CK1δ in lymphoma: gene expression and mutation analyses and validation of CK1δ kinase activity for therapeutic application.

The prognosis of lymphoid neoplasms has improved considerably during the last decades. However, treatment response for some lymphoid neoplasms is still poor, indicating the need for new therapeutic approaches. One promising new strategy is the inhibition of kinases regulating key signal transduction pathways, which are of central importance in tumorigenesis. Kinases of the CK1 family may represent an attractive drug target since CK1 expression and/or activity are associated with the pathogenesis of malignant diseases. Over the last years efforts were taken to develop highly potent and selective CK1-specific inhibitor compounds and their therapeutic potential has now to be proved in pre-clinical trials. Therefore, we analyzed expression and mutational status of CK1δ in several cell lines representing established lymphoma entities, and also measured the mRNA expression level in primary lymphoma tissue as well as in non-neoplastic blood cells. For a selection of lymphoma cell lines we furthermore determined CK1δ kinase activity and demonstrated therapeutic potential of CK1-specific inhibitors as a putative therapeutic option in the treatment of lymphoid neoplasms.

TGFß and IL10 have an impact on risk group and prognosis in childhood ALL.

BACKGROUND: Cytokines and their genes have been described to have an influence on incidence and prognosis in malignant, infectious and autoimmune disease. We previously described the impact of cytokine production on prognosis in paediatric standard-risk acute lymphoblastic leukaemia (ALL). PROCEDURE: In this study, we investigated the influence of cytokine gene polymorphisms (TNFα, TGFß, IL10 and IFNγ) on frequency, risk group and prognosis in 95 paediatric ALL-patients. We further report on intracellular production of these cytokines in T-cells. RESULTS: IL10 high-producer-haplotypes were reduced in ALL-patients compared with healthy controls and resulted in a reduced relapse rate compared with low-producer haplotypes. TGFß high-producer-haplotypes were correlated with a high initial blast-count (codon 25: G/G) and were elevated in high-risk ALL-patients (codon 10: T/T). IL10 was positively and IFNγ-production was negatively correlated with initial blast-count. At diagnosis the expression of TNFα and IFNγ was reduced in patients compared with healthy controls. This was more pronounced in high-risk and in T-ALL-patients. CONCLUSION: We conclude that gene-polymorphisms of the regulatory/anti-inflammatory cytokines, TGFß and IL10, but not of the pro-inflammatory cytokines, IFNγ and TNFα, have an impact on prognosis and risk-group of ALL. However, the reduced capacity to produce pro-inflammatory cytokines at diagnosis may serve as another important, functional risk factor. These data may help in further risk stratification and adaptation of therapy-intensity in paediatric patients with ALL.

Successful treatment of an infant with CDA type II by intrauterine transfusions and postnatal stem cell transplantation.

Congenital dyserythropoietic anemias are rare hematological disorders leading to ineffective erythropoiesis with chronic anemia, complicated by iron overload. Here we present a remarkable clinical course of an infant with CDA type II who first presented as a severe fetal hydrops, requiring serial intrauterine red cell transfusions. While postnatal transfusion dependency persisted, the patient was successfully transplanted with a myeloablative conditioning regimen and peripheral blood stem cells of a matched donor. We believe that allogeneic HSCT is a reasonable therapeutic approach for patients with very severe CDA, even if only a matched unrelated donor is available.

Indication for allogeneic stem cell transplantation in Glanzmann's thrombasthenia.

Glanzmann's thrombasthenia (GT) is an autosomal recessive disorder characterized by a lack of thrombocyte aggregation due to the absence of thrombocyte glycoproteins IIb and αIIbß3. The role of haematopoietic stem cell transplantation (HSCT) in GT remains controversial. However, HSCT offers the only curative approach for patients with a severe clinical phenotype. In this review, we will discuss the limitation of current status evidence and the specific risk of GT, in particular the alloimmunization and refractoriness to thrombocyte infusions. 19 successful HSCT in 18 GT type I patients have been reported. Mean age at transplantation was 5 years. All patients are still alive. The majority received sibling bone marrow transplant with busulfan and cyclophosphamid conditioning. GvHD incidence was within the normal range, but 10 patients showed alloimmunization of thrombocytes. Median follow up is 25 months.

N-terminal prohormone of brain natriuretic peptide: a useful tool for the detection of acute pulmonary artery embolism in post-surgical patients.

BACKGROUND: Acute pulmonary embolism (APE) is an important clinical problem in patients after major surgery and often remains a difficult diagnosis because of unspecific clinical symptoms. Therefore, we investigated the role of N-terminal prohormone of brain natriuretic peptide (NT-proBNP) for the detection of APE. METHODS: In 44 patients with suspected APE referred to the intensive care unit after major surgery, serum NT-proBNP, troponin-I, and D-dimers were measured according to the standard hospital protocol. To definitively confirm or exclude APE, all patients underwent an angiographic CT scan of the thorax. RESULTS: APE was confirmed in 28 and excluded in 16 patients by CT scan. NT-proBNP was significantly (P<0.01) higher in patients with APE [4425 (sd 8826; range 63-35 000) pg ml(-1)] compared with those without [283 (sd 327; range 13-1133) pg ml(-1)]. The sensitivity of the NT-proBNP screening was 93%, specificity 63%, positive predictive value 81%, and negative predictive value 83%. There were no significant (P = 0.96) differences in D-dimers between subjects with and without APE [confirmed APE: 511 (sd 207; range 83-750) µg litre(-1); excluded APE: 509 (sd 170; range 230-750) µg litre(-1)]. Troponin-I levels were not elevated in 32% of the patients with APE. CONCLUSIONS: D-dimer levels are frequently elevated in post-surgical patients and not applicable for confirmation or exclusion of APE. In contrast, NT-proBNP appears to be a useful biomarker for APE diagnosis in the postoperative setting. In the case of NT-proBNP levels below the upper reference limit, haemodynamically relevant APE is unlikely. Troponin-I in contrast is not considered to be helpful.

Heart failure resulting from giant left atrial synovial sarcoma metastasis.

Synovial sarcoma metastasis affecting the heart and infiltrating the mitral valve is a very rare pathology. We report the case of a 44-year-old male treated with chemotherapy for atypical synovial sarcoma of the oral mucosa who presented to our clinic after cardiac decompensation with a presumptive diagnosis of myxoma of the left atrium. A large necrotic tumour positive for CK 22, EMA, CD 99 and BCL-2 but negative for translocation in COBRA-FISH analysis by break-apart probe could be excised and revealed a very rare subtype of synovial sarcoma metastasis arising from the endocard of the left atrium. The tumour was resected and the mitral valve reconstructed through ring annuloplasty.

Allogeneic hematopoietic stem cell transplantation in Glanzmann thrombasthenia complicated by platelet alloimmunization.

BACKGROUND: For Thrombasthenia Glanzmann (GT) patients presenting with a severe clinical phenotype due to complete lack of thrombocyte function or increased titres of anti-platelet antibodies hematopoietic stem cell transplantation (SCT) is the only curative therapy. CASE REPORT: We report the case of a 13-month-old boy, presenting with a severe course of GT, who was successfully treated with an HLA-identical sibling bone marrow transplant. SCT was complicated by anti-platelet alloimmunization after platelet transfusion successfully treated with high dosage immunoglobulins (2 g/kg) and partial plasma exchange. CONCLUSION: SCT may be a viable option for selected patients with GT. However, SCT in GT carries its own significant risks, resulting from the development of anti-platelet antibodies. A critical risk-benefit analysis is mandatory prior to SCT.

Increased expression of vascular endothelial growth factor associated with accumulation of lipids in Bruch's membrane of LDL receptor knockout mice.

AIM: To investigate the pathogenesis of age related macular degeneration (ARM) with respect to lipid accumulation within Bruch's membrane (BrM) in a knockout model with low density lipoprotein (LDL) receptor deficiency. METHODS: LDL receptor deficient mice and C57BL/6 controls were fed a standard diet or a high fat (HF) diet. Plasma total cholesterol (pTC) was determined. Eyes were examined by transmission electron microscopy. Immunohistochemical staining for VEGF was performed. RESULTS: pTC were highest in LDL receptor deficient mice after HF diet and elevated after standard diet compared to controls with and without HF diet. While BrM of controls did not exhibit any visible changes, membrane bound translucent particles were seen in all BrM of knockout mice. The amount of these particles was substantially increased and membranes were thickened after HF diet. VEGF staining was positive in knockout mice only and was located in retinal pigment epithelial cells, the outer plexiform layer, and photoreceptor inner segments. Most intensive VEGF expression was documented after HF diet. CONCLUSION: LDL receptor deficient mice exhibit an accumulation of lipid particles in BrM which is further increased after fat intake. VEGF expression is found in the outer retinal layers of LDL receptor deficient mice and appears to correlate with the amount of lipid particles present in BrM.

High prevalence of anal squamous intraepithelial lesions and squamous-cell carcinoma in men who have sex with men as seen in a surgical practice.

INTRODUCTION: Anal high-grade squamous intraepithelial lesions are probable invasive anal squamous-cell cancer precursors, and although unproved, treatment of high-grade squamous intraepithelial lesions may prevent progression to anal squamous-cell cancer. Men who have sex with men are often treated for benign anorectal disorders without consideration given to the possibility of concurrent high-grade squamous intraepithelial lesions or anal squamous-cell cancer. We determined the prevalence of anal high-grade squamous intraepithelial lesions and anal squamous-cell cancer in an urban surgical practice of men who have sex with men referred for treatment of anal condyloma and other benign noncondylomatous anal disorders. METHODS: One hundred thirty-one HIV-positive and 69 HIV-negative men who have sex with men referred for surgical treatment of presumed benign anorectal disease were evaluated by anal cytology, high-resolution anoscopy, and biopsy. Anal cytology and histology were reported with a modified Bethesda classification. RESULTS: One hundred fifty-seven patients (79 percent) were referred for condyloma, 4 (2 percent) for anal squamous intraepithelial lesions (anal high-grade squamous intraepithelial lesions) diagnosed by primary care providers, and 39 (19 percent) for other benign anorectal disorders. One hundred forty-three patients (93 percent) had abnormal anal cytology, with 107 (54 percent) having high-grade squamous intraepithelial lesions on cytology. Biopsy results revealed 120 patients (60.0 percent) with high-grade squamous intraepithelial lesions and 5 patients (3 percent) with invasive squamous-cell carcinoma. Four of five men with anal squamous-cell cancer were HIV positive. Fourteen men (36 percent) who have sex with men referred for noncondylomatous benign anal disorders had high-grade squamous intraepithelial lesions, and three (8 percent) had anal squamous-cell cancer. High-grade squamous intraepithelial lesions and anal squamous-cell cancer were seen most often at the squamocolumnar junction. CONCLUSIONS: Men who have sex with men referred for treatment of either condyloma or noncondylomatous benign anorectal disease had a high prevalence of anal high-grade squamous intraepithelial lesions and anal squamous-cell cancer. All men who have sex with men referred for treatment of benign anorectal disease should have high-resolution anoscopy and aggressive biopsy of all abnormal areas. Treatment of external lesions alone could miss high-grade squamous intraepithelial lesions or anal squamous-cell cancer.

PNET-like features of synovial sarcoma of the lung: a pitfall in the cytologic diagnosis of soft-tissue tumors.

Fine-needle aspiration (FNA) cytology of soft-tissue tumors is evolving. As more experience is gained, we are becoming aware of potential pitfalls. We describe 2 cases of synovial sarcoma of the lung, primary and metastatic, in patients who had FNA biopsy performed on a lung mass. The cytologic smears showed extremely cellular groups of malignant small round cells, intersected by small blood vessels, with numerous loose single cells, in a background of macrophages and mature lymphocytes. The tumors displayed monomorphic cells forming rosettes and displaying occasional mitoses. A diagnosis of neuroendocrine tumor/primitive neuroepithelial tumor (PNET) was suspected. Furthermore, this suspicion was supported by immunohistochemical stains, which showed positivity for a neuroendocrine marker, Leu 7 (case 1), and for a neural marker, CD 99 (O 13 or HBA 71) (both cases); and negativity for cytokeratins (case 1). The resection specimen of case 1 had mostly tightly packed small round cells, with occasional rosettes, similar to the FNA biopsy, and focal areas composed of spindle cells, organized in a focal fibrosarcoma-like and hemangiopericytoma-like pattern. A balanced translocation between chromosomes X and 18, demonstrated by both karyotyping and fluorescent in situ hybridization (FISH), enabled us to make a diagnosis of synovial sarcoma, which was histologically classified as poorly differentiated. Case 2 was a metastatic biphasic synovial sarcoma of the arm, with a prominent epithelial component. Synovial sarcoma, when composed mainly of small round cells on cytologic smears, is a great mimicker of neuroendocrine/PNET tumors, with light microscopic and immunohistochemical overlap. Awareness of this potential pitfall may aid in preventing a misdiagnosis. Its recognition is of major concern, especially for the poorly differentiated variant, because it is associated with a worse prognosis.

Energy metabolism in human retinal Müller cells.

PURPOSE: To measure selected parameters of energy metabolism and adenosine triphosphate (ATP) production in passaged monolayer cultures of human retinal glial (Müller) cells to assess the effects of varying substrate and oxygen availability on the biochemistry and histologic integrity of these cells. METHODS: Confluent Müller cell cultures were incubated for up to 4 hours at 37 degrees C in a modified minimal essential medium (no serum) under aerobic or mitochondrial-inhibited conditions in the presence and absence of 5 mM glucose or in the presence of lactate, pyruvate, glutamate, or glutamine. Cellular ATP levels, lactic acid production, and (14)CO(2) production from labeled glucose or glutamate were measured along with an examination of cellular morphology. Immunohistochemistry with antibodies to glial cell-specific proteins was also performed. Cells were positive for vimentin, but negative for glial fibrillary acidic protein and glutamine synthetase. RESULTS: Human Müller cells maintained ATP content aerobically at the same level for 4 hours in the presence and absence of glucose. ATP content was also maintained anaerobically at a value equal to that found aerobically, but only in the presence of glucose. ATP content in human Müller cells declined to a very low level when glycolysis was blocked by iodoacetate, and inclusion of lactate, pyruvate, glutamate, or glutamine did not restore the level of ATP. Aerobically, lactic acid production accounted for 99% of the total glucose used, whereas the oxidation of glucose by the mitochondria accounted for only 1%. When mitochondria were inhibited with antimycin A, there was only a modest (1.3-fold) increase in the rate of lactic acid production. No significant differences were found in the histologic appearance of the cells after mitochondrial blockade, but there was massive death of cells after inhibition of glycolysis with iodoacetate. CONCLUSIONS: These results suggest that, in the presence of glucose and oxygen, cultured Müller cells obtain their ATP principally from glycolysis and have a low rate of oxygen consumption. This metabolic pattern may spare oxygen for retinal neurons, particularly in the inner nuclear and ganglion cell layers under normal physiological conditions. Furthermore, retinal Müller cells in culture are resistant to anoxia or absence of glucose, which provides a basis for understanding why Müller cells are less susceptible than neurons to ischemia or hypoglycemia.

Oxidative damage and age-related macular degeneration.

This article provides current information on the potential role of oxidation in relation to age-related macular degeneration (AMD). The emphasis is placed on the generation of oxidants and free radicals and the protective effects of antioxidants in the outer retina, with specific emphasis on the photoreceptor cells, the retinal pigment epithelium and the choriocapillaris. The starting points include a discussion and a definition of what radicals are, their endogenous sources, how they react, and what damage they may cause. The photoreceptor/pigment epithelium complex is exposed to sunlight, is bathed in a near-arterial level of oxygen, and membranes in this complex contain high concentrations of polyunsaturated fatty acids, all considered to be potential factors leading to oxidative damage. Actions of antioxidants such as glutathione, vitamin C, superoxide dismutase, catalase, vitamin E and the carotenoids are discussed in terms of their mechanisms of preventing oxidative damage. The phototoxicity of lipofuscin, a group of complex autofluorescent lipid/protein aggregates that accumulate in the retinal pigment epithelium, is described and evidence is presented suggesting that intracellular lipofuscin is toxic to these cells, thus supporting a role for lipofuscin in aging and AMD. The theory that AMD is primarily due to a photosensitizing injury to the choriocapillaris is evaluated. Results are presented showing that when protoporphyric mice are exposed to blue light there is an induction in the synthesis of Type IV collagen synthesis by the choriocapillary endothelium, which leads to a thickened Bruch's membrane and to the appearance of sub-retinal pigment epithelial fibrillogranular deposits, which are similar to basal laminar deposits. The hypothesis that AMD may result from oxidative injury to the retinal pigment epithelium is further evaluated in experiments designed to test the protective effects of glutathione in preventing damage to cultured human pigment epithelial cells exposed to an oxidant. Experiments designed to increase the concentration of glutathione in pigment epithelial cells using dimethylfumarate, a monofunctional inducer, are described in relation to the ability of these cells to survive an oxidative challenge. While all these models provide undisputed evidence of oxidative damage to the retinal pigment epithelium and the choriocapillaris that is both light- and oxygen-dependent, it nevertheless is still unclear at this time what the precise linkage is between oxidation-induced events and the onset and progression of AMD.

Regulation of corneal endothelial barrier function by adenosine, cyclic AMP, and protein kinases.

PURPOSE: To determine which processes or factors that regulate corneal hydration are responsible for the hydration-modulating effects of adenosine. Influx of fluid to the stroma and efflux to the aqueous humor are governed, respectively, by the imbibition pressure of the stromal matrix and the transendothelial ionic gradients determined by the permeability and active transport characteristics of this monolayer. The focus of this study was to assess the effects of adenosine on these endothelial parameters. METHODS: Isolated corneas freshly dissected from rabbit eyes were used throughout. Active ion transport was assessed by measurement of 86Rb+ uptake by the endothelial cells of intact corneas incubated for 30 minutes in 25 mM HCO3(-)-Ringer with agents promoting corneal deturgescence or corneal swelling. Intracellular and extracellular fluid in the scraped endothelial cell mass was estimated from simultaneous counts of 3H-mannitol and 14C-urea, allowing calculation of tissue-to-medium (T-M) ratios of 86Rb+ in cell water. Permeability of the endothelium was determined by measuring the efflux into the superfusate of 5-carboxyfluorescein (CF) applied to the stroma of deepithelialized corneas superfused at the endothelial surface with the same media described for 86Rb+ uptake. Thickness of these corneas and of others fixed for scanning electron microscopy was monitored with a specular microscope. RESULTS: In the control medium, 25 mM HCO3(-)-Ringer, 86Rb+ was accumulated to yield a T-M ratio of 6.21. Neither adenosine nor other agents that increase cyclic adenosine monophosphate (cAMP)--that is, forskolin and dibutyryl cAMP--changed this value to a significant extent. Bumetanide had no effect, but ouabain caused a decrease in T-M to 1.30, a 79% inhibition. Elimination of Na+ or HCO3- also caused marked decreases in uptake. Permeability to CF in control medium was 3.40 x 10(-4) cm/min. A decrease of more than 20% (P < 0.05) was seen in the presence of adenosine and cAMP promoters and also with the protein kinase inhibitor H-8, whereas phorbol myristate acetate caused an increase to 4.50 x 10(-4) cm/min (P < 0.01). Ouabain caused no change, but blocked the effects of adenosine. Reducing the Ca2+ concentration of the superfusing medium caused time-dependent increases in permeability to 4.57 at 15 to 45 minutes and 12.5 at 80 to 110 minutes. At the earlier time, this increase in permeability could be prevented by the addition of adenosine or H-8. Elimination of Na+ or HCO3- ions from the medium caused a small decrease in permeability and, like ouabain, blocked the effect of adenosine. Changes in thickness of corneas were consistent, in most cases, with the observed alterations in 86Rb+ uptake or permeability to CF. Scanning electron microscopy showed contraction and rounding of endothelial cells in low Ca2+ medium, with stretching of intercellular borders, features that were largely eliminated when adenosine was also present. CONCLUSIONS: Adenosine, through increasing cAMP, decreases permeability of the corneal endothelium. This effect, rather than a change in the active transport (fluid pump) mechanism, is responsible for the promotion of deturgescence and maintenance of lower steady state thickness of corneas exposed to adenosine. The mechanism may involve the phosphorylation state of cytoskeletal proteins and seems to be dependent on an undisturbed environment of monovalent ions.

Oro-palatal dysplasia Bettex-Graf--a new syndrome.

Four cases of an until now undescribed syndrome have been observed in Berne in the last 40 years. All four cases are members of the same family and have occurred in three consecutive generations. They present with a U-shaped palatal cleft, microstomia, hypoplasia of the mandibula and a partial anodontia. An autosomal dominant heredity was demonstrated. Karyograms have been made in three of the patients and in all patients showed an anomaly in the form of a "fragile site" in one chromosome (16 fra 16 [q22]). Surgical and orthopedic treatments were difficult.

Monocyte activation in angiogenesis and collateral growth in the rabbit hindlimb.

We have previously shown that monocytes adhere to the vascular wall during collateral vessel growth (arteriogenesis) and capillary sprouting (angiogenesis). In this study we investigated the association of monocyte accumulation with both the production of the cytokines-basic fibroblast growth factor (bFGF) and TNF-alpha-and vessel proliferation in the rabbit after femoral artery occlusion. In particular, we studied the effects of an increase in monocyte recruitment by LPS on capillary density as well as collateral and peripheral conductance after 7 d of occlusion. Monocytes accumulated around day 3 in collateral arteries when maximal proliferation was observed, and stained strongly for bFGF and TNF-alpha. In the lower limb where angiogenesis was shown to be predominant, macrophage accumulation was also closely associated with maximal proliferation (around day 7). LPS treatment significantly increased capillary density (424+/-26.1 n/mm2 vs. 312+/-20.7 n/mm2; P < 0.05) and peripheral conductance (109+/-33.8 ml/min/100 mmHg vs. 45+/-6.8 ml/min/100 mmHg; P < 0.05) as compared with untreated animals after 7 d of occlusion. These results indicate that monocyte activation plays a major role in angiogenesis and collateral artery growth.

An assessment of rat photoreceptor sensitivity to mitochondrial blockade.

PURPOSE: To report results of functional, biochemical and structural studies of photoreceptor mitochondria in isolated rat retinas under conditions of mitochondrial inhibition. METHODS: Dark-adapted rat retinas were incubated in a modified Ringer's bicarbonate medium under aerobic and anaerobic conditions. Several different procedures were used to inhibit mitochondrial function; N2, 0.01 mM antimycin A, and 1 and 10 mM potassium cyanide (KCN). Measurements were made of lactic acid production, retinal adenosine triphosphate (ATP) content, and receptor potentials. Morphology of the inner segment mitochondria was examined by electron microscopy. RESULTS: In the presence of N2, 0.01 mM antimycin, or 1 mM KCN, lactic acid production was linear throughout the 60- minute period; and the rate was similar for each condition. Retinal ATP content and the amplitude of the receptor potential were also maintained at high levels after short-term incubations with either N2, antimycin A, or 1 mM KCN. In contrast, use of 10 mM KCN produced an entirely different set of results. These effects were studied both at the alkaline pH (8.9) found when this concentration of KCN was simply added to bicarbonate-buffered media and at the normal pH (after readjustment) of 7.4. With 10 mM KCN (pH 8.9), retinal lactate production was severely depressed, retinal ATP content was nearly depleted within 5 to 10 minutes, and the amplitude of the receptor potential rapidly declined to a low level. The deleterious effects of 10 mM KCN on these parameters were lessened to varying degrees when pH was readjusted to 7.4. Electron microscopic observations of rat rod inner segments indicated generally excellent survival of these organelles after incubation with either N2, antimycin A, or 1 mM KCN in comparison with their appearance under oxygenated conditions. However, the inner segments were significantly disrupted after incubation of retinas with 10 mM KCN. CONCLUSIONS: Findings suggest that the loss of the receptor potential and depletion of ATP observed with minutes after exposing isolated rat retinas to media containing 10 mM KCN results from the inhibition of both respiration and glycolysis by this high concentration of KCN. In contrast, when conditions are chosen so that only respiration is impaired (as with N2, antimycin A, or 1 mM KCN) photoreceptor cells are resistant to short-term episodes of mitochondrial inhibition, principally because the upregulation of glycolysis generates sufficient ATP to compensate reasonably well for the loss in mitochondrially produced ATP.

Increased prevalence of abnormal Papanicolaou smears in urban adolescents.

OBJECTIVE: To determine the secular trend in the prevalence of cervical dysplasia as evidenced by abnormal Papanicolaou smear results in sexually active adolescents. DESIGN: Descriptive case series. SETTING: Outpatient department of an urban public hospital. PARTICIPANTS: All sexually active adolescents with Papanicolaou smear results recorded during 2 periods: January 1, 1982, through December 31, 1983 (n = 577), and January 1, 1992, through December 31, 1993 (n = 871). MEASUREMENTS: Age, ethnicity, patient care location in which the Papanicolaou smear preparation was performed, and Papanicolaou smear results were obtained for each patient. For patients with more than 1 Papanicolaou smear result during the specified period, only the first result was included in this study. Papanicolaou smear results were classified according to the Bethesda system as within normal limits, benign cellular change, atypical squamous cells of undetermined significance, lowgrade squamous intraepithelial lesion, or high-grade squamous intraepithelial lesion. Any Papanicolaou smear classified as atypical squamous cells of undetermined significance or low- or high-grade squamous intraepithelial lesion was defined as abnormal. RESULTS: The prevalence of abnormal Papanicolaou smear results was 2.8% in 1982 through 1983 vs 11.7% in 1992 through 1993; prevalence odds ratio was 4.7 (95% confidence interval, 2.7-8.3). The higher rate of abnormal Papanicolaou smear results in 1992 through 1993 persisted after controlling for age, patient care location, and ethnicity in a logistic regression model (adjusted prevalence odds ratio, 5.0; 95% confidence interval, 2.8-8.9). The prevalence of benign cellular change was 8.7% in 1982 through 1983 vs 20.1% in 1992 through 1993; prevalence odds ratio was 2.7 (95% confidence interval, 1.9-3.8). CONCLUSIONS: The prevalence of abnormal Papanicolaou smear results has significantly increased in the last decade in sexually active adolescents seen at a city hospital clinic. The results of this study emphasize the importance of routine Papanicolaou smear screening for all sexually active female adolescents.