Analysis of a National Programme for Selective Internal Radiation Therapy for Colorectal Cancer Liver Metastases.

AIMS: Patients with chemotherapy-refractory colorectal cancer liver metastases have limited therapeutic options. Selective internal radiation therapy (SIRT) delivers yttrium 90 microspheres as a minimally invasive procedure. This prospective, single-arm, observational, service-evaluation study was part of National Health Service England Commissioning through Evaluation. METHODS: Patients eligible for treatment had histologically confirmed carcinoma with liver-only/liver-dominant metastases with clinical progression during or following oxaliplatin-based and irinotecan-based chemotherapy. All patients received SIRT plus standard of care. The primary outcome was overall survival; secondary outcomes included safety, progression-free survival (PFS) and liver-specific PFS (LPFS). RESULTS: Between December 2013 and March 2017, 399 patients were treated in 10 centres with a median follow-up of 14.3 months (95% confidence interval 9.2-19.4). The median overall survival was 7.6 months (95% confidence interval 6.9-8.3). The median PFS and LPFS were 3.0 months (95% confidence interval 2.8-3.1) and 3.7 months (95% confidence interval 3.2-4.3), respectively. During the follow-up period, 143 patients experienced an adverse event and 8% of the events were grade 3. CONCLUSION: Survival estimates from this pragmatic study show clinical outcomes attainable in the National Health Service comparable with previously published data. This study shows the value of a registry-based commissioning model to aid national commissioning decisions for highly specialist cancer treatments.

Structure-function analysis of a novel member of the LIV-1 subfamily of zinc transporters, ZIP14.

Here, we report the first investigation of a novel member of the LZT (LIV-1 subfamily of ZIP zinc Transporters) subfamily of zinc influx transporters. LZT subfamily sequences all contain a unique and highly conserved metalloprotease motif (HEXPHEXGD) in transmembrane domain V with both histidine residues essential for zinc transport by ZIP (Zrt-, Irt-like Proteins) transporters. We investigate here whether ZIP14 (SLC39A14), lacking the initial histidine in this motif, is still able to transport zinc. We demonstrate that this plasma membrane located glycosylated protein functions as a zinc influx transporter in a temperature-dependant manner.

Maintenance intravenous iron therapy in pediatric hemodialysis patients.

Iron supplementation is required for optimal response to erythropoietin (EPO) in hemodialysis patients. This is due to blood lost in the dialysis tubing after dialysis and the increased demand for iron by EPO therapy. Maintenance intravenous (IV) iron was administered according to a standardized protocol to pediatric patients on hemodialysis in our institution. The effect of this protocol on EPO dose, iron indices, anemia, and medication costs was evaluated. Data on two groups of patients were retrieved from the health records. Group 1 (n=14) consisted of patients treated in the 18 months prior to the protocol. These patients received oral iron supplements and occasional IV iron. Group 2 (n=5) consisted of all patients treated with the IV iron protocol. There was no difference in clinical characteristics and mean values for monthly hemoglobin, serum iron, ferritin, and transferrin saturation between groups. The dose of EPO was significantly reduced in group 2 compared with group 1 (193.9 +/- 121.4 vs. 73.9 +/- 39.0 units/kg per week, P<0.05). Medication costs were reduced by 26% in group 2. No significant adverse events were seen. Maintenance IV iron reduced the dose of EPO required to maintain blood hemoglobin levels. Our results also suggest that maintenance IV iron is a more-economic method of iron supplementation for pediatric hemodialysis patients.

TENB2, a proteoglycan identified in prostate cancer that is associated with disease progression and androgen independence.

TENB2 encodes a putative transmembrane proteoglycan, related to the EGF/heregulin family of growth factors and follistatin, which has been identified through the application of a differential display technique to a xenograft model of prostate cancer. Northern analysis and competitive PCR were used to demonstrate significantly increased TENB2 expression (p = 0.0003) on the acquisition of androgen independence in the model system. TENB2 is also overexpressed in clinical prostate carcinoma vs. its benign counterpart (p < 0.0001), with particular prominence in high-grade tumours, and shows a high degree of tissue specificity, being detected on a multitissue Northern array exclusively in brain and prostate material. Studies of recombinant protein expression demonstrate that TENB2 is a chondroitin sulphate proteoglycan. The presence of an EGF and 2 follistatin domains suggests a role in the regulation of growth factor signalling either as a ligand precursor, a membrane-bound receptor or as a binding protein for growth factors. These data are indicative of a significant role for TENB2 in the progression of poorly differentiated tumour types, with implications for prostate cancer detection, prognosis and therapy.

Limitation of heart growth in neonatal piglets by simvastatin and atorvastatin: comparison with pravastatin.

The pig heart grows rapidly in the first few days after birth. We examined the effects of simvastatin, atorvastatin, and pravastatin on heart growth in piglets. After vehicle, 2 mg x kg(-1) x day(-1) simvastatin, 2 mg x kg(-1) x day(-1) atorvastatin, or 4 mg x kg(-1) x day(-1) pravastatin were administered orally for 6 days, the thoracic cavity was opened, and the heart was removed under pentobarbital sodium (30 mg/kg ip) anesthesia. The heart was perfused to remove residual blood. After the heart was blotted dry, the right and left ventricular free walls were dissected. Each free wall was weighed and used for determination of DNA, RNA, and protein concentrations and mitogen-activated protein (MAP) kinase activity. Simvastatin and atorvastatin resulted in smaller increases with age in the weight, concentrations of RNA and protein, and activity of MAP kinase in the left ventricular free wall, whereas pravastatin did not. The parameters of heart growth in the right ventricular free wall were not appreciably affected by either drug. The blood pressure and heart rate were not changed by the treatments. These results suggest that simvastatin and atorvastatin interfere with heart growth in neonatal piglets after birth, especially in the left ventricular free wall.

Characterization of ventricular myocytes from the newborn pig heart.

The differential rate of growth of the left-ventricular free wall (LVFW) and the right-ventricular free wall (RVFW) of the newborn pig has been studied by measuring the rates of ribosome formation and protein synthesis in the isolated perfused heart. These measurements are limited by the heterogeneity of the cells and the stability of the preparation. The hypothesis of the present study was that isolated cultured myocytes would offer much less cellular heterogeneity and a more prolonged period to explore the actions of anabolic agents. The rate of [3H] phenylalanine incorporation into total protein during 24 h of culture was established as a monitor of the rate of protein synthesis in myocytes and was found to be 64 and 61% of the rates measured in the LVFW and RVFW, respectively, of the perfused heart. The relative rates of protein synthesis in LVFW and RVFW were the same in myocytes and perfused hearts. Myocytes from the LVFW had increased rates of protein synthesis after exposure to a combination of norepinephrine and propranolol or endothelin for 24 h. Exposure to endothelin for 3 days increased rates of protein synthesis to a greater extent in LVFW myocytes than in RVFW myocytes. In LVFW myocytes from enalapril-treated pigs or in LVFW myocytes exposed to 40 mM KCl, angiotensin II increased the rate of protein synthesis by 14% during the third day of incubation. These studies indicated that cultured myocytes reflected the rates of protein synthesis observed in LVFW and RVFW of the perfused piglet heart. Differential effects of an alpha-adrenergic agonist, endothelin and angiotensin II in LVFW as compared to RVFW myocytes was observed. In each case, the response to the agonist was decreased or absent in RVFW as compared to LVFW myocytes.

Contributions of increased efficiency and capacity of protein synthesis to rapid cardiac growth.

Rapid cardiac growth depends upon faster synthesis than degradation of protein. The rate of protein synthesis is determined by the efficiency with which the existing components of the ribosome cycle make protein and by the quantity of the components that are present. The tissue content of RNA is taken as an index of the capacity of synthesis and efficiency is expressed as the amount of protein formed per amount of RNA over a certain time period. The efficiency of synthesis is regulated by hormones, including insulin, agents that increase cAMP, alpha-adrenergic agonists, endothelin I and angiotensin II. In addition, provision of non-carbohydrate substrates and mechanical factors such as stretch and contraction increase efficiency. Impaired energy availability as occurs in anoxic or ischemic muscle decreases efficiency. Increased phosphorylation of ribosomal protein, S6, or of the peptide chain initiation factor, elF-4E, have been suggested as mechanisms to regulate efficiency of mRNA translation. Increased efficiency of synthesis accounts for cardiac growth in the first few days following aortic banding, pulmonary artery constriction and thyroxine administration. Decreased efficiency accounts for cardiac atrophy in heterotopic transplanted hearts during the first 3 days following transplantation. The capacity of synthesis is increased by insulin, thyroid hormone, activators of protein kinase C, agents that increase cAMP, and endothelin-1. Stretch of the ventricular wall and contraction of cultured neonatal myocytes accelerates ribosome formation. An increased rate of ribosomal DNA transcription accounts for accelerated ribosome formation and depends on increased activity of a transcription factor, upstream binding factor (UBF). The activity of UBF is increased either by increased rates of synthesis or by phosphorylation of the protein. Increased capacity of synthesis is a major contributor to rapid cardiac growth in the newborn heart and after several days of pressure overload.

Rapid cardiac growth--mechanical, neural and endocrine dependence.

Rapid growth of the cardiac left ventricle is a hallmark of the neonatal period. During the first 2 weeks of life in the piglet, weight of the left ventricle increases 4 fold. The increase in weight is accompanied by approximately a 4 fold increase in myocyte volume indicating hypertrophic growth. Total RNA also increases approximately 4 fold indicating that the mechanism of growth involves greater ribosome content and greater capacity for protein synthesis. The rapid rate of ribosome formation and protein synthesis cannot be further accelerated in isolated perfused hearts by insulin, agents that increase 3',5'-cyclic monophosphate, alpha 1-adrenergic agonists or angiotensin II. In an attempt to slow cardiac growth and make it responsive to growth-promoting agonists, piglets are treated with an angiotensin converting enzyme inhibitor, enalapril maleate. Enalapril decreases left ventricular growth by 19% and total RNA content by 36%. When enalapril-treated hearts are perfused in vitro for 1 h, alpha 1-adrenergic agents restore rates of ribosome formation to control values but angiotensin II has no effect. In left ventricular myocytes that are cultured for 3 days, an alpha 1-adrenergic agonist and endothelin increases the rate of protein synthesis by 20 to 75% but angiotensin II has only a marginal effect (8%). These findings indicate that inhibition of growth by enalapril most likely is due to decreased ventricular pressure development that is secondary to peripheral vasodilation and a fall in mean arterial pressure.

Role of bradykinin in the antihypertrophic effects of enalapril in the newborn pig heart.

Rapid growth of the left ventricle of the newborn pig heart can be restrained by treating piglets with the angiotensin converting enzyme inhibitor, enalapril maleate. This reduced rate of growth is reflected in vitro by reduced rates of ribosome formation and protein synthesis, and may be due to decreased availability of angiotensin II (AII), a potentially hypertrophic agent; decreased numbers of AII receptors; increased availability of bradykinin, a potentially antihypertrophic agent; or reduced hemodynamic load on the left ventricle. Because enalapril decreases degradation of bradykinin, the role of bradykinin as an inhibitor of cardiac growth in the newborn heart was investigated. Addition of 1 x 10(-5) M bradykinin and 1 x 10(-6) M enalapril to the perfusate of isolated hearts from 2 day old piglets did not significantly alter heart rate, contents of ATP or creatine phosphate or rates of ribosome formation or protein synthesis during 1 h of perfusion. Similarly, exposure of myocytes isolated from the left ventricular free wall of piglets to 5 x 10(-6) M bradykinin for 72 h did not alter the rate of [3H]-phenylalanine incorporation into total protein. The reduced rate of left ventricular growth in vivo caused by enalapril administration was not reversed by simultaneous treatment with the specific bradykinin receptor antagonist, HOE 140. HOE 140 alone did not alter ventricular growth as compared to hearts from untreated piglets. In summary, these results demonstrate that the reduced rate of left ventricular growth in vivo and the reduced rate of ribosome formation and protein synthesis in the left ventricle in vitro after enalapril treatment of piglets is not the result of an inhibitory effect of bradykinin on cardiac growth.

American Heart Association-Bugher Foundation Centers for Molecular Biology in the Cardiovascular System.

BACKGROUND: The American Heart Association (AHA) and the Henrietta B. and Frederick H. Bugher Foundation in 1985 entered into a partnership to establish a group of Centers for Molecular Biology in the Cardiovascular System. The goal was to recruit and train young scientists with medical training to apply molecular and cellular biology knowledge and techniques to cardiovascular problems. METHODS AND RESULTS: Six Centers have been awarded (three in 1986 and three in 1991), and a total of 110 trainees have been involved as of June 30, 1994. Of these trainees, 77 were recruited and trained by the 1986 Centers. As of June 1994, 88% of these trainees remained in academic medicine and 54% progressed to higher academic ranks; 79% published papers in science and 66% in molecular biology; and 36% obtained extramural funding for their work. On this basis, the 1986 trainees appear to be well on their way to becoming successful academic cardiologists. CONCLUSIONS: The AHA-Bugher Foundation Center program has produced a cadre of cardiovascular scientists who are applying molecular biology knowledge to both basic and clinical problems.

Mechanisms of rapid growth in the neonatal pig heart.

During the first 2 weeks of life the left ventricular free wall of the neonatal pig heart grows rapidly. The mass of the left ventricular free wall (LVFW) increased from 2.22 +/- 0.10 g to 9.62 +/- 1.01 g while the right ventricular free wall (RVFW) increased from 2.03 +/- 0.24 g to 3.56 +/- 0.41 g from birth to 14 days of age. During the same period, the cellular volume of myocytes from the LVFW increased from 1075 microns3 to 3688 microns3 while myocytes from the RVFW increased in volume from 1511 microns3 to 2454 microns3. The number of RVFW myocytes did not change during the first 2 weeks of life, while the number of LVFW myocytes increased 28%. Myocytes from both ventricles were approximately 90% mononuclear from birth to 4-5 days of age. By 14 days, 67% of LVFW myocytes and 53% of RVFW myocytes were multinucleated. When growth of the heart was restrained by treatment of the piglet with enalapril maleate, the LVFW mass was reduced by 24% over 2 weeks compared to hearts from untreated piglets and was accounted for by a reduction in myocyte volume. Enalapril treatment did not alter the number of myocytes in either the LVFW or RVFW as compared to hearts from untreated piglets. After 14 days of enalapril treatment, the percentage of multinucleated cells was reduced in the LVFW and unchanged in the RVFW as compared to hearts from untreated piglets.(ABSTRACT TRUNCATED AT 250 WORDS)

Cellular aspects of cardiac failure.

Intracellular signaling systems that are involved in growth of cardiac myocytes and that are modified in congestive heart failure include the alpha 1- and beta-adrenergic systems and angiotensin II. These systems include G-protein-linked hormone receptors and their membrane enzyme including adenylyl cyclase and phospholipase C. In addition, membrane enzymes, and adenylyl cyclase in particular, respond directly to stretch of the cell membrane with an increase in cAMP formation. Furthermore, interactions between stretch and hormonal stimuli can potentiate each other and result in enhanced signal generation.

Alpha-adrenergic receptor agonists stimulate ribosome formation in hearts from enalapril-treated piglets.

Hearts from untreated or enalapril-treated piglets were used to measure rates of ribosome formation and total protein synthesis during perfusion as modified Langendorff preparations. Pretreatment of newborn piglets with enalapril maleate (5 mg, once daily for 3 days) resulted in a decreased rate of growth of the left ventricle. Addition of 1 microM angiotensin II to the perfusate had no effect on in vitro ribosome formation or protein synthesis in either the right or left ventricle of hearts from untreated or enalapril-treated piglets. Angiotensin II receptor number or affinity in the left ventricle was not decreased by enalapril treatment. In contrast, addition of combinations of 1 microM norepinephrine and 1 microM propranolol or 1 microM phenylephrine and 1 microM propranolol to the perfusate restored the rate of ribosome formation in the left ventricle of hearts from enalapril-treated piglets to that observed in the left ventricle of hearts from untreated piglets. Prazosin (100 nM) blocked the stimulatory effect of either norepinephrine or phenylephrine on ribosome formation in the left ventricle. Binding of [3H] prazosin to membranes from the left ventricle was unaltered by pretreatment of the piglet with enalapril maleate. Pretreatment of piglets with prazosin (1 mg, twice daily for 3 days) resulted in a small but significant decrease in mean arterial pressure as well as the rate of left ventricular growth. Pretreatment of piglets with hydralazine (10 mg, twice daily for 3 days) significantly reduced mean arterial pressure but did not alter left ventricular growth. These results support a role for alpha 1-adrenergic receptor stimulation in the regulation of neonatal cardiac growth.

Control of growth in neonatal pig hearts.

The pig heart grows at a maximal rate in the first 2-3 days of life due to a volume overload imposed on the heart at birth. Rates of ribosome formation and protein synthesis cannot be further accelerated during in vitro perfusion with agents that increase cyclic AMP, that bind to alpha 1-adrenergic receptors or that bind to angiotensin II receptors. Growth of the heart in vivo can be restrained by treatment with an angiotensin-converting enzyme inhibitor, enalapril maleate, or an angiotensin receptor antagonist, DuP 753. In the enalapril-treated heart, norepinephrine plus propranolol, but not angiotensin II, accelerated ribosome formation. Rapid growth of the left ventricle of pig heart during the first 10 days of life is due largely to eccentric hypertrophy.

Acceleration of growth of cultured cardiomyocytes and translocation of protein kinase C.

Phorbol 12-myristate 13-acetate (PMA), norepinephrine (NE), and contraction stimulate cardiomyocyte growth (increased protein content). Differences exist in the time course and extent of protein and RNA accumulation. Cells plated at 4 x 10(6) cells/60-mm dish and arrested with 50 mM KCl demonstrated no significant growth. Treatment with PMA stimulated growth to a maximum of 17% at 48 h. In contrast, maximal stimulation of growth was 36% at 48 h and 31% at 72 h for contracting and NE-treated cells, respectively. Maximal stimulation of the capacity for protein synthesis (RNA content) was 32% for PMA-treated cells at 24 h compared with 59% and 77% for NE-treated and contracting cells, respectively, at 72 h. In support of a primary role for altered capacity in the regulation of protein synthesis, there was a significant correlation (r = 0.84) between RNA and protein contents that was independent of the stimulus used. Angiotensin II increased RNA content by 28% at 48 h but had no effect on growth up to 72 h. Growth stimulation and increased nuclear protein kinase C (PKC) activity were induced by contraction, NE, and PMA treatment and were inhibited by staurosporine (a PKC inhibitor), suggestive of a central role for PKC.

Phorbol ester stimulation of protein kinase C activity and ribosomal DNA transcription. Role in hypertrophic growth of cultured cardiomyocytes.

The mechanism by which phorbol esters induce hypertrophic growth of cardiomyocytes was investigated. Control and 4 alpha-phorbol 12,13-didecanoate-treated myocytes demonstrated a slow rate of growth as measured by the protein/DNA ratio and cell area. In contrast, treatment with phorbol 12-myristate 13-acetate (PMA) stimulated protein accumulation by 34%, while cell area was increased by 68% over control myocytes after 72 h. RNA content in PMA-treated myocytes was 33% higher than in control cells and 4 alpha-phorbol 12,13-didecanoate-treated cells after 72 h. Membrane-associated protein kinase C activity was transiently increased after PMA treatment but returned to normal by 48 h. Cytosolic protein kinase C activity was not significantly altered by PMA. Membrane-associated and cytosolic protein kinase C activities were not altered by 4 alpha-phorbol 12,13-didecanoate. Protein kinase C activity, RNA polymerase I activity, and the transcriptional rate of ribosomal DNA (rDNA) were increased in nuclei isolated from PMA-treated cells. However, consistent with a high rate of processing of pre-ribosomal RNA (pre-rRNA), the pool size of pre-rRNA relative to the 28 S rRNA was unaltered by PMA treatment. These data demonstrated that PMA-induced hypertrophic growth of cardiomyocytes was due to an increase in the capacity for protein synthesis (rRNA), and suggest that this results from protein kinase C mediated increase in the rate of transcription of rDNA.

Control of growth in the neonatal pig heart.

The newborn heart is an excellent model in which to study cardiac growth because the neonatal period is a normal situation in which the left ventricle (LV) grows rapidly and the right ventricle grows slowly. Accelerated LV growth is in response to mechanical, neural, and endocrine changes at birth. Faster growth of the LV is accounted for by greater capacity for protein synthesis, as evidenced by greater RNA content. At 18 h of life, ribosomes are formed in preference to total heart protein, but at 48 h of life, faster rates of both ribosome formation and total protein synthesis are observed. In the LV of hearts from 2-day-old pigs, these rates are insensitive to the addition of glucagon, 1-methyl-3-isobutylxanthine, or a combination of norepinephrine and propranolol. These observations could result because of maximal growth stimulation already present in the LV of the newborn heart. To restrain LV growth in the neonatal period, we treated pigs with enalapril maleate, an angiotensin II-converting enzyme inhibitor. Enalapril blocked growth of the LV as well as the increase in RNA content. When hearts from enalapril-treated pigs were perfused in vitro, rates of protein synthesis and ribosome formation in the LV were lower. These studies suggest that angiotensin II is an important factor accounting for rapid growth of the neonatal heart in response to pressure overload at birth.

Angiotensin II and left ventricular growth in newborn pig heart.

The left ventricle of the neonatal pig heart is a model of rapid physiological cardiac growth that is dependent upon accelerated ribosome formation and increased RNA content. The goals of the present study were to investigate the role of angiotensin II in this rapid growth. Hearts from 3 d old control piglets or piglets that were treated with enalapril maleate, an angiotensin converting enzyme inhibitor, or DuP 753, an angiotensin II receptor antagonist, were used for measurements of left ventricular mass, RNA, DNA and protein. Hearts from enalapril-treated pigs also were used for measurements of rates of ribosome formation and total protein synthesis during perfusion as modified Langendorff preparations. Treatment of piglets with enalapril maleate resulted in decreased left ventricle/body wt ratio, RNA content, total RNA and total protein in the left ventricle. These parameters were unaffected in the right ventricle. In vitro perfusion of hearts from enalapril-treated piglets revealed decreased ribosome formation and total protein synthesis in the left ventricle. Piglets treated with DuP 753 had decreased left ventricle/body wt ratio as well as decreased RNA content, total RNA and RNA/DNA ratio in the left ventricle. These results suggest that angiotensin II may be required for rapid growth of neonatal pig hearts.