Combining Hepatic Percutaneous Perfusion with Ipilimumab plus Nivolumab in advanced uveal melanoma (CHOPIN): study protocol for a phase Ib/randomized phase II trial.

BACKGROUND: While immune checkpoint inhibition (ICI) has revolutionized the treatment of metastatic cutaneous melanoma, no standard treatments are available for patients with metastatic uveal melanoma (UM). Several locoregional therapies are effective in the treatment of liver metastases, such as percutaneous hepatic perfusion with melphalan (M-PHP). The available literature suggests that treatment with ICI following locoregional treatment of liver UM metastases can result in clinical response. We hypothesize that combining M-PHP with ICI will lead to enhanced antigen presentation and increased immunomodulatory effect, improving control of both hepatic and extrahepatic disease. METHODS: Open-label, single-center, phase Ib/randomized phase II trial, evaluating the safety and efficacy of the combination of M-PHP with ipilimumab (anti-CTLA-4 antibody) and nivolumab (anti-PD-1 antibody) in patients with unresectable hepatic metastases of UM in first-line treatment, with or without the limited extrahepatic disease. The primary objective is to determine the safety, toxicity, and efficacy of the combination regimen, defined by maximum tolerated dose (MTD) and progression-free survival (PFS) at 1 year. Secondary objectives include overall survival (OS) and overall response rate (ORR). A maximum of 88 patients will be treated in phase I and phase II combined. Baseline characteristics will be described with descriptive statistics (t-test, chi-square test). To study the association between risk factors and toxicity, a logistic regression model will be applied. PFS and OS will be summarized using Kaplan-Meier curves. DISCUSSION: This is the first trial to evaluate this treatment combination by establishing the maximum tolerated dose and evaluating the efficacy of the combination treatment. M-PHP has shown to be a safe and effective treatment for UM patients with liver metastases and became the standard treatment option in our center. The combination of ICI with M-PHP is investigated in the currently described trial which might lead to a better treatment response both in and outside the liver. TRIAL REGISTRATION: This trial was registered in the US National Library of Medicine with identifier NCT04283890 . Registered as per February 2020 - Retrospectively registered. EudraCT registration number: 2018-004248-49. Local MREC registration number: NL60508.058.19.

Transition of care in stroke patients discharged home: a single-center prospective cohort study.

INTRODUCTION: Approximately two-thirds of the patients admitted to the hospital with an ischemic stroke are discharged directly home. Discontinuity of care may result in avoidable patient harm, re-admissions and even death. We hypothesized that the transfer of information is most essential in this patient group since any future care for these patients relies solely on the information that is available to the care provider responsible at that time. AIM: The objective of this study was to evaluate the continuity of transmural care in ischemic stroke patients by assessing 1) the transfer of clinical information through discharge letters to general practitioners (GPs), 2) subsequent documentation of this information and early follow-up by GPs and 3) the documentation of medication-related information in discharge letters, at GPs and community pharmacies (CPs). METHODS: This prospective cohort study was conducted from September 2019 through March 2020 in OLVG, Amsterdam, the Netherlands, in patients with a first stroke discharged directly home. Outcome measures were derived from national guidelines and regional agreements. Results were analyzed using descriptive analysis. RESULTS: A total of 33 patients were included. Discharge letters (n = 33) and outpatient clinic letters (n = 24) to GPs contained most of the essential items, but 16% (n = 9) of the letters were sent in time. GPs (n = 31) infrequently adhered to guidelines since 10% (n = 3) of the diagnoses were registered using the correct code and 55% (n = 17) of the patients received follow-up shortly after discharge. Medication overviews were inaccurately communicated to GPs since 62% (n = 150) of all prescriptions (n = 243) were correctly noted in the discharge letter. Further loss of information was seen as only 39% (n = 95) of all prescriptions were documented correctly in GP overviews. We found that 59% (n = 144) of the prescriptions were documented correctly in CP overviews. CONCLUSION: In this study, we found that discontinuity of care occurred to a varying extent throughout transmural care in patients with a first stroke who were discharged home.

[Exchange of information between psychiatrist and pharmacist concerning uncollected medication]. / Informatie-uitwisseling tussen psychiater en apotheker over niet-opgehaalde medicatie.

Background Non- compliance with drug regimens has a negative effect on symptomatology and is the largest predictor of relapse in people with Severe Psychiatric Disorder (EPA). When care providers are informed in good time that medication has not been collected and can act on it, compliance can be increased. Aim Assessment of usefulness and feasibility of a system for the Signaling and Reporting by Pharmacists of Uncollected Medication for people with an EPA (Dutch: 'SMANOM-EPA') within the current legal context. Method The package of requirements was drawn up on the basis of questionnaires and telephone interviews with psychiatrists and pharmacists and focus group meetings with patients and significant others. Lawyers and ICT professionals were consulted to formulate the legal and technical preconditions. Results All parties involved considered SMANOM-EPA to be useful. The administrative burden was a determining factor for the feasibility and transparency was an important precondition. The exchange of information could take place securely with existing technology, despite the variation in prescribing and issuing systems. However, opinions were divided as to whether informing and documenting is sufficient or whether consent is necessary. Conclusion The GDPR and the WBGO safeguard patients' rights regarding the use of personal data. Uncertainty about the legal framework and technological possibilities add to the complexity of innovations to promote the exchange of information between practitioners, while the added value is seen by those involved and in comparable innovations. Tijdschrift voor Psychiatrie 63(2021)1, 32-38.

Neuropharmacology of the mesolimbic system and associated circuits on social hierarchies.

Most socially living species are organized hierarchically, primarily based on individual differences in social dominance. Dominant individuals typically gain privileged access to important resources, such as food, mating partners and territories, whereas submissive conspecifics are often devoid of such benefits. The benefits associated with a high social status provide a strong incentive to become dominant. Importantly, motivational- and reward-related processes are regulated, to a large extent, by the mesolimbic system. Consequently, several studies point to a key role for the mesolimbic system in social hierarchy formation. This review summarizes the growing body of literature that implicates the mesolimbic system, and associated neural circuits, on social hierarchies. In particular, we discuss the neurochemical and pharmacological studies that have highlighted the contributions of the mesolimbic system and associated circuits including dopamine signaling through the D1 or D2 receptors, GABAergic neurotransmission, the androgen receptor system, and mitochondria and bioenergetics. Given that low social status has been linked to the emergence of anxiety- and depressive-like disorders, a greater understanding of the neurochemistry underlying social dominance could be of tremendous benefit for the development of pharmacological treatments to dysfunctions in social behaviors. This article is part of the Special Issue entitled 'The neuropharmacology of social behavior: from bench to bedside'.

Diazepam actions in the VTA enhance social dominance and mitochondrial function in the nucleus accumbens by activation of dopamine D1 receptors.

Benzodiazepines can ameliorate social disturbances and increase social competition, particularly in high-anxious individuals. However, the neural circuits and mechanisms underlying benzodiazepines' effects in social competition are not understood. Converging evidence points to the mesolimbic system as a potential site of action for at least some benzodiazepine-mediated effects. Furthermore, mitochondrial function in the nucleus accumbens (NAc) has been causally implicated in the link between anxiety and social competitiveness. Here, we show that diazepam facilitates social dominance, ameliorating both the competitive disadvantage and low NAc mitochondrial function displayed by high-anxious rats, and identify the ventral tegmental area (VTA) as a key site of action for direct diazepam effects. We also show that intra-VTA diazepam infusion increases accumbal dopamine and DOPAC, as well as activity of dopamine D1- but not D2-containing cells. In addition, intra-NAc infusion of a D1-, but not D2, receptor agonist facilitates social dominance and mitochondrial respiration. Conversely, intra-VTA diazepam actions on social dominance and NAc mitochondrial respiration are blocked by pharmacological NAc micro-infusion of a mitochondrial complex I inhibitor or an antagonist of D1 receptors. Our data support the view that diazepam disinhibits VTA dopaminergic neurons, leading to the release of dopamine into the NAc where activation of D1-signaling transiently facilitates mitochondrial function, that is, increased respiration and enhanced ATP levels, which ultimately enhances social competitive behavior. Therefore, our findings critically involve the mesolimbic system in the facilitating effects of diazepam on social competition and highlight mitochondrial function as a potential therapeutic target for anxiety-related social dysfunctions.

The effects of stress during early postnatal periods on behavior and hippocampal neuroplasticity markers in adult male mice.

Infancy is a critical period for brain development. Emerging evidence indicates that stress experienced during that period can have long-term programming effects on the brain and behavior. However, whether different time periods represent different vulnerabilities to the programming of different neurobehavioral domains is not yet known. Disrupted maternal care is known to interfere with neurodevelopmental processes and may lead to the manifestation of behavioral abnormalities in adulthood. Mouse dams confronted with insufficient bedding/nesting material have been shown to provide fragmented maternal care to their offspring. Here, we compared the impact of this model of early-life stress (ELS) during different developmental periods comprising either postnatal days (PNDs) 2-9 (ELS-early) or PND 10-17 (ELS-late) on behavior and hippocampal cell adhesion molecules in male mice in adulthood. ELS-early treatment caused a permanent reduction in bodyweight, whereas this reduction only occurred transiently during juvenility in ELS-late mice. Anxiety was only affected in ELS-late mice, while cognition and sociability were equally impaired in both ELS-treated groups. We analyzed hippocampal gene expression of the γ2 subunit of the GABAa receptor (Gabrg2) and of genes encoding cell adhesion molecules. Gabrg2 expression was increased in the ventral hippocampus in ELS-late-treated animals and was correlated with anxiety-like behavior in the open-field (OF) test. ELS-early-treated animals exhibited an increase in nectin-1 expression in the dorsal hippocampus, and this increase was associated with the social deficits seen in these animals. Our findings highlight the relevance of developmental age on stress-induced long-term behavioral alterations. They also suggest potential links between early stress-induced alterations in hippocampal Gabrg2 expression and the developmental programming of anxiety and between changes in hippocampal nectin-1 expression and stress-induced social impairments.

Clinical phenotype of X-linked myotubular myopathy in Labrador Retriever puppies.

BACKGROUND: Seven male Labrador Retriever puppies from 3 different litters, born to clinically normal dams and sires, were evaluated for progressive weakness and muscle atrophy. Muscle biopsies identified a congenital myopathy with pathologic features consistent with myotubular myopathy. Further investigations identified a pathogenic mutation in the myotubularin gene, confirming that these puppies had X-linked myotubular myopathy (XLMTM). OBJECTIVE: To review the clinical phenotype, electrodiagnostic and laboratory features of XLMTM in this cohort of Labrador Retrievers. RESULTS: Male puppies with XLMTM were small and thin compared with their normal littermates. Generalized weakness and muscle atrophy were present by 7 weeks of age in some puppies and evident to most owners by 14 weeks of age. Affected puppies stood with an arched spine and low head carriage, and walked with a short, choppy stride. Muscle atrophy was severe and progressive. Patellar reflexes were absent. Laryngeal and esophageal dysfunction, and weakness of the masticatory muscles occurred in puppies surviving beyond 4 months of age. Serum creatine kinase activity was normal or only mildly increased. EMG findings were nonspecific and included positive sharp waves and fibrillation potentials. Clinical signs progressed rapidly, with most affected puppies unable to walk within 3-4 weeks after clinical signs were first noticed. CONCLUSIONS AND CLINICAL IMPORTANCE: Although initial clinical signs of XLMTM are similar to the phenotypically milder centronuclear myopathy in Labrador Retrievers, XLMTM is a rapidly progressive and fatal myopathy. Clinicians should be aware of these 2 distinct myopathies with similar clinical presentations in the Labrador retriever breed.

Increase in prophylaxis of glucocorticoid-induced osteoporosis by pharmacist feedback: a randomised controlled trial.

UNLABELLED: The aim of this study was to determine whether feedback by pharmacists to prescribers of patients eligible for glucocorticoid-induced osteoporosis prophylaxis would stimulate the prescribing of osteoporosis prophylaxis. The intervention did not significantly increase the prescribing of bisphosphonates in the total study population, but a significant increase was seen in men and in the elderly. However, the proportion of bisphosphonate-treated patients remained low. INTRODUCTION: The aim of this study was to determine whether feedback by pharmacists to prescribers of patients eligible for glucocorticoid-induced osteoporosis prophylaxis (GIOP) would stimulate the implementation of the Dutch GIOP guideline. METHODS: This randomised controlled trial included 695 patients who were dispensed ≥675 mg prednisone equivalents without a concomitant bisphosphonate prescription within 6 months before baseline. Pharmacists were asked to contact the physicians of GIOP-eligible patients in the intervention group to suggest osteoporosis prophylaxis. The primary endpoint was a bisphosphonate prescription. Secondary endpoints were a prescription of calcium supplements, vitamin D or any prophylactic osteoporosis drug (bisphosphonate, calcium supplements, vitamin D). RESULTS: The group assigned to the intervention was slightly younger than the control group (68.7 ± 15.4 vs. 65.9 ± 16.9 years, p = 0.02) and used hydrocortisone more often (7.0% vs. 3.1%, p = 0.02). Within 6 months, the intervention did not significantly increase the prescribing of bisphosphonates (11.4% after intervention vs. 8.0% for controls; hazard ratio [HR] 1.47, 95% confidence interval [CI] 0.91-2.39). However, subgroup analyses showed a significant increase for the primary endpoint in men (12.8% vs. 5.1%, HR 2.53, 95% CI 1.11-5.74) and patients ≥70 years (13.4% vs. 4.9%, HR 2.88, 95% CI 1.33-6.23). The prescribing of calcium and vitamin D was not significantly altered. CONCLUSION: This study showed that active identification of patients eligible for GIOP by pharmacists did not significantly increase the prescribing of bisphosphonates in the total study population, but there was an increase in men and the elderly. However, the proportion of GIOP-treated patients remained low.

[Autologous stem cell transplantation in haematological disorders,1980-2002]. / Autologe stamceltransplantatie bij hematologische aandoeningen, 1980-2002.

OBJECTIVE: To describe activities in the field of autologous stem cell transplantation in haematological disorders in the Netherlands in the periods before and after 1993 (at that time blood was introduced as source of stem cells). DESIGN: Descriptive, retrospective cohort study. METHOD: Data were collected from the Netherlands Stem Cell Transplantation Registry TYPHON. Details of all transplant patients were reported to TYPHON by the individual transplantation centres. In this overview we describe the changes in transplantation-related mortality, relapse rates and survival in the periods 1 January 1980-31 December 1992 and 1 January 1980-31 December 2002. RESULTS: The number of autologous stem cell transplantations increased almost five-fold in the period 1993-2002. Since 1993 the main indications for transplantation were multiple myeloma (MM) and non-Hodgkin lymphoma (NHL), as well as acute myeloid leukaemia (AML), which was the main indication in the period before 1993. In the period before 1993 most relapses were observed in patients with acute lymphoblastic leukaemia (ALL) and MM, which resulted in low survival rates. After 1993 no great differences in relapse or survival rates were observed between the different disorders. The survival rates for patients with ALL improved during the last research period, especially among younger patients (< 45 years). CONCLUSION: The number of autologous stem cell transplantations has increased considerably since 1993, especially in patients with MM and NHL.

First-trimester serum marker distribution in singleton pregnancies conceived with assisted reproduction.

OBJECTIVE: To evaluate marker distribution of free beta-human chorionic gonadotrophin (fbeta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) in singleton pregnancies conceived by assisted reproduction techniques (ART). METHODS: In vitro fertilization (IVF) (n = 203) and intracytoplasmic sperm injection (ICSI) (n = 192) cases from a database of 14 645 first-trimester combined tests (overall study group) were selected and matched to 1164 controls for gestational age at sample date and maternal age. RESULTS: In the IVF group and ICSI group, lnPAPP-A was lower (IVF 6.74 vs 7.08; P = 0.0001; ICSI 6.59 vs 7.07; P = 0.0001) compared with the matched controls. Lnfbeta-hCG was lower in the IVF group (3.75 vs 3.90; P = 0.005) but not significantly different in the ICSI group (3.87 vs 3.93; P = 0.27). The computed correction factors for PAPP-A and fbeta-hCG were 1.42 and 1.17 for the IVF group and 1.56 and 1.05 for the ICSI group.The false-positive rate (FPR) in the IVF and ICSI group compared with the matched controls was higher (IVF 10.3% vs 8.6% and ICSI 10.9% vs 7.5%). In the overall age-biased [maternal age significantly lower compared with all ART and control groups] study group the FPR was 6.8%. CONCLUSION: The increase in FPR in the ART groups can be explained by decreased PAPP-A values. Therefore, an adjustment in risk analysis for Down syndrome is suggested.

In vivo angiogenesis in normal and portal hypertensive rats: role of basic fibroblast growth factor and nitric oxide.

BACKGROUND: Angiogenesis plays a pivotal role in many processes. Here, we studied whether angiogenesis to basic fibroblast growth factor (bFGF) in normal and portal hypertensive rats requires nitric oxide (NO). METHODS: To measure angiogenesis in vivo, two Teflon rings filled with collagen I (Vitrogen 100) were fixed in the mesenteric cavity at day 0, with one supplemented with bFGF (100 ng). Portal hypertension was induced by partial portal vein ligation (PVL). Sham-operated rats served as controls (CON). The role of NO was tested by adding the NO formation antagonist N(omega)-nitro-L-arginine (NNA; 3.3 mg/kg per day) to the drinking water. After 16 days, rings were explanted and embedded, and vessels were morphometrically counted. RESULTS: bFGF significantly stimulated vessel formation per implant in CON rats (from 624 +/- 97 without stimulation to 1123 +/- 171, n = 11, P < 0.01), but not in PVL rats (from 1106 +/- 174 without stimulation to 1046 +/- 202, n = 9). Without stimulation, numbers of ingrown vessels were significantly (P < 0.05) higher in PVL compared to CON rats. NNA substantially inhibited angiogenesis in both groups (P < 0.01). Vessel numbers were 202 +/- 124 for PVL (n = 5) and 197 +/- 14 for CON (n = 5) animals. bFGF did not reverse angiogenesis prevented by NNA (373 +/- 98 for PVL, 265 +/- 26 for CON, n = 5 per group, NS). CONCLUSIONS: NO formation inhibition diminishes both unstimulated and bFGF-stimulated angiogenesis in CON rats. Moreover, bFGF cannot rescue NNA-inhibited angiogenesis in PVL rats.

Genotype versus phenotype: conflicting results in mapping a lung tumor susceptibility locus to the G7c recombination interval in the mouse MHC class III region.

Susceptibility to chemically induced lung tumorigenesis has previously been mapped to a genomic interval of 27 kb in the MHC class III region of the mouse using two H2 (a/b) intra- H2 recombinants, B10.A(1R) and B10.A(2R). Three genes are located within this interval, G7e (encoding a viral envelope protein), G7a/ Vars2 (encoding valyl-tRNA synthetase), and G7c (a gene with unknown function). A 70 kb contig, spanning the 27 kb region and extending 20 kb either side, was constructed from lambda phage libraries with genomic inserts derived from mouse strains B10.A(1R) and B10.A(2R). The region was analyzed for single-nucleotide polymorphisms, which would facilitate further fine mapping of the interval. Analysis of the expression levels of the candidate genes did not reveal any difference between B10.A(1R) and B10.A(2R). In addition, no differences were found at the sequence level in the 27 kb interval except for an A to T transition in intron 7 of G7c. A database comparison of the sequence surrounding this polymorphism did not identify any DNA-binding or enhancer consensus sequence. In conclusion, the previously observed phenotype could not be associated with or assigned to any of the candidate genes G7e, G7a/ Vars2, or G7c, nor could any of the other susceptibility loci, which have been reported to map to this region ( Cps1, Acp, Orch1, and Igis1).

Increased angiogenesis in portal hypertensive rats: role of nitric oxide.

Systemic and especially splanchnic arterial vasodilation accompany chronic portal hypertension. Different soluble mediators causing this vasodilation have been proposed, the strongest evidence being for nitric oxide (NO). No data exist if structural vascular changes may partly account for this vasodilatory state. Here, we developed a new in vivo quantitative angiogenesis assay in the abdominal cavity and determined if: 1) portal hypertensive rats show increased angiogenesis; and 2) angiogenesis is altered by inhibiting NO formation. Portal hypertension was induced by partial portal vein ligation (PVL). Sham-operated rats served as controls (CON). During the index operation (day 0), a teflon ring filled with collagen I (Vitrogen 100) was sutured in the mesenteric cavity. After 16 days, rings were explanted, embedded in paraffin, and ingrown vessels counted using a morphometry system. The role of NO was tested by adding an antagonist of NO formation (Nomega-nitro-L-arginine [NNA], 3.3 mg/kg/d) into the drinking water. The mean number of ingrown vessels per implant was significantly higher in PVL rats compared with CON rats, i.e., 1,453 +/- 187 versus 888 +/- 116, respectively (P <.05; N = 5 per group). NNA significantly (P <.01) inhibited angiogenesis in PVL (202 +/- 124; N = 5) and in CON (174 +/- 25; N = 6) rats, respectively. In contrast, the beta-adrenergic blocker, propranolol, did not prevent angiogenesis either in PVL or CON rats in a separate set of experiments (data not shown). The conclusions drawn from this study are that: 1) rats with portal hypertension show increased angiogenesis; and 2) inhibition of NO formation significantly prevents angiogenesis in both PVL and CON rats. Therefore, splanchnic vasodilation in chronic portal hypertension may also be a result of structural changes.

Meropenem versus cefuroxime plus gentamicin for treatment of serious infections in elderly patients.

In this multicenter study, the efficacy of and tolerability for meropenem were compared with those for the combination of cefuroxime-gentamicin (+/- metronidazole) for the treatment of serious bacterial infections in patients > or = 65 years of age. A total of 79 patients were randomized; thirty-nine received meropenem (1 g/8 h), and 40 received cefuroxime (1.5 g/8 h) plus gentamicin (4 mg/kg of body weight daily) for 5 to 10 days. Metronidazole (500 mg/6 h) could be added to the cefuroxime-gentamicin regimen for the treatment of intra-abdominal infections (n = 10). Seventy patients were evaluable for clinical efficacy; the primary diagnoses were as follows: pneumonia in 41 patients (20 treated with meropenem, 21 treated with cefuroxime-gentamicin), intra-abdominal infection in 10 patients (7 meropenem, 3 cefuroxime-gentamicin-metronidazole), urinary tract infection (UTI) in 11 patients (6 meropenem, 5 cefuroxime-gentamicin), sepsis syndrome in 7 patients (4 meropenem, 3 cefuroxime-gentamicin), and "other" in 1 patient (cefuroxime-gentamicin). The pathogens isolated from 18 patients with bacteremia were as follows: Staphylococcus spp. (n = 2), Streptococcus spp. (n = 2), members of the family Enterobacteriaceae (n = 11), and Bacteroides spp. (n = 3). A satisfactory clinical response at the end of therapy was achieved in 26 of 37 (70%) and 24 of 33 (73%) evaluable patients treated with meropenem and combination therapy, respectively. Clinical success was achieved in 23 of 31 (74%) and 21 of 28 (75%) evaluable patients with infections other than UTIs, respectively. A satisfactory microbiological response occurred in 15 of 22 (68%) patients in the meropenem group compared with 12 of 19 (63%) treated with combination therapy. Renal failure occurred during therapy in 2 of 39 (5%) meropenem recipients compared with 5 of 40 (13%) of those treated with combination therapy. The findings in this small study indicate that meropenem is as efficacious for and as well tolerated by elderly patients as the combination of cefuroxime-gentamicin (+/- metronidazole).

Human monocyte-derived macrophages express an approximately 120-kD Ox-LDL binding protein with strong identity to CD68.

A protein that specifically binds oxidized LDL (Ox-LDL) has recently been characterized in mouse peritoneal macrophages and identified as macrosialin, a protein with a molecular weight of 95 kD. First, the present work shows that human monocyte-derived macrophages express a membrane protein with a molecular weight of approximately 120 kD that selectively binds Ox-LDL. Second, we tested whether this approximately 120-kD Ox-LDL binding protein had any relation to CD68, the human homologue of macrosialin. The following evidence was obtained to support the role of CD68 as an Ox-LDL binding protein: (1) Ligand blots with Ox-LDL and Western blots with Ki-M6, an anti-human CD68 monoclonal antibody, revealed a single band with a molecular weight of approximately 120 kD under reducing and nonreducing condition. (2) The expression patterns of the approximately 120-kD Ox-LDL binding membrane protein and of CD68 paralleled each other during monocyte/macrophage differentiation. (3) Digestion with N-glycosidase F demonstrated that both CD68 and the Ox-LDL binding protein are glycoproteins; both showed a similar shift of approximately 18 kD in apparent molecular weight. (4) CD68, probed with monoclonal antibody Ki-M6, and the approximately 120-kD Ox-LDL binding protein were coprecipitated with EMB11, another anti-CD68 antibody. About 5000 molecules of CD68 are expressed on the cell surface of human macrophages. Ligation of 125I-Ki-M6 to cells leads to its internalization and degradation. This capacity would be sufficient to allow for the specific uptake and degradation of Ox-LDL. Taken together, these data support a role for CD68 as a specific Ox-LDL binding protein in human monocyte-derived macrophages.

Decrease in scavenger receptor expression in human monocyte-derived macrophages treated with granulocyte macrophage colony-stimulating factor.

To determine whether scavenger receptors are susceptible to regulation by granulocyte macrophage colony-stimulating factor (GM-CSF), a macrophage-specific cytokine, human monocytes were differentiated into macrophages in the absence or presence of 20 U/mL GM-CSF. Binding, uptake, and degradation of acetylated LDL (Ac-LDL) and oxidized LDL (Ox-LDL) were measured. Treatment with GM-CSF resulted in a significant twofold to threefold decrease in the number of binding sites for Ac-LDL and Ox-LDL on the surface of macrophages without affecting the affinity of the receptor for these ligands. Competition experiments revealed that two binding sites were responsible for the recognition and uptake of Ac-LDL; one specific for Ac-LDL and one that recognized both Ac-LDL and Ox-LDL. No binding site specific for Ox-LDL could be detected in either control or GM-CSF-treated macrophages. Treatment of human monocyte-derived macrophages with GM-CSF resulted in a decrease of the Ac-LDL/Ox-LDL receptor but did not affect the binding site specific for Ac-LDL. Northern blot analysis showed that mRNA levels of both types I and II scavenger receptor were reduced in macrophages differentiated in the presence of GM-CSF. Human macrophages that were differentiated in the presence of GM-CSF accumulated approximately 50% fewer cholesteryl esters. Taken together, these results indicate that GM-CSF can downregulate both types I and II scavenger receptor in human monocyte-derived macrophages, which might have implications for foam cell formation.

Leukocyte depletion of random single-donor platelet transfusions does not prevent secondary human leukocyte antigen-alloimmunization and refractoriness: a randomized prospective study.

We studied the value of leukocyte depletion of platelet transfusions for the prevention of secondary human leukocyte antigen (HLA)-alloimmunization in patients with a high-risk of prior immunization induced by pregnancies. Seventy-five female patients with hematologic malignancies (mostly acute leukemia) and a history of pregnancy were randomized to receive either standard random single-donor platelet transfusions (mean leukocytes, 430 x 10(6) per transfusion) or leukocyte-depleted random single-donor platelet transfusions. Leukocyte depletion to less than 5 x 10(6) leukocytes per platelet transfusion (mean leukocytes, 2 x 10(6) per transfusion) was achieved by filtration. Of the 62 evaluable patients, refractoriness to random donor platelets occurred in 41% (14 of 34) of the patients in the standard group and in 29% (8 of 28) of the patients in the filtered group (P = .52); anti-HLA antibodies developed in 43% (9 of 21) of individuals in the standard group and 44% (11 of 25) of cases in the filtered group. The time toward refractoriness and development of anti-HLA antibodies was similar for both groups. We conclude that leukocyte depletion of random single-donor platelet products to less than 5 x 10(6) per transfusion does not reduce the incidence of refractoriness to random donor platelet transfusion because of boostering of anti-HLA antibodies.