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Notes: Bipolar membranes consist of a layered ion-exchange structure composed of a cation selective membrane joined to an anion selective membrane. They are analogous to semiconductor p-n devices as both of them present current-voltage curves exhibiting similar rectification properties. In this article, we present some current-voltage curves obtained for different bipolar membranes at several temperatures. The results can be interpreted in terms of a simple model for ion transport and field-enhanced water dissociation previously developed. The mechanism responsible for water splitting is assumed to be a catalytic proton transfer reaction between the charged groups and the water at the membrane interface. The effects of temperature are taken into account by introducing an Arrhenius-type relationship for the dependence of the forward rate constant of the reaction on temperature. Finally, comparison between theory and experiments provides reasonable values for the parameters introduced in the theoretical model. The analysis aims at developing a better physical understanding of a process in which chemical reactions and transport phenomena are coupled in such a way that the potential technological applications depend strongly on this coupling.

Notes: Snoring is a characteristic feature of habitual snorers and patients with sleep apnoea syndrome. However, unlike snorers, sleep apnoea patients have an increased peri-operative morbidity. Presently available methods to differentiate between these two groups are either expensive, invasive or time consuming. As cardiac reflexes are impaired in sleep apnoea syndrome, we tested whether heart rate variability could discriminate between snorers and patients with sleep apnoea syndrome. Heart rate variability measurement detects cardiac autonomic dysfunction non-invasively in an ambulatory setting. We studied 32 male patients undergoing polysomnography for suspected sleep apnoea. Total, low- and high-frequency power were measured using a Holter electrocardiogram. Differences in night- and daytime variability were then calculated. Differences between day and night values were more pronounced in the sleep apnoea group and related to the apnoea-hypopnoea-index and low oxygen saturation. Higher values in sleep apnoea patients resulted from increasing variability at night. Heart rate variability might thus help to differentiate between snorers and patients with severe sleep apnoea syndrome.

Notes: Background : Rocuronium bromide, a steroid nondepolarizing muscle relaxant, has a rapid onset and an intermediate duration of action in infants, children and adults. However, clinical evidence shows a longer duration of recovery in small infants. The aim of this study was to investigate the influence of age on rocuronium recovery during the first year of life.Methods : ASA I–II infants, scheduled for elective surgery under general anaesthesia and intubation were included after ethics committee approval and parents’ written consent. According to age the patients were randomly allocated to receive either 0.45 mg·kg−1 or 0.6 mg·kg−1 rocuronium bromide in three age-groups: (A) 0–1 month, (B) 2–4 months and (C) 5–12 months. After induction with thiopentone (5–7 mg·kg−1), anesthesia was maintained with isoflurane without opioids. Prior to surgery, caudal block with bupivacaine (0.125%) 1.0 ml·kg−1 and paracetamol 25 mg·kg−1 rectally were given for analgesia. Efficacy variables were intubation conditions 60 s after administration of muscle relaxant (T0) and recovery of neuromuscular blockade measured as T1 at 10, 25, 50 and 75 % of baseline, train-of-four (TOF) of 0.7 and Recovery Index (RI). Data were characterized by summary statistics and analysis of variance.Results : A total of 61 infants with a median age range of 67 (2–364) days were included. Intubation conditions were excellent or good in all dose and age groups. T0 in group A was reached in a range of 15–30 s, in others up to 60 s. T1 recovery (T75) after 0.45 mg·kg−1 was 56.4 ± 16 (A), 62.7 ± 32 (B) and 45.8 ± 18 (C) min. Recovery times for of 0.6 mg·kg−1 were 100.8 ± 35 (A), 70.6 ± 19 (B) and 63.4 ± 21 (C) min, respectively. The TOF ratio (0.7) was 62.3 ± 18 (A), 64.1 ± 27 (B) and 43.7 ± 12 (C) min using 0.45 mg·kg−1 compared with 94.8 ± 31 (A), 63.8 ± 14 (B) and 67.5 ± 18 (C) min with 0.6 mg·kg−1. The differences of T75 and TOF 0.7 in A and C were significant (P ≤ 0.05).Conclusions : Recovery of muscle relaxation using rocuronium bromide under isoflurane anesthesia in infants differs widely and shows great differences between age groups as well as dose regimen. A dose of 0.6 mg·kg−1 resulted in a significantly longer duration of action in group A. The reduced dose of 0.45 mg·kg−1 resulted in rapid and good relaxation in all infants without very long lasting effects. Reduced doses of rocuronium should be used in newborns and small infants.

Notes: Summary Oil-in-water emulsions containing either mycobacterial cell walls (CW) or killed whole cells attached to the oil droplets were prepared by ultrasonication and by a modified grinding procedure. The immunotherapeutic potency of the ultrasonically prepared vaccines was at least as great as that of similar vaccines prepared by emulsification in a tissue grinder. Among the advantages of ultrasonication over grinding for the preparation of mycobacterial cell and cell wall vaccines are simplicity and the ease with which sterility may be maintained. Both the ultrasonic and modified grinding methods are less time-consuming than published procedures for preparing mycobacterial vaccines.

Notes: Summary Living BCG, killed Mycobacterium tuberculosis cells, or BCG cell walls (CW) augmented the immunogenicity of lyophilized syngeneic ascites hepatoma (line 10) of strain-2 guinea pigs. Effective vaccine contained living BCG and lyophilized line-10 cells, or mycobacterial cells or CW attached to oil droplets and lyophilized line-10 cells. Protection against the challenge tumor was evident 14 or 21 days after one administration of either vaccine.

Notes: Summary The effectiveness of each of two mycobacterial components and a synthetic analog of one of them in the eradication of pulmonary deposits of intravenously injected syngeneic fibrosarcoma 1023 in C3H mice was studied. BCG cell walls (BCG CW), trehalose 6,6′-dimycolate (TDM) or 6,6′-di-0-2-tetradecyl, 3-hydroxyoctadecanoyl-α,α-trehalose (C76), a synthetic analog of TDM, was administered in emulsified form by three different routes: intraperitoneal, intradermal, or intravenous, 24 h after intravenous injection of 1023 tumor cells. The most effective form of therapy was TDM given by the intraperitoneal route; about 50% of treated animals were cured. Higher doses of BCG CW or C76 also led to a significant number of cures. Each agent caused a significant prolongation of survival time of the treated mice at two or more of the dosages tested; however, their routes of optimal activity varied.

Notes: Summary BCG cell walls (CW) were compared to trehalose-6,6′-dimycolate (TDM) in admixture with endotoxin (ET) for their potency to cause regression of a transplanted guinea pig hepatoma. On a weight basis, CW were at least as active as ET-TDM. Toxicity of ET and of ET-TDM were greater than that of CW as judged by weight loss after intravenous administration to normal guinea pigs.

Notes: Summary Local immunotherapy is a form of cancer treatment where exogenous antigen is introduced into the area of the tumor. Under favorable circumstances, the perfused tumor regresses, systemic tumor-specific transplantation immunity is augmented, and distant microscopic metastases regress. Successful local immunotherapy requires an immunologically competent host, small tumor burden, and tumor located usually in the skin. A wide variety of biologic agents are capable of promoting local immunotherapy. BCG has been most widely studied. The antitumor activity of two different preparations of the Tice substrain of BCG were compared. No significant differences in antitumor activity were found. Alternative approaches to intralesional injection were sought. Intradermal injection of BCG adjacent to dermal tumors, prior to surgery, led to eradication of axillary metastases and to the development of tumor-specific transplantation immunity. Successful local BCG immunotherapy is a by-product of the host response to BCG infection. Involved are lymphocytes specifically sensitized to mycobacterial antigens, lymphocyte mediators, and macrophages which develop the capacity to kill tumor cells. Tumor-cell killing may be mediated by exocytosis of macrophage lysosomes into tumor cells. Complete and permanent tumor eradication probably requires the development of tumor-specific transplantation immunity mediated by sensitized lymphocytes. Local infection of the tumor may augment the development of this tumor-specific immunity.

Notes: Summary Metastases to the lungs of guinea pigs occurred at high frequency as a consequence of intradermal implantation of tumor cells derived from the syngeneic hepatocellular carcinoma line-10. Surgery had a major influence on the proportion of guinea pigs found to have pulmonary metastases at necropsy. Without surgery all guinea pigs died with extensive lymph node metastases; macroscopic pulmonary metastases were present in a minority of the animals. Animals treated by excision of dermal tumors survived longer than untreated animals, and macroscopic pulmonary metastases were present in the majority of the animals. Animals treated by excision of dermal tumor and regional lymph nodes were rendered tumor-free. The data suggest that lymph node metastases were the most likely source of the tumor cells that spread to the lungs in animals from whom the dermal tumor transplant had been removed.