Scopolamine patch to prevent seasickness: clinical response vs. plasma concentration in sailors

INTRODUCTION: Scopolamine is highly effective for the treatment of seasickness. Nevertheless, transdermal therapeutic system (TTS) scopolamine, despite high compliance on the part of persons treated by the drug, fails to provide protection against seasickness in 26-38% of patients. To the best of our knowledge, the correlation between scopolamine levels in plasma and its therapeutic effect under sailing conditions in the open sea is investigated for the first time in the present study. METHODS: Subjects were 61 crewmembers of naval vessels treated by TTS scopolamine. The therapeutic response at sea was documented by questionnaire. During a period ashore, a TTS scopolamine patch was applied in the same subjects. Blood samples were taken and an adverse effects questionnaire completed 8 h after scopolamine patch application. Scopolamine levels were determined using an established radio-receptor assay procedure. To verify the reproducibility of these measurements, blood samples were taken twice from most subjects, on separate days after different patch applications. Subjects were divided into "responders," who reported at least a moderate decrease in seasickness severity compared with their previous experience at sea without TTS scopolamine therapy, and "non-responders," who had only slight symptomatic relief or no relief at all. RESULTS: The mean scopolamine concentration in the plasma of the 37 responders (156.77 +/- 77.03 pg x ml(-1)) was significantly higher than the mean level in the 24 non-responders (97.03 +/- 73.34 pg x ml(-1); p = 0.005, simple t-test). CONCLUSIONS: Attempts to increase scopolamine levels in plasma by increasing the drug dosage or improving transdermal absorption should be considered for the treatment of "non-responders".     

Calcineurin Abeta is central to the expression of the renal type II Na/Pi co-transporter gene and to the regulation of renal phosphate transport

The sensing and response to extracellular phosphate (Pi) concentration is preserved from prokaryotes to mammals and ensures an adequate supply of Pi in the face of large differences in its availability. In mammals, the kidneys are central to Pi homeostasis. Renal Pi reabsorption is mediated by a Na/Pi co-transporter that is regulated by a renal Pi sensing system and humoral factors. The signal transduction by which Pi regulates type II Na/Pi activity is largely unknown. It is shown that calcineurin inhibitors specifically and dramatically decrease type II Na/Pi gene expression in a proximal tubule cell line and in vivo. Mice with genetic deletion of the calcineurin Abeta gene had a marked decrease in type II Na/Pi mRNA levels and remarkably did not show the expected increase in type II Na/Pi mRNA levels after the challenge of a low-Pi diet. In contrast, the regulation of renal 25(OH)-vitamin D 1alpha-hydroxylase gene expression by Pi was intact. This is the first demonstration that calcineurin has a crucial role in the signal transduction pathway regulating renal Pi homeostasis both in vitro and in vivo. These results suggest that the use of calcineurin inhibitors contributes to the renal Pi wasting seen in renal transplant patients.     

Hyperbaric oxygen in the treatment of sudden deafness

Currently, the treatment of sudden deafness (SD) is based mainly on complete bed rest and the administration of corticosteroids. Hyperbaric oxygen therapy (HBOT) has previously been suggested as adjunctive treatment. We describe two cases of successful HBOT for SD. The first patient presented with moderate mid-frequency hearing loss without accompanying symptoms, whereas the second patient had moderate low-frequency hearing loss with persistent tinnitus and a single episode of vertigo. HBOT in addition to conventional treatment soon after diagnosis resulted in full recovery of hearing in both patients. The pathogenesis of SD may involve a reduction in cochlear blood flow and perilymph oxygenation, making early HBOT a reasonable treatment modality for this condition.     

Dose-dependent bioavailability of tetracycline in man

Seven healthy male volunteers were administered, on different occasions, one, two, and three capsules of two commercially available brands (A and B) each containing 250 mg tetracycline HCl. Urinary excretion rates and cumulative amounts of drug excreted in the urine in 4 days were used to assess the bioavailability of the two brands at the different doses studied. The rate constants of absorption and elimination of tetracyline were similar at all dose levels. However, the extent of absorption (F)appears to be dependent on the brand, dose, and volume of water ingested with the drug. Fof Brand B was not significantly different than that of brand A at the 250-mg dose but was decreased by 23.3% (p<0.01)at the 500-mg dose and by 19.7% (p <0.05) at the 750-mg dose. With respect to dose, Fof each brand at the 500-mg dose was not significantly different than its value at the 250-mg dose. However, Fof brand A at the 750-mg dose was reduced by 14.8% (p <0.05) and that of brand B by 21.1% (p <0.05) relative to their respective values at the single dose. Surprisingly, when the 750-mg dose of brand A was ingested with a small volume of water, Fwas increased by 18.9% (p <0.05) compared to the ingestion of the identical dose of the same brand under waterloading conditions.     

Pharmacolinetics of fluorocarbon 11 and 12 in dogs and humans.

Blood levels and exhalation bag contents of FC-11 and FC-12 from dogs and humans were used to elucidate the pharmacokinetic model describing the time-course of these agents. The derived pharmacokinetic parameters were in good agreement with the physicochemical properties of these substances. The model was used to estimate the percentage of dose absorbed, which averaged 77 per cent for FC-11 and 55 per cent for FC-12, and to predict the level of FC-11 and FC-12 under a variety of conditions simulating both short- and long-term exposure to the maximum allowable concentrations of these agents. With similar doses, an 8-hour continuous exposure was estimated to produce levels of FC-11 and FC-12 that are much lower than the corresponding levels reported to induce cardiac sensitization in dogs.     

Organ donation and priority points in Israel: an ethical analysis

Israel's rates of organ donation have been one of the lowest among developed countries. An attempt to change this has led to the introduction of a pioneering new law, the Organ Transplant Act 2008, which came into effect in January 2010 and sets out principles underlying a new policy in relation to the allocation of organs for transplantation. According to this policy, a person can gain priority points by signing a donor card, making a nondirected organ donation during their lifetime, or as a result of a first-degree relative signing a donor card, or consenting to procurement of organs after death. In this opinion piece, we argue that although this approach merits attention for its innovative aspects and its potential benefits, it raises some ethical difficulties. In particular, we discuss some problems of justice and fairness inherent in the system, focusing on inequalities because of the (a) number of relatives one might have, (b) the type of living donation one makes, (c) the potential for strategic behavior, and (d) problems regarding the consent of family members.     

BRCA1/2 mutations and FMR1 alleles are randomly distributed: a case control study

BRCA mutation carriers were reported to display a skewed distribution of FMR1 genotypes, predominantly within the low normal range (CGG repeat number <26). This observation led to the interpretation that BRCA1/2 mutations are embryo-lethal, unless rescued by ‘low FMR1 alleles''. We undertook to re-explore the distribution of FMR1 alleles subdivided into low, normal and high (<26, 26–34, and >34 CGG repeats, respectively) subgenotypes, on a cohort of 125 Ashkenazi women, carriers of a BRCA1/2 founder mutation. Ashkenazi healthy females (n=368), tested in the frame of the Israeli screening population program, served as controls. BRCA1/2 carriers and controls demonstrated a comparable and non-skewed FMR1 subgenotype distribution. Taken together, using a homogeneous ethnic group of Ashkenazi BRCA1/2 mutation carriers, we could not confirm the reported association between FMR1 low genotypes and BRCA1/2 mutations. The notion that BRCA1/2 mutations are embryo-lethal unless rescued by the low FMR1 subgenotypes is hereby refuted.     

Real-world data on incidence,clinical characteristics and outcome of patients with macrofocal multiple myeloma (MFMM) in the era of novel therapies: A study of the Greco-Israeli collaborative myeloma working group

We investigated incidence, characteristics and outcome of patients with macrofocal multiple myeloma (MFMM) treated mainly with novel therapies. Based on definition (BMPCs <20% and lytic lesions/plasmacytomas, without anemia, renal insufficiency or hypercalcemia) we identified 140 patients with MFMM, among 4650 myeloma patients (3%). Twice the number of patients with typical myeloma were used as controls; 60% were <65 years and 70% had advanced bone disease. Plasmacytomas were more frequent in MFMM compared with standard myeloma (68% vs 15%, P < .05). Adverse prognostic parameters (high lactate dehydrogenase, advanced stage, high risk cytogenetics, immunoparesis) were less common in patients with MFMM compared with controls (P < .05); 90% received novel agents and 47% underwent autologous transplantation upfront; 90% achieved an objective response; 70% had at least very good partial response which was significantly higher compared with controls (P < .05). After a median follow-up of 52 months, 33 patients have died. Early death (<12 months) was infrequent in MFMM. Median progression-free survival and overall survival (OS) were 46 and 129 months respectively, both significantly longer compared with controls (P < .001). Proteasome inhibitor (PI)-based therapy was the only independent predictor for OS in the multivariate analysis (HR: 3.9; P < .001). In conclusion, MFMM is a distinct entity presented in young and elderly subjects, characterized by limited bone marrow infiltration, advanced bone disease and frequent presence of plasmacytomas; MFMM patients have less often adverse prognostic features and achieve excellent responses and prolonged OS especially when treated with PI-based therapies. Novel imaging will help in a more accurate classification of this entity.