Medicine shortages--a study of community pharmacies in Finland.

OBJECTIVES: To explore the frequency, the reasons behind, and the consequences of medicine shortages in Finnish community pharmacies. METHODS: During the 27-day study period in the autumn of 2013, randomly selected pharmacies reported on medicines that were in short supply from orders made to wholesalers. RESULTS: Altogether 129 (66%, n=195) pharmacies participated in the study, and the study material consisted of 3311 report forms. Of the study pharmacies, 79.8% had medicine shortages daily or almost daily. Medicines in short supply were most commonly medicines that affect the nervous system (30.8%) and the cardiovascular system (17.5%). The reason behind the shortage was reported to the pharmacies in 11.2% of the shortage cases. The medicine shortages caused problems for the pharmacies in 33.0% of the cases. In most cases (67.0%) the medicine shortages did not cause problems for the pharmacies, usually because a substitutable product was available (48.5%). CONCLUSIONS: Medicine shortages are common in Finnish community pharmacies. Medicines in short supply were commonly used medicines. The reason behind the shortage was rarely told to the pharmacies. Medicine shortages caused problems for the pharmacies in one-third of all the shortage cases. These shortages may be significant for the customers or the pharmacies, as they cause customer dissatisfaction and increase the workload of the pharmacy staff.

Role of mitochondria in tamoxifen-induced rapid death of MCF-7 breast cancer cells.

Tamoxifen (Tam) is widely used in chemotherapy of estrogen receptor-positive breast cancer. It inhibits proliferation and induces apoptosis of breast cancer cells by estrogen receptor-dependent modulation of gene expression, but recent reports have shown that Tam (especially at pharmacological concentrations) has also rapid nongenomic effects. Here we studied the mechanisms by which Tam exerts rapid effects on breast cancer cell viability. In serum-free medium 5-7 microM Tam induced death of MCF-7 and MDA-MB-231 cells in a time-dependent manner in less than 60 min. This was associated with release of mitochondrial cytochrome c, a decrease of mitochondrial membrane potential and an increase in production of reactive oxygen species (ROS). This suggests that disruption of mitochondrial function has a primary role in the acute death response of the cells. Accordingly, bongkrekic acid, an inhibitor of mitochondrial permeability transition, was able to protect MCF-7 cells against Tam. Rapid cell death induction by Tam was not associated with immediate activation of caspase-9 or cleavage of poly (ADP-ribose) polymerase. It was not blocked by the caspase inhibitor z-Val-Ala-Asp-fluoromethylketone either. Diphenylene ionodium (DPI), an inhibitor of NADPH oxidase, was able to prevent Tam-induced cell death but not cytochrome c release, which suggests that ROS act distal to cytochrome c. The pure antiestrogen ICI 182780 (1 microM) could partly oppose the effect of Tam in estrogen receptor positive MCF-7 cells, but not in estrogen receptor negative MDA-MB-231 cells. Pre-culturing MCF-7 cells in the absence of 17beta-estradiol (E(2)) or in the presence of a low Tam concentration (1 microM) made the cells even more susceptible to rapid death induction by 5 or 7 microM Tam. This effect was associated with decreased levels of the anti-apoptotic proteins Bcl-X(L) and Bcl-2. In conclusion, our results demonstrate induction of a rapid mitochondrial cell death program in breast cancer cells at pharmacological concentrations of Tam, which are achievable in tumor tissue of Tam-treated breast cancer patients. These mechanisms may contribute to the ability of Tam therapy to induce death of breast cancer cells.

Heat stress downregulates FLIP and sensitizes cells to Fas receptor-mediated apoptosis.

The heat shock response and death receptor-mediated apoptosis are both key physiological determinants of cell survival. We found that exposure to a mild heat stress rapidly sensitized Jurkat and HeLa cells to Fas-mediated apoptosis. We further demonstrate that Hsp70 and the mitogen-activated protein kinases, critical molecules involved in both stress-associated and apoptotic responses, are not responsible for the sensitization. Instead, heat stress on its own induced downregulation of FLIP and promoted caspase-8 cleavage without triggering cell death, which might be the cause of the observed sensitization. Since caspase-9 and -3 were not cleaved after heat shock, caspase-8 seemed to be the initial caspase activated in the process. These findings could help understanding the regulation of death receptor signaling during stress, fever, or inflammation.

Unreliability of the cytochrome c-enhanced green fluorescent fusion protein as a marker of cytochrome c release in cells that overexpress Bcl-2.

A cytochrome c-enhanced green fluorescent protein chimera (cyt-c.EGFP) was used to monitor the release of cytochrome c from mitochondria in Bcl-2-negative and Bcl-2-positive MDA-MB-468 breast cancer cells. A comparison was made with the intracellular distribution of endogenous cytochrome c based on Western blotting of cell fractions and immunocytochemistry. The release of endogenous cytochrome c from mitochondria into the cytoplasm was detected in Bcl-2-negative cells treated with the kinase inhibitor staurosporine or the calcium-ATPase inhibitor thapsigargin. No release of endogenous cytochrome c was evident in Bcl-2-positive cells, consistent with earlier evidence that Bcl-2 overexpression inhibits cytochrome c release from mitochondria. Cyt-c.EGFP appeared to be localized to the mitochondria in Bcl-2-negative cells and to be released into the cytoplasm following treatment with either staurosporine or thapsigargin. However, in Bcl-2-positive cells the pattern of distribution of cytochrome c-EGFP was inconsistent with that of endogenous cytochrome c, due to accumulation of both cyt-c.EGFP and free EGFP in the cytoplasm of both treated and untreated cells. In summary, cyt-c.EGFP may be useful for monitoring cytochrome c release in living cells that do not express high levels of Bcl-2 but is an unreliable marker of cytochrome c release in cells that overexpress Bcl-2.

Effects of 2-ethylhexanoic acid on the production of reactive oxygen species in human polymorphonuclear leukocytes in vitro.

2-Ethylhexanoic acid (2-EHA), is an industrial chemical and a toxic biotransformation product of the plasticizer di(2-ethylhexyl)phthalate. Its immunological effects are unknown. 2-EHA resembles structurally C18 fatty acids, which are known activators of respiratory burst in human polymorphonuclear leukocytes (PMNL). Therefore, we exposed PMNL to 2-EHA in vitro and measured the production of reactive oxygen species (ROS) and explored the associated cellular mechanisms. 2-EHA (10-2000 microM) inhibited dose-dependently formyl-methionyl-leucyl-phenylalanine (FMLP)-induced respiratory burst in PMNL. Moreover, 2-EHA decreased oxidative burst evoked by the protein kinase C (PKC) activators, phorbol myristate acetate (PMA) and dioctanoyl-s,n-glycerol (DIC(8)). 2-EHA affected neither the levels of free intracellular calcium nor inhibited PKC. The results indicate that 2-EHA inhibits activation of PMNL to produce ROS, i.e. has an immunosuppressive effect in vitro. The site of action in the PKC is after activation of this enzyme.

Differential antiproliferative and apoptotic response of sanguinarine for cancer cells versus normal cells.

Sanguinarine, derived from the root of Sanguinaria canadendid, has been shown to possess antimicrobial, anti-inflammatory, and antioxidant properties. Here we compared the antiproliferative and apoptotic potential of sanguinarine against human epidermoid carcinoma (A431) cells and normal human epidermal keratinocytes (NHEKs). Sanguinarine treatment was found to result in a dose-dependent decrease in the viability of A431 cells as well as NHEKs albeit at different levels because sanguinarine-mediated loss of viability occurred at lower doses and was much more pronounced in the A431 carcinoma cells than in the normal keratinocytes. DNA ladder assay demonstrated that compared to vehicle-treated control, sanguinarine treatment of A431 cells resulted in an induction of apoptosis at 1-, 2-, and 5-microM doses. Sanguinarine treatment did not result in the formation of a DNA ladder in NHEKs, even at the very high dose of 10 microM. The induction of apoptosis by sanguinarine was also evident by confocal microscopy after labeling the cells with annexin V. This method also identified necrotic cells, and sanguinarine treatment also resulted in the necrosis of A431 cells. The NHEKs showed exclusively necrotic staining at high doses (2 and 5 microM). We also explored the possibility of cell cycle perturbation by sanguinarine in A431 cells. The DNA cell cycle analysis revealed that sanguinarine treatment did not significantly affect the distribution of cells among the different phases of the cell cycle in A431 cells. We suggest that sanguinarine could be developed as an anticancer drug.

Mitochondrial depolarization accompanies cytochrome c release during apoptosis in PC6 cells.

Cytochrome c is released from mitochondria into the cytosol in cells undergoing apoptosis. The temporal relationship between cytochrome c release and loss of mitochondrial membrane potential was monitored by laser-scanning confocal microscopy in single living pheochromocytoma-6 cells undergoing apoptosis induced by staurosporine. Mitochondrial membrane potential monitored by tetramethylrhodamine methyl ester decreased abruptly in individual cells from 2 to 7 h after treatment with staurosporine. Depolarization was accompanied by cytochrome c release documented by release of transfected green fluorescent protein-tagged cytochrome c in these cells. The results show that mitochondrial depolarization accompanies cytochrome c release in pheochromocytoma-6 cells undergoing apoptosis.

Effects of 3-phenylamino-1,2-propanediol and its mono- and dioleylesters on the production of reactive oxygen metabolites in human polymorphonuclear leukocytes.

Human polymorphonuclear leukocytes (PMNL) were exposed to 3-phenylamino-1,2-propanediol (PAP) or to its mono- or dioleylesters. The dioleylester of PAP (140 microM) slightly increased the production of reactive oxygen metabolites (ROM) from 8 +/- 2 mV to 18 +/- 3 mV, whereas PAP and its mono-oleylester were without any effect on ROM production in PMNL. None of the compounds were able to modulate formyl-Methionyl-Leucyl-Phenylalanine-induced production of ROM. Moreover, PAP did not have any effect on the production of ROM induced by phorbol myristate acetate (PMA). On the other hand, both mono- and dioleylesters of PAP dose-dependently inhibited PMA-induced production of ROM. The dioleylester of PAP, at a concentration of 14 microM, inhibited PMA-induced production of ROM by 79%, whereas a 2.3 mM concentration of mono-oleylester of PAP was required for 65% inhibition of PMA-induced production of ROM. Moreover, both esters of PAP shifted the peak production of ROM by PMA to a later time-point. Our results suggest that mono- and dioleylesters of PAP modulate the responses of PMNL upon stimulation with PMA, whereas PAP does not have any effect on PMA-induced ROM production in PMNL.

Palmitic acid anilide-induced respiratory burst in human polymorphonuclear leukocytes is inhibited by a protein kinase C inhibitor, Ro 31-8220.

Human polymorphonuclear leukocytes (PMNL) were exposed to palmitic acid anilide, an impurity in the case oils that caused the Spanish Toxic Oil Syndrome in 1981, and to the corresponding fatty acid, palmitic acid. The effects of these compounds were studied on the production of reactive oxygen metabolites (ROM) and changes in the levels of free intracellular calcium. Palmitic acid anilide induced the production of reactive oxygen metabolites in PMNL. Interestingly, the palmitic acid anilide-induced respiratory burst was completely blocked by a protein kinase C inhibitor, Ro 31-8220. Moreover, palmitic acid anilide additively amplified the production of ROM caused by a chemotactic peptide, formyl-Methionyl-Leucyl-Phenylalanine (FMLP). In contrast, palmitic acid anilide did not have any effect on the production of ROM induced by a tumor promoter, phorbol myristate acetate (PMA). Palmitic acid, in turn, did not markedly induce the production of ROM nor did it amplify the agonist-induced respiratory burst. Neither of the compounds, alone or in combination with FMLP, affected the levels of intracellular calcium in PMNL. These results indicate that the aniline moiety in palmitic acid modifies its effects on the activation of human PMNL, and the subsequent oxidative burst. The present results also suggest that palmitic acid anilide may activate PMNL through a protein kinase C-dependent mechanism.

Effect of linoleic acid, linoleic acid anilide, and arachidonic acid on the expression of adhesion molecules on human neutrophils.

The effects of linoleic acid, linoleic acid anilide, and arachidonic acid on the expression of CD11b/ CD18, CD11c/CD18 integrins and L-selectin on human neutrophils were studied by flow cytometry in a whole blood assay. None of these compounds had any effect on the basal expression of CD11b, CD11c, or L-selectin in the concentration range of 20-100 microM. However, linoleic acid at a concentration of 1000 microM slightly up-regulated CD11b and CD11c by a factor of 2.1 and 1.7, respectively. Linoleic acid, linoleic acid anilide, and arachidonic acid did not affect the formyl-methionyl-leucyl-phenylalanine induced up-regulation of CD11b or CD11c. However, linoleic acid and linoleic acid anilide slightly inhibited the phorbol myristate acetate (PMA)-induced expression of CD11b, which was decreased by 27 and 21% at concentrations of 100 and 1000 microM, respectively. Likewise, arachidonic acid at 40 microM inhibited the PMA-induced expression of CD11b by 19%. Our results suggest that linoleic acid, linoleic acid anilide, and arachidonic acid do not dramatically affect the expression of leukocyte adhesion molecules in a whole blood assay.

Erucic acid and erucic acid anilide-induced oxidative burst in human polymorphonuclear leukocytes.

Human polymorphonuclear leukocytes (PMNL) were exposed to erucic acid or erucic acid anilide to explore their effects on the production of reactive oxygen species (ROS) and the levels of free intracellular calcium. The compounds did not change the levels of intracellular calcium, but both dose-dependently induced respiratory burst in PMNL. Maximal production of ROS by erucic acid exceeded that induced by its anilide 13-fold. A protein kinase C inhibitor, Ro 31-8220, completely inhibited erucic acid and erucic acid anilide-induced production of ROS. Neither erucic acid nor erucic acid anilide modified FMLP-induced production of ROS. However, erucic acid (500 microM) amplified 5 nM PMA-induced ROS production 1.8-fold, but did not have this effect at a lower PMA concentration. On the contrary, erucic acid anilide inhibited PMA-induced oxidative burst, and shifted the peak ROS production induced by PMA to a later time-point. The present results show that aniline moiety modifies the effects of erucic acid on the activation of PMNL, and suggest that both erucic acid and erucic acid anilide may activate PMNL through a protein kinase C-dependent mechanism.

Risk of low vitamin B6 status in infants breast-fed exclusively beyond six months.

Our aim was to ascertain the adequacy of human milk as the sole source of vitamin B6 and the associations between maternal and infant status during extended exclusive breast-feeding. Vitamin B6 status was followed in lactating mothers and their exclusively breast-fed infants by determinations of erythrocyte pyridoxal 5'-phosphate concentration and the erythrocyte aspartate transaminase stimulation test at 2 months (n = 118), 4 months (n = 118), 6 months (n = 112), 7.5 months (n = 70), 9 months (n = 36), 10 months (n = 14), 11 months (n = 11), and 12 months (n = 7) postpartum. Of the mothers, 54% had used vitamin B6 supplement during pregnancy, and all received a pyridoxine hydrochloride supplement of 1 mg/day throughout lactation. The infants had a higher vitamin B6 status than their mothers. During the first 4 months, infant vitamin B6 status was generally adequate independently of the actual vitamin status of the nursing mother. Most of the infants with low status at 2 months were those born to mothers who were not supplemented during pregnancy. By 6 months of exclusive breast-feeding, 30% of cases of low vitamin B6 status in nursing mothers were reflected in their infants. Thereafter, the risk of low vitamin B6 status in exclusively breast-fed infants increased even if the mother's status was adequate. Our findings suggest that gestationally accumulated stores are important for the maintenance of adequate vitamin B6 status of infants during the early months and that for some infants, human milk alone, without supplementary foods, may be insufficient to meet vitamin B6 needs after 6 months of age.

Formyl-methionyl-leucyl-phenylalanine and a calcium ionophore A23187 reverse the inhibition of phorbol myristate acetate-induced oxidative burst by linoleic and oleic acid anilides.

Linoleic and oleic acid anilides profoundly inhibited the production of reactive oxygen metabolites (ROM) in human polymorphonuclear leukocytes (PMNL) induced by a tumor promoter, phorbol myristate acetate (PMA). The addition of a Ca2+ ionophore, A23187, or a chemotactic peptide, formyl-methionyl-leucyl-phenylalanine (fMLP), readily reversed linoleic and oleic acid anilide-induced inhibiton of PMA-evoked respiratory burst in PMNL without affecting PMA-induced respiratory burst. fMLP or A23187 caused a marked increase in the production of ROM in PMNL that did not produce ROM after their co-exposure to PMA and cis-fatty acid anilides. This suggests a role for Ca2+ in this restoration of respiratory burst activity in PMNL. Oleic and linoleic acid anilides enhanced also respiratory burst in PMNL subsequent to their stimulation with fMLP. Interestingly, corresponding fatty acids, linoleic and oleic acid, also inhibited PMA-induced production of ROM in PMNL, but this inhibition was not reversed by A23187 or fMLP. These findings suggest that the aniline moiety of cis-fatty acids significantly modifies the effects of linoleic and oleic acids in the production of ROM in PMNL. Moreover, free intracellular Ca2+ may play a critical role in the activation of PMNL to produce ROM, and in the modulation of the effects of cis-fatty acid anilides.

Vitamin B-6 status during childhood: tracking from 2 months to 11 years of age.

To examine the development and tracking of long-term vitamin B-6 status from infancy to early adolescence, measurements of erythrocyte pyridoxal 5'-phosphate concentration (EPLP), the erythrocyte aspartate transaminase (EAST) stimulation test including measurements of basal activity (EASTo) and activation coefficient (alpha EAST), were made in a follow-up study of healthy children aged 2 (n = 139), 4 (n = 147), 6 (n = 157), 9 (n = 159) and 12 mo (n = 188) and 5 y (n = 148). The EAST stimulation test was repeated at 11 y (n = 153). Vitamin B-6 status, high during infancy, reached the adult level by 5 y of age. The 10th to 90th percentile ranges for EPLP values were 61-201 nmol/L at 4 mo, 49-101 nmol/L at 12 mo and 27-59 nmol/L at 5 y. The respective ranges for Easto were 16-24 microkat/L at 4 mo, 13-19 microkat/L at 12 mo, 9-14 microkat/L at 5 y and 25-39 microkat/L at 11 y of age. For alpha EAST values were 1.29-1.54 at 4 mo, 1.48-1.77 at 12 mo, 1.70-2.07 at 5 y and 2.00-2.57 at 11 y. Values for EPLP and the EAST stimulation test in the first year of life correlated with the values at 5 and 11 y. The individuals with values at the extreme ends of the distributions remained there from infancy to childhood up to 3.3 times more often than expected from random variation.(ABSTRACT TRUNCATED AT 250 WORDS)

Interactions of cis-fatty acids and their anilides with formyl-methionyl-leucyl-phenylalanine, phorbol myristate acetate and dioctanoyl-s,n-glycerol in human leukocytes.

Aniline-denaturated rape-seed food oils that contained anilides of linoleic and oleic acids caused a poisoning epidemic, known as Toxic Oil Syndrome, in Spain in 1981. Toxic Oil Syndrome affected mainly the lungs and the immune system of exposed individuals. Linoleic and oleic acids, and linoleic and oleic anilides increased the production of reactive oxygen metabolites in human polymorphonuclear leukocytes. Both cis-fatty acids inhibited a chemotactic peptide-, fMLP-induced production of reactive oxygen metabolites without affecting fMLP-induced elevation of intracellular calcium levels. Linoleic acid anilide slightly amplified fMLP-induced respiratory burst, whereas oleic acid anilide was without an effect. However, both fatty acid anilides decreased fMLP-induced elevation of levels of free intracellular calcium. Moreover, both cis-fatty acids and their anilides inhibited phorbol myristate acetate (PMA)- and dioctanoyl-s,n-glycerol (DiC8)-induced production of reactive oxygen metabolites. Thus, both cis-fatty acids and their anilides inhibited agonist-stimulated production of reactive oxygen metabolites; this is most likely due to interactions with cell signalling events. These results suggest that both linoleic and oleic acids and their anilides may inhibit immunological responses of leukocytes.

Low vitamin B6 status associated with slow growth in healthy breast-fed infants.

To evaluate the effect of vitamin B6 status on infant growth, we studied longitudinally anthropometry and the erythrocyte parameters that reflect long-term vitamin B6 status [erythrocyte pyridoxal 5'-phosphate concentration (EPLP), erythrocyte aspartate transaminase basal activity (EAST0), and its activation co-efficient (alpha EAST)] in 44 infants. The infants were exclusively breast-fed for 6 mo, given additional solids according a uniform schedule from 6-9 mo, and formula after 9 mo, if needed. In seven of these infants, a low vitamin B6 status (EPLP < 10th, and EAST0 > 10th or alpha EAST > 90th percentile for these values in reference infants) was observed between 4 and 6 mo of age. These seven infants showed slower length velocity (0.30 +/- 0.05 versus 0.40 +/- 0.02 mm/d, p < or = 0.02) and deeper fall in length-for-age (-0.69 +/- 0.20 versus -0.25 +/- 0.07 SD score, p < or = 0.03) from 6 to 9 mo of age than the similarly fed infants with higher vitamin B6 status. Preceding vitamin B6 status remained a significant explanatory factor for length velocity and change in length-for-age in addition to preceding and concomitant weight velocity, when sex, birth size, preceding length gain, and mid-parent height were taken into account. Change in weight-for-age alone explained 16% and 18% and, together with vitamin B6 status, 23 and 27% of the variation in length velocity and in change in length-for-age, respectively. Thus, in healthy breast-fed infants, according to our results, low vitamin B6 status is associated with reversibly reduced gain in length.

Altered enzyme activities of xenobiotic biotransformation in kidneys after subchronic administration of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) to rats.

Activities of the xenobiotic metabolizing enzymes were measured in the liver, kidney, duodenum and lung microsomes and cytosol fractions of Wistar rats after subchronic administration of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), a potent bacterial mutagen in chlorinated drinking water. MX was administered by gavage at the dose level of 30 mg/kg for 18 weeks (low dose), or at the dose level which was raised gradually from 45 mg/kg for 7 weeks via 60 mg/kg for 2 weeks to a clearly toxic dose of 75 mg/kg for 5 weeks (high dose). Microsomal and cytosolic preparations were made and the activities of 7-ethoxyresorufin-O-deethylase (EROD), pentoxyresorufin-O-dealkylase (PROD), NADPH-cytochrome-c-reductase, UDP-glucuronosyltransferase (UDPGT) and glutathione-S-transferase (GST) were measured. Kidneys were affected most. A dose-dependent decrease was observed in EROD (90% in males, 80% in females at the high dose) and in PROD (58% in females at the high dose) in kidneys. An increase was, however, detected in kidney NADPH-cytochrome-c-reductase (66% in females at high dose), UDPGT (89% in males and 97% in females at high dose) and GST activities (56% in males and 50% in females at high dose). MX caused only a few changes in the enzyme activities of the liver. The EROD activity was decreased 25% to 37%, both in the livers of males and females, but the total content of P450s was not altered. Hepatic GST activity was elevated in females in a dose-dependent manner (31% and 44%). GST activity was elevated in duodenum in females (59%) at the high dose. There were no marked changes in the enzyme activities in the lungs. MX was a weak inhibitor of EROD activity both in the liver and kidney microsomes in vitro, decreasing the EROD activity by 53% and 43%, respectively at the concentration of 0.9 mM. The results indicate that MX decreases the activity of phase I metabolism enzymes, but induces phase II conjugation enzyme activities, particularly in kidneys in vivo. It is possible that these changes contribute to metabolism of MX in kidneys and renders them susceptible to MX in the course of repeated exposure.

The effects of N-(5-vinyl-1,3-thiazolidin-2-ylidene)phenylamine (5-VTPA) on the changes in free intracellular calcium and the production of reactive oxygen metabolites in human leukocytes.

Human leukocytes were exposed to N-(5-vinyl-1,3-thiazolidin-2-ylidene)phenylamine (5-VTPA), a postulated impurity in the case oils that caused the Spanish Toxic Oil Syndrome in 1981. Changes induced by 5-VTPA alone and together with a chemotactic peptide, formyl-methionyl-leucyl-phenylalanine (FMLP), a tumor promoter, phorbol myristate acetate (PMA), or a synthetic diacylglycerol, dioctanoyl-s,n-glycerol (DiC8) in free intracellular calcium levels ([Ca2+]i) and in the induction of oxidative burst were measured. 5-VTPA elevated dose-dependently [Ca2+]i and induced the production of reactive oxygen metabolites in leukocytes. 5-VTPA also amplified FMLP-induced increase in [Ca2+]i, but was without an effect on FMLP-induced oxidative burst. On the contrary, 5-VTPA amplified dose-dependently PMA- and DiC8-induced respiratory burst. The present results indicate that 5-VTPA may interfere with transmembrane signalling in human leukocytes. 5-VTPA may elevate [Ca2+]i by acting directly on the membrane, or by acting through Ca(2+)-mobilizing receptors. Moreover, 5-VTPA also clearly amplified responses produced through protein kinase C stimulation. Thus, 5-VTPA may act on human leukocytes by affecting Ca(2+)-metabolism and the activity of protein kinase C.

Infant vitamin B-6 status changes with age and with formula feeding.

To study the effect of type of feeding on infant vitamin B-6 status, we determined erythrocyte pyridoxal 5'-phosphate concentration (EPLP) and erythrocyte aspartate aminotransferase basal activity (EASTo) and its activation coefficient (alpha EAST) in 109 infants at 2, 4, 6, 9, and 12 mo of age. Thirty-six infants were exclusively breast-fed for 9 mo. Forty-six infants were exclusively breast-fed for 6 mo, and then given solid foods in addition. Twenty-seven infants were weaned by 2-3 mo to an adapted cow milk-based formula (15 g protein/L and 0.6 mg pyridoxine/L) and given solid foods from 3 to 4 mo. Infant vitamin B-6 status was age-dependent; it was highest at 4 mo and thereafter gradually approached adult values. The larger the intake of formula, the higher the vitamin B-6 status. In formula-fed infants at ages 2-6 mo, 71-96% of the EPLP values and 57-70% of the EASTo values were above the 95th percentile, and 35-53% of the alpha EAST values were below the 5th percentile for these values in breast-fed infants. These findings raise the question of whether the vitamin B-6 content of formulas, especially in relation to protein content, should be reduced.

Reference ranges for erythrocyte pyridoxal 5'-phosphate concentration and the erythrocyte aspartate transaminase stimulation test in lactating mothers and their infants.

We determined reference ranges for erythrocyte pyridoxal 5'-phosphate concentrations (EPLP) and erythrocyte aspartate transaminase basal activities (EASTo) and activation coefficients (alpha EAST) in lactating mothers and infants from data of mothers receiving a vitamin B-6 supplement and infants breast-fed by mothers with adequate vitamin B6 status. The mothers' vitamin B6 status was assessed on the third day postpartum (pp) (n = 91) and at 2 mo (n = 114), 4 mo (n = 117), 6 mo (n = 110), and 9 mo (n = 40) pp and that of the exclusively breast-fed infants at 2 mo (n = 90), 4 mo (n = 106), and 6 mo (n = 99). We also examined 9-mo-old infants (n = 39) who, besides breast milk, had received solids after 6 mo, and 12-mo-old infants (n = 100) who had received solids beginning at 4-6 mo and dairy products at 9 mo. Values indicating deficiency for at least two of the three indexes distinguished the 5-10% of mothers and infants with the lowest vitamin B6 status. The reference ranges for EPLP, EASTo, and alpha EAST for infants and for mothers during the first months of lactation differ from those reported earlier for adults.