A comparison of two methods to determine the presence of high-risk HPV cervical infections

Clinical tests for human papillomavirus (HPV) DNA require clinical validation before being offered for use by laboratories. To determine the clinical viability of a laboratory-developed test using the Invader HPV reagents (Third Wave Technologies, Madison, WI), a retrospective study was designed using 213 patient cervical cytologic samples. The results of the Invader assay were directly compared with the results obtained using the Hybrid Capture 2 High-Risk HPV assay (Digene, Gaithersburg, MD). The results of both assays were also compared with cytologic evaluation. In addition, clinical performance was evaluated using a standard-of-care approach in which colposcopically guided biopsies were done in cases where standard of care dictated, and the histologic features of the biopsy specimens were noted. The Invader-based test demonstrated a clinical sensitivity in atypical squamous cells of undetermined significance cases of 98% for cervical intraepithelial neoplasia (CIN) 2 or worse and 100% for CIN 3 or worse and a negative predictive value of 96.9% (confidence interval, 89.3%-99.6%) using data generated mostly from the use of an earlier version of reagents. These findings support the clinical and laboratory benefits of the Invader method.

Clinical manifestations of hemoglobin Chico at high altitude

Hemoglobin Chico is a rare hemoglobinopathy characterized by low oxygen affinity and a right-shifted oxygen dissociation curve. Detailed clinical evaluations of affected individuals have not been previously reported. We therefore report on the clinical features of Hemoglobin Chico in a Latino male living at high altitude, who desired to participate in school sports. As a young boy with asthma, he had the unusual finding of growth delay and digital clubbing which improved with asthma control. At 16 years of age, he had mild anemia and a decreased pulse oximetry (83%) but sufficient pulmonary reserve to participate in physically demanding activities.

Peripheral T-cell lymphoma with extensive dendritic cell network mimicking follicular dendritic cell tumor: a case report with pathologic, immunophenotypic, and molecular findings

Peripheral T-cell lymphoma (PTCL) with a nodular pattern of growth is uncommon and may be misdiagnosed initially as a B-cell lymphoma or reactive process. We report a case of a rapidly growing PTCL with a distinctly nodular pattern in an axillary lymph node from an 89-year-old man. Immunohistochemical stains for CD21, CD23, and CD35 highlighted an extensive dendritic cell network that imparted the nodular appearance and, in addition, was associated intimately with the neoplastic cells. The neoplastic cells otherwise had an immunophenotype similar to previously reported cases of PTCL with a nodular pattern and germinal center origin (CD3+, CD4+, CD5+, bcl-6+, CD31+, subset CD10+, subset CXCL13+, and subset CD79a+). Molecular studies confirm a clonal T-cell receptor g gene rearrangement. This case emphasizes unusual morphologic features in a PTCL that may be mistaken for follicular lymphoma or a tumor of follicular dendritic cell origin.

Nonsecretory variant of immunoproliferative small intestinal disease: a case report with pathologic, immunophenotypic, and molecular findings

We report a case of the nonsecretory variant of immunoproliferative small intestinal disease involving the distal small bowel and the mesenteric and retroperitoneal lymph nodes in a 19-year-old woman from Mexico. This variant extranodal marginal zone B-cell lymphoma appeared similar in the different sites of involvement, with more interspersed large cells and greater plasmacytic differentiation present in intestinal specimens. Characteristic lymphoepithelial lesions and follicular colonization were seen in intestinal and lymph node sections, respectively. The neoplastic B cells were cytoplasmic immunoglobulin (Ig) A heavy-chain restricted and lacked surface and cytoplasmic light-chain expression by flow cytometric analysis. Serum and urine protein electrophoresis/immunofixation revealed hypogammaglobulinemia with no paraprotein. Molecular studies showed absence of immunoglobulin heavy-chain (IgH) gene rearrangement, with a nonfunctional clonotypic rearrangement of the kappa light-chain gene. This case highlights the role for kappa light-chain gene evaluation in immunoproliferative small intestinal disease, because IgH gene rearrangement analysis is often negative.

Medical management of orbital cellulitis

To determine the appropriate early management of orbital cellulitis and the current bacterial etiology and to evaluate the clinical usefulness of orbital computed tomographic imaging for this infection, a prospective study of orbital cellulitis was conducted during a 2-year period, 1999 to 2000, after the introduction of a conservative medical management plan designed by our pediatric infectious diseases, ophthalmology and otolaryngology services. Basically patients did not have surgical intervention unless progressive involvement of the optic nerve occurred after 24 to 36 h of intravenous antimicrobial therapy. Nine patients had orbital cellulitis and subperiosteal abscesses; only one required surgical drainage because of progressive disease, this case being culture-negative. One had a blood culture positive for Streptococcus pneumoniae; conjunctival cultures showed moderate to heavy growth for S. pneumoniae from this and two other patients, but otherwise bacterial etiology could not be defined. Haemophilus influenzae was not recovered from any of their blood or conjunctival cultures. This experience, during the computed tomography scan and Haemophilus vaccine era, supports an initial medical management approach for most patients with subperiosteal or retrobulbar abscesses resulting in orbital cellulitis.

Tumorigenic potential of a recombinant retrovirus containing sequences from Moloney murine leukemia virus and feline leukemia virus

A recombinant retrovirus, termed MoFe2-MuLV, was constructed in which the U3 region of T-lymphomagenic Moloney murine leukemia virus (Mo-MuLV) was replaced by that of FeLV-945, a provirus of unique long terminal repeat (LTR) structure identified only in non-T-cell, non-B-cell lymphomas of the domestic cat. The LTR of FeLV-945 is unusual in that it contains only a single copy of the transcriptional enhancer followed 25 bp downstream by a 21-bp sequence in triplicate in tandem. Infectivity of MoFe2-MuLV was demonstrated in vitro in SC-1 cells and in vivo in neonatal NIH-Swiss mice. Tumors occurred in MoFe2-MuLV-infected animals following a latency period of 4 to 10 months (average, 6 months). The results of Southern blot analysis of the T-cell receptor beta locus demonstrated that all tumors were lymphomas of T-cell origin. MoFe2-MuLV LTRs were amplified by PCR from tumor DNA and were characterized by nucleotide sequence analysis. LTRs from the tumors that occurred with relatively shorter latency predominantly retained the original MoFe2-MuLV sequence intact and unaltered. Tumors that occurred with relatively longer latency contained LTRs that also retained the 21-bp sequence triplication characteristic of the original virus but had acquired various duplications of enhancer sequences. The repeated identification of enhancer duplications in late-appearing tumors suggests that the duplication affords a selective advantage, although apparently not in the efficient induction of T-cell lymphoma. Proto-oncogenes known to be targets of insertional mutagenesis in the majority of Mo-MuLV-induced tumors or in feline non-T-cell, non-B-cell lymphomas were shown not to be rearranged in any tumor examined. Mink cell focus-inducing (MCF) proviral DNA was readily detectable in some, but not all, tumors. The presence or absence of MCF did not correlate with the kinetics of tumor induction. These studies indicate that the single-enhancer, triplication-containing FeLV LTR, typical of non-T-cell, non-B-cell lymphomas in cats, is competent in the induction of T-cell lymphoma in mice. The findings suggest that the mechanism of MoFe2-MuLV-mediated lymphomagenesis may differ from that of Mo-MuLV-mediated disease, considering the possible involvement of novel oncogenes and the variable presence of MCF recombinants.

Cooperating events in lymphomagenesis mediated by feline leukemia virus

Feline leukemia virus (FeLV)-mediated lymphomagenesis in the domestic cat has been examined as a model of lymphoid malignancy in a naturally outbreeding population. The pathogenesis of two distinct, naturally occurring types of FeLV-induced tumors has been investigated: (1) a thymic lymphoma of T-cell origin, typical of FeLV-induced lymphoma, and (2) an extrathymic, extranodal lymphoma of non-B non-T-cell origin. The genetic features of these tumors are clearly distinguishable, and include determinants encoded both by the virus and the host. Virally encoded determinants of pathogenesis include the long terminal repeat (LTR) and the envelope SU protein. Cellular determinants include the involvement of a set of proto-oncogenes, and other factors characteristic of the specific cell type of origin of the tumor. Functional studies are aimed at evaluating the action and interaction of these genetic determinants in the pathogenesis of lymphoma in an animal model system.

Primary sequence and evolutionary conservation of ribosomal protein genes from the domestic cat

Ribosomal proteins complex with ribosomal RNA to form the subunits of the ribosome, and as such, serve essential functions in protein synthesis. Accumulating evidence suggests that ribosomal proteins are bifunctional molecules with roles in diverse cellular processes in addition to protein synthesis. Previous studies have demonstrated that expression of four ribosomal proteins. L41, S3a, S4, and S17, is elevated in malignant lymphomas of the domestic cat. Reported here is the nucleotide sequence of cDNA clones encoding feline ribosomal proteins L41, S3a, S4, and S17.

Identification of differentially expressed genes in T-lymphoid malignancies in an animal model system

The molecular events characterizing lymphoid malignancy have been examined in an animal model system, specifically, the retroviral induction of leukemia and lymphoma in the domestic cat following infection with feline leukemia virus (FeLV). Genes differentially expressed in FeLV-induced lymphomas were isolated using a strategy of differential hybridization. Six genes were identified which demonstrate a higher level of expression in an FeLV-induced feline thymic tumor as compared with normal thymus. The differentially expressed genes encode the feline homologues of ribosomal proteins S3a, S4, S17, and L41, elongation factor-1 alpha, and cytochrome oxidase sub-unit I. Northern-blot analysis and quantification by phosphorimaging demonstrates that these genes are expressed at levels from 1.5- to 3.1-fold higher in J5-1 thymic tumor as compared with normal thymus. Expression of the selected ribosomal protein mRNA was further examined in a series of human and feline tissues, including normal tissues, malignant tumors and cell lines. Our data reveal that elevation of the selected ribosomal protein mRNA is associated with all FeLV-induced thymic lymphomas examined. The differentially expressed ribosomal protein mRNA accumulates in a balanced manner in thymic lymphomas. By contrast, the elevation in ribosomal protein mRNA levels is not associated uniformly with hematopoietic malignancy. T-lymphoid malignancy, solid tumors or actively proliferating cells. Rather, the elevation appears to be a uniform and distinctive feature of T-cell malignancy of this particular type. The elevated expression of these genes may be causally related to the neoplastic process.

Retroviral determinants of leukemogenesis

The slowly transforming, leukemogenic retroviruses of humans and other mammals induce malignant disease after prolonged latency but lack an oncogene to which their malignant potential can be attributed directly. The leukemogenic activity of these retroviruses can be attributed to at least three factors, including (1) transcriptional regulatory sequences in the long terminal repeat: (2) the insertional mutagenesis of cellular protooncogenes, thus activating their malignant potential; and (3) the actions of structural and regulatory proteins encoded by viral genes. The goal of this review is to summarize recent findings regarding the roles of these factors in retroviral leukemogenesis. The focus of the review is on the slowly transforming, leukemogenic retroviruses of mammals, including humans and experimental animals.