Improvement of platelet storage conditions by using new polyolefin containers

BACKGROUND : Storage of pooled platelet concentrates (PCs) with yields above 3.0 × 10¹¹ platelets per unit in a 1-L PL-732 polyolefin container for 5 days often results in a drop in pH to below 6.0. Recently, new oxygen-permeable platelet containers (1-L PL-2410, 1-L and 1.5-L Compoflex) have been developed. The maximal platelet storage capacities of the new containers and the PL-732 were compared. STUDY DESIGN AND METHODS : Large platelet pools (n = 27) with platelet concentrations between 1.2 and 1.4 × 10¹¹ per L were made from 3 to 5 PCs prepared from buffy coats. The pools were divided in equal volumes among the PL-732 and the three new platelet containers. Platelet counts in the PCs ranged from 1.0 to 5.0 × 10¹¹ per unit. All PCs were stored on a flatbed shaker at 22 ± 2°C and evaluated on Days 1, 3, 5, and 7 by measuring platelet count, pH, pO₂, pCO₂, HCO₃-, glucose, lactate, platelet swirling, and soluble p-selectin. RESULTS : Day 7 storage of PCs (n = 6) with yields between 3.0 and 4.0 × 10¹¹ platelets in PL-732 showed mean ± SD pH values of 5.93 ± 0.05 and lactate values of 32.3 ± 7.9 mmol per L; in 4 of these 6 PCs, pH was below 6.0. In contrast, storage of these PCs in 1-L PL-2410 and 1.5-L Compoflex containers and of 2 of these 6 PCs in 1-L Compoflex containers showed pH values above 6.8. Lactate values were 15.5 ± 1.3, 15.3 ± 1.8, and 19.5 ± 4.7 mmol per L, respectively (p < 0.001 vs. PL-732). The platelet storage capacity of the new containers with platelet yields between 4.0 and 5.0 × 10¹¹ per unit (n = 6) was evaluated. Day 7 storage of these PCs in the 1.5-L Compoflex showed an average pH value of 6.74 ± 0.20; in 2 of 6 PCs, pH was below 6.8. The average pH value in the PL-2410 was 6.38 ± 0.31, and in all PCs, pH was below 6.8. Average lactate values were 17.8 ± 5.7 and 25.8 ± 5.6 mmol per L (p < 0.05), respectively. Soluble p-selectin values on Day 7 of storage increased approximately twofold in all PCs. CONCLUSION : The new oxygen-permeable containers showed platelet quality comparable to that with the PL-732 and for longer storage periods and at higher platelet counts.     

Increased expression and altered intracellular distribution of adhesion/growth-regulatory lectins galectins-1 and -7 during tumour progression in hypopharyngeal and laryngeal squamous cell carcinomas

Aims:  To examine the level of expression of the pleiotropic regulators galectins-1 and -7 in relation to neoplastic progression of hypopharyngeal (HSCCs) and laryngeal (LSCC s ) squamous cell carcinomas.
Methods and results:  The presence of galectins-1 and -7 was investigated using quantitative immunohistochemistry in (i) a series of 78 HSCCs by comparison with 17 normal epithelia (N_E), 26 low-grade dysplasia (low_D) and 27 high-grade dysplasia (high_D) and (ii) a series of 56 LSCCs by comparison with 50 N_E, 23 low_D and 29 high_D. Galectin-1 positivity expressed as a percentage of cells was significantly higher in carcinomas (HSCCs and LSCCs) than in N_E, low _ D or high _ D ( P  < 10⁻⁶). Galectin-7 expression was elevated in low _ D ( P  = 0.0004) compared with N_E and in carcinomas (HSCC) compared with high _ D ( P  = 0.0002). Tumour progression from high_D to carcinomas was associated with a shift of galectin-1 localization from the nucleus towards the cytoplasm. Increased expression of galectin-7 in dysplasias was accompanied by a shift from the cytoplasmic compartment (N_E) to the nucleus (low_D and high_D).
Conclusions:  Our data reveal an association between the level of presence of galectins-1 and -7 and neoplastic progression of HSCCs and LSCCs. Moreover, inverse shifts between nuclear and cytoplasmic positivity intimating functional divergence were detected.     

Duodenal phytohaemagglutinin (red kidney bean lectin) stimulates gallbladder contraction in humans

Aim: Lectins, carbohydrate‐specific proteins without enzymatic activity on the ligand, are daily ingested plant proteins which survive the passage through the gastrointestinal tract in a biologically active form. Their binding to glycan determinants of natural glycoconjugates can trigger biological effects. The lectin phytohaemagglutinin (PHA) is abundantly present in red kidney beans and induces cholecystokinin (CCK) release in rats. The aim of the study was to investigate the effect of intraduodenal administration of PHA on plasma CCK levels and gallbladder contraction in humans and to elucidate potential mechanisms of action. Methods: Five healthy volunteers underwent four studies. After a basal intraduodenal saline infusion for 30 min, PHA or heat‐inactivated PHA was infused in increasing doses: 150 μg, 1.5 mg and 15 mg for 30 min each. Intravenous saline, CCK₁ receptor antagonist dexloxiglumide or atropine were administered in random order. Gallbladder volumes were measured by ultrasonography and plasma CCK levels by radioimmunoassay. Results: Intraduodenal PHA induced gallbladder contraction in a dose‐dependent fashion starting with the lowest dose. The highest dose reduced the gallbladder volume to 65.3 ± 9.4% of basal volume (P < 0.001) whereas heat‐inactivated PHA did not have any effect. Blocking CCK₁ or muscarinic receptors completely abolished PHA‐stimulated gallbladder contraction (dexloxiglumide 208.7 ± 23.7%; atropine 104 ± 7.0% of basal volume) while none of the treatments affected CCK levels. Conclusion: Duodenal administration of PHA potently stimulates gallbladder contraction in humans. This contraction is mediated via cholinergic pathway.