Calcium-dependent association of annexins with lipid bilayers modifies gramicidin A channel parameters.

In order to examine whether calcium-dependent binding of annexin to acidic phospholipids could change the lipid bilayer environment sufficiently to perturb channel-mediated transmembrane ion-transport, gramicidin A channel activity in planar lipid bilayers was investigated in the presence of calcium and annexins II, III or V. The experiments were performed with membranes consisting of phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine in 300 mM KCl solution buffered to pH 7.4 and with either 0.1 or 1 mM calcium added to the solution. Annexin (1 microM) was subsequently applied to the cis side of the membrane. All three annexins (II, III and V) when tested at 1 mM calcium decreased the gramicidin single-channel conductance. Annexins II and III increased the mean lifetime of the channels whereas annexin V seemed to have no influence on the mean lifetime. Since the lifetime of gramicidin A channels is a function of the rate constant for dissociation of the gramicidin dimer, which is dependent on the physical properties of the lipid phase, binding of annexins II and III seems to stabilize the gramicidin channel owing to a change of the bilayer structure.

[Poisoning with gamma-hydroxybutyrate. Cases reported in connection with "cultural festivals" in August 1999 in Kolding]. / Forgiftning med gammahydroxybutyrat. Tilfaelde i forbindelse med "kulturnatfestlighederne" i august 1999 i Kolding.

Eight cases of poisoning with the relatively newly introduced synthetic drug gamma-hydroxybutyric acid (GHB) are reported. The abuse of GHB was in most cases mixed with alcohol intake but not any opiates. The condition of some of the victims was serious with bradycardia and depressed respiration. The antidote Naloxone appeared to have a beneficial effect on the combined intoxication with GHB and alcohol.

Decontamination of drinking water by direct heating in solar panels.

A device was developed for direct heating of water by solar radiation in a flow-through system of copper pipes. An adjustable thermostat valve prevents water below the chosen temperature from being withdrawn. The results show that it is possible to eliminate coliform and thermotolerant coliform bacteria from naturally contaminated river water by heating to temperatures of 65 degrees C or above. Artificial additions of Salmonella typhimurium, Streptococcus faecalis and Escherichia coli to contaminated river water were also inactivated after heating to 65 degrees C and above. The total viable count could be reduced by a factor of 1000. The heat-resistant bacteria isolated from the Mlalakuva River (Tanzania) were spore-forming bacteria which exhibited greater heat resistance than commonly used test bacteria originating from countries with colder climates. To provide a good safety margin it is recommended that an outlet water temperature of 75 degrees C be used. At that temperature the daily production was about 501 of decontaminated water per m2 of solar panel, an amount that could be doubled by using a heat exchanger to recycle the heat.

Annexins from Ehrlich ascites cells inhibit the calcium-activated chloride current in Xenopus laevis oocytes.

The effect of annexins II, III and V, purified from different species, on the calcium-activated chloride current across the stage-V to stage-VI Xenopus laevis oocyte membrane was tested either directly, using calcium entry mediated by depolarization, by A23187 permeabilization of oocytes or indirectly by quisqualate stimulation of a metabotropic glutamate receptor in the membrane expressed by the oocyte after injection of mRNA. The annexins isolated from the Ehrlich ascites cell, which is a mouse tumor cell, were found to be potent inhibitors of the chloride current, showing half-maximal inhibition at 50 nM, whereas no block was found using bovine or porcine annexins isolated from lung tissue. Of the annexins tested, we found annexin III to be naturally occurring in the oocyte, while only trace amounts of annexins II and V could be demonstrated. The inhibition pattern varied somewhat according to the stimulus method, the inhibition being more complete when an indirect stimulus via the metabotropic receptor was applied compared to a direct calcium stimulus.

[Survival time after the diagnosis of AIDS in the county of Funen]. / Livslaengde efter diagnosen AIDS på Fyn.

Since the diagnosis of AIDS was first made, a lot of efforts have been made to improve survival. Different studies have found varied results, both geographically as well as over periods of time. During the period 1.1.1985 to 31.12.1993 142 patients that were HIV-positive were seen in the geographically well defined area of Funen. During the period 1.1.1985 to 31.12.1990 the median time elapsed between the patient being found to be HIV-positive and the patient presenting with an AIDS-defining disease was found to be 8.8 years. In the period 1.1.1991 to 31.12.1993 it was 2.6 years (95% CL 1,3-?). The AIDS defining diseases were Pneumocystis carinii pneumonia in 43% of the cases, and oesophageal candidiasis in 24%. The median survival time after being diagnosed with AIDS was 2.0 years (95% CL 1,7-2,4). Heterosexual infection seems more pronounced in our material than for the country as a whole.

[Reproducibility of a rapid test for HIV antibody]. / Reproducerbarheden af hurtigtest for HIV-antistoffer.

This study evaluated three rapid test kits for HIV antibody detection. Thirty consecutive blood specimens from the infectious diseases outpatient clinic were examined by three house officers who tested each specimen twice in a blind and randomized experiment. HIV-Chek (Du Pont) and HIV-1/HIV-2 TestPack (Abbott) were easy to handle and gave good intra- and interobserver agreement and good agreement with routine ELISA. Recombigen (BioScience) was difficult to interpret and gave poorer intra- and inter-observer variation. We suggest that HIV-Chek and TestPack can be used for assessment of patients' HIV antibody status in emergency circumstances with only minimal instruction of the staff.

Influence of tryptophan on the level of hepatic microsomal cytochrome P-450 in well-fed normal, adrenalectomized, and phenobarbital-treated rats.

In well-fed normal male rats, either force-feeding of tryptophan or a single injection of phenobarbital produced significant increments in hepatic microsomal cytochrome P-450 and the associated aniline hydroxylase activity. Administration of both tryptophan and phenobarbital together resulted in even greater stimulation than when the compounds were given alone. Adrenalectomy lowered instead the cytochrome P-450 concentration in comparison with that of normal rats, and administration of tryptophan and phenobarbital in this condition produced no significant increment in cytochrome P-450 concentration. In addition, phenobarbital administered either singly or in combination with tryptophan resulted in 80% mortality, which was reduced to zero by pretreatment with cortisol. While in cortisol-treated adrenalectomized rats administration of phenobarbital caused a 56% increment in cytochrome P-450 as compared to controls, tryptophan produced only a minor (9%) increase. In normal, as well as in adrenalectomized rats, tryptophan and phenobarbital administered either idividually or together increased microsomal protein concentration. In normal rats actinomycin-D treatment reduced both cytochrome P-450 and microsomal protein concentrations below that of the non-treated control levels. Further administration of either tryptophan or phenobarbital slightly increased the level of cytochrome P-450, and the two compounds together caused 40 and 21% increments of the same compared to actinomycin-treated and non-treated controls, respectively.