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.

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.

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.

OMA-AML-1: a leukemic myeloid cell line with CD34+ progenitor and CD15+ spontaneously differentiating cell compartments

OMA-AML-1 was established from a patient with acute myelomonocytic (M4) leukemia at fifth relapse when blasts were greater than 85% CD34+, CD15-. Leukemic cells were established in suspension culture and independently grown as subcutaneous tumors in SCID mice. Cells growing in suspension culture underwent differentiation by phenotypic and morphologic criteria. In contrast, cells grown as subcutaneous solid tumors in SCID mice maintained progenitor cell characteristics with high-density CD34 expression and lack of morphologic differentiation. A tendency toward differentiation to CD15+, CD34- cells in vitro and self-renewal of CD34+, CD15- cells in vivo was consistently demonstrated regardless of whether cells were initially grown in vitro or in vivo. The cell line maintains both a CD34+, CD15- progentitor cell pool and a non-overlapping, CD15+, CD34- differentiating cell compartment after more than 1 year in continuous culture. Cell cycle analysis and cloning experiments were consistent with terminal differentiation occurring in the CD15+, CD34- population. The cell line shows concentration-dependent proliferative responses to interleukin (IL)-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-6, but not to granulocyte CSF (G-CSF). OMA-AML-1 appears to mimic several features of normal myeloid hematopoiesis and should prove useful for the study of normal and malignant myeloid differentiation.

Esthetic and biomechanical considerations in reconstructions using dental implants

The single-tooth implant-supported restoration can provide an outstanding service to many patients. It requires an understanding of the biomechanical principles involved and attention to the many details involved with the diagnosis and treatment planning for these restorations. The clinician should realize that this restorative approach is contraindicated in many circumstances. As Peter K. Thomas said, "Spend more time planning than doing and doing becomes easier."

Effect of hygiene instrumentation on titanium abutments: a scanning electron microscopy study

Implant abutments can be exposed to a variety of oral prophylaxis procedures. In this in vitro study, titanium abutments were subjected to five oral prophylaxis treatment modalities; a metal scaler, a plastic scaler, a rubber cup, a rubber cup with tin oxide, and an air-powder abrasive. The abutment surfaces were then examined under both light and scanning electron microscopes. The metal scaler was seen to roughen the titanium surface. All other modalities tested appeared to smooth the titanium surface by removing surface debris and rounding off the sharp machined grooves present on the untreated abutment surface.

The effects on function of distal-extension removable partial dentures as determined by occlusal rest position

The mesial rest may be an excellent method of reducing unfavorable occlusal forces acting on the abutment tooth. However, when anatomic conditions and therapeutic necessity require alternatives, the distal rest may be used. The use of the distal rest demands that additional procedures be used to reduce the occlusal trauma to the abutment tooth.

The effect of carbon fiber orientation on the fatigue resistance and bending properties of two denture resins

The following conclusions were made concerning the effects of carbon fiber orientation on the flexural fatigue resistance and bending properties of two denture base acrylic resins. Hi-I resin, regardless of fiber presence or orientation, was more resistant to flexural fatigue than Lucitone resin. Carbon fibers placed perpendicular to the direction of applied stress produced the most favorable combination of increased resistance to bending and to flexural fatigue. Production of properly oriented fibers that are well centered within the resin is technically difficult and yields less predictable property improvements than result from randomly dispersed fibers.