5-HT-receptor-induced changes of the intracellular cAMP level monitored by a hyperpolarization-activated cation channel

The HvCNG channel from the moth Heliothis virescens is highly sensitive to cAMP concentrations ranging between 0.1 microM and 5 microM. This HvCNG channel was over-expressed in Spodoptera frugiperda (Sf.9) cells to measure endogenous cAMP levels. Hyperpolarization-activated inward currents were measured in the whole-cell patch-clamp configuration with pipettes filled with different cAMP concentrations to calibrate the system. Varying the cAMP concentration between 0 microM and 100 microM in the pipette, the half-maximal activation voltage ( V1/2) was shifted by +28.5+/-1.7 mV. The activation time constant (tau(a)) was used as a parameter for cAMP quantification because it was independent of the expression level of HvCNG channels. tau(a) changed from 1106+/-60 ms at 0 microM cAMP to 265+/-7 ms at a saturating concentration of 1 mM cAMP. A dose-response relationship yielded values of 0.6 microM for the half-maximal cAMP concentration and 1.5 for the Hill coefficient. Activation of endogenous adenylyl cyclases by 50 microM forskolin induced an elevation of the cAMP level by about 1.6+/-0.2 microM. Co-expressions of HvCNG channels in combination with the mouse 5-HT4a- or 5-HT1A- receptors and the corresponding Gs- or Gi-proteins were successful and allowed us to also verify receptor-induced changes of the cAMP level. Stimulation of m5-HT4a-receptors by 0.1 microM 5-HT induced an increase of cAMP of about 4.6+/-1.5 microM, whereas cAMP levels decreased from a control value of 1+/-0.2 microM to 0.41+/-0.1 microM after stimulation of the m5-HT1A-receptors.     

Schwangerschaft. Fehlgeburt. Geburt. Kindesmord

Ohne Zusammenfassung     

Aggressive therapy of infants with renal failure

Nine infants, who presented with renal failure within the first 3 months of life, were treated with continuous ambulatory peritoneal dialysis (CAPD). Seven infants survived to an age of 12–15 months, when they received transplants. Two patients died while on CAPD. Six infants are alive with a functioning renal allograft, at an average age of 35.5 months and an average of 22 months post-transplant. Neurological development is normal in four of the six infants tested. The mean current height of the six transplant recipients is just below 2 SD from the mean.     

Important risk factors of allograft survival in cadaveric renal transplantation. A study of 426 patients.

Multiple risk factors contribute to the allograft survival of patients who have cadaveric renal transplantation. A retrospective review of 19 such factors in 426 patients identified race, DR match, B + DR match, number of transplants, and preservation time to have a significant influence. The parametric analysis confirmed the effect to be primarily in the early phase, i.e., first 6 months. All patients received cyclosporine with other methods of immunosuppression resulting in an overall 1-year graft survival rate of 66%. The overall 1-year graft survival rate in the white race was 73% and in the black race was 57% (p = 0.002). Allograft survival and DR match showed white recipients with a 1 DR match to have 75% survival at 1 year compared with 57% in the black patient (p = 0.009). If HLA B + DR match was considered, the white recipient allograft survival increased to 76%, 84%, and 88% for 1, 2, and 3 match kidneys by parametric analysis. Patients receiving first grafts had better graft survival (68%) than those undergoing retransplantation (58%) (p = 0.05). Organ preservation less than 12 hours influenced allograft survival with a 78% 1-year survival rate compared with 63% for kidneys with 12-18 hours of preservation. Despite the benefits of B + DR typing, short preservation time, and first transplants to the white recipient, the allograft survival in the black recipient remained uninfluenced by these parameters.     

Benefits of quadruple immunosuppressive therapy in recipients of living related donor kidneys. A review of 855 operations.

Eight hundred fifty-five living related donor transplant recipients were analyzed according to 15 potential risk factors with regard to patient and graft survival according to immunosuppression. Group I, 1968 to 1983, (n = 440 patients) received azathioprine and prednisone; group II, 1984 to 1987, (n = 229 patients) received triple therapy--azathioprine, prednisone, and cyclosporine; and group III, 1988-1991, (n = 186 patients), quadruple therapy--azathioprine, prednisone, cyclosporine, and Minnesota antilymphocyte globulin. Three important risk factors included immunosuppression, tissue typing, and race. Groups II and III had improved allograft survival over group I (p = 0.03). Patients with two haplotype matches had similar survival in all three groups. Kidney survival in one-haplotype-matched recipients improved in group II and was equal to that of the two-haplotype-matched patients in group III. Cyclosporine improved allograft survival in both races when combined with azathioprine and prednisone. Quadruple therapy improved early survival in one-haplotype black patients, even though long-term results remained better in whites. Cyclosporine did not improve graft survival in two-haplotype recipients. The addition of cyclosporine and quadruple therapy did not increase morbidity and mortality rates.     

Renal transplant hypertension caused by iliac artery stenosis.

A captopril renal study performed with both radiohippuran and 99mTc-MAG3 demonstrated the typical changes of a hemodynamically significant renal artery stenosis in a hypertensive renal allograft recipient. Arteriography demonstrated high grade stenosis not of the renal artery but of the iliac artery. After successful angioplasty, the patient's hypertension resolved.     

Effect of statins combined with estradiol on the proliferation of human receptor-positive and receptor-negative breast cancer cells

OBJECTIVE: Combination of a statin plus estrogen may reveal benefits on the cardiovascular system in postmenopausal women by additively ameliorating both the lipid profile and vascular function. Long-term therapy with estrogens, however, is associated with an increase of breast cancer risk. In contrast, evidence is accumulating that statins may inhibit carcinogenesis because of their central action on important cellular functions. It is of special clinical interest whether a statin/estrogen combination may reduce the most undesired side effect of estrogen therapy, that is, an increase in breast cancer risk. Therefore, in the present in vitro study, for the first time we have compared the effect of five statins on the proliferation of human breast cancer cells alone and in the presence of stimulatory estradiol (E(2)). DESIGN: As cell models, the receptor-positive cell line MCF-7 and the receptor-negative cell line MDA-MB 231 were used. The statins atorvastatin, fluvastatin, lovastatin, pravastatin, and simvastatin were tested in the concentration range of 1.6 microm to 50 microm alone and in the range of 0.01 nm to 10 microm in combination with E(2). Cell proliferation was measured after 4 days by the adenosinetriphosphate-chemosensitivity test. RESULTS: All statins except pravastatin were able to significantly inhibit dose dependently the cell proliferation of both cell lines. The inhibitory values were between 10% and 90%, whereby the potency was greater in the case of receptor-negative cancer cells. A significant difference in the efficacy of the statins was observed for MCF-7 cells, in which atorvastatin was less effective than the other statins. In contrast, in the presence of E(2), the statins showed similar antiproliferative actions in MCF-7 cells when tested in the concentration range of 0.01 nm to 10 microm. A reduction of cell proliferation of less than 10% was observed at the lower concentrations and between 15% and 25% at the highest concentration of 10 microm. CONCLUSIONS: The present data indicate that statins can inhibit the proliferation of receptor-positive and -negative human breast cancer cells but failed to completely abrogate the E(2)-induced proliferation of receptor-positive breast cancer cells. Clinical trials, however, are necessary to prove this anticarcinogenic action of statins.     

Baseline Assessment of Circulating MicroRNAs Near Diagnosis of Type 1 Diabetes Predicts Future Stimulated Insulin Secretion

Type 1 diabetes is an autoimmune disease resulting in severely impaired insulin secretion. We investigated whether circulating microRNAs (miRNAs) are associated with residual insulin secretion at diagnosis and predict the severity of its future decline. We studied 53 newly diagnosed subjects enrolled in placebo groups of TrialNet clinical trials. We measured serum levels of 2,083 miRNAs, using RNA sequencing technology, in fasting samples from the baseline visit (<100 days from diagnosis), during which residual insulin secretion was measured with a mixed meal tolerance test (MMTT). Area under the curve (AUC) C-peptide and peak C-peptide were stratified by quartiles of expression of 31 miRNAs. After adjustment for baseline C-peptide, age, BMI, and sex, baseline levels of miR-3187-3p, miR-4302, and the miRNA combination of miR-3187-3p/miR-103a-3p predicted differences in MMTT C-peptide AUC/peak levels at the 12-month visit; the combination miR-3187-3p/miR-4723-5p predicted proportions of subjects above/below the 200 pmol/L clinical trial eligibility threshold at the 12-month visit. Thus, miRNA assessment at baseline identifies associations with C-peptide and stratifies subjects for future severity of C-peptide loss after 1 year. We suggest that miRNAs may be useful in predicting future C-peptide decline for improved subject stratification in clinical trials.     

Challenges and Opportunities for Real-World Evidence in Metastatic Luminal Breast Cancer

BackgroundThe therapeutic armamentarium for patients with metastatic breast cancer is becoming more and more specific. Recommendations from clinical trials are not available for all treatment situations and patient subgroups, and it is therefore important to collect real-world data.SummaryTo develop recommendations for up-to-date treatments and participation in clinical trials for patients with metastatic breast cancer, the Prospective Academic Translational Research PRAEGNANT Network was established to optimize the quality of oncological care in the advanced therapeutic setting. The main aim of PRAEGNANT is to systematically record medical care for patients with metastatic breast cancer in the real-life setting, including the outcome and side effects of different treatment strategies, to monitor quality-of-life changes during therapy, to identify patients eligible for participation in clinical studies, and to allow targeted therapies based on the molecular structures of breast carcinomas.Key MessagesThis article describes the PRAEGNANT network and sheds light on the question of whether the various end points from clinical trials can be transferred to the real-world treatment situation.