N-imidazolebenzyl-histidine substitution in somatostatin and in its octapeptide analogue modulates receptor selectivity and function

Despite 3 decades of focused chemical, biological, structural, and clinical developments, unusual properties of somatostatin (SRIF, 1) analogues are still being uncovered. Here we report the unexpected functional properties of 1 and the octapeptide cyclo(3-14)H-Cys-Phe-Phe-Trp(8)-Lys-Thr-Phe-Cys-OH (somatostatin numbering; OLT-8, 9) substituted by imBzl-l- or -d-His at position 8. These analogues were tested for their binding affinity to the five human somatostatin receptors (sst(1-5)), as well as for their functional properties (or functionalities) in an sst(3) internalization assay and in an sst(3) luciferase reporter gene assay. While substitution of Trp(8) in somatostatin by imBzl-l- or -d-His(8) results in sst(3) selectivity, substitution of Trp(8) in the octapeptide 9 by imBzl-l- or -d-His(8) results in loss of binding affinity for sst(1,2,4,5) and a radical functional switch from agonist to antagonist.

Functionalisation of PLLA nanofiber scaffolds using a possible cooperative effect between collagen type I and BMP-2: impact on colonization and bone formation in vivo

The reconstruction of large bone defects after injury or tumor resection often requires the use of bone substitution. Artificial scaffolds based on synthetic biomaterials can overcome disadvantages of autologous bone grafts, like limited availability and donor side morbidity. Among them, scaffolds based on nanofibers offer great advantages. They mimic the extracellular matrix, can be used as a carrier for growth factors and allow the differentiation of human mesenchymal stem cells. Differentiation is triggered by a series of signaling processes, including integrin and bone morphogenetic protein (BMP), which act in a cooperative manner. The aim of this study was to analyze whether these processes can be remodeled in artificial poly-(l)-lactide acid (PLLA) based nanofiber scaffolds in vivo. Electrospun matrices composed of PLLA-collagen type I or BMP-2 incorporated PLLA-collagen type I were implanted in calvarial critical size defects in rats. Cranial CT-scans were taken 4, 8 and 12 weeks after implantation. Specimens obtained after euthanasia were processed for histology and immunostainings on osteocalcin, BMP-2 and Smad5. After implantation the scaffolds were inhomogeneously colonized and cells were only present in wrinkle- or channel-like structures. Ossification was detected only in focal areas of the scaffold. This was independent of whether BMP-2 was incorporated in the scaffold. However, cells that migrated into the scaffold showed an increased ratio of osteocalcin and Smad5 positive cells compared to empty defects. Furthermore, in case of BMP-2 incorporated PLLA-collagen type I scaffolds, 4 weeks after implantation approximately 40 % of the cells stained positive for BMP-2 indicating an autocrine process of the ingrown cells. These findings indicate that a cooperative effect between BMP-2 and collagen type I can be transferred to PLLA nanofibers and furthermore, that this effect is active in vivo. However, this had no effect on bone formation. The reason for this seems to be an unbalanced colonization of the scaffolds with cells, due to insufficient pore size.

Homozygous Cys542-->Arg substitution in GPIIIa in a Swiss patient with type I Glanzmann's thrombasthenia

Glanzmann's thrombasthenia (GT) arises from a qualitative or quantitative defect in the GPIIb-IIIa complex (integrin alphaIIbbeta3), the mediator of platelet aggregation. We describe a patient in whom clinical and laboratory findings typical of type I GT were found together with a second pathology involving neurological and other complications symptomatic of tuberous sclerosis. Analysis of platelet proteins by Western blotting revealed trace amounts of normally migrating GPIIb and equally small amounts of GPIIIa of slightly slower than normal migration. Flow cytometry confirmed a much decreased binding to platelets of monoclonal antibodies to GPIIb, GPIIIa or GPIIb-IIIa, and an antibody to the alphav subunit also showed decreased binding. Nonradioactive PCR single-strand conformation polymorphism analysis followed by direct sequencing of PCR-amplified DNA fragments showed a homozygous point mutation (T to C) at nucleotide 1722 of GPIIIa cDNA and which led to a Cys542-->Arg substitution in the GPIIIa protein. The mutation gave rise to a HinP1 I restriction site in exon 11 of the GPIIIa gene and allele-specific restriction enzyme analysis of family members confirmed that a single mutated allele was inherited from each parent. This amino acid substitution presumably changes the capacity for disulphide bond formation within the cysteine-rich core region of GPIIIa and its study will provide new information on GPIIb-IIIa and alphavbeta3 structure and biosynthesis.

Chromium supplementation and substitution of barley grain with corn: Effects on performance and lactation in periparturient dairy cows

Thirty-two multiparous Holstein cows were used to investigate the effects of chromium-l-methionine (Cr-Met) supplementation and dietary grain source on performance and lactation during the periparturient period. Cows were fed a total mixed ration consisting of either a barley-based diet (BBD) or a corn-based diet (CBD) from 21 d before anticipated calving through 28 d after calving. The Cr-Met was supplemented at dosages of 0 or 0.08 mg of Cr/kg of metabolic body weight. The study was designed as a randomized complete block design with 2 (Cr-Met levels) x 2 (grain sources) factorial arrangement. There was no Cr effect on prepartum dry matter intake (DMI) or postpartum DMI, body weight (BW), net energy balance, and whole tract apparent digestibility of nutrients. Prepartum DMI as a percentage of BW tended to increase with Cr-Met. Supplemental Cr-Met tended to increase milk yield whereas milk protein percentage decreased. Pre- and postpartum DMI, BW, net energy balance, milk yield, and milk composition were not affected by substituting ground barley with ground corn. The addition of Cr-Met increased prepartum DMI and tended to increase postpartum DMI of the BBD but not the CBD. The change in prepartum DMI was smaller when the BBD was supplemented with Cr-Met but remained unchanged when the CBD was supplemented with Cr-Met. Yields of crude protein and total solids in milk and prepartum digestibility of DM and organic matter tended to increase when Cr-Met was added to the BBD but remained unchanged when added to the CBD. Periparturient cows failed to respond to the grain source of the diet, whereas they showed greater response in milk yield to diets supplemented with Cr-Met. In conclusion, the present results demonstrate that the beneficial effect of Cr-Met supplementation during the periparturient period to improve feed intake may depend on the grain source of the diet.

Stricture of the Afferent Isoperistaltic Tubular Segment: A Late and Rare Cause of Bilateral Dilation of the Upper Urinary Tract After Ileal Bladder Substitution

OBJECTIVE To evaluate the etiology and treatment of bilateral hydronephrosis not responding to bladder substitute drainage after ileal bladder substitution using an afferent isoperistaltic tubular segment. MATERIALS AND METHODS A retrospective analysis was performed of a consecutive series of 739 patients who had undergone bladder substitution from April 1985 to August 2012. RESULTS Of the 739 ileal bladder substitute patients, 10 (1.4%) developed bilateral hydronephrosis unresponsive to complete bladder substitute drainage. The etiology was stenosis of the afferent isoperistaltic tubular segment. The median interval to presentation was 131 months (range 45-192). The incidence of afferent tubular segment stenosis was significantly higher in the 61 ileal bladder substitute patients with recurrent urinary tract infection (9 [15%]) than in the 678 without recurrent urinary tract infection (1 [0.15%]; P <.001). Urine cultures revealed mixed infections (34%), Escherichia coli (18%), Staphylococcus aureus (13%), enterococci (11%), Candida (8%), Klebsiella (8%), and others (8%). Seven patients underwent 10 endourologic interventions, only 1 of which was successful (10%). After failed endourologic treatment, 7 open surgical revisions with resection of the stricture were performed, with all 7 (100%) successful. CONCLUSION Bilateral dilation of the upper urinary tract after ileal orthotopic bladder substitution unresponsive to complete bladder substitute drainage is likely to be caused by stenosis of the afferent isoperistaltic tubular segment. The stenosis occurs almost exclusively in patients with long-lasting, recurrent urinary tract infection and can develop many years after the ileal bladder substitution. Minimally invasive endourologic treatment is usually unsuccessful; however, open surgical revision offers excellent results.

Design, synthesis and pharmacological characterization of analogs of 2-aminoethyl diphenylborinate (2-APB), a known store-operated calcium channel blocker, for inhibition of TRPV6-mediated calcium transport

2-Aminoethyl diphenylborinate (2-APB) is a known modulator of the IP3 receptor, the calcium ATPase SERCA, the calcium release-activated calcium channel Orai and TRP channels. More recently, it was shown that 2-APB is an efficient inhibitor of the epithelial calcium channel TRPV6 which is overexpressed in prostate cancer. We have conducted a structure-activity relationship study of 2-APB congeners to understand their inhibitory mode of action on TRPV6. Whereas modifying the aminoethyl moiety did not significantly change TRPV6 inhibition, substitution of the phenyl rings of 2-APB did. Our data show that the diaryl borinate moiety is required for biological activity and that the substitution pattern of the aryl rings can influence TRPV6 versus SOCE inhibition. We have also discovered that 2-APB is hydrolyzed and transesterified within minutes in solution.

Crystal chemistry and hydrogen bonding of rustumite Ca10(Si2O7)2(SiO4)(OH)2Cl2 with variable OH, Cl, F

Three samples of the skarn mineral rustumite Ca10(Si2O7)2(SiO4)(OH)2Cl2, space group C2/c, a ≈7.6, b ≈ 18.5, c ≈ 15.5 Å, β ≈ 104°, with variable OH, Cl, F content were investigated by electron microprobe, single-crystal X-ray structure refinements, and Raman spectroscopy. “Rust1LCl” is a low chlorine rustumite Ca10(Si2O7)2(SiO4)(OH1.88F0.12)(Cl1.28,OH0.72) from skarns associated with the Rize batholith near Ikizedere, Turkey. “Rust2F” is a F-bearing rustumite Ca10(Si2O7)2(SiO4)(OH1.13F0.87) (Cl1 96OH0.04) from xenoliths in ignimbrites of the Upper Chegem Caldera, Northern Caucasus, Russia. “Rust3LClF” represents a low-Cl, F-bearing rustumite Ca10(Si2O7)2(SiO4)0.87(H4O4)0.13(OH1.01F0.99) (Cl1.00 OH1.00) from altered merwinite skarns of the Birkhin massif, Baikal Lake area, Eastern Siberia, Russia. Rustumite from Birkhin massif is characterized by a significant hydrogarnet-like or fluorine substitution at the apices of the orthosilicate group, leading to specific atomic displacements. The crystal structures including hydrogen positions have been refined from single-crystal X-ray data to R1 = 0.0205 (Rust1_LCl), R1 = 0.0295 (Rust2_F), and R1 = 0.0243 (Rust3_LCl_F), respectively. Depletion in Cl and replacement by OH is associated with smaller unit-cell dimensions. The substitution of OH by F leads to shorter hydrogen bonds O-H⋯F instead of O-H⋯OH. Raman spectra for all samples have been measured and confirm slight strengthening of the hydrogen bonds with uptake of F.This study discusses the complex crystal chemistry of the skarn mineral rustumite and may provide a wider understanding of the chemical reactions related to contact metamorphism of limestones.

Radical cystectomy and ileal orthotopic bladder substitution after radical retropubic prostatectomy: functional and oncological results

Men with good functional results following radical retropubic prostatectomy (RRP) and requiring radical cystectomy (RC) for subsequent bladder carcinoma seldom receive orthotopic bladder substitution. Four patients aged 62-72 years (median 67 years), who had undergone RRP for prostate cancer of stage pT2bN0M0 Gleason score 6 (n = 1), pT2cN0M0 Gleason score 5 and 6 (n = 2) and pT3bN0M0 Gleason score 7 (n = 1) 27 to 104 months before, developed urothelial bladder carcinoma treated with RC and ileal orthotopic bladder substitution. After radical prostatectomy three were continent and one had grade I stress incontinence, and three achieved intercourse with intracavernous alprostadil injections. Follow-up after RC ranged between 27 and 42 months (median 29 months). At the 24-month follow-up visit after RC daily urinary continence was total (0 pad) in one patient, two used one pad for mild leakage, and one was incontinent following endoscopic incision of anastomotic stricture. One patient died of progression of bladder carcinoma, while the other three are alive without evidence of disease. The three surviving patients continued to have sexual intercourse with intracavernous alprostadil injections. Men with previous RRP have a reasonable chance of maintaining a satisfactory functional outcome following RC and ileal orthotopic bladder substitution.

Superior functional outcome after radical cystectomy and orthotopic bladder substitution with restrictive intraoperative fluid management: a followup study of a randomized clinical trial

PURPOSE Continuous intraoperative norepinephrine infusion combined with restrictive deferred hydration improves surgical field visibility, and significantly decreases intraoperative blood loss and postoperative complications in patients undergoing radical cystectomy and urinary diversion. We determined whether the intraoperative fluid regimen would affect functional results (continence and erectile function) 1 year after orthotopic ileal bladder substitution. MATERIALS AND METHODS We analyzed a subgroup of 93 patients who received an ileal orthotopic bladder substitute. The subgroup was part of a randomized trial in 167 patients initially allocated to continuous norepinephrine administration starting with 2 μg/kg per hour combined with 1 ml/kg per hour initially and 3 ml/kg per hour crystalloid infusion after cystectomy (norepinephrine/low volume group of 51) or a standard crystalloid infusion of 6 ml/kg per hour throughout surgery (42 controls). We prospectively assessed daytime and nighttime continence, and erectile function 1 year postoperatively in the 93-patient subgroup. RESULTS Daytime continence was reported by 44 of 51 patients (86%) in the norepinephrine/low volume group and by 27 of 42 controls (64%) (p = 0.016), and nighttime continence was reported by 38 (75%) and 25 (60%), respectively (p = 0.077). Erectile function recovery was reported by 26 of 33 preoperatively potent patients (79%) in the norepinephrine/low volume group and by 11 of 29 controls (38%) (p = 0.002). CONCLUSIONS Patients who undergo radical cystectomy and orthotopic bladder substitution with continuous norepinephrine infusion and restrictive hydration during surgery have significantly better daytime continence and erectile function 1 year postoperatively.

Iron-Promoted Nucleophilic Additions to Diimine-Type Ligands: A Synthetic and Structural Study

We report here three examples of the reactivity of protic nucleophiles with diimine-type ligands in the presence of FeII salts. In the first case, the iron-promoted alcoholysis reaction of one nitrile group of the ligand 2,3-dicyano-5,6-bis(2-pyridyl)-pyrazine (L1) permitted the isolation of an stable E-imido−ester, [Fe(L1‘)2](CF3SO3)2 (1), which has been characterized by spectroscopic studies (IR, ES-MS, Mössbauer), elemental analysis, and crystallographically. Compound 1 consists of mononuclear octahedrally coordinated FeII complexes where the FeII ion is in its low-spin state. The iron-mediated nucleophilic attack of water to the asymmetric ligand 2,3-bis(2-pyridyl)pyrido[3,4-b]pyrazine (L2) has also been studied. In this context, the crystal structures of two hydration−oxidation FeIII products, [Fe(L2‘)2](ClO4)3·3CH3CN (2) and trans-[FeL2‘‘Cl2] (3), are described. Compounds 2 and 3 are both mononuclear FeIII complexes where the metals occupy octahedral positions. In principle, L2 is expected to coordinate to metal ions through its bipyridine-type units to form a five-membered ring; however, this is not the case in compounds 2 and 3. In 2, the ligand coordinates through its pyridines and through the hydroxyl group attached to the pyrazine imino carbon after hydration, that is, in an N,O,N tridentate manner. In compound 3, the ligand has suffered further transformations leading to a very stable diamido complex. In this case, the metal ion achieves its octahedral geometry by means of two pyridines, two amido N atoms, and two axial chlorine atoms. Magnetic susceptibility measurements confirmed the spin state of these two FeIII species:  compounds 2 and 3 are low-spin and high-spin, respectively.

Orthotopic Ileal Bladder Substitution in Women: Factors Influencing Urinary Incontinence and Hypercontinence.

BACKGROUND Urinary incontinence or the inability to void spontaneously after ileal orthotopic bladder substitution is a frequent finding in female patients. OBJECTIVE To evaluate how hysterectomy and nerve sparing affect functional outcomes and whether these relate to pre- and postoperative urethral pressure profile (UPP) results. DESIGN, SETTING, AND PARTICIPANTS Prospectively performed pre- and postoperative UPPs of 73 female patients who had undergone cystectomy and bladder substitution were correlated with postoperative voiding and continence status. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Outcome analyses were performed with the Kruskal-Wallis test, Wilcoxon-Mann-Whitney, or two-group post hoc testing with the Bonferroni correction. Chi-square or Fisher exact tests were applied for the categorical data. RESULTS AND LIMITATIONS Of postoperatively continent or hypercontinent patients, 22 of 43 (51.2%) had the uterus preserved; of incontinent patients, only 4 of 30 (13.3%, p<0.01) had the uterus preserved. Of postoperatively continent or hypercontinent patients, 27 of 43 patients (62.8%) had bilateral and 15 of 43 (34.9%) had unilateral attempted nerve sparing. In incontinent patients, 11 of 30 (36.7%) had bilateral and 16 of 30 (53.3%) had unilateral attempted nerve sparing (p=0.02). When compared with postoperatively incontinent patients, postoperatively continent patients had a longer functional urethral length (median: 32mm vs 24mm; p<0.001), a higher postoperative urethral closing pressure at rest (56cm H2O vs 35cm H2O; p<0.001) as well as a higher preoperative urethral closing pressure at rest (74cm H2O vs 47.5cm H2O; p=0.01). The main limitation was the limited number of patients. CONCLUSIONS In female patients undergoing radical cystectomy and bladder substitution, preservation of the uterus and attempted nerve sparing results in better functional outcomes. The preoperative UPPs correlate with postoperative voiding and continence status and may predict which patients are at a higher risk of functional failure after bladder substitution. PATIENT SUMMARY If preservation of the urethra's innervation is not possible during cystectomy, poor functional results with bladder substitutes are likely.

Interaction of the Trinuclear Triangular Secondary Building Unit [Cu 3 (μ 3 -OH)(μ-pz) 3 ] 2+ with 4,4′-Bipyridine. Structural Characterizations of New Coordination Polymers and Hexanuclear Cu II Clusters. 2°

By reacting 4,4′-bipyridine (bpy) with selected trinuclear triangular CuII complexes, [Cu3(μ3-OH)(μ-pz)3(RCOO)2(LL′)] [pz = pyrazolate anion; R = CH3, CH3CH2, CH2═CH, CH2═C(CH3); L, L′ = Hpz, H2O, MeOH] in MeOH, the substitution of monotopic ligands by ditopic bpy was observed. Depending on the stoichiometric reaction ratios, different compounds were isolated and structurally characterized. One- and two-dimensional coordination polymers (CPs), as well as two hexanuclear CuII clusters were identified. One of the hexanuclear clusters self-assembles into a supramolecular three-dimensional structure, and its crystal packing shows the presence of two intersecting channels, one of which is almost completely occupied by guest bpy, while in the second one guest water molecules are present. This compound also shows a reversible, thermally induced, single-crystal-to-single-crystal transition.

There is a place for radical cystectomy and urinary diversion, including orthotopic bladder substitution, in patients aged 75 and older: Results of a retrospective observational analysis from a high-volume center

INTRODUCTION The incidence of cancer increases with age and owing to the changing demographics we are increasingly confronted with treating bladder cancer in old patients. We report our results in patients>75 years of age who underwent open radical cystectomy (RC) and urinary diversion. MATERIAL AND METHODS From January 2000 to March 2013, a consecutive series of 224 old patients with complete follow-up who underwent RC and urinary diversion (ileal orthotopic bladder substitute [OBS], ileal conduit [IC], and ureterocutaneostomy [UCST]) were included in this retrospective single-center study. End points were the 90-day complication rates (Clavien-Dindo classification), 90-day mortality rates, overall and cancer-specific survival rates, and continence rates (OBS). RESULTS Median age was 79.2 years (range: 75.1-91.6); 35 of the 224 patients (17%) received an OBS, 178 of the 224 patients (78%) an IC, and 11 of the 224 patients (5%) an UCST. The 90-day complication rate was 54.3% in the OBS (major: Clavien grade 3-5: 22.9%, minor: Clavien Grade 1-2: 31.4%), 56.7% in the IC (major: 27%, minor: 29.8%), and 63.6% in the UCST group (major: 36.4%, minor: 27.3%); P = 0.001. The 90-day mortality was 0% in the OBS group, 13% in the IC group, and 10% in the UCST group (P = 0.077). The Glasgow prognostic score was an independent predictor of all survival parameters assessed, including 90-day mortality. Median follow-up was 22 months. Overall and cancer-specific survivals were 90 and 98, 47 and 91, and 11 and 12 months for OBS, IC, and UCST, respectively. In OBS patients, daytime continence was considered as dry in 66% and humid in 20% of patients. Nighttime continence was dry in 46% and humid 26% of patients. CONCLUSION With careful patient selection, oncological and functional outcome after RC can be good in old patients. Old age as the sole criterion should not preclude the indication for RC or the option of OBS. In old patients undergoing OBS, satisfactory continence results can be achieved.