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1. The beta-cell K(ATP) channel is composed of two types of subunit - the inward rectifier K(+) channel (Kir6.2) which forms the channel pore, and the sulphonylurea receptor (SUR1), which serves as a regulatory subunit. The N-terminus of Kir6.2 is involved in transduction of sulphonylurea binding into channel closure, and deletion of the N-terminus (Kir6.2DeltaN14) results in functional uncoupling of the two subunits. In this study, we investigate the interaction of the hypoglycaemic agents repaglinide and glibenclamide with SUR1 and the effect of Kir6.2 on this interaction. We further explore how the binding properties of repaglinide and glibenclamide are affected by functional uncoupling of SUR1 and Kir6.2 in Kir6.2DeltaN14/SUR1 channels. All binding experiments are performed on membranes in ATP-free buffer at 37 degrees C. 2. Repaglinide was found to bind with low affinity (K(D)=59+/-16 nM) to SUR1 alone, but with high affinity (increased approximately 150-fold) when SUR1 was co-expressed with Kir6.2 (K(D)=0.42+/-0.03 nM). Glibenclamide, tolbutamide and nateglinide all bound with marginally lower affinity to SUR1 than to Kir6.2/SUR1. 3. Repaglinide bound with low affinity (K(D)=51+/-23 nM) to SUR1 co-expressed with Kir6.2DeltaN14. In contrast, the affinity for glibenclamide, tolbutamide and nateglinide was only mildly changed as compared to wild-type channels. 4. In whole-cell patch-clamp experiments inhibition of Kir6.2DeltaN14/SUR1 currents by both repaglinide and nateglinde is abolished. 5. The results suggest that Kir6.2 causes a conformational change in SUR1 required for high-affinity repaglinide binding, or that the high-affinity repaglinide-binding site includes contributions from both SUR1 and Kir6.2. Glibenclamide, tolbutamide and nateglinide binding appear to involve only SUR1.

We used a population-based cohort study design to describe the demographic characteristics of the HIV-infected population in Denmark and their variation over time. HIV treatment in Denmark is restricted to 9 centres, and all 3941 HIV-1 infected patients more than 15 y old seen at these centres in 1995-2003 were included. We found an estimated HIV prevalence of 70 per 100,000, and a mean annual incidence rate of 5.1 per 100,000 persons. The number of newly infected individuals was stable with a median of 231 per y (period 1995-2002), whereas the number of deaths decreased from 166 in 1995 to 50 in 2000 (p=0.000) and remained stable thereafter. Of the enrolled patients, 75% were males, 80% were Caucasian, 13% were black African, and the primary risk behaviour was male-to-male sexual contact (44%), heterosexual contact (36%), and injection drug use (11%). During the y 1995-2003 we found an increase in age at diagnosis (p=0.000), and no major changes in gender, race, mode of infection, or baseline CD4+ cell count and viral load, neither overall not within subgroups of patients. In this period 14.5% had AIDS at the time of HIV diagnosis. Our data do not confirm concerns about unmonitored evolution in the HIV epidemic in Denmark.

IL-18 is an inducer of apoptosis/tissue injury. IL-18 messenger RNA expression was examined in adipose tissue (AT) obtained from HIV patients with lipodystrophy, without lipodystrophy and healthy controls. IL-18 mRNA was expressed in AT at increased levels in lipodystrophy-positive compared with lipodystrophy-negative patients and healthy controls. Higher levels of IL-18 mRNA were found in femoral-gluteal AT compared with abdominal AT, and correlated with limb fat loss. These findings suggest that IL-18 is linked to HIV-associated lipodystrophy.

Purpose: To present and discuss four cases of bilateral endogenous endophthalmitis., Methods: An observational study of four patients aged 55-80 years, seen within a 2-year period. All had diagnostic and therapeutic vitrectomy. The antibiotic therapy was guided by analyses of cultures of blood and vitreous., Results: Blood cultures demonstrated Streptococcus pneumoniae in two patients and Staphylococcus aureus and Morganella morganii, each in one patient. The findings corresponded with culture findings from vitreous material in two patients. The primary foci for the metastatic spread of infection were endocarditis, discitis and a subdural abscess of the lumbar spine, urinary tract infection, and infection of a recent hip alloplasty, respectively, in the four patients. Five eyes became blind, whereas three eyes recovered to visual acuity of 0.25-0.67., Conclusions: Endogenous bacterial endophthalmitis usually leads to total loss of vision. The disease is acute and the time span for intervention limited. We believe that an active therapeutic approach including intravitreal antibiotics and vitreoretinal surgery saved three eyes from blindness.

The level of interleukin-18 (IL-18) is elevated in patients with HIV infection as well as in people with insulin resistance (IR). As HIV-associated lipodystrophy (LD) shares metabolic characteristics with the metabolic syndrome, it was hypothesized that IL-18 would be elevated in patients with LD. Two groups of HIV-infected men with LD, one with fat accumulation (mixed group) (n = 12) and one without fat accumulation (lipoatrophic group) (n = 15) were included. Controls were HIV-positive men without LD (n = 15) and HIV-negative, age-matched men (n = 12). The levels of plasma IL-18 were elevated in all 3 HIV groups compared with HIV-negative controls (P <0.01). In the HIV groups the lipoatrophic group had the highest IL-18, followed by the mixed group and the HIV-positive controls. Only the differences between the lipoatrophic group and the HIV-positive controls were significant (P <0.01). Plasma IL-18 correlated with tumor necrosis factor-alpha (P <0.05), but not IL-6, adiponectin, or HOMA-IR (homeostasis model of insulin resistance). In contrast to the HIV-negative controls, IL-18 did not correlate with total or low-density cholesterol in either of the HIV groups. An inverse correlation was observed between IL-18 and limb fat (P <0.05). In conclusion, the level of IL-18 is elevated in patients with LD and closely linked to limb atrophy, whereas it is not associated with cholesterol or IR.

A 55-y-old male developed severe metabolic acidosis and renal failure during tenofovir therapy. Increased tenofovir exposure due to low body weight and chronic stable renal insufficiency could have enhanced the risk of nephrotoxicity, and creatinine clearance should be estimated before initiation of tenofovir.

Repaglinide and nateglinide represent a new class of insulin secretagogues, structurally unrelated to sulphonylureas, that were developed for the treatment of type 2 diabetes. The inhibitory effect of these drugs was investigated on recombinant wild-type and mutant Kir6.2/SUR1 channels expressed in HEK293 cells. Nateglinide and repaglinide dose-dependently inhibited whole-cell Kir6.2/SUR1 currents with half-maximal inhibitory concentration (IC(50)) values of 800 and 21 nmol/l, respectively. Mutation of serine 1237 in SUR1 to tyrosine (S1237Y) abolished tolbutamide and nateglinide block, suggesting that these drugs share a common point of interaction on the SUR1 subunit of the ATP-sensitive K(+) channel. In contrast, repaglinide inhibition was unaffected by the S1237Y mutation (IC(50) = 23 nmol/l). Radioligand binding studies revealed a single high-affinity binding site for [(3)H]repaglinide on membranes prepared from HEK293 cells expressing wild-type (equilibrium dissociation constant [K(D)] = 0.40 nmol/l) or mutant (K(D) = 0.31 nmol/l) Kir6.2/SUR1 channels. Nateglinide and tolbutamide displaced [(3)H]repaglinide binding to wild-type channels with IC(50) values of 0.7 and 26 micro mol/l, respectively, but produced <10% displacement of [(3)H]repaglinide bound to mutant channels. This is consistent with the idea that binding of nateglinide and tolbutamide, but not repaglinide, is abolished by the SUR1[S1237Y] mutation and that the binding site for repaglinide is not identical to that of nateglinde/tolbutamide. These results are discussed in terms of a conformational analysis of the drug molecules.