NO- and haem-independent activation of soluble guanylyl cyclase: molecular basis and cardiovascular implications of a new pharmacological principle

1. Soluble guanylyl cyclase (sGC) is the only proven receptor for the ubiquitous biological messenger nitric oxide (NO) and is intimately involved in many signal transduction pathways, most notably in regulating vascular tone and platelet function. sGC is a heterodimeric (alpha/ss) protein that converts GTP to cyclic GMP; NO binds to its prosthetic haem group. Here, we report the discovery of a novel sGC activating compound, its interaction with a previously unrecognized regulatory site and its therapeutic implications. 2. Through a high-throughput screen we identified BAY 58-2667, an amino dicarboxylic acid which potently activates sGC in an NO-independent manner. In contrast to NO, YC-1 and BAY 41-2272, the sGC stimulators described recently, BAY 58-2667 activates the enzyme even after it has been oxidized by the sGC inhibitor ODQ or rendered haem deficient. 3. Binding studies with radiolabelled BAY 58-2667 show a high affinity site on the enzyme. 4. Using photoaffinity labelling studies we identified the amino acids 371 (alpha-subunit) and 231 - 310 (ss-subunit) as target regions for BAY 58-2667. 5. sGC activation by BAY 58-2667 results in an antiplatelet activity both in vitro and in vivo and a potent vasorelaxation which is not influenced by nitrate tolerance. 6. BAY 58-2667 shows a potent antihypertensive effect in conscious spontaneously hypertensive rats. In anaesthetized dogs the hemodynamic effects of BAY 58-2667 and GTN are very similar on the arterial and venous system. 7. This novel type of sGC activator is a valuable research tool and may offer a new approach for treating cardiovascular diseases.     

Using prescribing health and population data to describe the health of a locality: the development and evaluation of a locality health profile

Objective To develop and evaluate a pharmaco‐epidemiological and public health profile that will aid in the determination and evaluation of the health and pharmaceutical needs of a local population with the National Health Service (NHS). Method Two local health areas (known as local health care co‐operatives (LHCCs)) in NHS Lothian with diverse population characteristics had health profiles formally developed using prescribing, hospitalisation and other public health data. The integrated report was able to highlight morbidity issues in each LHCC that could be acted on by either LHCC management or local pharmacy groups. A steering committee and focus groups were used in the design and evaluation process. An evaluation survey of participants including LHCC management, community and LHCC pharmacists and other healthcare professionals was conducted with the main outcome measure being the relative utility of the health profile. Key findings Participants evaluating the health profiles found them informative and useful in decision making and planning for the locality. Participants anticipated using prescribing data to fill information gaps in other datasets and/or provide a primary care perspective to health in the locality. Conclusions Health profiles were developed from prescribing health and population data that were shown to be meaningful and useful to local health authority management and other healthcare professionals. The health profiles contained information that could be used to inform decisions or identify areas where further investigation may be required to find out why a particular anomaly is occurring. In Scotland, the focus of a new community pharmacy contract is on the dual elements of chronic disease management and public health contributions, through prevention of disease and/or limitation of disease impact. There is an urgent need to develop tools that help to inform professional interventions involving pharmacists, and thereby improvements to multidisciplinary co‐operation. This study suggests a means of describing the population characteristics for informing a network of community pharmacists about public health priorities within their LHCC.     

Transepithelial paracellular leakiness induced by chronic phorbol ester exposure correlates with polyp-like foci and redistribution of protein kinase C-alpha

Although exposure of LLC-PK1 epithelial cell sheets to phorbol esters (TPA) causes a near immediate and total decrease of transepithelial electrical resistance (TER), continuation of exposure for 3 to 4 days results in a tachyphylactic response as TER begins to return to control levels. Recovery of TER is maximal by 5 to 6 days, but reaches only 70 to 80% of control level. A reciprocal change in the transepithelial flux of D-mannitol indicates that the TER decrease is indicative of an increase in tight junction permeability. Exposure of cell sheets to TPA for several days also results in the appearance of multilayered polyp- like foci (PLFs) across the otherwise one cell layer thick cell sheets. The pattern of penetration of the electron dense dye, ruthenium red, from the apical surface, across the tight junction and into the lateral intercellular space indicates that the tight junctions of the cell sheet become uniformly leaky after acute exposure to TPA. However, when exposure is continued for several days, only the junctions of cells in the PLFs manifest leakiness. The decrease in TER following acute TPA exposure correlates with the translocation of protein kinase C-alpha (PKC alpha) into a membrane-associated compartment. With exposure of several days, only a trace of PKC alpha is visible by Western immunoblot, and this is in the membrane-associated compartment. Immunofluorescent microscopy indicates that the trace of PKC alpha seen in the Western immunoblots is ascribable distinctly to cells of the PLFs. Monolayer areas between PLFs show no discernible immunofluorescent signal. The data therefore indicate that tight junction barrier function may be restored in certain areas by the down regulation of PKC alpha from the membrane-associated compartment. Failure to down regulate may result in the paracellular leakiness and abnormal cell architecture of the PLFs. Possible implications of this model for in vivo epithelial tumor promotion are discussed.      

Molecular analysis of PKU in Ireland

Classical phenylketonuria (PKU: McKusick No. 261600) is caused by mutations occurring at the phenylalanine hydroxylase (PAH) locus on chromosome 12 and has a prevalence in Ireland of 1 in 4500. We examined 304 independent alleles from 350 patients for the presence of six mutations and have characterized VNTR alleles within the minisatellite region 3' to the PAH gene in patients carrying the most prevalent mutation. R408W was the most common mutation found, with a relative frequency of 42%. All other mutations had relative frequencies of <10%. VNTR analysis showed that the R408W mutation is associated with the VNTR-8 allele in the Irish population, indicating that R408W is associated with RFLP haplotype 1. This differs from that reported from eastern Europe where R408W is associated with RFLP haplotype 2/VNTR-3; an observation which has led several groups to propose a Balto-Slavic origin for this mutation. These results support the hypothesis of a second, independent founding event for the R408W mutation on an RFLP haplotype 1 VNTR-8 chromsome background in the Irish/Celtic population.     

Controlled study of inline radiofrequency ablation (ILRFA) assisted transection of ovine liver

BACKGROUND: Liver resection is now a standard treatment for primary and secondary hepatic tumors around the world. Intra-operative blood loss during liver resection is a major factor associated with morbidity and mortality. We have developed a new instrument using radiofrequency energy (ILRFA), which is intended to achieve coagulative ablation in a plane. This plane can then be cut through with a scalpel, ultrasonic dissector, or diathermy with minimal blood loss. MATERIALS AND METHODS: Five sheep were used in this non-recovery experiment. In these sheep we performed five liver resections with the ILRFA and five similar resections using diathermy and suturing as control. Blood loss was measured by determining the difference in the weights of dry sponges and blood stained sponges after resection. RESULTS: ILRFA was successful in achieving coagulative ablation in all cases to a width of 1 cm. The mean blood loss in ILRFA was 43.2 g (SD36) and 221.8 g (SD147) in the control group. The bleeding was significantly reduced in ILRFA group with a P value of 0.005. CONCLUSIONS: Bleeding remains an important complication of liver resection. To reduce bleeding during liver surgery, different techniques have been used. In this study, we have demonstrated that by using ILRFA we can perform liver resections in sheep with minimal blood loss.     

Intimacy needs and chronic illness: strategies for sexual counseling and self-management

Individuals experiencing a chronic illness have many needs and concerns. One area frequently overlooked is that of intimacy. Those experiencing cardiovascular illnesses have concerns about the strain of sexual activity on their heart. Individuals with lung diseases may perceive that sexual activity is no longer possible because of breathing difficulties. Accurate information and strategies for self-management are needed to address the intimacy needs and concerns of these individuals. The purpose of this article is to identify intimacy needs and strategies for sexual counseling for individuals with cardiovascular illnesses such as myocardial infarction, heart failure, implantable defibrillators, hypertension, and for chronic lung problems.     

Protein quality comparison of a new isolated soy protein and milk in chilean preschool children

The protein quality of a newly developed soybean protein isolate (SPF-200) and milk were compared using apparent N digestibility (AND), N balance (ANB) and serum biochemical response to graded levels of N intake (NI). Seven healthy well nourished children aged 35 to 62 months, were given for 8 day periods 1.5, 1.25, 1.0 and 0.75 g protein/kg/day of SPF and milk in decreasing order at a constant energy intake of 100 Kcal/kg/day and a vitamin mineral supplement. AND for SPF ranged from 86 to 70% and for milk 83 to 75%, corresponding to highest and lowest NI, ANB for SPF ranged from 63 to 0 mg/kg/day and for milk from 90 to 28 mg/kg/day. Mean individual regressions of daily ANB and NI were ANB=0.49 NI-54 for SPF and ANB=0.51 NI-34 milk. The slopes were not significantly different. Non significant decreases in serum albumin and urea were observed. A°significant increases in transaminases was noted at the lowest NI for both proteins. Daily protein allowances to retain 39 mg N/kg/day were 1.27 and 0.91 g protein/kg/day for SPF and milk respectively.     

Melphalan-resistant multiple myeloma: results of treatment according to the M-2 protocol

Summary A group of 46 patients with melphalan-resistant multiple myeloma was treated according to the M-2 protocol with melphalan, prednisolone, BCNU, cyclophosphamide, and vincristine. According to the Salmon and Durie classification, four patients had stage II A; 36, stage III A; and six, stage III B disease. Treatment resulted in five patients (11%) entering remission, while 21 (46%) had stable and 20 (43%) had progressive disease. The median survival for all patients was 12.5 months, patients in remission surviving longer (median 46 months) than those with stable disease (median 15.4 months) or progressive disease (median 6.9 months). Compared with other treatment regimens used in melphalan-resistant myeloma, the remission rate is low but the median survival exceeds that reported by most other authors.     

Percutaneous Imaging–Guided Radiofrequency Ablation in Patients With Colorectal Pulmonary Metastases: 1-Year Follow-Up

Background: We assessed the safety and evidence of efficacy of radiofrequency ablation (RFA) for colorectal lung metastases with follow-up to 1 year.Methods: Twenty-three patients had percutaneous RFA for 52 colorectal pulmonary metastases under fluoro-computed tomography (CT). Patients received intravenous conscious sedation and local analgesia with routine hospitalization and monitoring for 24 hours after RFA. Patients had CT scanning at 1 month and then every 3 months, with serum carcinoembryonic antigen assessment monthly and every 3 months.Results: All ablations were technically successful. Tumor diameter ranged from .3 to 4.2 cm. Pneumothorax occurred in 43% (10 of 23) of patients. Six patients required intercostal chest drain placement. Six patients had a second RFA, four for new lesions and two for re-treatment of a previously treated lesion. The median admission was 2.0 days (range, 1–9 days). The median follow-up was 428 days (range, 173–829 days); data are reported to 1 year in this article. Five patients died at 5, 6, 8, 8, and 12 months after RFA from extrapulmonary (n = 1) or widespread (n = 4) disease. One patient developed a malignant pleural effusion at 6 months after RFA. Cavitation was seen in nine treated lesions (17%); all resolved with scar tissue contraction by 12 months. Eighteen patients with CT scan follow-up at 1 year have 40 lesions classified as disappeared (n = 17), decreased (n = 5), stable/same size (n = 4), or increased (n = 14).Conclusions: Percutaneous imaging–guided RFA of multiple colorectal pulmonary metastases is a minimally invasive treatment option with modest morbidity. A significant proportion of patients show good evidence of successful local control at 1 year.