Effect of thirst challenge on ADH levels in patients with bilateral Menière's disease

The aim of the study was to investigate plasma ADH levels and plasma/urine osmolality in patients suffering from bilateral Menière's disease since a disturbance in the water household after thirst challenge is a suspected pathogenic factor in the development of this disease. In this study the plasma ADH levels and plasma/urine osmolality of bilateral Menière's disease patients under thirst challenge were investigated to show whether the water balance is affected. 9 patients with bilateral Menière's disease and 9 healthy controls skipped water intake for 12 h. Plasma ADH, plasma/urine osmolality, and electrolytes were measured after this thirst period as well as 8 h later after food and fluid intake. During food and fluid intake the patients demonstrated a slightly higher plasma ADH level and plasma osmolality than controls, whereas at the end of the thirst period patients and the controls showed no significant change. Instead the urine osmolality differed significantly (p<0.001): showing a high urine osmolality in controls and an almost stable urine osmolality in patients after thirst challenge. This indicates that the water balance in patients is likely different from that of controls. These observations point to ADH and its target aquaporine 2 as keyplayers in the pathophysiological events leading to the development of Menière's disease.     

Incorporation of Copper-Doped Mesoporous Bioactive Glass Nanospheres in Experimental Dental Composites: Chemical and Mechanical Characterization

Experimental dental resin composites incorporating copper-doped mesoporous bioactive glass nanospheres (Cu-MBGN) were designed to impart antibacterial and remineralizing properties. The study evaluated the influence of Cu-MBGN on the mechanical properties and photopolymerization of resin composites. Cu-MBGN were synthesized using a microemulsion-assisted sol–gel method. Increasing amounts of Cu-MBGN (0, 1, 5, and 10 wt %) were added to the organic polymer matrix with inert glass micro- and nanofillers while maintaining a constant resin/filler ratio. Six tests were performed: X-ray diffraction, scanning electron microscopy, flexural strength (FS), flexural modulus (FM), Vickers microhardness (MH), and degree of conversion (DC). FS and MH of Cu-MBGN composites with silica fillers showed no deterioration with aging, with statistically similar results at 1 and 28 days. FM was not influenced by the addition of Cu-MBGN but was reduced for all tested materials after 28 days. The specimens with 1 and 5% Cu-MBGN had the highest FS, FM, MH, and DC values at 28 days, while controls with 45S5 bioactive glass had the lowest FM, FS, and MH. DC was high for all materials (83.7–93.0%). Cu-MBGN composites with silica have a potential for clinical implementation due to high DC and good mechanical properties with adequate resistance to aging.     

Our experience with epoetins in treating renal anemia

Epoetin treatment of renal anemia has been practiced in Slovenia since 1988. More than 90% of hemodialysis patients and 83% of peritoneal dialysis patients have been treated with epoetin. Epoetin has also been available for patients with renal anemia in the pre-dialysis period and for those with a failing kidney allograft. Although epoetin treatment did not accelerate the worsening of native kidney function or allograft function, intensified antihypertensive treatment was required in kidney graft recipients. In patients on peritoneal dialysis, hypervolemia had a greater effect on hypertension than did epoetin treatment. Epoetin resistance was connected with C-reactive peptide cryptorchidism, intact parathyroid hormone, and treatment with angiotensin-converting enzyme inhibitors. In hemodialysis patients, lower doses of epoetin were required for patients receiving low molecular heparin and those with lower iPTH. Epoetin alpha, epoetin beta and epoetin omega seemed to be effective and safe in the treatment of renal anemia. In the past 2 years, epoetins were administered to hemodialysis patients only intravenously.     

Platelet sialic acid as a potential pathogenic factor in coronary heart disease

It was previously reported that, compared to healthy individuals, patients with coronary heart disease (CHD) exhibit a higher proportion of platelets with lower densities and higher propensity to aggregate. Reasons for this increased tendency to aggregate were unknown but appeared to be independent of the patient's age, gender, or smoking habits. Sialic acid (N-acetyl-neuraminic acid), a negatively charged sugar and constituent of many glycoproteins and gangliosides, is known to confer the bulk of negative charges to mammalian cell surfaces. These negatively charged surfaces can help cells of the bloodstream to maintain a relative distance from each other due to repulsion of the same (negative) charges. In this study, we examined whether differences in platelet sialic acid are a potential pathogenic factor in patients with coronary heart disease. Upon isolating platelets, we found a significantly higher (p < 0.05) proportion of low density platelets in patients compared to healthy controls, which is in accordance with previously published data. We found significantly less (p < 0.05) sialic acid in platelets from patients compared to the control. Most of the platelet total sialic acid was susceptible to cleavage by neuraminidase, demonstrating sialic acid to be preferably localized at the outer platelet surface. We conclude that the lower sialic acid content found in platelets from CHD patients could represent a contributing factor for the observed higher aggregability of platelets from these patients. Due to the lower sialic acid content and resulting lower negative surface charge, less repulsion between the platelets could facilitate aggregation.     

Azithromycin vs doxycycline in the treatment of inclusion conjunctivitis

PURPOSE: The aim of the study was to compare the efficacy and safety of azithromycin and doxycycline in the treatment of chlamydial conjunctivitis in adults. DESIGN: An open, randomized clinical trial. METHODS: Seventy-eight adult patients with incluson conjunctivitis were enrolled in this multicenter clinical study. Patients with chlamydial conjunctivitis as indicated by a positive direct fluorescent antibody (DFA) test or cell culture were randomized to receive a single 1-g dose of azithromycin or doxycycline, 100 mg twice daily for 10 days. A conjuctival swab for cell culture was obtained from all patients immediately before the treatment for subsequent confirmation of the presence of chlamydial infection in the central laboratory. Control examinations were performed 10 to 12 days and 4 to 6 weeks after the treatment initiation. Clinical and bacteriological responses to the treatment were evaluated at the last visit. The occurrence and frequency of adverse events were analyzed as well. RESULTS: Of 78 patients enrolled, 51 completed the study and were evaluated for efficacy. The main reasons for withdrawal were lack of confirmation of the presence of chlamydial infection by the central laboratory and failure to attend the follow-up visit. Eradication of C. trachomatis was achieved in 23 of 25 (92%) patients treated with azithromycin and in 25 of 26 (96%) patients treated with doxycycline. Clinical cure was observed in 15 (60%) and 18 (69%) patients treated with azithromycin and doxycycline, respectively. Both drugs were equally well tolerated. CONCLUSIONS: A single 1-g azithromycin therapy was as effective as standard 10-day treatment with doxycycline (100 mg twice daily) in the treatment of adult inclusion conjunctivitis.     

The MEK1 inhibitor PD98059 sensitizes C8161 melanoma cells to cisplatin-induced apoptosis

The regulation of apoptosis is believed to be dependent on the balance of the activities of different intracellular signalling systems. Activation of the SAPK/JNK pathway is implied in pro-apoptotic signalling, while activation of the MEK1/ERK pathway may have a viability-promoting effect. We show here that treatment with the MEK1 inhibitor PD98059 sensitizes the human melanoma cell line C8161 to cisplatin-induced apoptosis. In these cells, cisplatin at 40 microM did not elicit significant cell death, whereas massive cell death was seen when cells were pretreated for 20 h with 40 microM PD98059 before the addition of cisplatin. Concomitant addition of PD98059 and cisplatin did not have any sensitizing effect, and PD98059 on its own did not induce apoptosis. However, in three other human melanoma cell lines PD98059 did not potentiate cisplatin-induced apoptosis. Instead, in one of these cell lines (AA), PD98059 protected against cisplatin-induced cytotoxicity. We conclude that blocking of the MEK1/ERK pathway may, in some instances, potentiate the cytotoxic effect of cisplatin on human melanoma cell lines, whereas in other instances it may have a protective effect. Thus it cannot be regarded as a general approach to sensitizing melanoma cells to drug-induced apoptosis.