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BACKGROUND: The risk of venous thrombotic events is elevated in people with HIV, but overall risk estimates and estimates specific to immune status and antiretroviral medication remain i mprecise. In this study, we aimed to estimate these parameters in a large cohort of people with HIV in the Netherlands.METHODS: In this retrospective cohort study, we used the Dutch ATHENA cohort to estimate crude, age and sex standardised, and risk period-specific incidences of a first venous thrombotic event in people with HIV aged 18 years or older attending 12 HIV treatment centres in the Netherlands. Crude and standardised incidences were compared with European population-level studies of venous thrombotic events. We used time-updated Cox regression to estimate the risk of a first venous thrombotic event in association with HIV-specific factors (CD4 cell count, viral load, recent opportunistic infections, antiretroviral medication use) adjusted for traditional risk factors for venous thrombotic events.FINDINGS: With data collected from Jan 1, 2003, to April 1, 2015, our study cohort included 14 389 people with HIV and 99 762 person-years of follow-up, with a median follow-up of 7·2 years (IQR 3·3-11·1). During this period, 232 first venous thrombotic events occurred, yielding a crude incidence of 2·33 events per 1000 person-years (95% CI 2·04-2·64) and an incidence standardised for age and sex of 2·50 events per 1000 (2·18-2·82). CD4 counts less than 200 cells per μL were independently associated with higher risk of a venous thrombotic event: adjusted hazard ratio (aHR) 3·40 (95% CI 2·28-5·08) relative to counts of 500 cells per μL. A high viral load (aHR 3·15, 95% CI 2·00-5·02; >100 000 copies per mL vs INTERPRETATION: Our findings support neither prescribing primary outpatient thromboprophylaxis nor avoiding any type of antiretroviral medication in people with HIV at high risk of a venous thrombotic event.FUNDING: Dutch Ministry of Health, Welfare and Sport.

To compare 2 regimens for HIV postexposure prophylaxis (PEP) as to safety, adherence, outcome, and follow-up in men who have sex with men (MSM) in Amsterdam. Since 2000, all MSM starting HIV PEP in Amsterdam have been followed in 1 location. The regimen was comprised of zidovudine or lamivudine and nelfinavir (regimen 1) until 2005, when nelfinavir was replaced by atazanavir (regimen 2). All patient data, including data on PEP side effects and testing for alanine aminotransferase (ALT), were systematically recorded and compared between the 2 regimens from 2000 to 2007. HIV PEP was prescribed 309 times to MSM. Of the 261 who were followed up, 237 (91%) completed their 28-day course. Although fewer patients had diarrhea on regimen 2 than on regimen 1 (P = 0.00), the proportion completing either course was the same: 98 of 110 (89%) and 139 of 151 (92%), respectively (P = 0.42). Only 1 patient with severely elevated ALT was advised to stop PEP, he also had serious illness. MSM at least 30 years of age and MSM who had sex with a partner known to be HIV-positive completed their course significantly more often than those under 30 and those who had sex with a partner of unknown HIV status (P

The aim of this study was to study the development of HCV-specific T cell immunity during acute HCV infection in the presence of an existing HIV-1 infection in four HIV-1 infected men having sex with men. A comprehensive analysis of HCV-specific T cell responses was performed at two time points during acute HCV infection using a T cell expansion assay with overlapping peptide pools spanning the entire HCV genome Three patients with (near) normal CD4+ T cell counts (range 400-970 x 10(6)/L) either resolved (n = 1) or temporary suppressed HCV RNA. In contrast, one patient with low CD4+ T cell counts (330 x 10(6)/L), had sustained high HCV RNA levels. All four patients had low HCV-specific CD8+ T cell responses, and similar magnitudes of CD4+ T cell responses. Interestingly, individuals with resolved infection or temporary suppression of HCV-RNA had HCV-specific CD4+ T cell responses predominantly against nonstructural (NS) proteins. While the individual with high HCV RNA plasma concentrations had CD4+ T cell responses predominantly directed against Core. Our data show that an acute HCV infection in an HIV-1 infected person can be suppressed in the presence of HCV-specific CD4+ T cell response targeting non-structural proteins. However further research is needed in a larger group of patients to evaluate the role of HIV-1 on HCV-specific T cell responses in relation to outcome of acute HCV infection

A bioanalytical method for the determination of most commonly prescribed protease inhibitors (atazanavir, darunavir, lopinavir and ritonavir) and non-nucleoside reverse transcriptase inhibitors (efavirenz and nevirapine) was developed and validated according to FDA guidelines. In brief, dried blood spots were punched out of a collection paper with a 0.25 in. diameter punch. The analytes were extracted from the punched-out disc using a mixture of acetonitrile, methanol and 0.2M zinc sulphate in water (1:1:2, v/v/v) containing the internal standards dibenzepine, 13C6-efavirenz and D5-saquinavir. 20 microL of the extract was injected onto the reversed-phase C18 column (150 mm x 2.0 mm) for separation from endogenous compounds and the analytes were quantified using a triple quadrupole mass spectrometer. The analytical run time was only 10 min. Validated concentration ranges covered the ranges encountered in routine clinical practice. The assay was linear over the concentration ranges tested (0.1-20 mg/L for atazanavir, lopinavir, nevirapine and efavirenz and 0.05-10 mg/L for darunavir and ritonavir). Accuracies and inter- and intra-run precisions at all levels ranged from 96.2 to 113.9% and 3.1 to 13.3%, respectively. Analytes in dried blood spots were stable for at least 7 days at 30 degrees C. The method enabled patient-friendly sample collection, easy and cheap sample shipment and non-hospital based sampling for therapeutic drug monitoring and pharmacokinetic studies.

Objective The objective of this study was to evaluate trends in HIV postexposure prophylaxis (PEP) requests after sexual exposure, compliance, and outcome of follow-up HIV tests. Study design The authors conducted a retrospective analysis of all HIV PEP requests after sexual exposure between January 1, 2000, and December 31, 2004, in Amsterdam. Results In 5 years, there was a very modest increase in PEP requests, of which most (75%) came from men who have sex with men (MSM). Although 70% reported side effects, 85% completed their PEP course. Sexual assault victims less often completed their course (odds ratio [OR] = 0.1; 95% confidence interval [CI] = 0.05-0.4, P = 0.001). People who used HIV PEP more often complied with follow-up tests than people who did not use PEP (OR = 3.5; 95% CI = 1.6-7.9, P = 0.002). One HIV seroconversion was found caused by a later exposure than that for which PEP was given. Conclusions Despite a widely available PEP program in Amsterdam, the number of PEP requests remained low. Most people completed their PEP course; compliance with follow-up HIV testing was high.

Background. Since 2000, incidence of sexually acquired hepatitis C virus (HCV)-infection has increased among human immunodeficiency virus (HIV)-infected men who have sex with men (MSM). To date, few case-control and cohort studies evaluating HCV transmission risk factors were conducted in this population, and most of these studies were initially designed to study HIV-related risk behavior and characteristics.Methods. From 2009 onwards, HIV-infected MSM with acute HCV infection and controls (HIV-monoinfected MSM) were prospectively included in the MOSAIC (MSM Observational Study of Acute Infection with hepatitis C) study at 5 large HIV outpatient clinics in the Netherlands. Written questionnaires were administered, covering sociodemographics, bloodborne risk factors for HCV infection, sexual behavior, and drug use. Clinical data were acquired through linkage with databases from the Dutch HIV Monitoring Foundation. For this study, determinants of HCV acquisition collected at the inclusion visit were analyzed using logistic regression.Results. Two hundred thirteen HIV-infected MSM (82 MSM with acute HCV infection and 131 MSM without) were included with a median age of 45.7 years (interquartile range [IQR], 41.0–52.2). Receptive unprotected anal intercourse (adjusted odds ratio [aOR], 5.01; 95% confidence interval [CI], 1.63–15.4), sharing sex toys (aOR, 3.62; 95% CI, 1.04–12.5), unprotected fisting (aOR, 2.57; 95% CI, 1.02–6.44), injecting drugs (aOR, 15.62; 95% CI, 1.27–192.6), sharing straws when snorting drugs (aOR, 3.40; 95% CI, 1.39–8.32), lower CD4 cell count (aOR, 1.75 per cubic root; 95% CI, 1.19–2.58), and recent diagnosis of ulcerative sexually transmitted infection (aOR, 4.82; 95% CI, 1.60–14.53) had significant effects on HCV acquisition.Conclusions. In this study, both sexual behavior and biological factors appear to independently increase the risk of HCV acquisition among HIV-infected MSM.

Aims To develop a population pharmacokinetic model for lopinavir in combination with ritonavir, in which the interaction between both drugs was characterized, and in which relationships between patient characteristics and pharmacokinetics were identified. Methods The pharmacokinetics of lopinavir in combination with ritonavir were described using NONMEM (version V, level 1.1). First, ritonavir data were fitted to a previously developed model to obtain individual Bayesian estimates of pharmacokinetic parameters. Hereafter, an integrated model for the description of the pharmacokinetics of lopinavir with ritonavir was designed. Results From 122 outpatients 748 lopinavir and 748 ritonavir plasma concentrations were available for analysis. The interaction between the drugs was described by a time-independent inverse relationship between the exposure to ritonavir over a dosing-interval and the apparent clearance (CL/F) of lopinavir. The model parameters volume of distribution and absorption rate constant were 61.6 l (95% prediction interval (PI) 22.4, 83.7) and 0.564 h−1 (95% PI 0.208, 0.947), respectively. The model yielded a theoretical value for the CL/F of lopinavir without ritonavir of 14.8 l h−1 (95%PI 12.1, 20.1), which translates to a value of 5.73 l h−1 in the presence of ritonavir. The only factor with significant effect on the pharmacokinetics was concurrent use of non-nucleoside reverse transcriptase inhibitors (NNRTI), which increased the CL/F of lopinavir by 39% (P

New stricter nitrogen effluent standards and increasing influent loads require existing wastewater treatment plans (WWTPs) to extend or optimize. At WWTPs with limited aeration capacity, limited denitrification capacity or shortage of aerobic sludge age, implementation of SHARON to improve nitrogen effluent quality can be a solution. SHARON is a compact, sustainable and cost-effective biological process for treatment of nitrogen-rich rejection waters. At WWTP Rotterdam-Dokhaven and WWTP Utrecht a SHARON has been in operation for several years. For both WWTPs the effect of SHARON on the nitrogen effluent quality has been evaluated. WWTP Rotterdam-Dokhaven has limited aeration capacity. By implementation of SHARON, the ammonia load of the effluent was reduced by 50%. WWTP Utrecht had limited denitrification capacity. The implementation of SHARON improved the effluent nitrate load by 40%. The overall TN removal efficiency increased from 65% to over 75% and strict nitrogen effluents standards (TN = 10 mg N/l) could be reached. Through modelling and supported by full scale practice it has been shown that by implementation of SHARON in combination with enhanced influent pre-treatment, the aerobic sludge age can be extended to maintain total nitrogen removal at lower temperatures.

The demand for new and sustainable systems for nitrogen removal has increased dramatically in the last decade. It is clear that the conventional systems cannot deal with the increasing nitrogen loads in a cost effective way. As an alternative, the implementation of the anammox (anaerobic ammonium oxidation) process in the treatment of wastewater with high ammonium concentrations has been started. The compact anammox reactors can sustain high nitrogen loads without any problems. The highest observed anammox capacity is 8.9 kg N removed m-3 reactor day-1. The first 75 m3 anammox reactor is operating in Rotterdam, the Netherlands, combined with the partial nitrification process Single reaction system for High Ammonium Removal Over Nitrite (SHARON). Partial nitrification and anammox can also be combined in one reactor systems like Completely Autotrophic Nitrogen removal Over Nitrite (CANON) or Oxygen Limited Ammonium removal via Nitrification Denitrification (OLAND) where aerobic ammonium-oxidizing bacteria (AOB) and anammox bacteria cooperate under oxygen-limitation. These systems remove about 1.5 kg N m-3 reactor day-1. In addition to ammonium, urea can also be converted in the CANON system after a two-week adaptation period. The ecophysiological properties of the anammox bacteria make them very well suited to convert ammonium and nitrite. The Ks values for ammonium and nitrite are below 5 μM. However, nitrite above 10 mM is detrimental for the anammox process, and oxygen reversibly inhibits the process at concentrations as low as 1 μM. Acetate and propionate can be used by the anammox bacteria to convert nitrite and nitrate, whereas methanol and ethanol severely inhibit the anammox reaction. The enzyme hydroxylamine/hydrazine oxidoreductase (HAO), one of the key enzymes, is located in the anammoxosome, which is a membrane bound organelle. The membranes of the anammox bacteria contain unique ladderane lipids and hopanoids. The bacteria responsible for the anammox reaction are related to the Planctomycetes. The first anammox bacteria were isolated via Percoll centrifugation and characterized as Candidatus “Brocadia anammoxidans”. Survey of different wastewater treatment plants using anammox specific 16S rRNA gene primers and anammox specific oligonucleotide probes has revealed the presence of at least three other anammox bacteria, which have been tentatively named Candidatus “Kuenenia stuttgartiensis”, Candidatus “Scalindua wagneri” and Candidatus “Scalindua brodae”. A close relative of the latter, Candidatus “Scalindua sorokinii” was found to be responsible for about 50% of the nitrogen conversion in the anoxic zone of the Black Sea, making the anammox bacteria an important player in the oceanic nitrogen cycle.

Because energy reserves limit flight range, wind assistance may be of crucial importance for migratory birds. We tracked eight Bewicks swans Cygnus columbianus bewickii, using 95-g satellite transmitters with altimeters and activity sensors, during their spring migration from Denmark to northern Russia in 1996. During the 82 occasions where a swans location was recorded in flight, average flight altitude was 165 m a.s.l. with a maximum of 759 m a.s.l., despite winds often being more favourable at higher altitudes. We also counted Bewicks swans departing from the Gulf of Finland and subsequently passing an observatory in the next major stop-over area 800 km further north in the White Sea, northern Russia, during the springs of 1994, 1995 and 1996. A comparison of these counts with wind data provided evidence for Bewicks swans using favourable changes in wind conditions to embark on migration. Changes in the numbers of birds arriving in the White Sea correlated best with favourable changes in winds in the Gulf of Finland 1 day earlier. Again, migratory volume showed a correlation with winds at low altitudes only, despite wind conditions for the swans being more favourable at high altitudes. We conclude that the relatively large Bewicks swan tends to gear its migration to wind conditions at low altitude only. We argue that Bewicks swans do not climb to high altitudes because of mechanical and physiological limitations with respect to the generation of power for flight and to avoid rapid dehydration. [KEYWORDS: Bewicks swan ; Cygnus columbianus bewickii ; Migration ; Flight altitude ;Tailwind vector ; Satellite transmitters]

Item does not contain fulltext OBJECTIVE: To evaluate the characteristics of patients who developed acute clinical hepatitis in an unselected outpatient population. METHODS: Patients who started a nevirapine-containing regimen in the period January 1999-February 2001 and presented with clinical symptoms in accordance with increased transaminase values within 12 weeks of initiation of nevirapine were considered possible cases of clinical hepatotoxicity. Patient characteristics, co-medicated drugs, HIV-1 RNA levels and clinical chemistry parameters were collected from outpatient medical records and clinical medical records. RESULTS: At the defined period, 306 patients started a nevirapine-containing regimen, of whom eight developed an acute hepatitis (2.6%) in a median of 24 days [interquartile range (IQR) 20-25 days]. Transaminases peaked at 28 days (IQR, 27-32 days). Injury pattern was in general mixed-hepatocellular. Withdrawal of the antiretroviral agent led to rapid restoration of transaminase levels and resolution of clinical symptoms. The reason for developing this hepatic reaction was not clear in every case as no specific risk factor(s) covering all patients in this case series could be identified. CONCLUSIONS: It is very important to monitor closely transaminase levels of all patients starting a nevirapine-containing regimen, including patients with no specific characteristics that put them at risk. The rapid onset of the clinical symptoms pleads for transaminase monitoring at a very early stage (i.e., within 2 weeks of initiation) of the nevirapine-containing regimen.

There is little information about the risk of treatment failure after a switch from human immunodeficiency virus (HIV) protease inhibitors (PIs) to nevirapine (Nvp) for patients with successful virus suppression. This study compared the 1-year risk of treatment failure for patients switching from a first PI-containing antiretroviral regimen to Nvp (Nvp group) with the risk for patients switching to second-line PIs (PI group) in the ATHENA (AIDS Therapy Evaluation, The Netherlands) study cohort (n 5 2470) whose HIV-1 RNA loads were < 500 copies/mL. Treatment failure was defined as measurement of HIV-1 RNA loads . 500 twice or . 10,000 copies/mL once or discontinuation of treatment for any reason. There were 446 eligible patients, 125 in the Nvp group and 321 in the PI group. The risk of treatment failure in the Nvp group, after data were adjusted for other risk factors, was 5-fold (95% confidence interval, 0.1‐ 0.4) lower than the risk in the PI group, primarily because the discontinuation rate was lower. In patients with virus suppression, a switch to Nvp is more likely than a switch to second-line PIs to result in sustained virus suppression and maintenance of the new regimen. Treatment of human immunodeficiency virus (HIV) type 1 infection with highly active antiretroviral therapy (HAART) that includes an HIV protease inhibitor (PI) may be associated with the need to take large quantities of capsules, stringent intake schedules, food restrictions, drug-drug interactions, and numerous adverse drug reactions [1, 2]. These factors may interfere with long-term adherence and therefore lead to premature virus rebound and the selection of resistant viral variants. Various strategies for maintenance treatment have been ineffective [3‐ 5].

SHARON ® is a very cost-effective treatment system for the total removal of nitrogen components, thru nitrification/denitrification, from wastewater flow streams containing high concentrations of nitrogen. The system is used in the treatment of municipal wastewater side streams from both dewatered digested primary sludge and waste activated biosolids to achieve high total overall nitrogen removal. It is also used for the treatment concentrate from sludge and biosolids drying facilities, of high strength land fill leachate, and manure treatment wastewaters. SHARON ® is a high rate process for the removal of total nitrogen operating with minimal sludge retention time. Due to differences in growth rates of the bacterial species at the process design temperature (30-40 O C) a selection can be made wherein the nitrite oxidizing bacteria can be washed out of the system while ammonia oxidizing bacteria are retained along with denitrifying bacteria. Using this metabolic mode of operation allows for a 25% reduction in aeration energy required for nitrification and a 40% reduction in the amount of BOD addition needed for denitrification. In addition since the process is accomplished in a side stream there are savings in mainstream reactor costs. The pertinent principles of both nitrification and denitrification and also the SHARON ® process design parameters are developed. Three full-scale SHARON ® systems have been constructed at large wastewater treatment plants in Europe and a fourth is under design. The results of the full scale operation at the Rotterdam, Dokaven Plant, Netherlands, are presented. The Utrecht Plant is illustrated.

A SHARON® system has been constructed at the Utrecht WWTP and at the Rotterdam Dokhaven WWTP. In the SHARON® process rejection water from dewatering of digested sludge is treated for N-removal. It concerns a high active process operating without sludge retention. Due to differences in growth rate nitrite oxidisers can be washed out of the system while ammonia oxidisers are maintained, resulting in N-removal over nitrite. The SHARON® process was selected in competition with several other techniques. The feed of a SHARON® system is concentrated, with ammonia concentrations ranging from 0.5 to 1.5 g N/l. The results show that conversion rates of 90% are well possible with N-removal mainly via the nitrite route. The process was shown to be stable. Due to the high ammonium influent concentrations pH control is of great importance, preventing process inhibitions. The acidifying effect of nitrification can be compensated completely by CO2 stripping during aeration and by denitrification. Heat production by biological conversions is significant, due to the high inlet concentrations, and contributes to the optimal operating temperature of 30-40°C.

At the Rotterdam Dokhaven WWTP the first full-scale application of the SHARON process has been constructed. In the SHARON process, rejection water from dewatering of digested sludge is treated for N-removal. It concerns a highly active process operating without sludge retention. The single tank reactor is intermittently aerated. Due to differences in growth rate nitrite oxidisers are washed out of the system while ammonia oxidisers can be maintained, resulting in N-removal over nitrite. The SHARON process has been selected after comparison with several other techniques. The feed of the SHARON tank is concentrated, with ammonia concentrations over 1 g N/l. The first results show that conversion rates of 90% are quite possible with N-removal mainly via the nitrite route. The process was shown to be stable. Due to the high inlet concentrations pH control is of great importance, preventing process inhibitions. The acidifying effect of nitrification can be compensated completely by CO2 stripping during aeration and by denitrification. Heat production by biological conversions appeared to be significant, due to the high inlet concentrations, and contributes to the optimal operating temperature of 30-40°C.

We tested whether the spatial variation in resource depletion by Tundra Swans (Cygnus columbianus) foraging on belowground tubers of sage pondweed (Potnmogeton pectinatus) was caused by differences in net energy intake rates. The variation in giving up densities within the confines of one lake was nearly eightfold, the giving-up density being positively related to water depth and, to a lesser extent, the silt content of the sediment. The swans' preference (measured as cumulative foraging pressure) was negatively related to these variables. We adjusted a model developed for diving birds to predict changes in the time allocation of foraging swans with changes in power requirements and harvest rate. First, we compared the behavior of free-living swans foraging in shallow and deep water where they feed by head-dipping and up-ending, respectively. Up-ending swans had 1.3-2.1 times longer feeding times than,head-dipping swans. This was contrary to our expectation, since the model predicted a decrease in feeding time with an increase in feeding power. However up-ending swans also had 1.9 times longer trampling times than head-dipping swans. The model predicted a strong positive correlation between trampling time and feeding time, and the longer trampling times may thus have masked any effect of an increase in feeding power. Heart rate measurements showed that trampling was the most energetically costly part of foraging. However, because the feeding time and trampling time changed concurrently, the rate of energy expenditure was only slightly higher in deep water (1.03-1.06 times). This is a conservative estimate since it does not take into account that the feeding costs of up-ending are possibly higher than that of head-dipping. Second, we compared captive swans foraging on sandy and clayey sediments. We found that the harvest rate on clayey sediment was only 0.6 times that on sandy sediment and that the power requirements for foraging were 1.2-1.4 times greater. Our results are in qualitative agreement with the hypothesis that the large spatial variation in giving-up densities was caused by differences in net rates of energy intake. This potentially has important implications for the prey dynamics, because plant regrowth has been shown to be related to the same habitat factors (water depth and sediment type.) [KEYWORDS: Bewick's Swan, Cygnus columbianus bewickii, energy expenditure, fennel pondweed, giving-up density, Lauwersmeer, The Netherlands, optimal foraging, patch use, plant-herbivore interaction, Potamogeton pectinatus, sago pondweed, Tundra Swan]

AIMS: To study the effect of fluconazole on the steady-state pharmacokinetics of the protease inhibitors ritonavir and saquinavir in HIV-1-infected patients. METHODS: Five subjects treated with saquinavir and three with ritonavir received the protease inhibitor alone (saquinavir 1200 mg three times daily, ritonavir 600 mg twice daily) on day 1, and the same protease inhibitor in combination with fluconazole (400 mg on day 2 and 200 mg on days 3 to 8). Pharmacokinetic parameters were determined on days 1 and 8. RESULTS: In the saquinavir group, the median increase in the area under the plasma concentration vs time curve was 50% from 1800 microg l(-1) h to 2700 microg l(-1) h (P = 0.04, median increase: 900 microg l(-1) h; 2.5 and 97.5 percentile: 500-1300), and 56% for the peak concentration in plasma (from 550 to 870 microg l(-1), P = 0.04; median increase: 320 microg l(-1) h, 2.5 and 97.5 percentile: 60-450 microg l(-1)). In the ritonavir group, there were no detectable changes in the pharmacokinetic parameters on addition of fluconazole. CONCLUSIONS: Because of the favourable safety profile of saquinavir, dose adjustments are probably not necessary with concomitant use of fluconazole, as is the case for ritonavir.

Contains fulltext : 119509.pdf (Publisher’s version ) (Open Access) OBJECTIVE: To describe the pharmacokinetics, safety, and efficacy of twice-daily indinavir + ritonavir regimens DESIGN: A cohort-based survey of HIV-infected patients who either used indinavir 800 mg + ritonavir 100 mg twice daily or indinavir 400 mg + ritonavir 400 mg twice daily. METHODS: Data were extracted from a database of samples sent to our laboratory for measurement of indinavir + ritonavir plasma concentrations. Patient characteristics, safety, and efficacy measurements were collected by retrospective chart review. RESULTS: 100 Patients using 800-mg indinavir + 100-mg ritonavir twice daily and 32 patients using 400-mg indinavir + 400-mg ritonavir twice daily were eligible. Median peak and trough concentrations of indinavir were 6.8 and 0.77 mg/L in the 800/100 group and 2.6 and 0.45 mg/L in the 400/400 group. The most frequently found side effects were nausea and vomiting, which occurred in 22.1% and 34.9% of the patients in the 800/100 and the 400/400 groups, respectively. Viral load data were analyzed for patients who switched from 800-mg indinavir three times daily to one of the indinavir + ritonavir twice daily regimens. At the time of switch 63% (800/100 group) and 60% (400/400 group) had an undetectable viral load and this increased to 77% and 70%, respectively, during follow-up. Patients who switched to the 400/400 group discontinued treatment more frequently than patients who switched to the 800/100 group (70% vs. 26%, p =.008). CONCLUSIONS: Indinavir + ritonavir regimens show improved pharmacokinetic properties, allowing twice-daily dosing with food. Clinical data suggest that safety and efficacy is at least as good as with indinavir three-times-daily regimens without ritonavir. Prospective, comparative trials are needed to properly assess the role in HIV therapy of these twice-daily indinavir + ritonavir regimens.

The objective of this study was to evaluate the applicability of saliva as an alternative body fluid for therapeutic drug monitoring of nevirapine. The pharmacokinetics of nevirapine in plasma and saliva during a dosing interval was assessed in HIV-1-infected patients taking nevirapine (200 mg twice daily) to explore the relation between the concentration of nevirapine in plasma and saliva. To validate the anticipated relationship prospectively, single, paired plasma and saliva samples were obtained from nevirapine-treated HIV-1-infected outpatients. The plasma nevirapine concentration was strongly correlated with the salivary concentration. The mean saliva/plasma concentration ratio was 0.51 and was independent of the time after ingestion. Salivary nevirapine concentrations were used to estimate the corresponding plasma concentrations for 31 outpatients. Compared with the true plasma concentrations, the estimated concentrations were biased by -4.2%, with a precision of 13.3%. These data show a strong correlation between the salivary and plasma concentrations of nevirapine at a dosage of 200 mg twice daily. This relation has been validated prospectively, and the prediction of plasma concentrations was accurate and precise. Therefore, the authors conclude that saliva can be a useful body fluid for therapeutic drug monitoring of nevirapine.

The presence of the HIV-protease inhibitor indinavir in saliva was analyzed to investigate whether salivary indinavir concentrations are applicable to monitor compliance and/or predict plasma indinavir levels. Fourteen HIV-infected outpatients treated with indinavir and 24 healthy volunteers who ingested a single dose of indinavir were included. Paired plasma and citric-acid-stimulated saliva samples were analyzed by high-performance liquid chromatography (HPLC). Stimulated salivary indinavir concentrations showed a high correlation (r = 0.85, p0.01) with corresponding plasma levels. The median saliva/plasma ratio was 65% (P25 50%; P75 94%). The ratios were independent of the plasma concentration; however, a relation with time after ingestion was seen. The unbound fraction of indinavir in plasma was not significantly correlated with the saliva/plasma ratio after stimulated saliva collection, in contrast with a subset of nonstimulated saliva from healthy volunteers, where we did find a significant correlation. Although stimulated salivary indinavir concentrations are highly correlated with plasma concentrations, it is not possible to predict plasma indinavir levels by the salivary concentrations for purposes of therapeutic drug monitoring, due to large interindividual and intraindividual variation. Nevertheless, monitoring compliance by measuring the presence of indinavir in saliva is possible: ingestion of indinavir can be assessed with a sensitivity of 84.8% in the whole dosing interval or with 98.8% between 1 and 6 hours after the last dose, which is comparable with plasma.

The use of highly active antiretroviral therapy, the combination of at least three different antiretroviral drugs for the treatment of HIV-1 infection, has greatly improved the prognosis for HIV-1-infected patients. The efficacy of a combination of a protease inhibitor (PI) plus two nucleoside analogue reverse transcriptase inhibitors has been well established over a period of up to 3 years. However, virological treatment failure has been reported in 40–60% of unselected patients within 1 year after initiation of a PI-containing regimen. This observation may, at least in part, be attributed to the poor pharmacokinetic characteristics of the PIs. Given as a single agent the PIs have several pharmacokinetic limitations; relatively short plasma-elimination half-lives and a modest and variable oral bioavailability, which is, for some of the PIs, influenced by food. To overcome these suboptimal pharmacokinetics, high doses (requiring large numbers of pills) must be ingested, often with food restrictions, which complicates patient adherence to the prescribed regimen. Positive drug–drug interactions increase the exposure to the PIs, allowing administration of lower doses at reduced dosing frequencies with less dietary restrictions. In addition to increasing the potency of an antiretroviral regimen, combinations of PIs may enhance patient adherence, both of which will contribute to a more durable suppression of viral replication. The favourable pharmacokinetics of PIs in combination are a result of interactions through cytochrome P450 3A4 (CYP3A4) isoenzymes and, possibly, the multi-drug transporting P-glycoprotein (P-gp). Antiretroviral synergy between PIs and non-overlapping primary resistance patterns in the HIV-1 protease genome may further enhance the anti-retroviral potency and durability of combinations of PIs. Many combinations contain ritonavir because this PI has the most pronounced inhibiting effects on CYP3A4. The combination of saquinavir and ritonavir, both in a dose of 400 mg twice-a-day, is the most studied double PI combination, with clinical experience extending over 3 years. Combination of a PI with a low dose of ritonavir (≤400 mg/day), only to boost its pharmacokinetic properties, seems an attractive option for patients who cannot tolerate higher doses of ritonavir. A recently introduced PI, lopinavir, has been co-formulated with low-dose ritonavir, which allows for a convenient three-capsules, twice-a-day dosing regimen. In an attempt to prolong suppression of viral replication combinations of PIs are becoming increasingly popular. However, further clinical studies are needed to identify the optimal combinations for treatment of antiretroviral naive and experienced HIV-1-infected patients. This review covers combinations of saquinavir, indinavir, nelfinavir, amprenavir and lopinavir with different doses of ritonavir, as well as the combinations of saquinavir and indinavir with nelfinavir.

Objective: To investigate the steady-state pharmacokinetics of a once-daily dosing regimen of saquinavir soft gelatin capsules in combination with a low dose of ritonavir in HIV-1-infected individuals. Design: Open-label, multi-dose, pharmacokinetic pilot study. Patients: Seven HIV-1-infected individuals who were treated with saquinavir hard gelatin capsules 400 mg twice daily + ritonavir liquid formulation 400 mg twice daily were switched to saquinavir soft gelatin formulation 1600 mg once daily in combination with ritonavir liquid formulation 200 mg once daily (day 0). Patients were instructed to ingest saquinavir and ritonavir simultaneously in the morning and with a meal. Methods: Steady-state pharmacokinetics of saquinavir and ritonavir were assessed during a 24 h dosing interval after 2 weeks of continued therapy (day 14). Plasma saquinavir and ritonavir concentrations were measured using a validated high performance liquid chromatography assay. In addition, plasma HIV-1 RNA, and fasting total cholesterol, high-density lipoprotein, low-density lipoprotein, and triglyceride levels were measured on days 0 and 14. A non-compartmental pharmacokinetic method was used to calculate the area under the plasma concentration versus time curve (AUC [0-24h] ), the maximum and trough plasma concentrations (C max and C min ), the time to reach C max (T max ), the elimination half-life (t 1/2 ), the apparent clearance (CI/F), and the apparent volume of distribution (V/F), Results: Median (range) values of the pharmacokinetic parameters for saquinavir after 2 weeks of treatment were: AUC [0-24h] , 19 802h * ng/ml (3720-74016); C max 2936 ng/ml (573-6848); C min , 84 ng/ml (11-854); T max , 3.5 h (3.0-4.0), t 1/2 , 6.8 h (4.6-10.2); Cl/F, 81 l/h (22-430); V/F, 11891 (215-3086). Ritonavir concentrations were always below the 90% effective concentration of 2100 ng/ml (median C max , 1323 ng/ml; range, 692-1528 ng/ml). No significant changes were observed for total serum cholesterol, high-density lipoprotein, and low-density lipoprotein levels between days 0 and 14 (P ≥ 0.24). In six out of seven patients the fasting serum triglyceride levels were lower 2 weeks after the treatment switch (median decrease was 32%, P = 0.03). No significant changes in plasma HIV-1 RNA concentrations were observed between days 0 and 14. The regimen was generally well tolerated. Conclusions: This pharmacokinetic study indicates that the combination of 1600 mg of saquinavir (soft gelatin capsules) and 200 mg of ritonavir (liquid formulation) in a once-daily dosing regimen generally results in therapeutic plasma concentrations of saquinavir. Due to the large interindividual variation in saquinavir exposure, the monitoring of saquinavir concentrations in plasma is warranted. These pharmacokinetic findings rationalize the further clinical evaluation of once-daily dosing of this combination of protease inhibitors.

Purpose: To describe the pharmacokinetics of paclitaxel and to investigate the interaction potential with protease inhibitors (indinavir, ritonavir, saquinavir) and the nonnucleoside reverse transcriptase inhibitor nevirapine, for which strong theoretical indications for clinically relevant drug interactions exist. Methods: The 24-h plasma pharmacokinetics of paclitaxel (Taxol, given at 100 mg/m2 by 3-h intravenous infusion) and concomitantly infused antiretroviral drugs were determined in a human immunodeficiency virus 1 (HIV-1)-infected male patient with refractory Kaposi's sarcoma (KS) during high-activity antiretroviral therapy and after discontinuation of this regimen. The plasma pharmacokinetics of paclitaxel, indinavir, ritonavir, saquinavir, and nevirapine were closely monitored. Since all these drugs are extensively metabolized via the cytochrome P450 enzyme system and are substrates for the multidrug transporter P-glycoprotein, investigation of drug-drug interactions was considered important. Results: In this case report study the pharmacokinetics of paclitaxel given concomitantly with various antiretroviral drugs were comparable with those of historical controls who had been treated with single-agent paclitaxel. The pharmacokinetics of indinavir, ritonavir, saquinavir, and nevirapine were also not statistically significantly different from those recorded for historical controls. Paclitaxel was well tolerated and resulted in a significant clinical response in this patient. Conclusion: Dose adjustments of paclitaxel, indinavir, ritonavir, saquinavir, or nevirapine are apparently not needed if HIV-1-associated KS is treated with paclitaxel at a dose of 100 mg/m2 as shown in the present case. It is stressed, however, that controlled studies are necessary to substantiate these preliminary case report findings.

Recently, the authors were confronted with interference of stavudine and co-trimoxazole when analyzing the antiretroviral drug didanosine (ddI) in plasma of HIV-1-infected patients using reverse-phase high-performance liquid chromatography with ultraviolet detection. After increasing the percentage of methanol in the mobile phase from 4% to 8% vol/vol and after decreasing the pH of the mobile phase from 6.8 to 5.8, the authors were able to separate didanosine from stavudine and co-trimoxazole (both are frequently used drugs in combination with didanosine). Subsequently, the adapted bioanalytic methodology was validated, and validation results showed that this new methodology can be used for the quantitative determination of didanosine in human plasma. This observation makes clear that combination therapy for human immunodeficiency virus with multiple (often chemically related) drugs has the potential of unexpectedly complicating bioanalytic analyses because therapeutic strategies may change rapidly after publication of a bioanalytic methodology. Thus, it is evident that the investigation of interference of potentially coadministered drugs should be a standard procedure during the development of any bioanalytical methodology in any laboratory.

The purpose of this paper is to present the experience with 4 adult CLP patients with severe maxillary hypoplasia and an unacceptable upper lip. This was corrected with a Le Fort I advancement osteotomy en bloc or in two segments, bone grafting the alveolar cleft if present and an Abbe flap. The combination of a Le Fort I osteotomy and an Abbe flap resulted in satisfactory functional and aesthetic improvement in all 4 adult CLP patients without complications.

A new biological process for ammonia removal from flows containing hundreds to thousands milligrams NH+4 per litre has been developed at the Delft University of Technology. The SHARON process operates at a high temperature (30–40 °C) and pH (7–8). The process is performed without sludge retention. This enables the prevention of nitrite oxidation, leading to lower operational costs. Denitrification is used to control the pH. A full scale plant was designed (1500 m3) based on kinetic and stoichiometric parameters determined at 1.5 1. scale and model predictions. Total costs are estimated at about $1.7 per kg removed NH4+-N. The first full scale SHARON plant will be operational at the Dokhaven waste water treatment plant in Rotterdam in the beginning of 1998. This contribution focuses on the principles of the process and evaluates conditions for which application seems feasible.

Objective: To investigate the relationship between exposure to antiretroviral drugs and the initial decline of plasma HIV-1 RNA. Design: Open-label study in antiretroviral-naive HIV-1 infected patients using a quadruple drug regimen [nelfinavir (NFV), saquinavir (SQV), stavudine, and lamivudine]. Methods: The elimination rate constant (k) for HIV-1 clearance was calculated during the first 2 weeks of treatment in 29 patients. Exposure to NFV and SQV was quantified on each study visit. Observed NFV and SQV concentrations were related to those expected in a reference population and a concentration ratio was calculated. The median concentration ratios for NFV and SQV, the baseline CD4+ lymphocyte count and baseline log10 HIV-1 RNA were correlated with k. Results: A significant positive correlation was observed between k and the median NFV (P = 0.001) or SQV concentration ratio (P = 0.016) in univariate analysis. In multivariate analyses, the median NFV concentration ratio remained significantly correlated with k. Conclusions: The variation in the rate of decline of plasma HIV-1 RNA between patients after the initiation of a quadruple drug regimen could be explained by differences in exposure to NFV or SQV. Determination of k could be used to optimise further antiretroviral drug therapy and may be a first tool to assess antiretroviral activities of new or increasing doses of drugs administered in combination regimens. Furthermore, our data suggest that exposure to antiretroviral drugs should be incorporated in mathematical models to describe HIV-1 dynamics in more detail.

Recent advances in molecular genetics have importantly improved our understanding of the development of colorectal cancer. The present review gives an overview of the clinical value of the tumour-suppress or gene, p53, and the CD44 cell adhesion molecule in colorectal cancer and the pitfalls encountered in the immunohistochemical detection of these proteins. Immunohistochemistry potentially forms a procedure applicable for routine diagnosis and prognostication. Therefore, p53 expression and the independent prognostic importance of CD44v6 expression is given particular emphasis, and other molecular events underlying colorectal carcinogenesis are only mentioned briefly

In this review the clinical pharmacology of HIV protease inhibitors, a new class of antiretroviral drugs, is discussed. After considering HIV protease function and structure, the development of inhibitors of HIV protease is presented. Three protease inhibitors are reviewed in more detail: saquinavir, indinavir, and ritonavir. Clinical trial results with these agents are evaluated. Furthermore, adverse effects, resistance, dosage and administration, clinical pharmacokinetics, pharmacokinetic-pharmacodynamic relationships, and drug interactions are discussed.

The surgical aim of genital reassignment surgery in male-to-female transsexuals is to create a perineogenital complex as feminine in appearance and function as possible. In this paper, we present a review of the various methods to line the neovagina in male-to-female transsexuals. These methods may be classified in five categories involving, respectively, application of nongenital skin grafts, penile skin grafts, penile skin flaps, nongenital skin flaps, and pedicled intestinal transplants. Based on this review and our extensive personal experience, we come to certain recommendations regarding the eligibility of these methods.

We have conducted a pharmacokinetic study of didanosine (ddI), formulated in sachets and in tablets, in patients with acquired immune deficiency syndrome (AIDS). Fifteen subjects received 250 or 167 mg of ddI twice daily as the sachet formulation and used this for at least 1 month. Subsequently, the patients were converted to receive ddI chewable/dispersible tablets (250-mg sachets to 200-mg tablets; 167-mg sachets to 125-mg tablets). Four subjects withdrew because of clinical deterioration or adverse effects. Serial blood samples were collected for pharmacokinetic monitoring during the use of the sachets and after 1 month of use of the tablets. No statistically significant differences were found in the maximum plasma concentration (Cmax), the time to reach Cmax (tmax), the area under the plasma concentration-time curve (AUC), or the terminal elimination half-life (t1/2) between the two formulations. Patients who received low-dose ddI (sachets, 167 mg; tablets, 125 mg) displayed lower plasma concentrations than did the patients receiving high-dose ddI (sachets, 250 mg; tablets, 200 mg), despite an equal weight-normalized dose of ddI in these two groups.

In untreated, asymptomatic human immunodeficiency virus type 1 (HIV-1) infection, elevated serum concentrations of soluble receptors for tumor necrosis factor (sTNFR) types I and II are associated with progression to AIDS. To assess the utility of sTNFRs as markers for the assessment of antiretroviral treatment, sTNFRs were sequentially determined in 47 asymptomatic HIV-1-infected men, who participated in a double-blind, randomized, placebo-controlled study. Progression to AIDS or severe AIDS-related complex occurred in six zidovudine (ZDV)- and six placebo-treated subjects. During ZDV treatment (n = 28) both types of sTNFRs declined compared with baseline and placebo, whereas they increased during placebo treatment (n = 19). A sustained decline of sTNFRs occurred only in subjects who experienced no disease progression. During the first 3 months of ZDV treatment, the hazard ratio for disease progression when sTNFR type II rose above the baseline value plus 5% was significantly increased (hazard ratio: approximately 25; 95% confidence interval: approximately 1.5-400; p < 0.03). Simultaneously determined CD4+ counts and serum neopterin levels showed a similar pattern in progressors and nonprogressors. Thus, in contrast to CD4+ counts and neopterin levels, sTNFR concentrations, especially those of the type II STNFR, appear to be valuable surrogate markers for monitoring the efficacy of ZDV treatment in asymptomatic HIV-1 infection.

This paper describes the development and validation of an assay for the simultaneous quantification of the antiviral and antiretroviral drugs zidovudine, abacavir, emtricitabine, lamivudine, tenofovir and ribavirin in human plasma using liquid chromatography coupled to tandem mass spectrometry. Sample pretreatment consisted of protein precipitation with 0.1% (v/v) formic acid in methanol, evaporation and reconstitution. Chromatographic separation was performed on a Synergy Polar reversed phase C18 column (150 mm × 2.0 mm ID, particle size 4 μm) using a stepwise gradient with 0.1% (v/v) formic acid in water and 0.1% (v/v) formic acid in methanol at a flow rate of 300 μL/min. A triple quadrupole mass spectrometer operating in the positive ionization mode was used for drug detection and quantification. Isotopically labeled zidovudine, lamivudine, tenofovir and ribavirin were used as internal standards. The method was validated over a clinical range of 20-2500 ng/mL for zidovudine, lamivudine and tenofovir, 4-500 ng/mL for abacavir and emtricitabine and 160-20,000 ng/mL for ribavirin. The inter and intra-assay accuracies and precisions were between -8.47% and 14.2% for zidovudine, emtricitabine and ribavirin. For abacavir, lamivudine and tenofovir, the inter and intra-assay accuracies and precisions at the lower limit of quantification were between -11.0% and 18.3%, whereas at all other levels these accuracies and precisions were between -11.7% and 12.0%. The described method is suitable for the determination of zidovudine, abacavir, emtricitabine, lamivudine, tenofovir and ribavirin in human plasma in clinical practice to monitor plasma concentrations in selected cases to optimize therapy.

OBJECTIVE To investigate determinants of inter- and intraindividual variability of zidovudine (ZDV) pharmacokinetics in HIV-infected patients. DESIGN A prospective study in a general 525-bed hospital with special funding for treatment and research of HIV-infected patients. METHODS Serial blood samples were collected from 68 HIV-infected individuals providing a total of 95 pharmacokinetic curves. ZDV was measured with high-performance liquid chromatography and radioimmunoassay. Pharmacokinetic parameters were calculated by non-compartmental analysis. Patient characteristics were investigated by multivariate analysis for an influence on ZDV pharmacokinetics. RESULTS Apparent ZDV clearance was significantly lower in patients with a lower body weight, in women, and in patients with a more advanced stage of HIV disease. Co-administration of methadone with ZDV resulted in higher plasma concentrations of ZDV, while rifampin and ganciclovir increased apparent ZDV clearance. Age, the duration of ZDV use, CD4+ cell count, creatinine clearance, elevated serum liver enzyme levels, and the use of 11 other co-administered medications were not independently related to apparent ZDV clearance. CONCLUSIONS The pharmacokinetic profile of ZDV in several subpopulations has been evaluated, as well as the observation of possible drug-drug interactions between ZDV and 14 different drugs or groups of drugs. These data suggest that patient-individualized antiretroviral therapy may be appropriate once pharmacokinetic-pharmacodynamic relationships have been established.

Fluorescence in situ hybridization (FISH) is a powerful tool for detection of numerical and structural chromosomal aberrations. We have compared conventional banding techniques and FISH for the detection of monosomy 7 (-7) and trisomy 8 (+8) in 89 patients with myeloid malignancies. Of these patients, 21 had -7, 30 had +8, four had both, and 34 had no aberrations or aberrations other than -7 or +8 as assessed by banding techniques. Sequential samples were available in 23 patients. Alphoid DNA probes specific for chromosomes no. 7 and 8 were used for FISH. As controls, 10 normal bone marrow (BM) samples were hybridized with the chromosomes no. 7 and 8 probes, and in addition all tumor samples were hybridized with a chromosome no. 1 specific probe. The cut-off value for -7 was 18% one-spot cells, and for +8 was 3% three-spot cells. FISH analysis of 44 samples with -7 or +8, and at least 10 metaphases evaluated, showed that the proportions of aberrant metaphase cells mirrored the interphase clone sizes. Most samples with nonclonal metaphase aberrations, including those with only a few metaphases, had increased numbers of aberrant interphase cells: 20% to 80% for -7, and 3% to 43% for +8. Interphase cytogenetics of the 34 samples without -7 or +8 did not show significant cell populations with -7 or +8. In four patients, -7 or +8 could not be confirmed by FISH due to additional structural aberrations, marker chromosomes, or wrongly interpreted banding results. As FISH will be used more and more in cytogenetic diagnosis, clinical follow-up, and therapy monitoring, it will be necessary to standardize FISH procedures and supplement the Standing Committee on Human Cytogenetic Nomenclature (ISCN) definitions of a clone with criteria specifically for in situ hybridization.

Summary. We studied the prevalence and risk factors for thrombocytopenia among 299 drug users and 461 homosexual men. The prevalence of thrombocytopenia was 3·3% in HIV-negative homosexual men, 8·7% in HIV-negative drug users, 16·4% in HIV-positive homosexual men, and 36·9% in HIV-positive drug users. With multivariate logistic regression HIV-seropositivity (odds ratio 3·3), a history of injecting drugs (OR 3·9), an increased number of lymphocytes (OR 0·44), an increased number of neutrophils (OR 0·53) and a larger mean platelet volume (OR 2·8) were independently and significantly associated with thrombocytopenia. The results obtained with linear regression analysis were consistent with the results of the logistic regression. The higher prevalence of thrombocytopenia among drug users was related to a history of intravenous drug use but not to recent injecting. The mechanisms causing thrombocytopenia among HIV-positives and HIV-negatives seem to be related, but HIV-infection seems to enhance thrombocytopenia in an independent way.

Congenital absence of skin is rare; it usually presents in the midline over the vertex of the skull. There may be a lack of skin only, but a defect in the skull, with or without dura, may also be present. Two cases of congenital scalp defect have been treated. A male neonate was seen on the day of birth and the soft tissue defect was closed by a rotation flap. A female baby of 2 months was seen for recurrent episodes of severe wound infection and profuse bleeding. The infection could only be sufficiently treated after coverage of the soft tissue defect with a scalp flap. Scalp defects should be treated operatively in cases where spontaneous epithelization from the edges of the wound cannot be expected to be complete within a few weeks. Skin defects wider than 1 cm. should preferably be covered by scalp flaps. Bony defects should always be covered by skin flaps or grafts.

Atazanavir is a commonly prescribed protease inhibitor for treatment of HIV-1 infection. Thus far, only limited data are available on the in vivo metabolism of the drug. Three systemic circulating metabolites have been reported, but their chemical structures have not been released publicly. Atazanavir metabolites may contribute to its effectiveness but also to its toxicity and interactions. Thus, there is a need for extensive metabolic profiling of atazanavir. Our goals were to screen and identify previously unknown atazanavir metabolites and to develop a sensitive metabolite profiling method in plasma. Five atazanavir metabolites were detected and identified in patient samples using liquid chromatography coupled to linear ion trap mass spectrometry: one N-dealkylation product (M1), two metabolites resulting from carbamate hydrolysis (M2 and M3), a hydroxylated product (M4), and a keto-metabolite (M5). For sensitive semiquantitative analysis of the metabolites in plasma, the method was transferred to liquid chromatography coupled to triple quadrupole mass spectrometry. In 12 patient samples, all the metabolites could be detected, and possible other potential atazanavir keto-metabolites were found. Atazanavir metabolite levels were positively correlated with atazanavir levels, but interindividual variability was high. The developed atazanavir metabolic screening method can now be used for further clinical pharmacological research with this antiretroviral agent.

Pierre Robin sequence (PRS) is a congenital malformation in which micrognathia causes retroposition of the tongue. This results in feeding and breathing difficulties that can lead to severe complications. If conservative treatment is not sufficient, a surgical procedure such as a tongue-lip adhesion can be performed. The objective of this study was to evaluate our benefits and complications with this operation.All patients under the care of the Department of Plastic and Reconstructive Surgery of the VU University Medical Center, Amsterdam, The Netherlands, in the period 1993 to 2002.A consecutive series of 22 patients who needed operative intervention for PRS. All underwent a tongue-lip adhesion.Retrospective analysis of the patient charts. Follow-up has been performed for a minimum of 1 year.In 16 (73%) of the patients operated on, feeding and breathing have improved. In 6 children, the results were limited because of concomitant congenital anomalies. Complications, all without lasting effect, were observed in 12 (55%) of the patients: 4 of 5 children with dehiscence of the adhesion needed reoperation, 6 developed small chin abscess that resolved after removal of the supporting suture, and 1 patient was reintubated for bronchospasm.Tongue-lip adhesion is a good surgical treatment for most children with PRS who have an isolated tongue-base airway obstruction. More invasive procedures such as mandibular distraction can be reserved for patients where a tongue-lip adhesion has not been successful.

beta 2-microglobulin levels were determined in the serum of 18 initially asymptomatic HIV-1 p24 antigenaemic subjects who were treated with zidovudine (+/- acyclovir) and who were followed for 2 1/2 years. The median serum beta 2-microglobulin level at week 0 was 2.5 mg/l and decreased to 2.3 mg/l after 12 weeks of treatment (p = 0.001). A correlation was found between individual changes in serum beta 2-microglobulin levels and individual changes in serum p24 antigen levels during the first 48 weeks of treatment (p less than 0.05). Six out of 18 subjects progressed to AIDS after 60-126 weeks of treatment. In this group during a period of more than one year before disease progression median serum beta 2-microglobulin levels increased from 2.5 mg/l to 3.3 mg/l (p = 0.03) and median CD4+ cell counts decreased from 0.3 x 10(9)/l to 0.08 x 10(9)/l (p = 0.03), while in that period the pattern of serum p24 antigen levels was inconsistent. Although the variability in serum beta 2-microglobulin levels appeared to make this marker unsuitable for management decisions in individuals, a decline in beta 2-microglobulin levels was found to parallel a decline in p24 antigen levels during the early phase of zidovudine treatment. Moreover, after prolonged treatment, rising beta 2-microglobulin levels--in contrast to p24 antigen levels--were shown to have predictive value for disease progression.

Declining CD4+ T-cell numbers and anti-CD3-induced T-cell responsiveness are prognostic markers for progression of HIV infection. We investigated the effect of long-term (2-year) zidovudine treatment on these immunological markers in a group of nine asymptomatic p24-antigenaemic men, five of whom progressed to AIDS. A group of 10 untreated HIV-infected men, five of whom progressed to AIDS, was studied as a control. At intake, 1 year before the start of treatment, CD4+ T-cell numbers in the groups were not significantly different. However, at that time progressors already exhibited an extremely low anti-CD3-induced T-cell responsiveness compared with non-progressors. In all people T-cell responsiveness and the number of CD4+ T-cells had improved 6 months after the start of zidovudine treatment. However, CD4+ T-cell numbers were not persistently elevated, and restoration of T-cell responsiveness was of only short duration. Our results show that zidovudine treatment in the asymptomatic phase of HIV infection did not result in a sustained improvement in T-cell function. Furthermore, they suggest that differences in clinical course among zidovudine-treated asymptomatics may be caused by heterogeneity of this group with respect to T-cell functional capacity at the start of treatment.

Hormonal therapy and gender-confirming surgery are the treatments of choice in appropriately selected male-to-female transsexuals. Penectomy and vaginoplasty are the paramount surgical requests of the male transsexual, but breast enlargement greatly increases subjective feelings of femininity. There are only limited reports on augmentation mammaplasty in male transsexuals, and hardly any attention has been paid to the differences between the female mammary anatomy and its male counterpart. The basic anatomic and surgical considerations of augmentation mammaplasty for 201 male-to-female transsexuals who were operated on from 1979 to 1997 are reviewed and discussed. They include the differences between male and female anatomy and how to feminize the male chest, the results of hormonal therapy and the proper timing of surgery, the choice of implant size and surgical approach, the results that may be expected after surgery, and the implications of all mentioned on the long-term outcome and follow-up after augmentation mammaplasty. Because the referring doctor may not check on the breasts or may not be trained to examine augmented breasts for pathologic conditions, the mammaplastic surgeon has an obligation to ensure the proper follow-up of these patients.

For the quantification of the HIV-integrase inhibitor raltegravir in human plasma, dried blood spots and peripheral blood mononuclear cell (PBMC) lysate, an assay was developed and validated, using liquid chromatography coupled with tandem mass spectrometry. The assay also allowed detection, but no quantification due to absence of reference substance, of the main metabolite, raltegravir-glucuronide. Raltegravir was extracted from plasma by means of protein precipitation with a mixture of methanol and acetonitrile using only 50microL plasma. Extraction from dried blood spots was performed with a simple one-step extraction with a mixture of methanol, acetonitrile and 0.2M zincsulphate in water (1:1:2, v/v/v) and extraction from cell lysate was performed in 50% methanol in water. Chromatographic separation was performed on a reversed phase C18 column (150mmx2.0mm, particle size 5microm) with a quick stepwise gradient using an acetate buffer (pH 5) and methanol, at a flow rate of 0.25mL/min. The analytical run time was 10min. The triple quadrupole mass spectrometer was operated in the positive ion-mode and multiple reaction monitoring was used for drug quantification. The method was validated over a range of 50-10,000ng/mL in plasma and dried blood spots and a range of 1-500ng/mL in PBMC lysate. Dibenzepine was used as the internal standard. The method was proven to be specific, accurate, precise and robust. Accuracies ranged from 104% to 105% in plasma, from 93% to 105% in dried blood spots and from 82% to 113% in PBMC lysate. Precision over the complete concentration range was less than 6%, 11% and 13% in plasma, dried blood spots and PBMC lysate, respectively. The method is now applied for therapeutic drug monitoring and pharmacological research in HIV-infected patients treated with raltegravir.