Rectus Urinoma Leading to Abscess Following Urethral Perforation From Self-Catheterization: A Case Report.

Urinomas are an accumulation of urine in the perirenal or paraureteral space due to urinary tract leakage. Stimulation of an inflammatory response results in the formation of a thick wall that encapsulates the urine. Etiologies of urinomas include trauma, surgery, or spontaneous occurrence. Complications when untreated vary and include peritonitis, fibrosis, abscess formation, and septic shock. We present a 52-year-old male with a neurogenic bladder who developed a rectus urinoma from the thorax to the scrotum. This likely developed from urethral trauma from intermittent self-catheterization. The patient received antibiotic therapy and percutaneous drainage catheters were placed in the rectus and pelvis, resolving the urinoma. We conclude that patients who perform intermittent self-catheterization may be more susceptible to formation of urinomas due to improper catheter usage. The intricate fascial connections between the pelvis and abdomen make proper interventions for suspected urinary tract injury crucial in patients who self-catheterize.

Spontaneous Rupture of the Renal Pelvis Due to Extrinsic Obstruction by Metastatic Retroperitoneal Lymphadenopathy.

Spontaneous rupture of the renal pelvis due to metastatic disease is a rare complication. Renal pelvis rupture often goes undiagnosed in cases of non-traumatic origin due to its vague abdominal and flank symptoms. We present a case of an 81-year-old male with primary non-small cell lung cancer who had renal pelvis rupture due to extrinsic compression of the ureter by retroperitoneal lymphadenopathy secondary to metastatic disease.

Emphysematous Pyelonephritis From a Perinephric Hematoma Complicated by Fournier's Gangrene: A Case Report.

Fournier's gangrene and emphysematous pyelonephritis are rare necrotizing infections of the genitourinary system. Many cases of this rapidly progressive infection occur from abscesses and urinary tract infections; however, Fournier's gangrene secondary to emphysematous pyelonephritis is seldom discussed in the literature. Emphysematous pyelonephritis is defined as a gas-forming, necrotizing infection of the renal parenchyma or its surrounding tissue. Emphysematous pyelonephritis has been observed in high-risk individuals, including those with poor glycemic control and urinary tract obstruction. We present a 61-year-old male with emphysematous pyelonephritis arising from a perinephric hematoma with tracking of the infection to the scrotum, resulting in Fournier's gangrene. The perinephric hematoma most likely developed from increased intrarenal hydrostatic pressure during nephroureteral stent placement. Broad-spectrum antibiotic therapy and surgical debridement of the retroperitoneum, groin, and scrotum were performed ultimately requiring left orchiectomy. We conclude that an existing hematoma can precipitate emphysematous pyelonephritis with tracking from the retroperitoneum to scrotum, causing Fournier's gangrene. High-risk patients with perinephric hematomas can be susceptible to this pathologic transformation.

Metastatic Adenocarcinoma of the Prostate to the Brain Initially Suspected as Meningioma by Magnetic Resonance Imaging.

Brain metastasis from prostate cancer is rare, occurring in less than 1% of metastatic prostate cancer patients. Brain metastasis can cause edema, neurologic symptoms, and may be misdiagnosed as primary brain tumors on imaging. A 68-year-old male presented to the emergency department complaining of headaches, right-sided weakness, multiple falls, and a 45 pounds of unintentional weight loss. Computerized tomography (CT) scan without contrast of the head showed a 3.2 cm right frontal mass with edema suspicious for meningioma. Associated nonspecific bony lesions were found on CT of the abdomen and pelvis. Magnetic resonance imaging (MRI) of the brain showed a 2.8 cm right frontal mass with an enhanced dural tail. Preoperative labs were noteworthy for a hemoglobin of 9.7 and prostate-specific antigen (PSA) of 66.7 ng/ml. Craniotomy with resection of tumor was performed with a frozen sample diagnosed as meningioma. Permanent pathology with stains were positive for PSA and prostatic-specific acid phosphatase (PSAP), making the diagnosis of metastatic prostate adenocarcinoma. Postoperatively, nuclear bone scan showed uptake in the axial skeleton consistent with metastasis. After the diagnosis of metastatic prostate cancer was made, bicalutamide was administered followed by degarelix with plans to transition to leuprorelin one month later. This is to be followed up by whole brain radiation therapy (WBRT). PSA was 118.53 ng/ml three weeks after craniotomy, but prior to androgen deprivation therapy. Metastatic prostate cancer can present with neurological symptoms most commonly following spread to the axial skeleton and impingement of the spinal cord. Metastasis to the brain is rare and is usually associated with vague symptomatology depending on extent and location of the lesion. While brain metastasis can occur in known prostate cancer patients, this case shows that metastasis can occur prior to any formal prostate cancer diagnosis and can be mistaken for meningioma on imaging and frozen sectioning. Practitioners must be vigilant, and precautions should be taken to rule in metastatic prostate cancer as a possible cause for a brain lesion in patients of the appropriate demographics.

A diurnal flux balance model of Synechocystis sp. PCC 6803 metabolism.

Phototrophic organisms such as cyanobacteria utilize the sun's energy to convert atmospheric carbon dioxide into organic carbon, resulting in diurnal variations in the cell's metabolism. Flux balance analysis is a widely accepted constraint-based optimization tool for analyzing growth and metabolism, but it is generally used in a time-invariant manner with no provisions for sequestering different biomass components at different time periods. Here we present CycleSyn, a periodic model of Synechocystis sp. PCC 6803 metabolism that spans a 12-hr light/12-hr dark cycle by segmenting it into 12 Time Point Models (TPMs) with a uniform duration of two hours. The developed framework allows for the flow of metabolites across TPMs while inventorying metabolite levels and only allowing for the utilization of currently or previously produced compounds. The 12 TPMs allow for the incorporation of time-dependent constraints that capture the cyclic nature of cellular processes. Imposing bounds on reactions informed by temporally-segmented transcriptomic data enables simulation of phototrophic growth as a single linear programming (LP) problem. The solution provides the time varying reaction fluxes over a 24-hour cycle and the accumulation/consumption of metabolites. The diurnal rhythm of metabolic gene expression driven by the circadian clock and its metabolic consequences is explored. Predicted flux and metabolite pools are in line with published studies regarding the temporal organization of phototrophic growth in Synechocystis PCC 6803 paving the way for constructing time-resolved genome-scale models (GSMs) for organisms with a circadian clock. In addition, the metabolic reorganization that would be required to enable Synechocystis PCC 6803 to temporally separate photosynthesis from oxygen-sensitive nitrogen fixation is also explored using the developed model formalism.

Utilization of individualized prostate cancer and genomic biomarkers for the practicing urologist.

Prostate cancer encompasses a complex heterogeneous disease spectrum. Physicians and patients are faced with the ambiguity of who should be screened, biopsied, rebiopsied, treated, or provided with adjuvant therapy. Personalized outcomes and treatments are especially important given the varied nature of the disease, plethora of treatment options, risks of morbidity, and quality of life. Today's practicing urologist has a multitude of tests from which to choose, creating the difficult task of appropriate use. This review focuses on two blood-, one urine-, and five genomic-based tests, which, when used in the appropriate clinical setting, can facilitate the patient-physician decision-making process.

Identifying the Metabolic Differences of a Fast-Growth Phenotype in Synechococcus UTEX 2973.

The photosynthetic capabilities of cyanobacteria make them interesting candidates for industrial bioproduction. One obstacle to large-scale implementation of cyanobacteria is their limited growth rates as compared to industrial mainstays. Synechococcus UTEX 2973, a strain closely related to Synechococcus PCC 7942, was recently identified as having the fastest measured growth rate among cyanobacteria. To facilitate the development of 2973 as a model organism we developed in this study the genome-scale metabolic model iSyu683. Experimental data were used to define CO2 uptake rates as well as the biomass compositions for each strain. The inclusion of constraints based on experimental measurements of CO2 uptake resulted in a ratio of the growth rates of Synechococcus 2973 to Synechococcus 7942 of 2.03, which nearly recapitulates the in vivo growth rate ratio of 2.13. This identified the difference in carbon uptake rate as the main factor contributing to the divergent growth rates. Additionally four SNPs were identified as possible contributors to modified kinetic parameters of metabolic enzymes and candidates for further study. Comparisons against more established cyanobacterial strains identified a number of differences between the strains along with a correlation between the number of cytochrome c oxidase operons and heterotrophic or diazotrophic capabilities.

Raman spectroscopy of the N-N bond in rare earth dinitrogen complexes.

Raman spectra have been collected on single crystals of over 20 different rare earth complexes containing reduced dinitrogen ligands to determine if these data will correlate with periodic properties or relative stability. Four types of complexes were examined: [(C5Me5)2Ln]2(µ-η(2):η(2)-N2), 1-Ln, [(C5Me4H)2(THF)Ln]2(µ-η(2):η(2)-N2), 2-Ln, [(C5H4Me)2Ln]2(µ-η(2):η(2)-N2), 3-Ln, and {[(Me3Si)2N]2(THF)Ln}2(µ-η(2):η(2)-N2), 4-Ln. Although each of the complexes contains a side-on bound dinitrogen ligand that is formally (N2)(2-), the N-N bond distances determined by X-ray crystallography range from 1.088(12) to 1.305(6) Å. In the 4-Ln series (Ln = Gd, Tb, Dy, Ho, Er and Tm), the 1.26-1.31 Å N-N distances do not follow any periodic trends, but the Raman stretching frequencies for Gd-Tm were found to decrease regularly with decreasing atomic number and increasing Lewis acidity of the metal. Similar correlations can be seen with the late metals in complexes of the other series, 1-Ln, 2-Ln and 3-Ln, but exceptions exist, particularly for the larger metals. Comparisons between the several types of complexes as a function of ligand were more complicated and variations in stretching frequency as a function of L in the {[(Me3Si)2N]2Y(L)}2(µ-η(2):η(2)-N2) substituted versions of 4-Y did not give trends consistent with bond distances or Gutmann donor numbers.

Identifying Regulatory Changes to Facilitate Nitrogen Fixation in the Nondiazotroph Synechocystis sp. PCC 6803.

The incorporation of biological nitrogen fixation into a nondiazotrophic photosynthetic organism provides a promising solution to the increasing fixed nitrogen demand, but is accompanied by a number of challenges for accommodating two incompatible processes within the same organism. Here we present regulatory influence networks for two cyanobacteria, Synechocystis PCC 6803 and Cyanothece ATCC 51142, and evaluate them to co-opt native transcription factors that may be used to control the nif gene cluster once it is transferred to Synechocystis. These networks were further examined to identify candidate transcription factors for other metabolic processes necessary for temporal separation of photosynthesis and nitrogen fixation, glycogen catabolism and cyanophycin synthesis. Two transcription factors native to Synechocystis, LexA and Rcp1, were identified as promising candidates for the control of the nif gene cluster and other pertinent metabolic processes, respectively. Lessons learned in the incorporation of nitrogen fixation into a nondiazotrophic prokaryote may be leveraged to further progress the incorporation of nitrogen fixation in plants.

Methane oxidation by anaerobic archaea for conversion to liquid fuels.

Given the recent increases in natural gas reserves and associated drawbacks of current gas-to-liquids technologies, the development of a bioconversion process to directly convert methane to liquid fuels would generate considerable industrial interest. Several clades of anaerobic methanotrophic archaea (ANME) are capable of performing anaerobic oxidation of methane (AOM). AOM carried out by ANME offers carbon efficiency advantages over aerobic oxidation by conserving the entire carbon flux without losing one out of three carbon atoms to carbon dioxide. This review highlights the recent advances in understanding the key enzymes involved in AOM (i.e., methyl-coenzyme M reductase), the ecological niches of a number of ANME, the putative metabolic pathways for AOM, and the syntrophic consortia that they typically form.

Capturing the response of Clostridium acetobutylicum to chemical stressors using a regulated genome-scale metabolic model.

BACKGROUND: Clostridia are anaerobic Gram-positive Firmicutes containing broad and flexible systems for substrate utilization, which have been used successfully to produce a range of industrial compounds. In particular, Clostridium acetobutylicum has been used to produce butanol on an industrial scale through acetone-butanol-ethanol (ABE) fermentation. A genome-scale metabolic (GSM) model is a powerful tool for understanding the metabolic capacities of an organism and developing metabolic engineering strategies for strain development. The integration of stress-related specific transcriptomics information with the GSM model provides opportunities for elucidating the focal points of regulation. RESULTS: We describe here the construction and validation of a GSM model for C. acetobutylicum ATCC 824, iCac802. iCac802 spans 802 genes and includes 1,137 metabolites and 1,462 reactions, along with gene-protein-reaction associations. Both (13)C-MFA and gene deletion data in the ABE fermentation pathway were used to test the predicted flux ranges allowed by the model. We also describe the CoreReg method, introduced in this paper, to integrate transcriptomic data and identify core sets of reactions that, when their flux was selectively restricted, reproduced flux and biomass-formation ranges seen under all regulatory constraints. CoreReg was used in response to butanol and butyrate stress to tighten bounds for 50 reactions within the iCac802 model. These bounds affected the flux of tens of reactions in core metabolism. The model, incorporating the regulatory restrictions from CoreReg under chemical stress, exhibited an approximate 70% reduction in biomass yield for most stress conditions. CONCLUSIONS: The regulation placed on the model for the two stresses using CoreReg identified differences in the respective responses, including distinct core sets and the restriction of biomass production similar to experimental observations. Given the core sets predicted by the CoreReg method, remedial actions can be taken to counteract the effect of stress on metabolism. For less well-known systems, plausible regulatory loops can be suggested around the affected metabolic reactions, and the hypotheses can be tested experimentally.

Electronic structures of organometallic complexes of f elements LXXXIII: First comparison of experimental and calculated (on the basis of density functional theory) polarized Raman spectra of an oriented organometallic single crystal: Tris(pentamethylcyclopentadienyl)lanthanum.

The polarized Raman spectra of an oriented La(η(5)-C5Me5)3 (1) single crystal (where the principal axes of the two molecules per unit cell are uniformly oriented) as well as the mid (ca. 90K) and far infrared spectra of pellets have been recorded. Applying the selection rules of C3h symmetry to the spectra obtained, the irreducible representations (irreps) of numerous lines/bands of intra-ligand character were derived. In the range <400cm(-1), where 28 Raman-allowed lines and 20 FIR-allowed bands of both skeletal and intra-ligand character are expected, only few assignments based on symmetry considerations were possible. In order to increase the number of identifications, model calculations on the basis of density functional theory (DFT) were performed. In the intra-ligand range >400cm(-1), the obtained results agree well with the experimental findings. Because of the strong mixing at lower wavenumbers, even the separation of calculated skeletal and intra-ligand modes and the identification of the former was only successful by comparing the calculated FIR and averaged Raman spectra of compound 1 with those of La(η(5)-C5Me4H)3 (2). Making use of both the calculated frequencies of normal modes and their polarizability tensors, the polarized Raman spectra of an oriented single crystal of 1 in the range <400cm(-1) were calculated and compared to the experimental ones. Because of an overestimation of the mixing of normal vibrations of A' symmetry, the experimental intensities of the lines of the symmetric stretch ν1(A') were not reproduced by the calculation for compound 1 but by that for Sm(η(5)-C5Me5)3 (3). Skeletal and intra-ligand modes were separated and designated. Neglecting νC-H modes, the DFT calculation for 1 achieved an r.m.s. deviation of 17.9cm(-1) for 72 assignments.

Rapid construction of metabolic models for a family of Cyanobacteria using a multiple source annotation workflow.

BACKGROUND: Cyanobacteria are photoautotrophic prokaryotes that exhibit robust growth under diverse environmental conditions with minimal nutritional requirements. They can use solar energy to convert CO2 and other reduced carbon sources into biofuels and chemical products. The genus Cyanothece includes unicellular nitrogen-fixing cyanobacteria that have been shown to offer high levels of hydrogen production and nitrogen fixation. The reconstruction of quality genome-scale metabolic models for organisms with limited annotation resources remains a challenging task. RESULTS: Here we reconstruct and subsequently analyze and compare the metabolism of five Cyanothece strains, namely Cyanothece sp. PCC 7424, 7425, 7822, 8801 and 8802, as the genome-scale metabolic reconstructions iCyc792, iCyn731, iCyj826, iCyp752, and iCyh755 respectively. We compare these phylogenetically related Cyanothece strains to assess their bio-production potential. A systematic workflow is introduced for integrating and prioritizing annotation information from the Universal Protein Resource (Uniprot), NCBI Protein Clusters, and the Rapid Annotations using Subsystems Technology (RAST) method. The genome-scale metabolic models include fully traced photosynthesis reactions and respiratory chains, as well as balanced reactions and GPR associations. Metabolic differences between the organisms are highlighted such as the non-fermentative pathway for alcohol production found in only Cyanothece 7424, 8801, and 8802. CONCLUSIONS: Our development workflow provides a path for constructing models using information from curated models of related organisms and reviewed gene annotations. This effort lays the foundation for the expedient construction of curated metabolic models for organisms that, while not being the target of comprehensive research, have a sequenced genome and are related to an organism with a curated metabolic model. Organism-specific models, such as the five presented in this paper, can be used to identify optimal genetic manipulations for targeted metabolite overproduction as well as to investigate the biology of diverse organisms.

Reconstruction and comparison of the metabolic potential of cyanobacteria Cyanothece sp. ATCC 51142 and Synechocystis sp. PCC 6803.

Cyanobacteria are an important group of photoautotrophic organisms that can synthesize valuable bio-products by harnessing solar energy. They are endowed with high photosynthetic efficiencies and diverse metabolic capabilities that confer the ability to convert solar energy into a variety of biofuels and their precursors. However, less well studied are the similarities and differences in metabolism of different species of cyanobacteria as they pertain to their suitability as microbial production chassis. Here we assemble, update and compare genome-scale models (iCyt773 and iSyn731) for two phylogenetically related cyanobacterial species, namely Cyanothece sp. ATCC 51142 and Synechocystis sp. PCC 6803. All reactions are elementally and charge balanced and localized into four different intracellular compartments (i.e., periplasm, cytosol, carboxysome and thylakoid lumen) and biomass descriptions are derived based on experimental measurements. Newly added reactions absent in earlier models (266 and 322, respectively) span most metabolic pathways with an emphasis on lipid biosynthesis. All thermodynamically infeasible loops are identified and eliminated from both models. Comparisons of model predictions against gene essentiality data reveal a specificity of 0.94 (94/100) and a sensitivity of 1 (19/19) for the Synechocystis iSyn731 model. The diurnal rhythm of Cyanothece 51142 metabolism is modeled by constructing separate (light/dark) biomass equations and introducing regulatory restrictions over light and dark phases. Specific metabolic pathway differences between the two cyanobacteria alluding to different bio-production potentials are reflected in both models.

Sigma bond metathesis with pentamethylcyclopentadienyl ligands in sterically crowded (C5Me5)3M complexes.

To further explore the reactivity of the (C(5)Me(5))(-) ligand in the sterically crowded (C(5)Me(5))(3)M complexes, reactions with PhEEPh (E = S, Se, Te) have been examined. With M = La, Pr, Nd, Sm, and Y, PhSSPh reacts to form the expected reduction products, [(C(5)Me(5))(2)M(SPh)](2), but the major organic byproduct is not the sterically induced reduction product, (C(5)Me(5))(2). Instead, the sigma bond metathesis product, C(5)Me(5)SPh, is the major byproduct. In contrast, reactions with (C(5)Me(5))(3)Ce and (C(5)Me(5))(3)U gave a mixture of C(5)Me(5)SPh and (C(5)Me(5))(2) as byproducts. PhSSPh reactions with the lanthanide nitrile adducts, (C(5)Me(5))(3)Ln(NCCMe(3))(2) (Ln = La, Ce) and (C(5)Me(5))(3)Nd(NCCMe(3)), formed [(C(5)Me(5))(2)Ln(SPh)(NCCMe(3))](2) and only C(5)Me(5)SPh as the byproduct. PhSeSePh reactions paralleled the PhSSPh results, but reactions of PhTeTePh with (C(5)Me(5))(3)La, (C(5)Me(5))(3)Sm, and (C(5)Me(5))(3)La(NCCMe(3))(2) gave only (C(5)Me(5))(2) as a byproduct.

Lanthanide versus actinide reactivity in the formation of sterically crowded [(C(5)Me(5))(3)ML(n)] nitrile and isocyanide complexes.

The limits of steric crowding in organometallic metallocene complexes have been examined by studying the synthesis of [(C(5)Me(5))(3)ML(n)] complexes as a function of metal in which L=Me(3)CCN, Me(3)CNC, and Me(3)SiCN. The bis(tert-butyl nitrile) complexes [(C(5)Me(5))(3)Ln(NCCMe(3))(2)] (Ln=La, 1; Ce, 2; Pr, 3) can be isolated with the largest lanthanide metal ions, La(3+), Ce(3+), and Pr(3+). The Pr(3+) ion also forms an isolable mono-nitrile complex, [(C(5)Me(5))(3)Pr(NCCMe(3))] (4), whereas for Nd(3+) only the mono-adduct [(C(5)Me(5))(3)Nd(NCCMe(3))] (5) was observed. With smaller metal ions, Sm(3+) and Y(3+), insertion of Me(3)CCN into the M--C(C(5)Me(5)) bond was observed to form the cyclopentadiene-substituted ketimide complexes [(C(5)Me(5))(2)Ln{NC(C(5)Me(5))(CMe(3))}(NCCMe(3))] (Ln=Sm, 6; Y, 7). With tert-butyl isocyanide ligands, a bis-isocyanide product can be isolated with lanthanum, [(C(5)Me(5))(3)La(CNCMe(3))(2)] (8), and a mono-isocyanide product with neodymium, [(C(5)Me(5))(3)Nd(CNCMe(3))] (9). Silicon-carbon bond cleavage was observed in reactions between [(C(5)Me(5))(3)Ln] complexes and trimethylsilyl cyanide, Me(3)SiCN, to produce the trimeric cyanide complexes [{(C(5)Me(5))(2)Ln(mu-CN)(NCSiMe(3))}(3)] (Ln=La, 10; Pr, 11). With uranium, a mono-nitrile reaction product, [(C(5)Me(5))(3)U(NCCMe(3))] (12), which is analogous to 5, was obtained from the reaction between [(C(5)Me(5))(3)U] and Me(3)CCN, but [(C(5)Me(5))(3)U] reacts with Me(3)CNC through C--N bond cleavage to form a trimeric cyanide complex, [{(C(5)Me(5))(2)U(mu-CN)(CNCMe(3))}(3)] (13).

Ureteral fibrin sealant injection of the distal ureter during laparoscopic nephroureterectomy--a novel and simple modification of the pluck technique.

OBJECTIVES: To describe a novel technique to block the distal ureter, thus preventing spillage of tumor cell bearing urine during laparoscopic pluck nephroureterectomy. Currently, there is no consensus on the appropriate management of distal ureter during laparoscopic nephroureterectomy. METHODS: A review was performed of patients who underwent modified laparoscopic pluck nephroureterectomy for upper tract transitional cell carcinoma from July 2007 to December 2008. After confirming an absence of bladder tumors, an 8F olive-tipped ureteral catheter was introduced into the ureteral orifice. Five milliliters of Tisseel was injected into the ureter. Five milliliters of indigo carmine was injected intravenously to confirm the presence of ureteral blockage. Using a Collins knife, the ureteral orifice was dissected until the extravesical fat was visualized. A Foley catheter was placed and a laparoscopic nephroureterectomy was then completed. The drain was removed on the 3rd postoperative day and Foley was removed on the 10th postoperative day after a normal cystogram. RESULTS: We performed 8 procedures using the above-described technique. The median age was 62 years, all were males; 2 were operated on the right side and 6 on the left. The average operative time and estimated blood loss was 308 minutes and 150 mL, respectively. The average length of stay was 6 days. One major and 2 minor complications (ileus) were noted. Mean cancer follow-up is 11 months. All specimen margins free of tumor. No extravesical or intravesical recurrences were noted. CONCLUSIONS: Ureteral fibrin sealant injection produces dependable ureteral obstruction during laparoscopic pluck nephroureterectomy and may prevent tumor spillage in the extravesical tissues.

Reactivity of (C5Me5)3LaL(x) complexes: synthesis of a tris(pentamethylcyclopentadienyl) complex with two additional ligands, (C5Me5)3La(NCCMe3)2.

The limits of steric crowding in tris(pentamethylcyclopentadienyl) complexes have been expanded by isolation of the first compound with this ligand set and two additional ligands, (C(5)Me(5))(3)ML(2). This result was obtained in a study of the effect of added ligands on the reactivity of sterically crowded (C(5)Me(5))(3)La, 1. Although neither THF nor Ph(3)PO formed crystallographically characterizable (C(5)Me(5))(3)LaL(x) complexes with 1, these (C(5)Me(5))(3)La/L(x) mixtures displayed enhanced reactivity compared to 1 with substrates such as C(8)H(8) and CO(2). Attempts to use adamantyl azide, AdN(3), to make (C(5)Me(5))(3)LaL(x) complexes led to the first example of azide insertion into a metal cyclopentadienyl linkage to generate (C(5)Me(5))(2)La[eta(2)-(N,N')-(C(5)Me(5))NN'N''Ad](N(3)Ad). Addition of Me(3)CCN to 1 produced the first crystallographically characterized (C(5)Me(5))(3)ML(2) complex, (C(5)Me(5))(3)La(NCCMe(3))(2).