Dry Rehydratable Film Method for Enumerating Confirmed Escherichia coli in Poultry, Meats, and Seafood: Collaborative Study

A rehydratable dry-film plating method for Escherichia coli, the Petrifilm E. coli/Coliform (EC) Count Plate in foods, has been compared with the AOAC INTERNATIONAL most probable number (MPN) method. Eleven laboratories participated in the collaborative study. Three E. coli levels in 8 samples each of frozen raw ground turkey, frozen raw ground beef, and frozen cooked fish were tested in duplicate. Mean log counts for the Petri film plate procedure were not significantly different from those for the MPN procedure for cooked fish samples inoculated with low or high inocula levels, for samples of raw turkey inoculated at medium level, and for beef inoculated at low, medium, and high levels. Repeatability and reproducibility vari ances of the Petrifilm EC Plate method recorded at 24 h were as good as or better than those of the MPN method. The dry rehydratable film method for enumerating confirmed E. coli in poultry, meats, and seafood has been adopted first action by AOAC INTERNATIONAL.

Petrifilm™ Rapid S. aureus Count Plate Method for Rapid Enumeration of Staphylococcus aureus in Selected Foods: Collaborative Study

A rehydratable dry-film plating method for Staphylococcus aureusin foods, the 3M™ Petrifilm™ Rapid S. aureus Count Plate method, was compared with AOAC® Official MethodSM 975.55 (Staphylococcus aureus in Foods). Nine foods—instant nonfat dried milk, dry seasoned vegetable coating, frozen hash browns, frozen cooked chicken patty, frozen ground raw pork, shredded cheddar cheese, fresh green beans, pasta filled with beef and cheese, and egg custard—were analyzed for S. aureus by 13 collaborating laboratories. For each food tested, the collaborators received 8 blind test samples consisting of a control sample and 3 levels of inoculated test sample, each in duplicate. The mean log counts for the methods were comparable for pasta filled with beef and cheese; frozen hash browns; cooked chicken patty; egg custard; frozen ground raw pork; and instant nonfat dried milk. The repeatability and reproducibility variances of the Petrifilm Rapid S. aureus Count Plate method were similar to those of the standard method.

The sequence of the human genome

A 2.91-billion base pair (bp) consensus sequence of the euchromatic portion of the human genome was generated by the whole-genome shotgun sequencing method. The 14.8-billion bp DNA sequence was generated over 9 months from 27,271,853 high-quality sequence reads (5.11-fold coverage of the genome) from both ends of plasmid clones made from the DNA of five individuals. Two assembly strategies-a whole-genome assembly and a regional chromosome assembly-were used, each combining sequence data from Celera and the publicly funded genome effort. The public data were shredded into 550-bp segments to create a 2.9-fold coverage of those genome regions that had been sequenced, without including biases inherent in the cloning and assembly procedure used by the publicly funded group. This brought the effective coverage in the assemblies to eightfold, reducing the number and size of gaps in the final assembly over what would be obtained with 5.11-fold coverage. The two assembly strategies yielded very similar results that largely agree with independent mapping data. The assemblies effectively cover the euchromatic regions of the human chromosomes. More than 90% of the genome is in scaffold assemblies of 100,000 bp or more, and 25% of the genome is in scaffolds of 10 million bp or larger. Analysis of the genome sequence revealed 26,588 protein-encoding transcripts for which there was strong corroborating evidence and an additional approximately 12,000 computationally derived genes with mouse matches or other weak supporting evidence. Although gene-dense clusters are obvious, almost half the genes are dispersed in low G+C sequence separated by large tracts of apparently noncoding sequence. Only 1.1% of the genome is spanned by exons, whereas 24% is in introns, with 75% of the genome being intergenic DNA. Duplications of segmental blocks, ranging in size up to chromosomal lengths, are abundant throughout the genome and reveal a complex evolutionary history. Comparative genomic analysis indicates vertebrate expansions of genes associated with neuronal function, with tissue-specific developmental regulation, and with the hemostasis and immune systems. DNA sequence comparisons between the consensus sequence and publicly funded genome data provided locations of 2.1 million single-nucleotide polymorphisms (SNPs). A random pair of human haploid genomes differed at a rate of 1 bp per 1250 on average, but there was marked heterogeneity in the level of polymorphism across the genome. Less than 1% of all SNPs resulted in variation in proteins, but the task of determining which SNPs have functional consequences remains an open challenge.

Adjuvant sequential dose-dense doxorubicin, paclitaxel, and cyclophosphamide (ATC) for high-risk breast cancer is feasible in the community setting

PURPOSE

This study evaluated the feasibility, when given in the community, of dose-dense, sequential ATC (doxorubicin, paclitaxel, cyclophosphamide) as adjuvant therapy for breast cancer with four or more metastatic axillary lymph nodes.

PATIENTS AND METHODS

Patients were recruited after definitive breast cancer surgery if four or more axillary nodes were involved by metastatic cancer and if distant metastases were not present on computed tomographic scan or bone scan. Forty patients received doxorubicin, 90 mg/m2 every 14 days for three cycles; paclitaxel, 250 mg/m2 every 14 days for three cycles; and cyclophosphamide, 3 g/m2 every 14 days for three cycles with filgrastim support. Chemotherapy was administered by the referring physician.

RESULTS

Mean dose intensity was 99% for doxorubicin, 96% for paclitaxel, and 99% for cyclophosphamide. Grade 3 toxicities included mucositis (13%), nausea/vomiting (10%), neuropathy (13%), and myalgia/arthralgia (10%). Thirteen patients had neutropenic fever. One patient developed acute leukemia. Three relapses have occurred. Ninety percent of patients are alive and disease-free at a median follow-up of 24 months.

DISCUSSION

ATC can be administered in the community at full doses with acceptable toxicity. Preliminary efficacy data suggest that this high-dose, intensively scheduled regimen warrants comparison with standard therapy for high-risk patients.

Factor VIII gene inversions in severe hemophilia A: results of an international consortium study

Twenty-two molecular diagnostic laboratories from 14 countries participated in a consortium study to estimate the impact of Factor VIII gene inversions in severe hemophilia A. A total of 2,093 patients with severe hemophilia A were studied; of those, 740 (35%) had a type 1 (distal) factor VIII inversion, and 140 (7%) showed a type 2 (proximal) inversion. In 25 cases, the molecular analysis showed additional abnormal or polymorphic patterns. Ninety-eight percent of 532 mothers of patients with inversions were carriers of the abnormal factor VIII gene; when only mothers of nonfamilial cases were studied, 9 de novo inversions in maternal germ cells were observed among 225 cases (approximately 1 de novo maternal origin of the inversion in 25 mothers of sporadic cases). When the maternal grandparental origin was examined, the inversions occurred de novo in male germ cells in 69 cases and female germ cells in 1 case. The presence of factor VIII inversions is not a major predisposing factor for the development of factor VIII inhibitors; however, slightly more patients with severe hemophilia A and factor VIII inversions develop inhibitors (130 of 642 [20%]) than patients with severe hemophilia A without inversions (131 of 821 [16%]).

Severe haemophilia A in a female resulting from two de novo factor VIII mutations

A 2-year-old girl is described with severe haemophilia A (factor VIII: C < 0.01 units/ml). Both of her parents were phenotypically normal. Cytogenetic analysis on the proband demonstrated an interstitial X chromosome deletion encompassing Xq26-q28. Molecular studies with several polymorphic markers close to and within the factor VIII gene showed that the proband had inherited only the paternal factor VIII gene, indicating that the X chromosome deletion had occurred de novo in the maternal germ line. Further study of the factor VIII gene inherited by the proband from her father showed the presence of a de novo gene inversion mutation (a type 1, distal pattern inversion). Neither parent showed any evidence of the factor VIII inversion in their somatic DNA. The severe haemophilia A documented in this girl is therefore the result of two de novo mutations affecting the factor VIII gene, a maternally derived X chromosome deletion and a paternal factor VIII inversion mutation.

Direct detection of a common inversion mutation in the genetic diagnosis of severe hemophilia A

Two recent reports suggest that approximately 50% of the cases of severe hemophilia A (factor VIII:C < 0.01 U/mL) may be caused by a gross rearrangement of the factor VIII gene. The mutation involves genomic sequence from exon 1 to within intron 22 of the gene in an inversion event. This rearrangement can be detected on a Southern blot using a probe that is complementary to sequence from within intron 22. In this report, we describe the analysis of 71 severe hemophilia A patients for the presence of this mutation. Thirty-two of the patients (45%) showed evidence of the rearrangement, a figure that confirms the initial reports on 28 patients. Five different patterns of rearrangement have been noted, although two of these patterns (pattern 1 [70%] and pattern 2 [16%]) account for the majority of cases. The other patterns of rearrangement appear to be confined to individual families and may represent the result of additional sequence variation within the region of the genome to which the proximal 22 exons of factor VIII are translocated. Analysis of this patient population for the factor VIII inversion mutation has been extremely useful in a molecular diagnostic sense. In 23 of the cases studied (72%), the affected individual was the only documented hemophiliac in the family and, thus, previous linkage analysis had been limited to the provision of exclusion testing only. In conclusion, it appears that testing for the factor VIII inversion mutation will be positive in approximately 45% of severe hemophiliacs and as such should constitute the initial stage in the genetic testing protocol for these patients' families.

Multiplex analysis of two intragenic microsatellite repeat polymorphisms in the genetic diagnosis of haemophilia A

Use of molecular genetic studies for carrier detection and prenatal diagnosis of haemophilia A will be informative in approximately 75% of kindreds with a prior history of the disorder if previously reported bi-allelic intragenic polymorphisms are used. In this study we report the use of two multi-allelic, microsatellite repeat polymorphisms within the factor VIII gene in genetic testing for this disease. These two, dinucleotide repeat, polymorphisms have been analysed using a multiplex polymerase chain reaction (PCR) protocol, and results can be available within 3 d of receipt of samples. At the intron 13 polymorphic locus we have confirmed the original observation of eight alleles, whilst at the intron 22 locus, in contrast to a preliminary report of this polymorphism, we have seen five alleles. We have analysed 32 families (174 subjects) with the two microsatellite repeat markers and have found that using these two polymorphisms alone, 81% of families are informative for linkage analysis. The intron 13 repeat was informative in 22/31 families tested (71%) and the intron 22 polymorphism was informative in 12/17 families (71%). We have also found that in 11/32 families tested (34%) the microsatellite repeats were the only informative intragenic markers. In view of these observations, we believe that the most effective strategy for initiating haemophilia A genetic testing is to combine the multiplex PCR analysis of the intron 13 and 22 dinucleotide repeats with the PCR analysis of the intron 18 BclI marker. In our population this protocol provided informative results in approximately 88% of families and results can be available within 3 d of receiving the samples for testing.

Suramin interferes with interleukin-6 receptor binding in vitro and inhibits colon-26-mediated experimental cancer cachexia in vivo

Neoplastic diseases are frequently associated with metabolic changes collectively known as cancer cachexia. The presence of cachexia complicates therapeutic intervention and is an important cause of death in cancer patients. At present there is no effective treatment for cachexia. Recently, the involvement of interleukin-6 (IL-6) in the wasting of colon-26 adenocarcinoma-bearing mice was demonstrated. The research presented here establishes an anticachectic role for the experimental drug suramin, since it partially blocks (up to 60%) the catabolic effects associated with the growth of this tumor in vivo. Suramin prevents the binding of IL-6 to its cell surface receptor subunits, as demonstrated by radioreceptor binding assay and affinity crosslinking experiments. Furthermore, the uptake of radioactive IL-6 by the liver is significantly reduced in suramin-treated mice. On the other hand, the drug is approximately 10-fold less potent in inhibiting the binding of tumor necrosis factor-alpha to indicator cell line in vitro and fails to block liver uptake of this cytokine in vivo. Collectively, these results suggest that suramin inhibits cancer-associated wasting, in part by interfering with the binding of IL-6 to its receptor. Whether suramin inhibits the action of other factors/cytokines that may also participate in colon-26-mediated cachexia is not yet known.

The role of interleukin-6 in lipopolysaccharide-induced weight loss, hypoglycemia and fibrinogen production, in vivo

It was recently shown that interleukin (IL)-6 is an important mediator involved in the Colon (C)-26 model of experimental cancer cachexia. In this study, we wished to determine whether IL-6 is also involved in several metabolic changes associated with lipopolysaccharide (LPS) challenge. Administration of a relatively high amount of LPS to mice induced a transient weight loss, hypoglycemia, hypertriglyceridemia and an increase in the hepatic acute phase reactant, fibrinogen. Pretreatment of mice with the rat anti-murine IL-6 antibody (20F3), but not with a control antibody, resulted in a significant improvement of LPS-induced hypoglycemia and weight loss as well as a significant decrease of plasma fibrinogen. Anti-IL-6 antibody had no effect on LPS-induced hypertriglyceridemia. On the other hand, the pretreatment of mice with anti-murine TNF (TN3.19) antibody was able to completely inhibit elevation of triglycerides and modestly improve LPS-induced weight loss although it had no effect on hypoglycemia and fibrinogen production. Taken together, these results suggest that IL-6 plays a role in some of the metabolic changes associated with both an acute (i.e. LPS challenge) and chronic (C-26 cachexia) inflammatory conditions.

Absence of allelic loss on chromosome 5q by RFLP analysis in preleukemia

Thirty-eight patients with various forms of myelodysplastic syndrome (MDS) were studied for the loss of restriction fragment length polymorphism (RFLP) heterozygosity on chromosome 5q as inferential support for the presence of a growth regulatory locus in this area of the genome. Conventional chromosomal analysis was performed in addition to RFLP studies of constitutive and granulocyte DNA using five polymorphisms from chromosome 5. Allelic loss in granulocyte DNA was identified in only one patient in whom monosomy 5 had already been defined cytogenetically. These results suggest that DNA sequence loss from chromosome 5q other than that observed cytogenetically is a rare event in MDS. Thus the potential involvement of a growth regulatory gene(s), from this area of the genome, in the leukemogenic process most likely involves a more subtle genetic change.

Absence of a bleeding tendency in severe acquired von Willebrand's disease. The role of platelet von Willebrand factor in maintaining normal hemostasis

A 67-year-old male with a prolonged activated partial thromboplastin time (APTT) of 43 seconds (normal, 25-40 seconds) was found to have laboratory features of von Willebrand's disease and IgA myeloma but had a normal bleeding time and no bleeding tendency. Plasma Factor VIII coagulant activity (F.VIII:C) was 80 U/L (0.08 U/mL), Factor VIII antigen (F.VIII:Ag) 70 U/L (0.07 U/mL), and von Willebrand's factor antigen (vWF:Ag) 50 U/L (0.05 U/mL) and ristocetin cofactor (vWF:RiCoF) 10 U/L (0.10 U/mL). The platelet vWF:Ag level was normal, whereas both platelet lysate and plasma vWF high molecular weight multimers were decreased. Patient plasma had no inhibitory effect on either F.VIII:C or vWF:RiCoF. However, when patient plasma was incubated with normal plasma, crossed immunoelectrophoresis for vWF:Ag demonstrated the presence of immune complexes. Infusion of 1-desamino-8-D-arginine vasopressin led to a transient correction of the plasma vWF:Ag multimer pattern. The survival of all components of vWF/F.VIII was decreased, as also occurred after cryoprecipitate. The levels of plasma F.VIII/vWF increased as the IgA values decreased after chemotherapy, whereas the platelet high molecular weight multimers remained decreased. The data suggest that the plasma vWF/F.VIII deficiency results from complexing of the IgA myeloma protein with vWF, resulting in premature clearance of the vWF/F.VIII complex. The absence of clinical bleeding likely results from the combination of a normal platelet vWF:Ag level and persistence of intermediate molecular weight vWF multimers.