Vitamin content of foods : a summary of the chemistry of vitamins, units of measurement, quantitative aspects in human nutrition and occurrence in foods /

Contribution from Bureau of Home Economics.

Vitamin values of foods in terms of common measures /

Chiefly tables.

Experiment station research on the vitamin content and the preservation of foods /

"March, 1944."

Vitamin A in butter /

Cover title.

Vitamin and mineral content of certain foods as affected by home preparation /

"Issued January 1948."

Vitamin and mineral values of vegetables as served in an Army mess /

"Issued August 1947."

Butter as a source of vitamin A in the diet of the people of the United States /

"In cooperation with the agricultural experiment stations of Alabama, Arizona, California, Idaho, Indiana, Iowa, Kansas, Louisiana, Maryland, Minnesota, Mississippi, Montana, Nebraska, New York (Cornell), North Carolina, Ohio, Oregon, Pennsylvania, Washington, Wisconsin, and Wyoming."

A simplified endogenous erythroid colony assay for the investigation of polycythaemia

The in vitro growth of erythroid colonies in the absence of erythropoietin, known as endogenous erythroid colonies (EEC) forms part of the diagnostic criteria for polycythaemia vera (PV). The availability of EEC culture in routine laboratory setting is limited as culture methods are technically demanding, difficult to standardize, expensive and laborious. In this study, we assessed the performance characteristics of a simplified method using ammonium chloride red cell lysis followed by culture on commercially available, batch-tested, methylcellulose media. Seventy-six patients were included; four were secondarily excluded on the basis of culture failure. Of the 14 patients with PV, 13 (93%) were positive for EEC on at least one occasion: 90% (nine of 10) of bone marrow and 67% (six of nine) of peripheral blood specimens were positive. All 30 patients with secondary polycythaemia (n = 12) or apparent polycythaemia (n = 18) were negative for EEC. The incidence of EEC in idiopathic erythrocytosis was 40% (eight of 28); 50% (five of 10) in those who met one of the minor criteria for PV and 17% (three of 18) in those who did not. We conclude that our EEC assay yield results comparable with that of more elaborate methods.

Monitoring dendritic cells in clinical practice using a new whole blood single-platform TruCOUNT assay

Dendritic cells (DC) from distinct DC subsets are essential contributors to normal human immune responses. Despite this, reliable assays that enable DC to be counted precisely have been slow to evolve. We have now developed a new single-platform flow cytometric assay based on TruCOUN(TM) beads and the whole blood Lyse/No-Wash protocol that allows precise counting of the CD14(-) blood DC subsets: CD11c(+)CD16(-) DC, CD11c(+)CD16(+) DC, CD123(hi) DC, CD1c(+) DC and BDCA-3(+) DC. This assay requires 50 mul of whole blood; does not rely on a hematology blood analyser for the absolute DC counts; allows DC counting in EDTA samples 24 It after collection; and is suitable for cord blood and peripheral blood. The data is highly reproducible with intra-assay and inter-assay coefficients of variation less than 3% and 11%, respectively. This assay does not produce the DC-T lymphocyte conjugates that result in DC counting abnormalities in conventional gradient-density separation procedures. Using the TruCOUNT assay, we established that absolute blood DC counts reduce with age in healthy individuals. In preliminary studies, we found a significantly lower absolute blood CD11c(+)CD16(+) DC count in stage III/IV versus stage I/II breast carcinoma patients and a lower absolute blood CD123(hi) DC count in multiple myeloma patients, compared to age-matched controls. These data indicate that scientific progress in DC counting technology will lead to the global standardization of DC counting and allow clinically meaningful data to be obtained. (C) 2003 Elsevier B.V. All rights reserved.

A sensitive, specific, and cost-effective multiplex reverse transcriptase-PCR assay for the detection of seven common respiratory viruses in respiratory samples

Cell culture and direct fluorescent antibody (DFA) assays have been traditionally used for the laboratory diagnosis of respiratory viral infections. Multiplex reverse transcriptase polymerase chain reaction (m-RT-PCR) is a sensitive, specific, and rapid method for detecting several DNIA and RNA viruses in a single specimen. We developed a m-RT-PCR assay that utilizes multiple virus-specific primer pairs in a single reaction mix combined with an enzyme-linked amplicon hybridization assay (ELAHA) using virus-specific probes targeting unique gene sequences for each virus. Using this m-RT-PCR-ELAHA, we examined the presence of seven respiratory viruses in 598 nasopharyngeal aspirate (NPA) samples from patients with suspected respiratory infection. The specificity of each assay was 100%. The sensitivity of the DFA was 79.7% and the combined DFA/culture amplified-DFA (CA-DFA) was 88.6% when compared to the m-RT-PCR-ELAHA. Of the 598 NPA specimens screened by m-RT-PCR-ELAHA, 3% were positive for adenovirus (ADM), 2% for influenza A (Flu A) virus, 0.3% for influenza B (Flu B) virus, 1% for parainfluenza type I virus (PIV1), 1% for parainfluenza type 2 virus (PIV2), 5.5% for parainfluenza type 3 virus (PIV3), and 21% for respiratory syncytial virus (RSV). The enhanced sensitivity, specificity, rapid result turnaround time and reduced expense of the m-RT-PCR-ELAHA compared to DFA and CA-DFA, suggests that this assay would be a significant improvement over traditional assays for the detection of respiratory viruses in a clinical laboratory.

Differential expression of N-methyl-D-aspartate receptor NR2 isoforms in Alzheimer's disease

We have previously shown that the expression of NMDA receptor NR1 subunit mRNA splice variants in Alzheimer's disease (AD) brain varies according to regional susceptibility to pathological damage. Here we investigated the expression of the modulatory NR2 subunits of the NMDA receptor using quantitative RT-PCR to assay all NR2 isoforms. Significantly lower expression of NR2A and NR2B transcripts was found in susceptible regions of AD brain, whereas expression of NR2C and NR2D transcripts did not differ from that in controls. Western blot analysis confirmed a lower expression of the NR2A and NR2B isoforms at the protein level. The results suggest that NR2 subunit composition may modulate NMDA receptor-mediated excitotoxicity. NMDA receptor dysfunction might give rise to the regionally selective pattern of neuronal loss that is characteristic of AD.

Intracranial haemorrhage due to late onset vitamin K deficiency bleeding in Hanoi province, Vietnam

Background: In many developing countries vitamin K prophylaxis is not routinely administered at birth. There are insufficient data to assess the cost effectiveness of its implementation in such countries. Objective: To estimate the burden of intracranial haemorrhage caused by late onset vitamin K deficiency bleeding in Hanoi, Vietnam. Methods: Cases of intracranial haemorrhage in infants aged 1 - 13 weeks were identified in Hanoi province for 5 years ( 1995 - 1999), and evidence for vitamin K deficiency was sought. The data were compared with those on vitamin K deficiency bleeding in developed countries and used to obtain an approximation to the incidence of intracranial haemorrhage caused by vitamin K deficiency bleeding in Hanoi. Results: The estimated incidence of late onset vitamin K deficiency bleeding in infants who received no prophylaxis was unexpectedly high ( 116 per 100 000 births) with 142 and 81 per 100 000 births in rural and urban areas respectively. Mortality was 9%. Of the surviving infants, 42% were neurologically abnormal at the time of hospital discharge. Identified associations were rural residence, male sex, and low birth weight. A significant reduction in the incidence was observed in urban Hanoi during 1998 and 1999, after vitamin K prophylaxis was introduced at one urban obstetric hospital. Conclusions: Vitamin K deficiency bleeding is a major public health problem in Hanoi. The results indicate that routine vitamin K prophylaxis would significantly reduce infant morbidity and mortality in Vietnam and, costing an estimated US$87 (pound48, E72) per disability adjusted life year saved, is a highly cost effective intervention.

A new confirmatory Neisseria gonorrhoeae real-time PCR assay targeting the porA pseudogene

The Roche Cobas Amplicor system is widely used for the detection of Neisseria gonorrhoeae but is known to cross react with some commensal Neisseria spp. Therefore, a confirmatory test is required. The most common target for confirmatory tests is the cppB gene of N. gonorrhoeae. However, the cppB gene is also present in other Neisseria spp. and is absent in some N. gonorrhoeae isolates. As a result, laboratories targeting this gene run the risk of obtaining both false-positive and false-negative results. In the study presented here, a newly developed N. gonorrhoeae LightCycler assay (NGpapLC) targeting the N. gonorrhoeae porA pseudogene was tested. The NGpapLC assay was used to test 282 clinical samples, and the results were compared to those obtained using a testing algorithm combining the Cobas Amplicor System (Roche Diagnostics, Sydney, Australia) and an in-house LightCycler assay targeting the cppB gene (cppB-LC). In addition, the specificity of the NGpapLC assay was investigated by testing a broad panel of bacteria including isolates of several Neisseria spp. The NGpapLC assay proved to have comparable clinical sensitivity to the cppB-LC assay. In addition; testing of the bacterial panel showed the NGpapLC assay to be highly specific for N. gonorrhoeae DNA. The results of this study show the NGpapLC assay is a suitable alternative to the cppB-LC assay for confirmation of N. gonorrhoeae-positive results obtained with Cobas Amplicor.

Neuroprotectant effects of iso-osmolar D-mannitol to prevent Pacific ciguatoxin-1 induced alterations in neuronal excitability: A comparison with other osmotic agents and free radical scavengers

The basis for the neuroprotectant effect of D-mannitol in reducing the sensory neurological disturbances seen in ciguatera poisoning, is unclear. Pacific ciguatoxin-1 (P-CTX-1), at a concentration 10 nM, caused a statistically significant swelling of rat sensory dorsal root ganglia (DRG) neurons that was reversed by hyperosmolar 50 MM D-mannitol. However, using electron paramagnetic resonance (EPR) spectroscopy, it was found that P-CTX-1 failed to generate hydroxyl free radicals at concentrations of toxin that caused profound effects on neuronal excitability. Whole-cell patch-clamp recordings from DRG neurons revealed that both hyper- and iso-osmolar 50 MM D-mannitol prevented the membrane depolarisation and repetitive firing of action potentials induced by P-CTX-1. In addition, both hyper- and iso-osmolar 50 MM D-mannitol prevented the hyperpolarising shift in steady-state inactivation and the rise in leakage current through tetrodotoxin (TTX)-sensitive Na-v channels, as well as the increased rate of recovery from inactivation of TTX-resistant Nav channels induced by P-CTX-1. D-Mannitol also reduced, but did not prevent, the inhibition of peak TTX-sensitive and TTX-resistant I-Na amplitude by P-CTX-1. Additional experiments using hyper- and isoosmolar D-sorbitol, hyperosmolar sucrose and the free radical scavenging agents Trolox (R) and L-ascorbic acid showed that these agents, unlike D-mannitol, failed to prevent the effects of P-CTX-1 on spike electrogenesis and Na-v channel gating. These selective actions of D-mannitol indicate that it does not act purely as an osmotic agent to reduce swelling of nerves, but involves a more complex action dependent on the Nav channel subtype, possibly to alter or reduce toxin association. (c) 2005 Elsevier Ltd. All rights reserved.