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.     

Voiding cystourethrography using the suprapubic versus transurethral route in infants and children: results of a prospective pain scale oriented study

PURPOSE: We determined the advantages and disadvantages of different types of contrast medium injection into the bladder for imaging children during evaluation for urinary tract infection in regard to child behavior and distress during urethral catheterization or suprapubic puncture. MATERIALS AND METHODS: From December 2000 to September 2001 we prospectively compared transurethral catheter and suprapubic voiding cystourethrography in children with a history of urinary tract infection. A total of 65 children with a mean age of 33.8 months were entered into the study, of whom 32 underwent transurethral catheterization and 33 underwent suprapubic puncture with topical anesthesia. Each child was evaluated, particularly in regard to discomfort and pain using an objective pain score that measures stress and pain during a medical procedure. RESULTS: Objective pain score recording showed a mean pain score plus or minus SD of 4.25 +/- 1.3 in the transurethral catheterization and 3.03 +/- 1.21 in the suprapubic puncture groups. Correlation studies of age in the 2 groups also showed a significant impact of age on the objective pain score. In the transurethral group the score increased with age (p <0.001), whereas in the suprapubic group it decreased with age (p <0.001). CONCLUSIONS: The current study shows that the suprapubic puncture technique with topical anesthesia was well tolerated and associated with a low pain score independent of patient age. Transurethral catheterization was also tolerated but it was associated with a low pain score only in the younger age group. Thus, we recommend that voiding cystourethrography in children older than 24 months should be done via the suprapubic route.     

Repeated transurethral resection of recurrent superficial bladder tumors--does it affect the spread and stage of the tumor?

OBJECTIVES: This prospective study was done to demonstrate the effect of repeated resection of superficial bladder tumors (TURT) on deep malignant cell infiltration in bladder wall. MATERIAL AND METHODS: Thirty-six patients underwent radical cystectomy for invasive bladder cancer, 16 patients originally had superficial cancer that became invasive after repeated TURT (group I) and the other 20 patients (group II) presented with invasive bladder cancer from the start. Each cystectomy specimen was subjected to a thorough histopathological study. RESULTS: There was a statistically significant difference in pattern of local spread of malignant cells between the two groups. Isolated clusters of malignant cells in-between normal bladder muscle fibers, isolated subserosal malignant deposits as well as cells reaching the adjacent cervix uteri were found only in group I. Intravesical pressure was measured in another 10 patients during TURT and was found to be high reaching up to 80 cm H2O. CONCLUSIONS: We conclude that some malignant cells penetrate through the denuded urothelium during TURT by the effect of high intravesical pressure. This may be responsible, among other factors, for tumor recurrence with deeper stages.     

Impact of cardiac surgery using cardiopulmonary bypass on course of chronic lymphatic leukemia: a case-control study

BACKGROUND: Chronic lymphatic leukemia (CLL) is a common disease among elderly individuals. The number of older patients undergoing operations with cardiopulmonary bypass (CPB) is increasing. The aim of the present study was to evaluate the impact of cardiac surgery using CPB on the long-term course of CLL. METHODS: From 1992 to 2000, a total of 28 patients with CLL underwent heart surgery using CPB at our institution (group I). These patients were compared with 25 patients from the CLL register who were retrospectively matched with regard to preoperative administration of chemotherapy, Binet classification, age, and sex (group II). A time-point was selected for each patient in group II so that the variables for the two groups corresponded in relation to the time of operation of the patients in group I. Midterm follow-up data in both groups were analyzed. RESULTS: There were no differences between groups regarding matched variables. The mean follow-up time was similar in both groups (2.6 +/- 2.2 vs 2.3 +/- 1.3 years, p > 0.5). The 30-day mortality in group I was 14.3%. The mean stay in the intensive care unit was 4.2 +/- 7.5 days; the median number of units of packed red blood cells transfused was three (range 0 to 17). Compared with group II, in group I significantly fewer patients (11 vs 17, p = 0.049) required chemotherapy significantly later (1.98 +/- 2.06 vs 0.84 +/- 1.18 years, p = 0.018). During follow-up, no difference was found between groups regarding severe infections (10 vs 14, p = 0.14). Despite postoperative mortality in group I, the long-term mortality was similar in both groups (p = 0.3). CONCLUSIONS: Cardiac surgery using CPB did not have a negative impact on the natural course of CLL. Moreover, this procedure seems to be associated with a decrease in the number of postoperative chemotherapy administrations and with an increase of chemotherapy-free survival time. Although CLL may be a risk factor in the early postoperative period, it is not a contraindication for cardiac surgery using CPB.     

Assessment of transport rates of proteins and peptides across primary human alveolar epithelial cell monolayers.

In this study, we investigated bi-directional fluxes (i.e., in absorptive and secretive directions) of human serum proteins [albumin (HSA), transferrin (TF), and immunoglobulin G (IgG)] and peptides/proteins of potential therapeutic relevance [insulin (INS), glucagon-like peptide-1 (GLP-1), growth hormone (GH), and parathyroid hormone (PTH)] across tight monolayers of human alveolar epithelial cells (hAEpC) in primary culture. Apparent permeability coefficients (P(app); x10(-7)cm/s, mean+/-S.D.) for GLP-1 (6.13+/-0.87 (absorptive) versus 1.91+/-0.51 (secretive)), HSA (2.45+/-1.02 versus 0.21+/-0.31), TF (0.88+/-0.15 versus 0.30+/-0.03), and IgG (0.36+/-0.22 versus 0.15+/-0.16) were all strongly direction-dependent, i.e., net absorptive, while PTH (2.20+/-0.30 versus 1.80+/-0.77), GH (8.33+/-1.24 versus 9.02+/-3.43), and INS (0.77+/-0.15 versus 0.72+/-0.36) showed no directionality. Trichloroacetic acid precipitation analysis of tested molecules collected from donor and receiver fluids exhibited very little degradation. This is the first study on permeability data for a range of peptides and proteins across an in vitro model of the human alveolar epithelial barrier. These data indicate that there is no apparent size-dependent transport conforming to passive restricted diffusion for the tested substances across human alveolar barrier, in part confirming net absorptive transcytosis. The obtained data differ significantly from previously published reports utilising monolayers from different species. It can be concluded that the use of homologous tissue should be preferred to avoid species differences.     

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.     

Differential gene expression in peripheral blood lymphocytes of cancer patients treated with whole body hyperthermia and chemotherapy: a pilot study.

PURPOSE: The effect of whole body hyperthermia (WBH) at 41.8-42 degrees C on the cellular immune system is still poorly investigated. The aim of this study was to identify genes that become upregulated in peripheral blood lymphocytes (PBLs) of cancer patients during a combined treatment with WBH and chemotherapy by generating complex arrays of cDNA. METHODS: PBLs were obtained from four patients with different malignancies treated with WBH and varying cytostatic schedules before treatment and immediately thereafter. After constructing subtracted cDNA libraries, clones were screened for cDNA induction by dot-blot and semi-quantitative RT-PCR (sq-RT-PCR). RESULTS: Among 192 clones, 39 cDNAs were significantly upregulated. Sequencing revealed three groups of genes for which upregulation of mRNA was confirmed by sq-RT-PCR. The first group consisted of genes encoding for various heat shock proteins (HSP 60, 90a, 90b, 105). Further sq-RT-PCR demonstrated differential expression of HSP27 and HSP70 as well. The second group (calcyclin-binding-protein, haemoglobin-beta-chain) comprised genes without pre-specified association to hyperthermia. The cDNA encoding macrophage-inflammatory-protein-1-beta was also observed and may be associated with the pre-described activation of lymphocyte sub-populations during WBH. CONCLUSION: Treatment with WBH and chemotherapy elicits significant short-term effects on the expression of a variety of genes responsible for cellular integrity, stimulation and migration of immune effector cells. Further investigation is warranted to more clearly define the role of those genes for the clinical effect of WBH.     

Preservation of periprostatic autonomic nerves during total perineal prostatectomy by intrafascial dissection

A modification of Young's total perineal prostatectomy technique is described to prevent damage to the apical branches of the cavernous nerves. Based on anatomic relationships between investing prostatic fascial layers and the neurovascular bundle, emphasis is placed on division of the apical prostatic urethra between the anterolateral endopelvic fascia and Denonvilliers fascia (intrafascial dissection) in avoidance of the apical nerves. Vertical incision in the fused distal portion of Denonvilliers fascia is necessary to make this dissection atraumatic regarding the adjacent paraprostatic neurovascular bundle. Clinical application of this completely intrafascial prostatic dissection is exemplified. It is concluded that careful modification of Young's technique of total perineal prostatectomy may result in increased postoperative potency rates.