Biomedical subjects

J W Smit

Publications and source records attributed to J W Smit.

At least 73 records · Page 4Linked to original sources

PubMed1995

Effects of alcohol consumption on pharmacokinetics, efficacy, and safety of fluvastatin.

Alcohol consumption is known to have beneficial effects on cardiac mortality, probably by increasing high density lipoprotein cholesterol (HDL-C). Alcohol also increases triglycerides and, in some studies, total cholesterol and low density lipoprotein cholesterol (LDL-C). Nothing is known, however, of the effects of alcohol on the pharmacokinetics and efficacy of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors. Consequently, 2 studies have been carried out to determine the effects of alcohol consumption on the pharmacokinetics and efficacy of the HMG-CoA reductase inhibitor fluvastatin. Firstly, the effects of acute alcohol consumption on a single, oral 40 mg dose of fluvastatin were examined in a reference-controlled, randomized, crossover study in 10 healthy volunteers. Measurements were made after ingestion of 70 g of ethanol diluted to 20% with lemonade and, following a 7-day period, after ingestion of lemonade alone (reference). The half-life (t1/2) of a single dose of fluvastatin was significantly reduced by acute alcohol consumption compared with reference, whereas the area under the time-concentration curve (AUC), peak concentration (Cmax), and time to peak concentration (tmax) did not differ from the reference group. The lipid profile, measured 8 hr after administration, did not differ significantly from baseline in the reference group, apart from a slight reduction in apolipoprotein (apo)-AI. Triglyceride levels increased with alcohol, probably due to impaired fatty acid oxidation. Surprisingly, total cholesterol and LDL-C fell significantly, possibly due to altered pharmacokinetics, as reflected by the lower t1/2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Treatment of combined hyperlipidemia with fluvastatin and gemfibrozil, alone or in combination, does not induce muscle damage.

Although combination therapy using 3-hydroxy-3-methylglutaryl coenzyme A (HMG-Co-A) reductase inhibitors and fibrates is efficacious in combined hyperlipidemia, such treatment has been associated with myopathy. For this reason, we studied the effects of fluvastatin and gemfibrozil, alone or in combination, on muscle. A total of 21 patients with combined hyperlipidemia were recruited who were matched for age, body mass index, and baseline levels of total cholesterol, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), triglycerides, creatine phosphokinase, and myoglobin. Patients were randomized to three groups for 6-week treatment with fluvastatin at 40 mg/day, gemfibrozil at 600 mg twice daily, or a combination of the two drugs. Parameters for muscle damage were rises in levels of serum creatine phosphokinase and myoglobin compared with pre-exercise levels; these were assessed 1 hr and 8 hr after a 45 min lean body mass standardized ergometer test, which was performed before and after treatment in all patients. Biopsies from the quadriceps muscle were taken 48 hr after each test. Fluvastatin lowered total cholesterol and LDL-C by 23% and 35%, respectively (p < 0.01), with no effects on triglycerides and HDL-C. Gemfibrozil lowered triglycerides by 40% (p < 0.01) but did not lower total cholesterol or LDL-C significantly. The combination therapy decreased total cholesterol, LDL-C, and triglycerides by 28%, 29%, and 39%, respectively (p < 0.05). Pre-exercise creatine phosphokinase and myoglobin levels were not affected by treatment in any group.(ABSTRACT TRUNCATED AT 250 WORDS)

Anticholesteremic Agents↗

PubMed1995

Effects of alcohol and fluvastatin on lipid metabolism and hepatic function.

OBJECTIVE: To determine the effects of fluvastatin, a synthetic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, combined with moderate alcohol consumption on lipid profiles and hepatic function in patients with primary hypercholesterolemia. DESIGN: Randomized, placebo-controlled, crossover study. SETTING: Lipid clinic of a university hospital. PATIENTS: 31 patients with primary hypercholesterolemia (low-density lipoprotein cholesterol levels > or = 4.2 mmol/L) who had previously received a lipid-lowering diet. INTERVENTIONS: After a dietary baseline period, 26 patients were randomly assigned to receive 6 weeks of treatment with either 1) fluvastatin, 40 mg/d, added to 20 g of ethanol and diluted to 20% with orange juice or 2) fluvastatin added to orange juice alone. After a 6-week washout period, the two groups crossed over. MAIN OUTCOME MEASURES: Plasma fluvastatin levels, lipid levels, and clinical variables were determined at the end of each treatment period. RESULTS: Six patients left the study prematurely. The remaining patients (15 men, 5 women; mean age +/- SD 49.1 +/- 14.5 years; mean body mass index +/- SD 24.5 +/- 2.2 kg/m2) completed the study. Fluvastatin, alone and combined with alcohol, resulted in similar decreases in levels of total cholesterol (22% and 23%, respectively; P < 0.001 when compared with baseline), low-density lipoprotein cholesterol (28% and 29%, respectively; P < 0.001 compared with baseline), and apolipoprotein B (17% and 20%, respectively; P < 0.001 compared with baseline). High-density lipoprotein cholesterol and triglyceride levels were not changed. Fluvastatin with alcohol resulted in a significantly greater area under the plasma concentration curve (23.4 +/- 4.7 compared with 18.2 +/- 3.2 x 10(3) ng.min/mL) and in a greater time to maximum concentration (187.5 +/- 16.6 min compared with 130.9 +/- 7.0 min) than fluvastatin alone. Terminal half-life tended to increase. No important adverse clinical effects were observed. CONCLUSION: Six weeks of daily, moderate alcohol consumption influenced the metabolism of fluvastatin but did not interfere with its lipid-lowering efficacy and had no adverse effects.

Adult↗

PubMed1995

A comparison of the effects of simvastatin and pravastatin monotherapy on muscle histology and permeability in hypercholesterolaemic patients.

1. In this double-blind, placebo controlled, prospective study, it was assessed whether simvastatin or pravastatin monotherapy have adverse effects on muscle histology and muscle membrane permeability in hypercholesterolaemic patients. 2. Twenty-four patients, seven females and 17 males, with primary hypercholesterolaemia (LDL cholesterol levels > or = 4.14 mmol l-1) were selected from the outpatient lipid clinic of a 650 bed academic medical centre. 3. After a 6-week lipid lowering diet and placebo period, patients were randomized into two groups of 12 subjects with similar characteristics, to receive either simvastatin or pravastatin in dosages of 10-40 mg day-1 for three periods of 6 weeks. After each 3-week period the dose was adjusted to LDL cholesterol to aim for equipotent dosage. 4. All subjects performed a 45 min, lean body mass standardized bicycle ergometer test, before and after 18 weeks of treatment. As parameter for muscle damage, the exercise-induced rise of the muscle proteins, creatine kinase (CK) and myoglobin (Mb), relative to pre-exercise levels, were determined 1 and 8 h after the test. Forty-eight hours after each test a biopsy was taken from the quadriceps muscle and histology was judged by three independent observers. 5. Eighteen weeks of monotherapy with simvastatin and pravastatin did not affect the exercise induced release of CK and Mb, neither were any differences observed in muscle histology before and after treatment with either of the drugs. 6. Although simvastatin doses were lower than pravastatin, reductions in total- and LDL-cholesterol were greater in the simvastatin treated patients than in the pravastatin treated group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

The effect of cyclosporine on haematological parameters in patients with paroxysmal nocturnal haemoglobinuria.

Four patients with paroxysmal nocturnal haemoglobinuria (PNH) were treated with cyclosporine. The treatment with cyclosporine was based on the hypothesis that immune-mediated bone-marrow damage is the common pathogenetic mechanism of aplasia and PNH, with lack of GPI-linked ligands for an immune attack (i.e. LFA-3, CD58) rendering PNH cells a growth advantage over other bone marrow cells. In the first patient, presenting with a mixed AA/PNH syndrome, a gradual recovery from aplasia was seen after prolonged treatment with cyclosporine. In a second patient, with a mixed AA/PNH syndrome, no haematological improvement was noted during cyclosporine administration, but this patient became transfusion-independent with increasing neutrophil and platelet counts after a course of ATG in combination with androgen therapy. Both these patients showed an increment in the proportion of neutrophils with normal expression of GPI-linked proteins concurrently with the improvement of haematological characteristics. In the two other patients, presenting with typical PNH, cyclosporine treatment did not result in any change in haematological characteristics, nor in PNH parameters. No significant change in haemolytic parameters was seen in any of the patients. It is concluded that immunosuppressive therapy may be of benefit in patients with a mixed AA/PNH syndrome. This effect became apparent after prolonged treatment with cyclosporine in one patient, and after a subsequent course of ATG with concomitant androgen therapy in another.

Adult↗

PubMed1995

Heterozygous familial hypercholesterolaemia is associated with pathological exercise-induced leakage of muscle proteins, which is not aggravated by simvastatin therapy.

The objective of this study was to assess the relationship between therapy with the HMG-CoA reductase inhibitor simvastatin and muscle damage and the possible causal role of hypercholesterolaemia. The exercise-induced release of muscle proteins as a parameter of muscle damage was studied in two equicholesterolaemic groups of male patients with heterozygous familial hypercholesterolaemia (FH); one group without treatment, the second group on simvastatin. To assess the role of cholesterol, a third group of healthy male volunteers was studied as well. The study took place at the Lipid Clinic of an 800-bed University Hospital. One group of 21 male patients with heterozygous FH did not receive treatment, except for a lipid-lowering diet. A second group of 13 male FH patients were treated with 40 mg simvastatin day-1 for at least 1 year and matched for cholesterol levels with the first group. A third group consisted of 25 normocholesterolaemic male controls. All subjects underwent a 45 min lean body mass (LBM) standardized ergometer muscle provocation test (2 Watt/kg LBM). Levels of creatine kinase (CK) and myoglobin (Mb) were assessed before and 1 and 8 h after exercise and compared with baseline levels. The exercise-induced release of muscle proteins is reflected by peak CK and Mb levels expressed as a percentage of baseline levels. The exercise-induced increase in Mb and CK levels did not differ between untreated and simvastatin-treated FH patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Effects of simvastatin and cholestyramine on bile lipid composition and gall bladder motility in patients with hypercholesterolaemia.

Although the effects of 3-hydroxy, 3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors and bile acid sequestrants on bile lipid composition have been studied separately, no data are available on combination therapy of these drugs. Moreover, the effects of prolonged (four weeks) administration of these drugs on gall bladder motility, an important determinant of cholesterol gall stone formation, have not been studied so far. A prospective study was therefore performed with eight patients who had hypercholesterolaemia (age 53 (5) (SEM), body mass index 27.4 (1.1) kg m-2, low density lipoprotein cholesterol 5.9 (0.3) mmol/l). They received treatment during three periods of four weeks with simvastatin 20 mg/day, cholestyramine 4 g twice daily, and a combination of both in random order, each treatment period separated by a two week wash out period. Before treatment and after each treatment period, postprandial gall bladder motility was studied with ultrasound, followed by duodenal bile sampling. Serum cholesterol decreased in all subjects in any treatment period illustrating good compliance. Molar percentages in duodenal bile of cholesterol, phospholipids, and bile salts were unchanged during simvastatin and cholestyramine treatment. During combined therapy percentage bile salts was lower (72.5 (2.9)% v 77.8 (1.7)% at baseline, p < 0.05) whereas phospholipids were higher (21.2 (2.4)% v 16.4 (1.3)% at baseline, p < 0.05). As a result cholesterol saturation index (CSI) did not change in any treatment period. No cholesterol crystals were detected in any bile sample, taken at baseline and after each treatment period. Bile salt hydrophobicity index during cholestyramine (0.19 (0.02)) and combined treatment (0.22 (0.01)) decreased strongly compared with baseline (0.34 (0.01), p < 0.001, p < 0.01, respectively), resulting from increased proportions of glycocholate (59.4 (3.9)% (cholestyramine), 55.6 (2.4)% (combination), and 28.2 (2.2) (baseline), p < 0.001)) and decreased proportions of deoxycholic acid and chenodeoxycholic acid. Fasting gall bladder volume was increased during simvastatin (28.7 (2.8) ml) v baseline (23.2 (2.3) ml, p < 0.01) whereas, residual volume did not differ (5.7 (0.9) ml (simvastatin) v 5.9 (0.7) (baseline). During cholestyramine and combined treatment, no significant differences in gall bladder motility were seen. In conclusion, this study suggests that HMG-CoA reductase inhibitors alone and combined with cholestyramine do not affect major determinants of cholesterol gall stone formation, for example, CSI and gall bladder emptying. In addition cholestyramine alone and combined with simvastatin leads to a strong decrease of bile salt hydrophobicity, which may be beneficial in the prevention of nucleation of cholesterol crystals.

Anticholesteremic Agents↗

PubMed1995

The effects of the 3-hydroxy, 3-methylglutaryl coenzyme A reductase inhibitor pravastatin on bile composition and nucleation of cholesterol crystals in cholesterol gallstone disease.

3-hydroxy,3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors reduce biliary cholesterol saturation index (CSI) in duodenal bile in hypercholesterolemic patients and might be useful for gallstone dissolution. However, preliminary data suggest that these drugs are not effective in this respect. We therefore studied 33 patients with radiolucent gallstones in an opacifying gallbladder who were scheduled for elective cholecystectomy. Patients were treated with 40 mg pravastatin day-1 or placebo during the 3 weeks before surgery. Six patients could not be evaluated. Baseline characteristics (age, sex, body mass index, serum cholesterol, and the solitary/multiple gallstone ratio) were similar in both groups. Serum cholesterol fell by 39% in the pravastatin group (P < .001) and remained unchanged in the placebo group. Biliary cholesterol (9.5 +/- 1.3 vs. 14.3 +/- 1.5 mmol/L, P = .026), and phospholipid concentrations (24.8 +/- 3.9 vs. 36.7 +/- 3.9 mmol/L, P = .043) were lower in the pravastatin group. Although bile salt concentrations were lower in the pravastatin group (114 +/- 21 vs. 152 +/- 15 mmol/L), this difference was not significant. CSI was not different between both groups (142 +/- 27% [pravastatin] vs. 113 +/- 6% [placebo], P = NS). Cholesterol crystals were present in fresh bile in 7 of 13 patients in the pravastatin group and in 11 of 14 controls (P = NS). Nucleation time was comparable between the 2 groups (13 +/- 3 vs. 9 +/- 3 days, P = NS). Bile salt species and molecular species of phospholipids determined with high-performance liquid chromatography did not differ either between both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Bile↗

PubMed1994

Tumor necrosis factor alpha-induced endothelial tissue factor is located on the cell surface rather than in the subendothelial matrix.

Because there is no consensus regarding the precise distribution of induced endothelial tissue factor (TF), we studied TF activity in and on tumor necrosis factor alpha-stimulated cultured human umbilical vein endothelial cells (ECs) and their underlying matrix. TF was mainly expressed on the cell surface. Only small traces were found on the apical surface suggesting that TF is predominantly located on the basolateral side of the cell membrane. The presence of TF on the cell surface was confirmed by flow cytometry. Subendothelial TF activity appeared to be dependent upon the procedure used to remove the stimulated EC monolayer. Whereas ammonium hydroxide or hypotonic lysis resulted in relatively high levels of matrix-associated TF, virtually no TF was found on the matrix after mild enzymatic detachment of stimulated ECs. Cell removal with EDTA resulted in intermediate levels of matrix-associated TF. Neither the enzymatic treatment nor EDTA degraded or removed this TF activity. Similar patterns were observed for matrix-associated TF antigen and EC surface markers. Electron microscopic analysis showed cell fragments on the matrix after monolayer lysis. The findings strongly suggest that induced endothelial TF associated with the subendothelial matrix actually represents TF on EC remnants.

Antibodies, Monoclonal↗

PubMed1994

Myelodysplasia following paroxysmal nocturnal haemoglobinuria: evidence for the emergence of a separate clone.

A patient with paroxysmal nocturnal haemoglobinuria (PNH) who developed a myelodysplastic syndrome (MDS) is described. After the onset of myelodysplasia the neutrophils of the patient fully expressed GPI-linked proteins. It is concluded that the myelodysplasia does not originate from transformed PNH stem cells, but represents the emergence of a separate clone arising from an injured marrow.

Anemia, Refractory, with Excess of Blasts↗

PubMed1993

The course of preexistent immune abnormalities in HIV negative haemophiliacs treated for two years with a monoclonal purified factor VIII concentrate.

The administration of factor VIII concentrates has been associated with immune abnormalities in patients with severe haemophilia A, even in the absence of HIV infection. The effects of a monoclonal purified factor VIII concentrate, Hemofil M (Baxter), on preexistent immune abnormalities were assessed over a 2 year period in 22 HIV negative haemophiliacs. They were treated previously with other concentrates, and received Hemofil T from 1983 to 1988. No HIV infection was demonstrated. No serologic evidence for other viral (re)-infections was seen. A decrease of HLA-DR expression on non-B lymphocytes in the first year (P = 0.026), and a decrease of T4-T8 ratio over the 2 years were found (P = 0.0016). Skin tests were non-contributive. The decrease in HLA-DR expression is suggestive for an improved immune function, possibly due to a reduced content of protein or virus in this concentrate.

Adolescent↗

PubMed1993

Clonal chronic lymphocytic leukaemia-like B lymphocytes in the blood of patients with cutaneous T-cell disorders.

A population of B cells with characteristics of chronic lymphocytic leukaemia was found in the peripheral blood of four patients who presented with cutaneous infiltration of atypical CD4+ T cells with cerebriform nuclei. The B cells had a low density of immunoglobulin on their surface membrane, expressed CD5-positivity, and showed monoclonality based on the restriction to either kappa or lambda light chains. In one patient with tumourous pleiomorphic CD4+CD30- T-cell lymphoma of the skin, it was the first manifestation of a concomitant B-cell non-Hodgkin's lymphoma of low-grade malignancy. In three other patients with reactive atypical T-cell erythroderma, there was no evidence for the coexistence of a B-cell malignancy. The number of CD5+ B cells decreased in two erythroderma patients with clinical remission of the cutaneous lesions. It is speculated that the presence of a monoclonal B cell population in patients with T-cell disorders of the skin is due either to a reactive process possibly conferring some protective effect, or a response to an unknown stimulus produced by the T cells.

Aged↗

PubMed1992

The supportive effects of IL-7 on eosinophil progenitors from human bone marrow cells can be blocked by anti-IL-5.

Human rIL-7 was studied for its effects on myeloid and erythroid progenitors from human bone marrow cells. IL-7 did not support the granulocytic/monocytic or erythroid lineage but exclusively stimulated eosinophil colony formation (CFU-Eo) (4 +/- 3 vs 48 +/- 17 CFU-Eo/10(5) nonadherent fraction-non-T cell (NAF-NT) cells). This supportive effect was not mediated by T cells or monocytes because similar results were obtained with or without T cell or adherent depleted cell fractions. In addition, it was shown that CD34+ sorted cells could be stimulated by IL-7 (0 vs 15 +/- 9 CFU-Eo/3 x 10(3) CD34+ cells) Furthermore studies with IL-3 or granulocyte-macrophage CSF (GM-CSF) demonstrated an additive effect on the IL-7 supported colony formation. Finally, experiments were performed with anti-IL-3, anti-GM-CSF, anti-IL-1, and anti-IL-5 to exclude the possibility that IL-7 indirectly stimulated the eosinophil progenitor cell. Anti-GM-CSF, anti-IL-1, or anti-IL-3 did not influence the supportive effects of IL-7. However, anti-IL-5 did abolish the effects of IL-7 on the eosinophil colony formation (69 +/- 15 vs 3 +/- 2 CFU-Eo/10(5) NAF-NT, n = 3). Similar results were obtained with CD34+ sorted cells. Moreover, IL-5 mRNA expression could be demonstrated in IL-7-stimulated NAF-NT cells. These data suggest that the supportive effects of IL-7 on eosinophil precursors are mediated by the endogenous release of IL-5.

Antigens, CD↗

PubMed1992

Correction of neutropenia by GM-CSF in patients with a large granular lymphocyte proliferation.

The in vivo and in vitro effects of GM-CSF were tested in four patients with large granular lymphocyte proliferation (LGLP) and severe granulocytopenia. All patients had an increased percentage of LGL cells (greater than 20%), whereas 3/4 patients demonstrated rearranged T-cell-receptor genes. An effect on the peripheral granulocyte counts was noticed in 3/4 patients after 14 days of GM-CSF administration (5 micrograms/kg/day, subcutaneously); 2.5, 7, and 0.45 x 10(9)/l, respectively. These changes were associated with a two- to five-fold increase in monocytes and a strong increment in eosinophils. In one patient GM-CSF was not effective in increasing the granulocyte count. B lymphocytes showed a variable increase, ranging from 1.2-fold to 3.8-fold, while the number of NK cells remained almost constant during the GM-CSF treatment. No consistent effect of GM-CSF on T lymphocytes was observed. These data suggest that GM-CSF may be a therapeutic option in some patients with LGLP complicated by granulocytopenia and/or infection.

Adult↗

PubMed1992

Successful dissolution of cholesterol gallstone during treatment with pravastatin.

This case report describes a 51-year-old hypercholesterolemic male patient who had a large solitary cholesterol gallstone. The patient was treated with the 3-hydroxy 3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor pravastatin, 40 mg/day. After 3 months of therapy, serum cholesterol level normalized (7.7 mmol/L before and 5.2 mmol/L during treatment), and biliary cholesterol saturation index decreased from 1.3 before to 0.8 during treatment. Repeatedly performed ultrasonography showed complete gallstone dissolution. Pravastatin may be valuable in the nonsurgical treatment of cholesterol gallstone disease particularly when there is an additional indication for HMG-CoA reductase inhibitors because of hypercholesterolemia.

Cholelithiasis↗

PubMed1992

Polyclonal expansion of T-cell receptor-gamma delta+ T lymphocytes associated with neutropenia and thrombocytopenia.

A patient with large granular lymphocyte (LGL) expansion (T-gamma lymphocytosis), neutropenia and thrombocytopenia was studied longitudinally. Analysis of peripheral blood mononuclear cells (PBMC) demonstrated an unusual large proportion of CD3+ T-lymphocytes expressing a gamma delta T-cell receptor (TcR-gamma delta). Immunofluorescence (IF) stainings with subset-specific monoclonal antibodies showed a fluctuating expansion of TcR-gamma delta+ T-cells expressing V gamma 9 and V delta 2 variable (V) gene segments. Biochemical characterization of PBMC showed the presence of a disulphide-linked TcR-gamma delta. TcR gene rearrangement studies on sorted TcR-gamma delta+ T-cells showed rearrangements of V gamma 9-J gamma 1.2 and V delta 2-J delta 1 V and joining (J) gene segments, thereby confirming the IF staining results. These data alone did not allow us to determine whether the TcR-gamma delta+ LGL expansion represented a polyclonal or monoclonal proliferation, because the combinatorial repertoire of TcR-gamma delta receptors is limited due to the availability of only a few V and J segments within the TcR-gamma and TcR-delta genes and because of the preferential usage of V gamma 9-J gamma 1.2 and V delta 2-J delta 1 rearrangements by TcR-gamma delta+ T-cells in blood of healthy individuals. We therefore used polymerase chain reaction (PCR)-mediated amplification of the TcR-gamma delta rearrangements, using specific V gamma 9, J gamma 1.2, V delta 2, and J delta 1 oligonucleotides to determine the junctional diversity of the TcR-gamma delta+ T-cell population. Sequence analysis of the PCR products obtained revealed a mixture of different junctional region sequences compatible with a polyclonal expansion. This is in contrast to the few reported TcR-gamma delta+ LGL and the majority of TcR-alpha beta+ LGL expansions, which appeared to consist of monoclonal proliferations.

Antigens, Differentiation, T-Lymphocyte↗

PubMed1991

In vitro evaluation of a high-efficiency leukocyte adherence filter.

In view of the currently available data, prevention of alloimmunization requires filters with higher efficiency to achieve a reduction in the number of leukocytes below 10 million per transfusion. Two versions (Pall PL-100 and PL-50) of the new generation leukocyte-depletion filters were studied. Single donor (SDPC)- and pooled multiple donor (MDPC) platelets were run in parallel. At a flow rate of 10 ml/min, the PL-100 filter was shown to effectively reduce the number of residual leukocytes to far below the critical immunogenic threshold of 10 million in all SDPC units and in 77% of MDPC units. Apheresis platelets appear not only to be better depleted than pooled multiple donor platelets, but also to have a better post-filtration platelet recovery (96% versus 84%). The efficiency of the smaller version of the filter (Pall-50) was higher than that of the Pall-100 filter for both single and pooled multiple donor platelet concentrates (PC). Leukocytes were absent in more than 92% of units in both types of concentrates. The maximal number of detected leukocytes was 2.2 million in a pool of 6 units. The outcome of filtration of 5-day-old pooled platelets was less favorable than filtration of 1- or 2-day-old pooled platelets, indicating that filtration soon after preparation is preferred to filtration after storage. Post-filtration platelet integrity, activation state, function, and morphology were all well preserved in both single and multiple PCs.

Blood Component Removal↗

PubMed1991

Immunoelectron microscopic characterization of lymphocytes containing parallel tubular structures induced by natural but not recombinant interferon-alpha.

Activation of natural killer (NK) cell activity is one of the immune functions which can be altered by the interferons (IFNs). We previously incubated healthy donor peripheral blood lymphocytes (PBMC) in the presence of natural (n) IFN-alpha and found induction of granular lymphocytes, a proportion of which expressed CD 8 and CD 57. In the present study we further delineated the membrane characteristics of these induced granular lymphocytes and observed the greatest proportion to be CD 16+, with lesser proportions positive for CD 8, CD 57, or coexpressing CD 16 and CD 8. Thus, nIFN-alpha-induced granular lymphocytes have both the morphological and membrane characteristics of functional NK cells. However, in contrast to nIFN-alpha, incubations with recombinant (r) IFN-alpha and n- and rIFN-gamma were found to only enhance NK activity; the concomitant increase in granular lymphocytes as observed after nIFN-alpha incubation was absent. Therefore, even though the different IFNs applied had comparable effects on the function of cytotoxic effector cells, taking into account the observed morphological discrepancy, the unknown mechanisms or pathways by which this is achieved are apparently not identical.

Antigens, CD↗