Mark H. Stoler

Tissue-specific expression of murine IP-10 mRNA following systemic treatment with interferon γ

We have examined the tissue distribution of 10‐kd inflammatory protein (IP‐10) mRNA expression in C57Bl/6 mice injected intravenously (i.v.) with various inflammatory stimuli. IP‐10 mRNA was strongly induced by interferon‐γ (IFN‐γ) in liver and kidney but only poorly in skin, heart, and lung. IFN‐γ had nearly equivalent access to these tissues as indicated by the distribution of radiolabeled recombinant IFN‐γ 1 h after injection. The time course of IP‐10 mRNA appearance was rapid and transient in both liver and kidney; maximal expression in the liver (2 h) preceded that in the kidney (3 h) and declined rapidly thereafter in both tissues. Expression of IP‐10 mRNA in the liver and kidney was highly sensitive to IFN‐γ treatment; nearly maximal stimulation occurred with injection of 500 U of IFN‐γ per mouse. Comparable stimulation of IP‐10 mRNA expression in splenic macrophages required 10,000 U of IFN‐γ administered i.v., indicating that liver and kidney responses are 10‐ to 20‐fold more sensitive. IP‐10 mRNA expression in both tissues was not restricted to stimulation by IFN‐γ but was also seen with injection of lipopolysaccharide (LPS) (25 μg/mouse) or IFN‐β (100,000 U/mouse). Two other members of the IP‐10 gene family, KC (gro) and JE (MCP‐1), were expressed at lower levels under similar treatment conditions. Analysis of IP‐10 mRNA distribution in the liver and kidney by in situ hybridization indicated that expression in both tissues was most prominent in the reticuloendothelial cell system, particularly in the endothelial lining of the microvascular circulation. Although the function of the IP‐10 gene product has not been defined, these results suggest that it may play an important role in the response of both the liver and kidney to systemic inflammation.

ASCUS and AGUS Criteria

ISSUES: The conference participants addressed the following issues: (1) reporting of equivocal diagnoses, (2) strategies to minimize the use of such diagnoses, (3) morphologic criteria, and (4) management of women with equivocal diagnoses. CONSENSUS POSITION: Equivocal diagnoses should be minimized, to the extent possible, by emphasizing cytologist education and training, improved specimen collection and quality assurance monitoring of individual and laboratory diagnosis rates. Cases fulfilling criteria for other diagnostic entities should not be included in the equivocal category. Regardless of the term utilized, an equivocal diagnosis should be qualified in some manner to indicate that the diagnosis defines a patient at increased risk of a lesion, particularly for those cases which raise concern about a possible high grade lesion. Qualification of an equivocal diagnosis can also be accomplished by appending laboratory statistics of the likelihood of various clinical outcomes or recommendations for patient follow-up. In contrast to favoring a reactive process versus squamous intraepithelial lesion (SIL), a more rationale approach to qualification of atypical squamous cells of undetermined significance may be to separate cases equivocal for low grade SIL from those suspicious for high grade SIL. With regard to glandular lesions, the conference participants expressed unanimous support for the separation of adenocarcinoma in situ (AIS) from atypical endocervical cells of undetermined significance when sufficient criteria are present. However, the diagnosis of a precursor lesion to AIS, endocervical glandular dysplasia, was controversial. The majority of conference participants discourage the use of such terms as mild glandular dysplasia and low grade glandular dysplasia for cytologic diagnoses. ONGOING ISSUES: Conference participants agreed that a term reflecting diagnostic uncertainty is necessary to communicate findings that are equivocal. However, participants could not agree on the wording of such a term. Opinions differed as to: (1) use of atypical, abnormal or morphologic changes to describe cell changes, (2) whether the diagnosis should indicate a squamous or glandular origin of the cells in question when this determination can be made, and (3) the value of defining morphologic criteria for such a diagnosis. The debate over terminology, as well as morphologic criteria, is ongoing, and the readership is invited to communicate opinions to Acta Cytologica. Management of women with equivocal diagnoses varies widely from locale to locale and may differ based on how the equivocal diagnosis is qualified. Findings insufficient for the diagnosis of a high grade lesion may warrant more aggressive follow-up than cases equivocal for a low grade lesion. Where sensitivity of detection of lesions is of paramount importance, follow-up will generally consist of more frequent cytology screening or colposcopy and biopsy. However, in some countries it is considered unethical to have a high percentage of false positive diagnoses, which result in overtreatment and an unnecessary burden for women participating in cervical screening. Future studies may provide a morphologic, or perhaps molecular, basis for distinguishing true precursors of neoplasia from minor lesions of no significant clinical import; this would allow a more coherent and rational approach to diagnosis and management of women with equivocal cytologic findings.

Induction of proliferating cell nuclear antigen in differentiated keratinocytes of human papillomavirus-infected lesions.

The expression of proliferating cell nuclear antigen (PCNA) was studied in human papillomavirus (HPV)-infected, benign and malignant lesions of the genital tract and larynx using immunocytochemical staining of formalin-fixed clinical specimens. We observed the induction of PCNA in squamous carcinomas and adenocarcinomas, as has been demonstrated with other malignancies. In addition, the differentiated keratinocytes of the upper spinous cells and granulocytes in condylomata acuminata and low-grade intraepithelial neoplasias showed a consistent induction of PCNA compared with the normal squamous epithelium, in which only some of the parabasal and basal cells were positive. This reactivation of PCNA synthesis correlated with the presence of high copy numbers of HPV DNA and was independent of the oncogenic risk potential of the infecting HPV genotype. We postulate that HPV gene products induce the expression of PCNA and other components of the host DNA replication machinery in differentiated cells of squamous lesions to facilitate vegetative viral replication.

Chemokine expression in trinitrochlorobenzene-mediated contact hypersensitivity

The expression of the murine IP‐10 and MCP‐1 genes has been examined in the skin of mice during contact hypersensitivity reactions to the hapten trinitrochlorobenezene (TNCB). In both naive and passively sensitized animals, challenge with TNCB resulted in elevated expression of both genes as early as 4 h as detected by Northern hybridization analysis. Twenty‐four hours after challenge, expression was markedly reduced in naive animals but remained elevated in sensitized animals. This prolonged expression of chemokine gene products correlates with the tissue swelling response generally used as a measure of delayed‐type hypersensitivity (DTH) in this model and suggests that the continued expression of these genes results from the stimulation of hapten‐specific T helper cells. Examination of cell type expression patterns by in situ hybridization using 3H‐radiolabeled riboprobes confirmed the results of Northern hybridization experiments. Both genes were expressed predominantly in cells exhibiting the morphology of connective tissue fibroblasts, although the distribution of cells positive for IP‐10 mRNA expression differed from that of cells expressing MCP‐1 mRNA. IP‐10 expression was localized almost exclusively to a population of connective tissue cells surrounding the fur follicle. MCP‐1 expression was rarely found associated with fur follicles but instead was distributed throughout the dermis in cells embedded in the collagenous extracellular matrix. Surprisingly, neither endothelial cells lining the small vessels located deep within the dermis nor epidermal keratinocytes were positive under any of the conditions utilized in the present study. Expression of both IP‐10 and MCP‐1 has been previously reported in a variety of distinct cell types in vitro. The present results indicate that only a subset of the cell types with such potential are stimulated to express these chemokine genes in vivo during hapten‐mediated DTH responses, implying the presence of subtle cell type‐ and tissue‐specific control mechanisms. J. Leukoc. Biol. 55: 452–460; 1994.

Efficacy and safety of 0.5% podofilox solution in the treatment and suppression of anogenital warts

PURPOSE For the patient-administered treatment of anogenital warts, 0.5% podofilox (podophyllotoxin), one of the active compounds of podophyllin, has been shown to be more effective than the vehicle alone. This study was designed to evaluate the safety and efficacy of 0.5% podofilox treatment followed by prophylaxis. PATIENTS AND METHODS A total of 103 patients were entered in stage 1 of the study. Stage 1 was an open label study, and patients self-administered 0.5% podofilox twice daily for 3 consecutive days per week for 4 weeks. A total of 100 patients remained available for efficacy and safety analyses. At the end of stage 1, patients who had a complete response proceeded to stage 2 of the study. Patients who had a 50% to 99% reduction in measured total wart area were offered cryotherapy every 10 days, up to 5 times. If cleared of warts, they were also entered into stage 2. A total of 57 patients were enrolled into stage 2, a double-blind, randomized, placebo-controlled prophylactic study of 0.5% podofilox self-administered once daily for 3 days per week for 8 weeks, on the sites of healed warts. A total of 45 patients in stage 2 were available for efficacy analysis. RESULTS By the end of stage 1, 68% of the warts had disappeared, and 29 of 100 patients (29%) had a complete response. A total of 49 patients had a 50% or greater improvement in wart area and underwent cryotherapy. Rates of local side effects after 1 week of treatment were 57% for inflammation, 39% for erosion, 47% for pain, 48% for burning, and 44% for itching. However, these symptoms and signs were mostly mild to moderate in intensity and diminished over time. Therefore, overall treatment was well tolerated. In stage 2, only 4 of 21 patients (19%) in the podofilox group experienced a recurrence as opposed to 12 of 24 (50%) in the placebo group (P = 0.031). As in stage 1, the side effects were modest, and the drug was well tolerated. CONCLUSION This study confirms the efficacy and good tolerance of 0.5% podofilox in the treatment of anogenital warts. It also establishes the safety and superior efficacy of patient-administered podofilox over the vehicle alone as prophylaxis against recurrence of lesions. Although long-term efficacy and tolerance remain to be established, podofilox appears to be a useful agent in the control of this disease.

Spindle cell reaction to nontuberculous mycobacteriosis in AIDS mimicking a spindle cell neoplasm. Evidence for dual histiocytic and fibroblast-like characteristics of spindle cells.

We report 5 patients with AIDS who had an unusual spindle cell proliferation in the lymph nodes and skin caused by nontuberculous mycobacteriosis. The spindle cell proliferation in these tissues may mimic a spindle cell neoplasm and pose a diagnostic problem if an infectious aetiology is not suspected. The fibroblast-like spindle cells contained numerous acid fast bacilli. They were strongly positive for antibody markers of monocyte/macrophage and leukocyte derivation: Leu M3, Mo-9, T-200, and HLA-DR, and variably positive for alpha-1 anti-chymotrypsin and lysozyme. Ultrastructurally these spindle cells were predominantly fibroblast-like with poorly developed features of macrophages. These results reveal the dual macrophage and fibroblastic character of the spindle cells and probably imply a functional differentiation rather than a histogenetic one.

Human Papillomavirus Type 6 in Grade I Transitional Cell Carcinoma of the Urethra

Of 4 patients who underwent cystourethroscopy, biopsy and laser excision of suspected urethral condylomata acuminata 3 had coexistent grade I papillary transitional cell carcinoma of the urethra. Human papillomavirus type 6 messenger ribonucleic acid was demonstrated within biopsy specimens using tritium-labeled single-stranded antisense ribonucleic acid probes. Compared to condylomata the papillary transitional epithelium expressed less viral message, which might be expected in an epithelium that does not show full squamous epithelial or koilocytotic differentiation. Among these patients there was 1 papillary transitional lesion in the bladder that, although histologically similar, did not express human papillomavirus message, suggesting differential susceptibility of epithelium between the bladder and urethra. The finding of active human papillomavirus transcription within the urethral papillary transitional lesions raises the possibility of an active role for the virus in the pathogenesis of these lesions. These findings broaden the spectrum of epithelial types reported to support human papillomaviruses and provides impetus for a wider search for these viruses in other transitional cell neoplasms.

Intraepithelial neoplasia of the anal canal in hemorrhoidal tissue: a study of 19 cases.

The investigators report the clinical and pathologic features of 19 cases of intraepithelial neoplasia occurring in the anal canal mucosa of routinely excised hemorrhoidal tissue, a condition that has been infrequently described. The patients were 12 women and seven men having an age range of 21 to 74 years (mean, 48 years). Two patients had coexistent anogenital condylomata acuminata. Leukoplakia of the hemorrhoidal surface was noted in two patients. Intraepithelial neoplasia arose in the transition zone of the anal canal of 11 cases, in the squamous zone of three cases, and in both sites of five cases. All were high-grade intraepithelial neoplasms; one was classified moderate to severe dysplasia, 17 exhibited severe dysplasia/carcinoma in situ, and one contained microinvasive carcinoma. Both keratinizing and cloacogenic type neoplasms were observed. Associated koilocytotic atypia was identified in 16 cases (84%). In situ hybridization for human papillomavirus (HPV) messenger RNA demonstrated HPV RNA sequences in seven of nine neoplasms (78%) studied by that technique (five HPV type 16, one HPV type 18, and one coinfection with HPV types 6 and 18). Eighteen patients had no clinically evident recurrent or progressive disease at mean follow-up of 6.6 years. Residual/recurrent intraepithelial neoplasia was noted in one patient at 1, 2, 5, and 49 months posthemorrhoidectomy. Our data indicate that incidentally discovered high-grade intraepithelial neoplasia present in hemorroidal tissue is a clinically nonaggressive lesion frequently associated with HPV infection. Hemorrhoidectomy alone is curative in most cases.

Precursor langerhans cell histiocytosis

Background. Langerhans cell precursors are considered to be identical to their mature counterparts except for the lack of Birbeck granules. Proliferations composed of such histiocytes appear to be uncommon.

Cell differentiation-related gene expression of human papillomavirus 33

The gene expression of human papillomavirus (HPV) 33, which can be detected both in benign and malignant genital tumors, was analyzed in a cervical condyloma acuminatum by in situ hybridization using open reading frame-specific RNA probes. Viral mRNA concentrations increased with the degree of differentiation of the keratinocytes. The probes for reading frames E4 and E5 generated the most intense signals. The patterns of the specific viral mRNAs were very similar to those in condylomas induced by HPV 6 or 11, which are only rarely associated with malignancies. This implies that in tumors of the same degree of morphological differentiation the gene expression program of different HPV types is essentially identical. The pattern observed here most likely corresponds to a productive phase of viral infection.