Effects of 7-O substitutions on estrogenic and anti-estrogenic activities of daidzein analogues in MCF-7 breast cancer cells

Daidzein (1) is a natural estrogenic isoflavone. We report here that 1 can be transformed into anti-estrogenic ligands by simple alkyl substitutions of the 7-hydroxyl hydrogen. To test the effect of such structural modifications on the hormonal activities of the resulting compounds, a series of daidzein analogues have been designed and synthesized. When MCF-7 cells were treated with the analogues, those resulting from hydrogen substitution by isopropyl (3d), isobutyl (3f), cyclopentyl (3g), and pyrano- (2) inhibited cell proliferation, estrogen-induced transcriptional activity, and estrogen receptor (ER) regulated progesterone receptor (PgR) gene expression. However, methyl (3a) and ethyl (3b) substitutions of the hydroxyl proton only led to moderate reduction of the estrogenic activities. These results demonstrated the structural requirements for the transformation of daidzein from an ER agonist to an antagonist. The most effective analogue, 2, was found to reduce in vivo estrogen stimulated MCF-7 cell tumorigenesis using a xenograft mouse model.

A Comparison of Two Different Doses of Rectal Ketamine Added to 0.5 mg.kg-1 Midazolam and 0.02 mg.kg-1 Atropine in Infants and Young Children

In some circumstances, a high degree of sedation that results in a child being unconscious at the time of parental separation is desirable. We set out to investigate the efficacy and safety of a rectal premedication regimen designed to produce this increased level of sedation.

Sixty-seven children aged two to 24 months were randomised into two groups. Group MK received 4 mg.kg-1 ketamine, 0.5 mg.kg-1 midazolam and 0.02 mg.kg-1 atropine and group MKK received 8 mg.kg-1 ketamine, 0.5 mg.kg-1 midazolam and 0.02 mg.kg-1 atropine per rectum. The sedation score at the time of parental separation 30 minutes after drug administration and the response to intravenous cannulation were evaluated on a four-point scale. Respiratory rate, heart rate and arterial oxygen saturation were recorded immediately before parental separation.

More patients in group MKK were asleep during separation (62 vs 35%, P <0.05). Fewer patients in group MKK cried during intravenous cannulation (37 vs 68%, P <0.05). Sedation scores were significantly increased at both time points. There was no difference between groups in vital signs at the time of parental separation and no adverse respiratory events occurred during the study period.

In cases where a high degree of sedation following premedication in infants and toddlers is desired, the addition of 8 mg.kg-1 ketamine to 0.5 mg.kg-1 midazolam and 0.02 mg.kg-1 atropine administered rectally is more efficacious than 4 mg.kg-1 ketamine.

Activation of Akt and MAPK pathways enhances the tumorigenicity of CD133+ primary colon cancer cells

Cancer stem cells (CSCs) play an important role in carcinogenesis, resistance to treatment and may lead to cancer recurrence and metastasis. However, the molecular mechanism of CSC involved in these events needs to be further elucidated. In this study, CD133(+) colon cancer cells were cultured, which showed CSC properties both in vitro and in vivo from metastatic tissue. Upstream molecules in Akt and mitogen-activated protein kinase (MAPK) pathways were preferentially expressed in these CD133(+) cells, as revealed by a global gene chip. The kinase activities of Akt and extracellular signal-regulated kinase (Erk)1/2 were also significantly upregulated in CD133(+) cells. In addition, the clonogenic growth of CD133(+) cell was reduced greatly by inhibiting the activity of Akt and Erk1/2. The results revealed the Akt and MAPK pathways were involved in the tumorigenesis of CD133(+) colon cancer cells, suggesting that molecules in these two pathways might be potential targets in the future therapy.

Bone marrow-derived mesenchymal stem cells inhibit acute rejection of rat liver allografts in association with regulatory T-cell expansion

Bone marrow-derived mesenchymal stem cells (MSCs) exhibit immunosuppressive functions in vitro and in vivo. We investigated the immunoregulatory effects of rat MSCs in a model of allogeneic liver transplantation. Brown Norway rats received livers from inbred Lewis rats, and at designated intervals, infusions of MSCs derived from recipient, donor, or third-party rats. Allograft rejection and recipient survival rates were recorded. In particular, changes in circulating regulatory T cells (Tregs) were measured. After administration of MSCs derived from each of the 3 strains, allograft recipients demonstrated markedly longer survival compared with control animals. Histologic analysis revealed significant inhibition of allograft rejection. The MSCs induced generation of CD4+CD25+Foxp3+ Tregs. We concluded that MSCs inhibit acute rejection of allografts after liver transplantation, and propose that the immunoregulatory effects of MSCs are associated with expansion of Tregs.

Meta-analysis of dose-response characteristics of hydrochlorothiazide and chlorthalidone: effects on systolic blood pressure and potassium

BACKGROUND

Evidence supporting the benefit of low-dose thiazide-based regimens to reduce cardiovascular events is primarily derived from studies using chlorthalidone, yet low-dose hydrochlorothiazide (HCTZ) (12.5-25 mg) remains more widely prescribed. We sought to describe their comparative dose-response relationships for changes in systolic blood pressure (SBP) and potassium.

METHODS

PubMed from 1948 to July 2008 was systematically searched to identify clinical trials using either HCTZ or chlorthalidone monotherapies. A total of 108 clinical trials with HCTZ and 29 with chlorthalidone were analyzed. Data were pooled to evaluate the effects on SBP and potassium of both drugs throughout their respective dose-response curves. Equivalence analysis was performed for the clinically recommended low-dose range of 12.5-25 mg, grouped by study duration, using the two one-sided tests procedure described by Schuirmann.

RESULTS

When evaluated on a milligram-per-milligram basis using pooled data, chlorthalidone generally produces slightly greater reductions in SBP and potassium than HCTZ. In the low-dose range of 12.5-25 mg, equivalence analysis reveals that the reductions in SBP are not equivalent between the two drugs, using upper and lower equivalence bounds of 4 mm Hg. Within the same dosing range, the mean changes in potassium were determined to be equivalent when upper and lower equivalence bounds of 0.29 mEq/l are used.

CONCLUSIONS

Equivalence analysis using data from several studies suggests that the SBP reductions achieved with HCTZ and chlorthalidone cannot be considered equivalent within the low-dose range currently recommended. However, within this dosing range, reductions in potassium can be considered equivalent.

Screening of heterogeneous surfaces: charge renormalization of Janus particles

Nonlinear ionic screening theory for heterogeneously charged spheres is developed in terms of a mode decomposition of the surface charge. A far-field analysis of the resulting electrostatic potential leads to a natural generalization of charge renormalization from purely monopolar to dipolar, quadrupolar, etc, including 'mode couplings'. Our novel scheme is generally applicable to large classes of surface heterogeneities, and is explicitly applied here to Janus spheres with differently charged upper and lower hemispheres, revealing strong renormalization effects for all multipoles.

Diagnosis of C4d+ Renal Allograft Acute Humoral Rejection by Urine Protein Fingerprint Analysis

This study aimed to develop urine protein fingerprint models for the diagnosis of acute rejection (AR) and complement split product positive (C4d+) acute humoral rejection (AHR) following renal allograft transplantation. Urine samples from 101 renal transplant recipients were analysed by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry combined with bioinformatics. The patients comprised 36 with stable allograft function (stable group), 10 with acute tubular necrosis (ATN) and 55 with AR (20 with C4d- acute cellular rejection [ACR] and 15 with C4d+ AHR). The ATN group was differentiated from the stable group with a sensitivity and specificity of 100% (pattern 1). The stable group was differentiated from the AR group with a specificity of 86.4% and a sensitivity of 85.4% (pattern 2). The C4d- ACR subgroup was differentiated from the C4d+ AHR subgroup with a specificity and sensitivity of 95% and 80%, respectively (pattern 3). It is concluded that urine protein fingerprint analysis can provide a noninvasive tool to diagnose AR and C4d+ AHR.

Caspofungin for post solid organ transplant invasive fungal disease: results of a retrospective observational study

M. Winkler, J. Pratschke, U. Schulz, S. Zheng, M. Zhang, W. Li, M. Lu, D. Sgarabotto, G. Sganga, P. Kaskel, S. Chandwani, L. Ma, J. Petrovic, M. Shivaprakash. Caspofungin for post solid organ transplant invasive fungal disease: results of a retrospective observational study. Transpl Infect Dis 2010: 12: 230–237. All rights reserved

Brazilein inhibits survivin protein and mRNA expression and induces apoptosis in hepatocellular carcinoma HepG2 cells

Hepatocellular carcinomas represent the third leading cause of cancer-related deaths worldwide. Survivin, a structurally unique member of the inhibitor of apoptosis protein (IAP) family, is overexpressed in a wide range of malignancies, including hepatocellular carcinoma. Due to its involvement in cancer progression and treatment resistance, survivin is currently undergoing extensive investigation as a novel intervention target to induce apoptosis in cancer cells by phytochemicals or synthetic agents. Brazilein, a compound obtained in a large amount from the dried heartwood of Caesalpinia sappan Linn., which has long been used in traditional medicine in China, has some pharmacological activities. Human hepatocellular carcinoma HepG2 cells were treated with brazilein and analyzed for survivin protein and mRNA levels by Western blotting and real-time RT-PCR, respectively. Brazilein treatment of cells for 48 h at 5 and 10 microg/ml doses resulted in significantly decrease in survivin protein expression. We also observed that brazilein caused a strong decrease in survivin mRNA expression. In other studies, down-regulation of survivin by brazilein was associated with a strong and prominent caspases-9 and -3 activation as well as PARP cleavage. It was also shown that brazilein induced a strong apoptotic cell death, as shown by DNA ladder assay, and growth inhibition of HepG2 cells. Further studies are needed to investigate in vivo effect of brazilein on survivin expression and associated biological effects in hepatocellular carcinoma that could provide useful information for brazilein efficacy in the prevention/intervention of human hepatocellular carcinoma.

Toward the elimination of medical oncology admissions

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Background: While medical oncology is growing in volume, it is increasingly becoming an outpatient enterprise. Issues leading to hospital admissions in the past are commonly either prevented or managed on an outpatient basis. We sought out trends within our practice on the frequency and reasons for hospital admissions. Methods: Computerized office visit and hospital admissions data were obtained on admissions by physician and year, for Pa. Oncology-Hematology Associates from 2000–2007. A retrospective chart review was also done for one physician from 6/08–12/08 to determine the reasons for admission. Results: While the total number of patients seen per year increased by 40% over the review period from 2000–2007, the relative number of admissions has steadily declined. Adjusting the number of admissions per patients in the practice (since the overall increase in volume partially masks the decline in admission frequency), the reduction in admissions is further evident. The frequency of admissions for the 4 senior oncologists showed a 50% reduction in admissions per patient over the past 8 years. Of 56 admissions reviewed from 6/08–12/08, 20 were related to infections (although only a minority were neutropenic), 13 for symptom management of disease progression, 6 for anemia/bleeding, 3 for bowel obstruction, 3 for non-infectious complications of treatment, and only 1 for chemotherapy administration. Conclusions: Trends in our practice indicate a continued decline in the frequency of admissions per patient. Elective admissions for diagnosis, work-up, and chemotherapy are rare. Improved medications for symptoms related to cancer, its complications and treatment-related toxicities and improvements in palliative care (psychosocial support, communication about prognosis and treatment goals, and end-of-life care) have contributed to decreased admissions. Increasingly, even patients with incurable disease are managed from diagnosis to death entirely as outpatients. Optimizing outpatient management and avoiding admissions in medical oncology has major implications for practice quality, patient quality of life, cost and allocation of health care resources.

No significant financial relationships to disclose.

Platelet adhesion to multimerin 1 in vitro: influences of platelet membrane receptors, von Willebrand factor and shear

BACKGROUND

Multimerin 1 (MMRN1) is a large, homopolymeric adhesive protein, stored in platelets and endothelium, that when released, binds to activated platelets, endothelial cells and the extracellular matrix.

OBJECTIVES

The goals of our study were to determine if (i) MMRN1 supports adhesion of resting and/or activated platelets under conditions of blood flow, and (ii) if MMRN1 enhances platelet adhesion to types I and III collagen.

PATIENTS/METHODS

Platelet adhesion was evaluated using protein-coated microcapillaries, with or without added adhesive proteins and receptor antibodies. Platelets from healthy controls, Glanzmann thrombasthenia (GT) and severe von Willebrand factor (VWF)-deficient donors were tested.

RESULTS

MMRN1 supported the adhesion of activated, but not resting, washed platelets over a wide range of shear rates. At low shear (150 s(-1)), this adhesion was supported by integrins alphavbeta3 and glycoprotein (GP) Ibalpha but it did not require integrins alphaIIbbeta3 or VWF. At high shear (1500 s(-1)), adhesion to MMRN1 was supported by beta3 integrin-independent mechanisms, involving GPIbalpha and VWF, that did not require platelet activation when VWF was perfused over MMRN1 prior to platelets. MMRN1 bound to types I and III collagen, independent of VWF, however, its enhancing effects on platelet adhesion to collagen at high shear were VWF dependent.

CONCLUSIONS

MMRN1 supports platelet adhesion by VWF-dependent and -independent mechanisms that vary by flow rate. Additionally, MMRN1 binds to, and enhances, platelet adhesion to collagen. These findings suggest that MMRN1 could function as an adhesive ligand that promotes platelet adhesion at sites of vascular injury.

The chemistry of escapin: identification and quantification of the components in the complex mixture generated by an L-amino acid oxidase in the defensive secretion of the sea snail Aplysia californica

Escapin is an L-amino acid oxidase in the ink of a marine snail, the sea hare Aplysia californica, which oxidizes L-lysine (1) to produce a mixture of chemicals which is antipredatory and antimicrobial. The goal of our study was to determine the identity and relative abundance of the constituents of this mixture, using molecules generated enzymatically with escapin and also using products of organic syntheses. We examined this mixture under the natural range of pH values for ink-from approximately 5 at full strength to approximately 8 when fully diluted in sea water. The enzymatic reaction likely forms an equilibrium mixture containing the linear form alpha-keto-epsilon-aminocaproic acid (2), the cyclic imine Delta(1)-piperidine-2-carboxylic acid (3), the cyclic enamine Delta(2)-piperidine-2-carboxylic acid (4), possibly the linear enol 6-amino-2-hydroxy-hex-2-enoic acid (7), the alpha-dihydroxy acid 6-amino-2,2-dihydroxy-hexanoic acid (8), and the cyclic aminol 2-hydroxy-piperidine-2-carboxylic acid (9). Using NMR and mass spectroscopy, we show that 3 is the major component of this enzymatic product at any pH, but at more basic conditions, the equilibrium shifts to produce relatively more 4, and at acidic conditions, the equilibrium shifts to produce relatively more 2, 7, and/or 9. Studies of escapin's enzyme kinetics demonstrate that because of the high concentrations of escapin and L-lysine in the ink secretion, millimolar concentrations of 3, H(2)O(2), and ammonia are produced, and also lower concentrations of 2, 4, 7, and 9 as a result. We also show that reactions of this mixture with H(2)O(2) produce delta-aminovaleric acid (5) and delta-valerolactam (6), with 6 being the dominant component under the naturally acidic conditions of ink. Thus, the product of escapin's action on L-lysine contains an equilibrium mixture that is more complex than previously known for any L-amino acid oxidase.

Design, synthesis, and structure-activity relationship, molecular modeling, and NMR studies of a series of phenyl alkyl ketones as highly potent and selective phosphodiesterase-4 inhibitors

Phosphodiesterase 4 catalyzes the hydrolysis of cyclic AMP and is a target for the development of anti-inflammatory agents. We have designed and synthesized a series of phenyl alkyl ketones as PDE4 inhibitors. Among them, 13 compounds were identified as having submicromolar IC(50) values. The most potent compounds have IC(50) values of in the mid- to low-nanomolar range. Compound 5v also showed preference for PDE4 with selectivity of >2000-fold over PDE7, PDE9, PDE2, and PDE5. Docking of 5v, 5zf, and 5za into the binding pocket of the PDE4 catalytic domain revealed a similar binding profile to PDE4 with rolipram except that the fluorine atoms of the difluoromethyl groups of 5v, 5za, and 5zf are within a reasonable range for hydrogen bond formation with the amide hydrogen of Thr 333 and the long alkyl chain bears additional van der Waals interactions with His 160, Asp 318, and Tyr 159.

The tolerance time limits of biliary tracts of liver grafts subjected to warm ischemia and cold preservation: an experimental study in swine

OBJECTIVE

The objective of this study was to investigate the tolerance time limits of liver grafts and biliary tracts with warm ischemia to cold preservation providing experimental data to the prevent primary graft nonfunction and biliary necrosis after orthotopic liver transplantation (OLT).

METHODS

OLTs were performed in Bama miniature swine. Morphological and functional changes in the liver graft and biliary tracts were investigated after 10 minutes of warm ischemia and various durations of cold preservation.

RESULTS

When grafts were subjected to 10 minutes of warm ischemia followed by less than 16 hours of cold preservation, all animals survived 1 week; no animal died of biliary necrosis. However, when the cold preservation time exceeded 16 hours, the incidence of biliary necrosis increased significantly (P < .05) with deaths due to bile leaks. As cold preservation persisted, primary graft nonfunction and intraoperative or early postoperative deaths occurred, and all surviving animals developed biliary necrosis. When compared with the group undergoing less than 16 hours of cold preservation, the morphological scores and apoptosis index of epithelial cells of graft bile ducts were significantly increased among the group subjected to more than 16 hours of cold preservation after reperfusion (P < .05), whereas the activity of Na+-K+-ATPase and Ca2+-ATPase of graft bile ducts were reduced significantly (P < .05). Liver function tests showed the concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyl transpeptidase, and alkaline phosphatase (ALP) decreased more slowly among the group undergoing more than 16 hours of cold preservation after operation.

CONCLUSIONS

We concluded that given 10 minutes of warm ischemia, cold preservation should be less than 16 hours to avoid early biliary necrosis; the corresponding tolerance time limit of the liver to cold preservation was less than 20 hours.

Primary Hepatic Carcinoid Tumours: Clinical Features with an Emphasis on Carcinoid Syndrome and Recurrence

This study sought to determine the clinical profiles and optimal management of primary hepatic carcinoid tumours. The clinical features of nine Chinese patients and 64 patients reported in the English-language literature were characterized. Recurrence rate and survival analysis were performed with the Kaplan–Meier method. The impact of surgical resection and post-operative recurrence on survival was determined by means of the log-rank test. Carcinoid syndrome complicated 10 cases (14%). Sixty-two patients (85%) underwent surgical resection. Actuarial 5-and 10-year survival rates for resected patients were 80% and 75%, respectively. Twelve patients experienced recurrences: the recurrence rate at 5 years post-operatively was 26%. All patients with resectable recurrent disease achieved good long-term survival and no significant relationship was found between recurrence and survival. Owing to the high incidence of recurrence, long-term follow-up is necessary and it is recommended that recurrent cases should be managed with judicious surgical resection.