Measurements from normal umbilical cord blood of four lysosomal enzymatic activities: alpha-L-iduronidase (Hurler), galactocerebrosidase (globoid cell leukodystrophy), arylsulfatase A (metachromatic leukodystrophy), arylsulfatase B (Maroteaux-Lamy).

Umbilical cord blood (UCB) has received increasing attention as a source of unrelated hematopoietic stem cells for transplantation. Lysosomal diseases have been effectively treated and normal enzymatic activity has occurred subsequent to engraftment using UCB. The use of donor cells with normal amounts of enzyme, rather than those from carriers whose level may be 50% or less, is an obvious goal. The frequency of such heterozygotes varies from 1:10 to 1:140 or lower depending upon the disease at issue. We assayed the levels of lysosomal enzymes in normal UCB in random samples as well as those used for transplantation. We measured the following enzymatic activities: alpha-l-iduronidase (Hurler), galactocerebrosidase (globoid cell leuko- dystrophy) and arylsulfatase A (metachromatic leukodystrophy). For the latter, levels of activity in UCB are comparable to those found in adult blood. In the case of arylsulfatase B (Maroteaux-Lamy) a level lower than adult level was found. An informed choice by the transplanting physician based on the activity of the relevant enzyme in the UCB donor will provide a better opportunity for an improved prognosis for more complete correction of the recipient's primary disease. Bone Marrow Transplantation (2000) 25, 541-544.

Interferon-alpha and 3'-azido-3'-deoxythymidine are highly synergistic in mice and prevent viremia after acute retrovirus exposure.

This study was undertaken to calculate the in vivo drug interactions between recombinant human interferon-alpha A/D (rHuIFN-alpha A/D) and 3'-azido-3'-deoxythymidine (AZT) in a quantitative model for retroviral viremia. When given as single agents, both AZT and rHuIFN-alpha A/D suppressed virus-induced splenomegaly in a dose-dependent fashion in mice inoculated with Rauscher murine leukemia virus (RLV). However, suppressive doses of single-agent AZT caused anemia after 20 days of therapy. Combining rHuIFN-alpha A/D with AZT allowed drastic dose reductions for each agent while maintaining greater than or equal to 93% inhibition of splenomegaly. No clinically significant toxicity was seen. Computer analysis with the isobologram technique and combination index method showed that these combination regimens were highly synergistic. A 20-day course of AZT + rHuIFN-alpha A/D started 4 h after virus exposure was protective against RLV viremia and disease. After cessation of therapy, the animals were resistant to rechallenge with fully infectious RLV. We conclude that prompt initiation of effective combination therapy after retroviral exposure prevented viremia and disease and led to protective immunity.

Human 6-phosphofructo-1-kinase gene has an additional intron upstream of start codon.

A 6-phosphofructo-1-kinase-coding gene (pfk) has been purified from a human genomic library cloned in the lambda EMBL4 phage vector. This clone contains the nontranslated 5' flanking region of the human muscle pfk gene. Comparison of the nucleotide sequence determined by us with that of the human muscle pfk cDNA [Nakajima et al., FEBS Lett. 223 (1987) 113-116] indicates the presence of an additional intron extending from nucleotide (nt) -97 to -9 upstream of the ATG start codon. Furthermore, the human muscle pfk gene is more AT-rich than the rabbit gene. The available sequence of the two cDNAs shows 256 nt differences. Surprisingly, 71% of these sites are A's and T's in the human cDNA and C's and G's in the rabbit gene.