pH sensing in skin tumors: Methods to study the involvement of GPCRs,acid-sensing ion channels and transient receptor potential vanilloid channels

Solid tumors exhibit an inversed pH gradient with increased intracellular pH (pH_i) and decreased extracellular pH (pH_e). This inside-out pH gradient is generated via sodium/hydrogen antiporter 1, vacuolar-type H + ATPases, monocarboxylate transporters, (bi)carbonate (co)transporters and carboanhydrases. Our knowledge on how pH_e-signals are sensed and what the respective receptors induce inside cells is scarce. Some pH-sensitive receptors (GPR4, GPR65/TDAG8, GPR68/OGR1, GPR132/G2A, possibly GPR31 and GPR151) and ion channels (acid-sensing ion channels ASICs, transient receptor potential vanilloid receptors TRPVs) transduce signals inside cells. As little is known on the expression and function of these pH sensors, we used immunostainings to study tissue samples from common and rare skin cancers. Our current and future work is directed towards investigating the impact of all the pH-sensing receptors in different skin tumors using cell culture techniques with selective knockdown/knockout (siRNA/CRISPR-Cas9). To study cell migration and proliferation, novel impedance-based wound healing assays have been developed and are used. The field of pH sensing in tumors and wounds holds great promise for the development of pH-targeting therapies, either against pH regulators or sensors to inhibit cell proliferation and migration.     

Indoor 222Rn levels in New York State, North Carolina, and South Carolina

Results are presented from approximately 9000 Rn measurements made in New York state, North Carolina, and South Carolina. The estimated statewide geometric mean concentrations were 28.1 Bq m-3 and 55.8 Bq m-3 for basements in New York state, 27.5 Bq m-3 for living rooms and 108.9 Bq m-3 for basements in North Carolina, and 25.0 Bq m-3 for living rooms in South Carolina.     

Epithelial permeability in corneal grafts by fluorophotometry

The epithelial permeability to fluorescein of 27 clear corneal grafts in 23 patients was determined by fluorophotometry at > 1 year after penetrating keratoplasty (PKP) so as to study the recovery of corneal epithelial function. The mean epithelial permeability of the corneal grafts did not differ significantly from that of normal corneas (0.042 ± 0.016 and 0.038 ± 0.017 nm/s, respectively; P>0.3). Multiple linear regression analysis showed that permeability correlated with recipient age but not with donor age (permeability increase, 0.00054 nm/s per year; r=0.6, P<0.005 and r=0.1, P>0.5, respectively). These results indicate that corneal grafts can regain a normal epithelial barrier function and that recovery of epithelial function is better in young than in old recipients. Offprint requests to: J.A. van BestSupported by the Stichting Blindenpenning, the Stichting Vrienden van het Oogziekenhuis, the Stichting Blindenhulp and the Diabetes Fonds Nederland     

Prehospital versus hospital fibrinolytic therapy using automated versus cardiologist electrocardiographic diagnosis of myocardial infarction: abortion of myocardial infarction and unjustified fibrinolytic therapy

Background

This study investigated the incidence of abortion of myocardial infarction and of unjustified fibrinolysis by using automated versus cardiologist-assisted diagnosis of acute ST-elevation myocardial infarction. The results of prehospital diagnosis and treatment (2 cities in the Netherlands) were compared with those of inhospital treatment. Unjustified fibrinolysis must be differentiated from justified thrombolysis resulting in aborted myocardial infarction. Both have the absence of a significant rise in cardiac enzymes in common. In aborted myocardial infarction, this is a result of timely reperfusion; in unjustified thrombolysis, this is the result of an incorrect diagnosis.

Methods

In the city of Rotterdam, 118 patients were treated before hospitalization for myocardial infarction, diagnosed through the use of a mobile computer electrocardiogram; in the city of Nijmegen, 132 patients were treated before hospitalization with the use of transtelephonic transmission of the electrocardiogram to the coronary care unit and judged by a cardiologist. Their data were compared with those of 269 patients treated inhospital in the city of Arnhem, using the same electrocardiographic criteria. Abortion of myocardial infarction was diagnosed as the absence of a significant rise in cardiac enzymes and the presence of resolution of chest pain and 50% of ST-segment deviation within 2 hours after onset of therapy. Lacking these, the diagnosis of unjustified fibrinolytic therapy was made.

Results

Unjustified treatment occurred in 8 (3.2%) prehospital-treated patients (4 in Rotterdam and 4 in Nijmegen). Of the inhospital-treated patients in Arnhem, 5 (1.9%) were treated unjustifiably (P = .49). Aborted myocardial infarction occurred in 15.3% and 18.2% in Rotterdam and Nijmegen, respectively, against 4.5% in inhospital treatment in Arnhem (P < .001).

Conclusions

Abortion of myocardial infarction is associated with prehospital thrombolysis. Unjustified fibrinolysis for acute myocardial infarction occurs in prehospital fibrinolysis as frequently as in the inhospital setting. The use of different electrocardiographic methods for diagnosing acute myocardial infarction does not appear to make any difference.     

Corneal endothelial permeability and aqueous humor dynamics in normal pressure glaucoma

Corneal endothelial permeability and aqueous humor dynamics were studied in 17 non-treated normal pressure glaucoma patients in order to analyse the relevance of these parameters in the pathophysiology of this disease. Corneal endothelial permeability and aqueous humor flow were measured by fluorophotometry and aqueous outflow facility was determined by tonography. The results were compared with those of 17 healthy controls of similar age. The mean corneal endothelial permeability values and the aqueous flow and outflow facility values of the patients did not differ significantly from those of the healthy controls (P=0.8, P=0.2 and P=0.5, respectively). Normal pressure glaucoma does not affect the corneal endothelial permeability. The aqueous humor dynamics are not primarily involved in the pathophysiology of normal pressure glaucoma.Abbreviations IOP intraocular pressure - NPG normal pressure glaucoma - POAG primary open-angle glaucoma Part of this study was presented at the Annual Meeting of the Association for Eye Research on September 16, 1993 in Granada, Spain     

Cumulative probability of achieving an ongoing pregnancy after in-vitro fertilization and intracytoplasmic sperm injection according to a woman's age, subfertility diagnosis and primary or secondary subfertility

The aim of this study was to estimate reliable cumulative probabilities of achieving an ongoing pregnancy after successive in-vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI) cycles, according to a woman's age, subfertility diagnosis and primary or secondary subfertility. Therefore reasons for quitting treatment without achieving an ongoing pregnancy were taken into account. Moreover, we studied whether there were trends in cumulative probabilities after adjustment for potential confounding effects of the other two characteristics, duration of subfertility, year of first treatment and reason for quitting treatment. In total, 2984 IVF/ICSI cycles were performed in 1315 couples at the University Hospital Nijmegen, The Netherlands, between 1991 and 1998. The 'realistic' cumulative probability of achieving an ongoing pregnancy was 54.5% after five consecutive IVF/ICSI cycles, which was about 10% lower (absolute value) than the optimistic probability calculated by life-table analysis and about 10% higher (absolute value) than the most pessimistic estimate. Women of 35 years or younger had a higher probability of achieving an ongoing pregnancy than the older women. As ICSI is now an option, there were no obvious differences between the subfertility diagnosis subgroups. The cumulative probability after the first two IVF/ICSI cycles was higher in women with secondary subfertility than in those with primary subfertility; this advantage disappeared after further treatment. These trends remained valid after adjustment for confounding factors.     

A more realistic approach to the cumulative pregnancy rate after in-vitro fertilization

As most studies overestimate the cumulative pregnancy rate,a method is proposed to estimate a more realistic cumulativepregnancy rate by taking into account the reasons for an earlycessation of treatment with in-vitro fertilization (IVF). Threemethods for calculating cumulative pregnancy rates were compared.The first method assumed that those who stopped treatment hadno chance at all of pregnancy. The second method, the one usedmost often, assumed the same probability of pregnancy for thosewho stopped as for those who continued. The third method assumedthat only those who stopped treatment, because of a medicalindication, had no chance at all of pregnancy and that the otherswho stopped had the same probability of pregnancy as those whocontinued treatment Data were used from 616 women treated atthe University Hospital Nijmegen, Nijmegen, The Netherlands.The cumulative pregnancy rates after five initiated IVF cyclesfor the three calculation methods were in the ranges 37–51%for the positive pregnancy test result, 33–55% for a clinicalpregnancy and 30–56% for an ongoing pregnancy. As expected,the first method underestimated the cumulative pregnancy rateand the second overestimated it The third method produced themost realistic cumulative pregnancy rates.