Impact of pharmacy-based syringe access on injection practices among injecting drug users in Minnesota, 1998 to 1999.

In Minnesota, state legislation, enacted July 1998, provided for voluntary pharmacy sales of syringes/needles without a prescription for an accompanying drug. The goal was to stem HIV transmission among injecting drug users (IDUs) by providing greater access to sterile syringes. We used a pre/post evaluation design to investigate the impact of less restrictive syringe/possession laws on IDUs' HIV-related syringe practices. Independent cross-sectional samples of IDUs were recruited from street sites and a correctional facility immediately before and 1 year after enactment of the laws. Of the 671 IDUs interviewed, 570 (270 prelegislation and 300 postlegislation) had injected at least once in the 30 days before the interview. IDUs were more likely to purchase syringes at pharmacies after enactment of the laws (odds ratio [OR], 2.66; 95% confidence interval [CI], 1.83-3.85), yet did not change their behaviors regarding carrying unused syringes (OR, 0.90; 95% CI, 0.63-1.28). After adjusting for speedball injection and criminal history, syringe sharing decreased among IDUs (adjusted OR, 0.67; 95% CI, 0.45-1.00) yet syringe reuse remained the same (adjusted OR, 0.67; 95% CI, 0.40-1.11). Safe disposal of syringes did not differ significantly across the sampling periods (adjusted OR, 1.32; 95% CI, 0.84-2.06). Increased access to pharmacy syringes offers a first step at reducing HIV-related syringe practices but must be coupled with strong HIV prevention messages, drug treatment referrals, and safe syringe disposal options.

Building strong linkages across the HIV prevention continuum: the practical lessons learned from a comprehensive evaluation effort in Minnesota.

This article describes practical lessons learned from an evaluation of a continuum of HIV prevention efforts and is intended to assist other states in strengthening their own HIV prevention evaluation activities. In 1996 Minnesota launched several evaluation activities and began to examine how they could be linked across the HIV prevention continuum. Although each evaluation activity generated its own findings, this article examines the challenges faced and the solutions created when integrating these findings into the original steps of the HIV prevention continuum. Key points are highlighted to guide HIV professionals in their endeavors to develop an integrated approach to evaluation and to establish clear and logical linkages across the HIV prevention continuum.

Subchronic administration of phenobarbital alters the mutation spectrum of lacI in the livers of Big Blue transgenic mice.

Phenobarbital (PHE) is a liver carcinogen in B6C3F1 mice and a weak mutagen that does not appear to form DNA adducts. To investigate PHE mutagenicity in vivo, B6C3F1 Big Blue(R) male transgenic mice harboring the lambdaLIZ shuttle vector containing the lacI target gene were fed PHE at 2500 ppm for 180 days. A modest increase in the mutant frequency (MF) from 5.02+/-2.4x10(-5) in the control group to 6.88+/-0.754x10(-5) in the PHE-treated group, which was marginally different (p<0.05), was obtained. To better assess the relevance of this increase in MF, a random collection of mutants from each PHE-exposed mouse was sequenced. After correcting for clonal expansion, which is the most conservative approach, the MF in the PHE-treated mice decreased to 6.39+/-1.02x10(-5), an insignificant difference (p=0.10) from that in control group. Despite this modest increase in MF, the mutation spectrum obtained from the PHE-exposed group was significantly different (pA:T transitions remained the same in the two spectra. It is postulated that the increase in transversions at G:C base pairs found in the PHE-derived spectrum is likely due to oxidative damage as a result of induction of CYP2B isozymes by the chronic administration of PHE. Results from this study demonstrate that PHE alters the spectrum of mutations, rather than inducing a significant global increase in the MF. The PHE-derived spectrum of lacI mutants from the liver of Big Blue(R) B6C3F1 male mice was remarkably similar (p=0.8) to that generated by oxazepam (OX), a compound which also induces CYP2B isozymes following chronic administration of the drug.

Tissue-specific mutant frequencies and mutational spectra in cyclophosphamide-treated lacI transgenic mice.

The induction and nature of mutations in the lacI transgene were evaluated in multiple tissues after exposure of adult male B6C3F1 lacI transgenic mice to cyclophosphamide (CP). Mice were given a single i.p. injection of 25 mg CP/kg, 100 mg CP/kg, or vehicle (PBS) and then necropsied 6 weeks after treatment to allow DNA extraction and lacI mutant recovery. Tissues evaluated included target tissues for tumorigenesis (lung, urinary bladder) and sites not susceptible to tumor formation in B6C3F1 mice (kidney, bone marrow, splenic T-lymphocytes). After exposure to the high dose of CP, a significant increase in the mutant frequency (Mf) was detected in the lungs and urinary bladders, compared to the respective tissues from vehicle-treated controls. In contrast, the Mfs in kidney, bone marrow, and splenic T cells from CP-treated mice were not significantly different from controls. The spectra of mutations in lacI from lung and urinary bladder were significantly changed after high-dose CP treatment, with a significant increase in the frequency of A. T --> T. A transversions found in both tissues and a significantly elevated frequency of deletions in the lungs. Conversely, in vehicle-treated mice, the two predominant classes of lacI mutations recovered in lung and urinary bladder were G. C --> A. T transitions at CpG sites and G. C --> T. A transversions. These CP exposures were also genotoxic as measured by the significant induction of micronuclei in peripheral blood 48 hr after exposure. These data indicate that under these study conditions, CP-induced mutations are detectable in the lacI transgene in the target tissues, but not in nontarget tissues for CP-induced cancer. With the lacI assay it is possible to study mutagenicity in a variety of critical tissues to provide mechanistic information related to genotoxicity and carcinogenicity in vivo.

Detection of cyclophosphamide-induced mutations at the Hprt but not the lacI locus in splenic lymphocytes of exposed mice.

The relative sensitivities and specificities of the endogenous Hprt gene and the lacI transgene as mutational targets were evaluated in splenic lymphocytes from male standard B6C3F1 mice (only Hprt assayed) and from lacI transgenic B6C3F1 mice treated at 6-7 weeks- of-age with the indirect-acting agent, cyclophosphamide (CP). To define the effects of the time elapsed since CP treatment on Hprt mutant frequencies (Mfs), nontransgenic mice were given single i.p. injections of 25 mg CP/kg or vehicle (PBS) alone and then necropsied 2, 4, 6, 8, or 10 weeks after treatment. Peak Mfs were found at 6 weeks postexposure, with mean Mf values ranging from 2.27 to 3.27 x 10(-5) using two different lots of CP in standard packaging (compared with mean control Mf values of 0.14 to 0.26 x 10(-5) in various experiments). To determine the dose response for Hprt Mfs, nontransgenic mice were given single doses of 0, 12.5, 25, 50, or 100 mg CP/kg and necropsied 4 weeks postexposure. These treatments produced a supralinear dose response curve for CP-induced Hprt Mfs. Based on these experiments, CP mutagenicities at Hprt and lacI were compared in transgenic mice treated with 0, 25, or 100 mg CP/kg (using another lot of CP in ISOPAC((R)) bottles; Sigma) and necropsied 6 weeks later. There was a significant increase in Hprt Mfs in treated transgenic mice (100 mg CP/kg: 0.75 +/- 0.09 x 10(-5); 25 mg CP/kg: 0.39 +/- 0.05 x 10(-5)) versus controls (0.10 +/- 0.01 x 10(-5)); however, the Mfs in lacI of lymphocytes from the same CP-treated animals were not significantly different from controls (100 mg CP/kg: 9.4 +/- 1.1 x 10(-5); 25 mg CP/kg: 6.7 +/- 0. 8 x 10(-5); control: 7.7 +/- 0.7 x 10(-5)). Hprt mutational spectra data in CP-treated transgenic and nontransgenic mice were different from those of control mice, whereas the spectra of mutations in lacI of lymphocytes from Big Blue((R)) transgenic mice were not significantly changed after CP treatment. These data indicate that, under these treatment conditions, CP-induced mutations in splenic lymphocytes were detectable in the Hprt gene but not the lacI transgene of this nontarget tissue for CP-induced cancer.

Oxazepam is mutagenic in vivo in Big Blue transgenic mice.

Although oxazepam (Serax), a widely used benzodiazepine anxiolytic, does not induce gene mutations in vitro or chromosomal aberrations in vivo, it was found to be a hepatocarcinogen in a 2 year bioassay in B6C3F1 mice. Thus, it was of interest to determine whether this carcinogen is mutagenic in vivo. Male B6C3F1 Big Blue transgenic mice were fed 2500 p.p.m. oxazepam or control diet alone for 180 days and killed on the next day. The mutant frequency (MF) of lacI in control mice was 5.02 +/- 2.4x10(5), whereas the MF in the oxazepam-treated mice was 9.17 +/- 4.82x10(-5), a significant increase (P < 0.05). Correction of the mutant frequency of lacI from the oxazepam-treated mice for clonality resulted in a decrease in the mean mutant frequency to 8.15 +/- 2. 54x10(-5). Although the mutant frequency difference was small, sequencing of a random collection of the mutants from each oxazepam-exposed mouse showed a significant difference (P < 0.015) in the mutation spectrum compared with that from control mice. In the oxazepam-exposed mice, an increase in G:C-->T:A and G:C-->C:G transversions and a concomitant decrease in G:C-->A:T transitions were observed. Clonal expansion of mutations at guanines in 5'-CpG-3' sequencing contexts at three sites was noted. It is postulated that some of the mutations found in the oxazepam-derived spectrum were due to oxidative damage elicited by induction of CYP2B isozymes as the result of chronic oxazepam administration. This study demonstrates that the in vivo Big Blue transgenic rodent mutation assay can detect mutations derived from a carcinogen that did not induce gene mutations in vitro or micronuclei in mouse bone marrow. Moreover, the sequencing of the recovered mutants can distinguish between the mutation spectrum from treated mice compared with that from control mice, thereby confirming the genotoxic consequences.

A population-based study of sexually transmitted disease incidence and risk factors in human immunodeficiency virus-infected people.

BACKGROUND AND OBJECTIVES: The Minnesota Department of Health conducts active surveillance for cases of human immunodeficiency virus (HIV) infection and passive surveillance for gonorrhea, Chlamydia trachomatis infection, and syphilis. The authors linked two computerized surveillance databases to assess gonorrhea incidence and risk factors for sexually transmitted disease (STD) acquisition among people with known HIV infection. STUDY DESIGN: People diagnosed with adolescent/adult HIV infection before 1993 and still alive as of December 31, 1994 were compared to people diagnosed with gonorrhea, chlamydial infection, or primary/secondary syphilis in 1993 or 1994. Records were matched on name, date of birth, and gender. The incidence of reported gonorrhea was calculated and risk factors for STD acquisition were examined. RESULTS: Thirty (1.3%) of 2,315 HIV-infected people were diagnosed with one or more STDs after HIV diagnosis (median interval: 3 years). There were 31 episodes of gonorrhea, seven episodes of chlamydial infection, and one episode of secondary syphilis. The gonorrhea incidence among HIV-infected people was high compared to the general population in Minnesota, even after stratifying by gender, age, and county of residence. STD acquisition was independently associated with female gender (odds ratio [OR] = 3.8; 95% confidence interval [CI] = 1.7, 8.3) and residence in Hennepin County (OR = 2.9; 95% CI = 1.2, 7.1), the most populous county in Minnesota. CONCLUSIONS: Linkage of STD and HIV surveillance data is useful as a sentinel for high-risk sexual behavior among HIV-infected people, and it can help identify individuals who require additional interventions to prevent HIV transmission. State and local health departments should consider linking these data sources to assess trends and allocate resources.

Characterization of a human myxoid malignant fibrous histiocytoma cell line, OH931.

Malignant fibrous histiocytoma (MFH), the most common soft-tissue sarcoma of late adult life, includes several histopathologic subtypes. The myxoid MFH subtype is characterized by the presence of abundant mucopolysaccharide within a loose connective tissue stroma. Although the myxoid variant is typically distinguished clinically by its better prognosis, we report a case of myxoid MFH that exhibited an aggressive phenotype with early metastases and death. A cell line, OH931, was established from this myxoid MFH. The primary tumor, OH931 cell line, and cells recovered from tumors generated in nude mice shared similar morphologic features, including the continued production of abundant mucopolysaccharide. Cytogenetic analysis of the primary tumor and a subsequently established cell line (OH931) revealed a complex hypertriploid mainline. Chromosomal breakpoints involved in all three specimens analyzed (diagnostic biopsy, definitive surgical, and cell line) included 1p33, 1q21, 2p14, 4p15, 5q13, 12q13, 14p13, 15p13, 19q13 and 20q13.1. The OH931 cell line, which appears to maintain its peculiar characteristics in vitro, should be useful in studies investigating the role of mucopolysaccharide production in the process of neoplasia.

A 3 milliTesla 60 Hz magnetic field is neither mutagenic nor co-mutagenic in the presence of menadione and MNU in a transgenic rat cell line.

The mechanisms by which an electromagnetic field (EMF) influences biological material are poorly understood. One potentially important model suggests that a magnetic field can stabilize free radicals in such a way as to permit their dispersement rather than their return to the ground state (Okazaki et al., 1988; Scaiano, 1995). We have tested this hypothesis by examining mutagenesis in the E. coli lacI gene target carried in the Big Blue rat embryo fibroblast cell line, R2 lambda LIZ. Mutant frequencies were determined in cells exposed to a magnetic field, cells pretreated with the mutagens N-methylnitrosourea (MNU) or 2-methyl-1,4-naphthoquinone (menadione), prior to being held in a 60 Hz 3 milliTesla (mT) magnetic field and cells concurrently exposed to the mutagens and the magnetic field. Menadione was selected because its mutagenic mechanism involves the formation of free radicals, while MNU is an alkylating agent not thought to act through radical formation. According to the radical stabilization hypothesis the application of a magnetic field to menadione treated cells would accentuate the mutagenic effects. Our results failed to indicate that the magnetic field affects mutagenesis by the oxygen-radical mediated mutagen, menadione.

Frequency and spectrum of ethylnitrosourea-induced mutation at the hprt and lacI loci in splenic lymphocytes of exposed lacI transgenic mice.

The development of mouse models with the endogenous hypoxanthine-guanine phosphoribosyl transferase (hprt) gene and lacI transgene as mutational targets provides an excellent opportunity to compare the mutant frequency (Mf) and types of mutations induced in vivo in different sequence contexts. To this end, a study was conducted to determine the Mfs and spectrum of mutations induced at these loci in splenic T cells from male B6C3F1 Big Blue mice (6 weeks old) exposed to N-ethyl-N-nitrosourea (ENU). Six weeks after i.p. injection of 40 mg ENU/kg, T cells were isolated from control (n = 7) and treated (n = 8) mice for the culture of hprt mutants and for the extraction of DNA and recovery of lacI mutants. Mutations in hprt exon 3 and in lacI were quantified and analyzed using published procedures (S. W. Kohler et al., Proc. Natl. Acad. Sci. USA, 88: 7958-7962, 1991; T. R. Skopek et al., Proc. Natl. Acad. Sci. USA, 89: 7866-7870, 1992). In treated mice, the Mfs (average +/- SE) in hprt (6.0 +/- 0.2 x 10(-5)) and lacI (11.4 +/- 1.8 x 10(-5)) were approximately 16.2-fold (P = 0.006) and 3.4-fold (P = 0.009), respectively, above controls. However, the average induced Mfs (i.e., induced Mf = treatment Mf - background Mf) in hprt and lacI were similar, with the respective increases in Mf being 5.6 +/- 0.2 x 10(-5) and 8.0 +/- 2.3 x 10(-5) over background. Eleven of the 107 hprt mutants from treated Big Blue mice had mutations in exon 3, with 73% being substitutions at AxT bp. These data are similar to those observed in ENU-exposed nontransgenic B6C3F1 mice, in which 62 of 69 exon 3 mutations were substitutions at AxT bp (T. R. Skopek et al., Proc. Natl. Acad. Sci. USA, 89: 7866-7870, 1992). For comparison, the sequences of the lacI genes in two to five mutants from each mouse were determined, and a total of 75 mutations (70 different mutations) was detected. In exposed mice, 55% (24 of 44) of the mutations in lacI were substitutions at AxT bp. In controls, substitutions at AT bp comprised only 20% of the recovered mutations in either hprt exon 3 (1 of 5) or lacI (5 of 26). These data indicate that the lacI mutation assay is less sensitive than the hprt assay for detecting increases in Mf induced by ENU exposure of mice as indicated by the lower relative increase in Mf in the lacI gene, but, given a 6-week expression time, the types of mutations induced by ENU in the transgene reflect those observed in the native transcribed gene.

Cytogenetic analysis of a malignant triton tumor and a malignant peripheral nerve sheath tumor and a review of the literature.

Cytogenetic analyses of malignant peripheral nerve sheath tumors (MPNST) and malignant triton tumors (MTT) are few to date. Two separate triton tumor specimens from one patient and a MPNST specimen from another patient, both with peripheral neurofibromatosis (NF-1, von Recklinghausen disease), showed complex near-triploid complements and partial deletion of the short arm of chromosome 1. Notably, a structural abnormality of chromosome 17 was detected in the MPNST, and loss of chromosome 22 was detected in the MTT. The genes for peripheral neurofibromatosis (NF-1) and central neurofibromatosis (NF-2) have been mapped to these two chromosomes respectively.

Translocation t(3;12)(q28;q14) in parosteal lipoma.

Parosteal lipoma is a rare primary benign bone tumor demonstrating histopathologic features similar to those seen in the commonly occurring lipoma of soft tissue. Cytogenetic studies of soft tissue lipoma have demonstrated frequent abnormalities of 12q13-15. To the best of our knowledge the cytogenetic findings in parosteal lipoma have not yet been described. Cytogenetic analysis of a parosteal lipoma of the femur of a 51-year-old female revealed a t(3;12)(q28;q14), indicating that bone and soft tissue lipomas are cytogenetically similar and likely share a common histopathogenesis.

Clonal chromosomal abnormalities in osteofibrous dysplasia. Implications for histopathogenesis and its relationship with adamantinoma.

BACKGROUND: The pathogenesis of osteofibrous dysplasia, a rare fibroosseous lesion occurring almost exclusively in the tibia of children younger than 10 years of age, is not known. One theory is that osteofibrous dysplasia results from excessive resorption of bone with fibrous repair of the defect. Alternatively, osteofibrous dysplasia has been considered a congenital lesion or a variant of fibrous dysplasia. It has been hypothesized that osteofibrous dysplasia is a secondary reactive process to adamantinoma. Cytogenetic analysis is one form of investigation that has been instrumental in determining the origin of many disorders. METHODS: Short-term cultures of two separate osteofibrous dysplasia specimens (approximately 1 year apart) from the tibia of an 11-year-old boy and 2 separate specimens (approximately 2 years apart) from the tibia of a 16-year-old boy were cytogenetically examined using standard procedures. Additionally, fluorescence in situ hybridization (FISH) studies were performed on uncultured cells of both specimens of the first patient using an alpha-satellite probe for chromosome 12. RESULTS: Cytogenetic and FISH analysis revealed trisomy 12 in both specimens of the first patient. Trisomy for chromosomes 7, 8, and 22 was seen in both specimens of the second patient. CONCLUSIONS: Osteofibrous dysplasia has not previously been subjected to cytogenetic analysis. Trisomy 7 and 12, however, have been reported in a clonally aberrant adamantinoma, potentially providing further support for a relationship between these two lesions. Most importantly, these findings demonstrate a clonal and possibly neoplastic origin for osteofibrous dysplasia of long bone.

Simultaneous interphase cytogenetic analysis and fluorescence immunophenotyping of dedifferentiated chondrosarcoma. Implications for histopathogenesis.

Cytogenetic analysis of four specimens (biopsy, definitive surgical, and two separately occurring lung metastases) of a dedifferentiated chondrosarcoma with a rhabdomyosarcomatous component revealed clonal karyotypic abnormalities in each. Anomalies seen in all specimens included a structurally aberrant chromosome 17 and extra copies of chromosomes 5, 7, 12, and 20. The derivation of the chromosomally abnormal cells was determined by a combined immunocytochemical/cytogenetic approach that allowed simultaneous assessment of cytogenetic aberrations and immunophenotypic features of individual cells. S-100 protein and desmin antibodies were used to evaluate the chondrosarcomatous and rhabdomyosarcomatous components, respectively. A chromosome 7-specific centromeric probe was used for determination of aneuploidy. In both specimens obtained from the primary lesion, S-100 protein and desmin-positive and -negative aneuploid cells were observed. These findings: 1) suggest that both the chondrocytic and rhabdomyoblastic cells arose from the same abnormal clone, 2) support the theory of a common primitive mesenchymal cell progenitor with the ability to differentiate or express features of more than one line of mesenchymal differentiation, and 3) indicate that the term dedifferentiated may be an inaccurate designation for this neoplasm.

Edentulous implants: overdenture versus fixed.

Implant restorations for edentulous patients may be planned as either fixed restorations or removable overdentures. Several factors should be considered when deciding between these treatment alternatives. They may be grouped into factors related to (1) the entire patient, (2) both arches, (3) maxillary restorations, and (4) mandibular restorations.