(OAc)(2)-promoted oxidative ring closure leads to dehydro[14]annulenes and dehydro[14]benzoannulenes fused to a cyclobutadiene(cyclopentadienylcobalt) complex. Five of these fused dehydroannulenes were structurally characterized. (1)H NMR spectroscopy of the organometallic dehydro[14]annulenes incorporating the (bistrimethylsilyl)cyclobutadiene(cyclopentadienylcobalt) unit suggested that the aromaticity of the fused cyclobutadiene complex might be stronger than that of benzene according to the ring-current criterion.

Control of the stereochemical impact of the lone pair in lead(II) tris(pyrazolyl)methane complexes. Improved preparation of Na[B[3,5-(CF3)2C6H3]4]

The reaction of Pb(acac)2 with 2 equiv of [H(Et2O)2][B[3,5-(CF3)2C6H3]4] (HBAr(f)) in CH2Cl2 followed by addition of 2 equiv of either HC(pz)3 or HC(3,5-Me2pz)3 (pz = pyrazolyl ring) leads to the formation of [Pb[HC(pz)3]2][B[3,5-(CF3)2C6H3]4]2 (1) and [Pb[HC(3,5-Me2pz)3]2][B[3,5-(CF3)2C6H3]4]2 (2), respectively. The cation in 1 has a distorted octahedral structure with a stereochemically active lone pair on lead(II). In contrast, the cation in 2 is trigonally distorted octahedral with the lone pair on the lead(II) clearly stereochemically inactive. The driving force for this cation to have a stereochemically inactive lone pair is that in this geometric arrangement the interligand distances between adjacent 3-position methyl groups are close to 4.0 A, the sum of the van der Waals radii of two methyl groups. To facilitate this chemistry, the synthesis of Na[B[3,5-(CF3)2C6H3]4], needed to prepare HBAr(f), has been dramatically improved. The main change is to add NaBF4 to the reaction mixture before forming the Grignard from the reaction of magnesium and 3,5-(CF3)2C6H3Br. The Grignard reacts with the NaBF4 as it forms, reducing the danger of explosion and leading to a higher isolated yield of the product. Crystallographic information: 1 is triclinic, P1, a = 13.0133(6) A, b = 17.2210(7) A, c = 24.7634(11) A, alpha = 71.7300(10) degrees, beta = 82.3630(10) degrees, gamma = 70.5120(10) degrees, Z = 2; 2 is triclinic, P1, a = 12.756(4) A, b = 13.469(4) A, c = 17.160(5) A, alpha = 82.454(7) degrees, beta = 89.904(8) degrees, gamma = 72.995(7) degrees, Z = 1.

Molecular identification and characterization of the platelet ADP receptor targeted by thienopyridine antithrombotic drugs

ADP plays a critical role in modulating thrombosis and hemostasis. ADP initiates platelet aggregation by simultaneous activation of two G protein-coupled receptors, P2Y1 and P2Y12. Activation of P2Y1 activates phospholipase C and triggers shape change, while P2Y12 couples to Gi to reduce adenylyl cyclase activity. P2Y12 has been shown to be the target of the thienopyridine drugs, ticlopidine and clopidogrel. Recently, we cloned a human orphan receptor, SP1999, highly expressed in brain and platelets, which responded to ADP and had a pharmacological profile similar to that of P2Y12. To determine whether SP1999 is P2Y12, we generated SP1999-null mice. These mice appear normal, but they exhibit highly prolonged bleeding times, and their platelets aggregate poorly in responses to ADP and display a reduced sensitivity to thrombin and collagen. These platelets retain normal shape change and calcium flux in response to ADP but fail to inhibit adenylyl cyclase. In addition, oral clopidogrel does not inhibit aggregation responses to ADP in these mice. These results demonstrate that SP1999 is indeed the elusive receptor, P2Y12. Identification of the target receptor of the thienopyridine drugs affords us a better understanding of platelet function and provides tools that may lead to the discovery of more effective antithrombotic therapies.

Analysis of the cell infiltrate and expression of matrix metalloproteinases and granzyme B in paired synovial biopsy specimens from the cartilage-pannus junction in patients with RA

OBJECTIVES

Examination of synovial tissue (ST) obtained at surgery because of end stage destructive rheumatoid arthritis (RA) showed that macrophages and fibroblasts are the major cell types at the cartilage-pannus junction (CPJ). This study aimed at defining the cell infiltrate and mediators of joint destruction in ST selected at arthroscopy from the CPJ in patients with RA who did not require joint surgery.

METHODS

Paired synovial biopsy specimens were obtained at arthroscopy from ST adjacent to the CPJ and the suprapatellar pouch from the knee joints of 17 patients with RA. Immunohistological analysis was performed using monoclonal antibodies to detect T cells, B cells, plasma cells, macrophages, fibroblast-like synoviocytes, mast cells, and granzyme B+ cytotoxic cells as well as the expression of metalloproteinase (MMP)-1, MMP-3, and MMP-13. The sections were evaluated by computer assisted image analysis and semiquantitative analysis.

RESULTS

The cell infiltrate comprised mainly T cells, macrophages, and plasma cells. The ST was also infiltrated by the other cell types, but at lower numbers. Expression of MMPs was abundant, especially MMP-3. The features of ST at the CPJ were generally similar to those at the suprapatellar pouch.

CONCLUSIONS

The synovium at the CPJ in patients with RA who did not require joint surgery exhibits, in general, the same type of cell infiltrate and expression of MMPs and granzymes as ST from the suprapatellar pouch. The pathological changes that have been described at the CPJ in patients with RA with end stage, destructive disease may well reflect the transition to a process in which macrophages, fibroblast-like synoviocytes, and other cell types become increasingly important.

Two Versatile N,N‘-Bipyridine-Type Ligands for Preparing Organic−Inorganic Coordination Polymers: New Cobalt- and Nickel-Containing Framework Materials

The Schiff base ligands 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene (L1, monoclinic, P2(1)/c, a = 3.856(1) A, b = 11.032(2) A, c = 12.738(3) A, beta = 92.21(3) degrees, Z = 2) and 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene (L2, monoclinic, P2(1)/c, a = 10.885(2) A, b = 4.613(1) A, c = 14.978(3) A, beta = 92.827(4) degrees, Z = 2) were used in the synthesis of four new organic-inorganic coordination polymers, each of them adopting a different structural motif. Synthesis, X-ray structural determinations, and spectroscopic and thermogravimetric analyses are presented. The reaction between Co(NO(3))(2).6H(2)O and L1 afforded a two-dimensional noninterpenetrating brick-wall structure, [Co(C(12)N(4)H(10))(1.5)(NO(3))(2)(H(2)O)(CH(2)Cl(2))(2)](n)() (1, triclinic, P1; a = 10.242(7) A, b = 10.802(7) A, c = 15.100(1) A, alpha = 70.031(1), beta = 75.168(11), gamma = 76.155(11), Z = 2), while Ni(NO(3))(2).6H(2)O combined with L1 yielded an interpenetrating three-dimensional rhombus-grid polymer, [Ni(C(12)N(4)H(10))(2)(NO(3))(2)(OC(4)H(8))(1.66)(H(2)O)(0.33)](n) (2, monoclinic, C2/c; a = 20.815(8) A, b = 23.427(8) A, c = 17.291(6) A, beta = 116.148(6), Z = 8). The reaction of Co(NO(3))(2).6H(2)O and L2 was found to be solvent-sensitive and resulted in the formation of two different noninterpenetrating compounds: [Co(C(14)N(4)H(14))(2)(NO(3))(2)(C(6)H(6))(1.5)](n)() (3, monoclinic, C2/c; a = 22.760(2) A, b = 21.010(3) A, c = 25.521(2) A, beta = 97.151(2), Z = 8), which adopts a two-dimensional square-grid motif formed by propeller-type modules, and [Co(C(14)N(4)H(14))(1.5)(NO(3))(2)(CH(2)Cl(2))(2)](n)() (4, monoclinic, P2(1)/n; a = 14.432(2) A, b = 14.543(8) A, c = 15.448(4) A, beta = 96.968(0), Z = 4), consisting of T-shaped building blocks assembled into a one-dimensional ladder-type structure. These four coordination polymers all exhibit impressive thermal stability. Thermogravimetric studies showed that after complete removal of the solvents, the frameworks are stable to temperatures between 234 degrees C and 260 degrees C.

Scleroderma in South Australia: epidemiological observations of possible pathogenic significance

BACKGROUND

Scleroderma is an autoimmune disorder of unknown cause. Previous epidemiological studies have suggested some regional clustering and associations with occupations involving exposure to silica dusts and hydrocarbons.

AIMS

To determine: (i) prevalence and incidence of scleroderma in South Australia (SA), a state with a stable population living in well-defined urban, rural and industrial regions, (ii) hospital separation rates, (iii) cumulative survival rates, (iv) gender and disease subclassification, (v) geographical residency and occupations, (vi) familial associations and (vii) age at onset versus age-specific incidence rate.

METHODS

Creation of the South Australian Scleroderma Register (SASR) to identify demographics and clinical and serological features of all scleroderma patients resident in SA.

RESULTS

Scleroderma occurs in South Australia with a point prevalence of 23 per 10(5) and an incidence of approximately 1/15th of this. However, this prevalence is high compared with other regional world studies. Scleroderma is predominantly a female disease, with most patients having the limited form of scleroderma characterized by the presence of the anticentromere antibody and a mean survival of 27.6 years. In contrast, diffuse scleroderma is a less benign disease occurring at an early age of onset and has a mean survival of 9.6 years. Scleroderma occurs throughout SA without regional localization. Weak associations are seen in males, but not females, with occupations involving possible environmental exposure to silica or hydrocarbons. Scleroderma rarely occurs in families.

CONCLUSION

No strong genetic or environmental influences were found to account for the relatively common occurrence of scleroderma in SA. The age at onset versus age-specific incidence curve suggests that scleroderma can be considered as a stochastic illness involving a number of random events occurring in a predisposed population. These random events may involve mutations of pivotal somatic genes.

Treatment-induced remission in rheumatoid arthritis patients is characterized by a reduction in macrophage content of synovial biopsies

OBJECTIVES

To document the change in synovial membrane macrophage and T-lymphocyte content in rheumatoid arthritis (RA) patients who achieve remission induced by disease-modifying anti-rheumatic drugs (DMARDs).

METHODS

Arthroscopic synovial biopsies were taken from four to seven sites around a knee joint in 13 patients with RA before and at regular intervals after commencing treatment with a DMARD. The cellular content of synovial membrane biopsies taken at regular intervals for a period of up to 3 yr after commencing treatment was quantitated by routine histopathology and immunohistochemical labelling with anti-macrophage (CD68) and anti-T lymphocyte (UCHL-1) antibodies. Synovial biopsies were quantitated with a validated semiquantitative scoring system and video image analysis.

RESULTS

Nine patients obtained clinical remission, as defined by American College of Rheumatology (ACR) criteria. The changes that occurred in the synovial biopsies included a reduction in lining layer thickness, reduced vascularity and cellular infiltrate. The most significant reduction in cellular infiltrate was in the lining layer macrophages, with less dramatic change in the subintimal macrophage infiltrate. Although there was a reduction in CD45 Ro-positive T lymphocytes in the synovial membranes of patients who attained ACR-defined disease remission, it was less significant than the reduction in macrophage content of the synovial membranes and tended to plateau at a reduced level of T-cell infiltration.

CONCLUSIONS

Remission in RA patients is characterized by a predominant reduction in macrophage content of the synovial membrane, suggesting that current DMARDs may target this cell and its inflammatory mediators.

Sr3ZnPtO6 and Sr3CdPtO6

The flux synthesis of single crystals of the isostructural compounds tristrontium zinc platinum hexaoxide, Sr(3)ZnPtO(6), and tristrontium cadmium platinum hexaoxide, Sr(3)CdPtO(6), is reported. The compounds adopt the pseudo-one-dimensional rhombohedral K(4)CdCl(6) structure type, and feature chains of face-shared distorted ZnO(6) or CdO(6) trigonal prisms and PtO(6) octahedra, surrounded by columns of Sr(2+) ions. All transition metals are located on the threefold axis of symmetry, while the Sr(2+) cations lie on twofold axes.