Hydrophobic Bombyx mori Silk Fibroin: Routes to Functionalization with Alkyl Chains

Bombyx mori silk fibroin (SF) is a very versatile biopolymer due to its biocompatibility and exceptional mechanical properties which make possible its use as a functional material in several applications. SF can be modified with a large variety of chemical approaches which endow the material with tailored chemical–physical properties. Here, a systematic investigation of different routes is reported to graft long alkyl chains on SF based on both liquid- and solid-phase, aiming to modulate its hydrophobic behavior. The liquid phase method involves direct activation of SF tyrosine residues via diazo coupling and cycloaddition reactions, generating hydrophobic materials insoluble in any common solvent. The solid phase approach consists of the chemical modification of drop-casted SF films by esterification of hydroxyl groups of serine, threonine, and tyrosine SF residues with acyl chlorides of fatty acids. For the solid-state functionalization, a new class of hydrophobic pendant groups is synthesized, based on triple esters of gallic acid anhydrides, that are reacted with the biopolymer to further enhance its resulting hydrophobic features.     

p16 expression in primary ovarian mucinous and endometrioid tumors and metastatic adenocarcinomas in the ovary: utility for identification of metastatic HPV-related endocervical adenocarcinomas

Distinction of primary ovarian epithelial tumors from metastatic adenocarcinomas is challenging for tumors exhibiting mucinous, endometrioid, or mixed endometrioid/mucinous differentiation. Metastatic carcinomas with these types of differentiation can be derived from several sites, including the gastrointestinal tract and the uterus. Most endocervical adenocarcinomas exhibit mucinous and/or endometrioid differentiation; they infrequently metastasize to the ovaries but may simulate primary ovarian tumors [both atypical proliferative (borderline) and carcinoma]. Most are high-risk human papillomavirus (HPV)-related and demonstrate diffuse p16 over-expression due to complex molecular mechanisms by which high-risk HPV transforming proteins interact with cell cycle regulatory proteins. The performance of this expression pattern for identifying metastatic endocervical adenocarcinomas in the ovaries among primary ovarian tumors and other metastatic adenocarcinomas having mucinous and/or endometrioid/endometrioidlike differentiation has not been evaluated. Immunohistochemical expression of p16 was assessed in 195 tumors, including 98 primary ovarian tumors (51 mucinous, 47 endometrioid, and 4 mixed mucinous-endometrioid tumors), 93 metastatic adenocarcinomas of known primary sites (colorectum: 34, endocervix: 19, pancreaticobiliary tract: 17, appendix: 7, stomach: 5), 11 metastatic adenocarcinomas of unknown origin (7 established as noncervical), and 4 adenocarcinomas of uncertain (primary ovarian vs. metastatic) origin. The HPV status of the endocervical adenocarcinomas was determined by in situ hybridization and polymerase chain reaction (when in situ hybridization was negative). Expression was assessed based on the percentage of moderately to strongly positive cells, estimated to the nearest 10%. Mean and median expression values for HPV-positive endocervical adenocarcinomas (99%, 100%; range 90% to 100%) were substantially higher than those for primary ovarian mucinous (5%, 0%; range 0% to 70%) and endometrioid (20%, 10%; range 0% to 100%) tumors, HPV-unrelated endocervical adenocarcinomas (0%, 0%; range 0% to 60%), metastatic adenocarcinomas of unknown origin (11%, 0%; range 0% to 30%), and adenocarcinomas of uncertain (primary ovarian vs. metastatic) origin (40%, 35%; range 0% to 90%); only the 15 HPV-positive endocervical adenocarcinomas and 6 other tumors had values of 80% or greater. Diffuse (>75% positive tumor cells) moderate to strong p16 expression is a sensitive (100%) and specific (97%) marker for identifying HPV-related endocervical adenocarcinomas metastatic to the ovary among the primary ovarian tumors and metastatic adenocarcinomas from other sites that are in the differential diagnosis of ovarian tumors having mucinous and/or endometrioid/endometrioidlike differentiation. p16 is useful as part of a panel of immunohistochemical markers for distinguishing primary ovarian tumors from metastases and, when diffusely positive, can suggest the cervix as a potential primary site for metastatic adenocarcinomas of unknown origin.     

Silk Fibroin Processing from CeCl3 Aqueous Solution: Fibers Regeneration and Doping with Ce(III)

Silk fibroin (SF) obtained from Bombyx mori cocoon is a very promising biopolymer. It can be processed from aqueous solutions to obtain many versatile scaffolds useful in optoelectronics, photonics, and biomedicine. Aqueous solutions are prepared by dissolving degummed fibroin with chaotropic agents and then purifying by dialysis. This work presents, for the first time, a solubilization protocol, involving CeCl₃·7H₂O as chaotropic salt in water and ethanol, that allows to regenerate SF under a fibrous form, unlike the standard Ajisawa’s method, which uses CaCl₂ and allows to obtain aqueous gels. All the experimental analyses performed (SEM, XPS, WAXS, ATR‐FTIR, NMR) suggest that the fiber recovered preserves most of the morphological and structural features of the pristine SF and is doped with Ce(III) ions, that interact mainly with the oxygen atoms of C?O moieties and side‐chains of amino acids. Ce(III) doped SF could be the base for new luminescent materials.     

The role of pre-operative CT-guided FNAB for parapharyngeal space tumors.

OBJECTIVE: To determine the role of computed tomography (CT)-guided fine needle aspiration biopsy (FNAB) in surgical planning for parapharyngeal space (PPS) tumors. DESIGN AND SETTING: Chart review of 49 consecutive patients with surgically treated PPS tumors from 1995 to 2005. RESULTS: Twenty-nine patients had CT-guided FNAB. A cytopathologic diagnosis that was the same as final pathology was rendered in 14 (48%) patients; suggestive but not conclusive in 6 (21%) patients; discordant in 3 (10%) patients; and 6 (21%) patients had a nondiagnostic result. Fourteen of 15 patients who had a final histopathologic finding of pleomorphic adenoma had a correct or highly suggestive preoperative FNAB diagnosis. The positive predictive value for CT-guided FNAB to identify benign tumors is 90%, (18 of 20) but to identify malignant PPS tumors is 75% (3 of 4). CONCLUSION: CT-guided FNAB of PPS tumors is helpful to predict the nature of the PPS tumors (especially benign), which allows the surgeon and patient to plan for treatment, accordingly.     

CYP2A6 polymorphisms: is there a role for pharmacogenomics in preventing coumarin-induced hepatotoxicity in lymphedema patients?

Lymphedema is a chronic progressive and significantly disabling disease that affects over 150 million people worldwide. Coumarin is an effective pharmacological treatment, but is banned in some countries due to incidences of hepatotoxicity in rats and mice, and the rare finding of similar hepatotoxicity in humans. Cytochrome P450 (CYP)2A6 is the major enzyme involved in metabolizing coumarin to 7-hydroxycoumarin. A reduction in CYP2A6 activity will lead to shunting of coumarin into other metabolic pathways. In particular, coumarin is metabolized by CYP3A4 to form 3-hydroxycoumarin, the major metabolite in mice and rats. It has been shown that an increase in the 3-hydroxycoumarin ratio is associated with an increased production of the significant cytotoxic product o-hydroxyphenylacetylacetaldehyde (o-HPA), suggesting that a shunting of coumarin metabolism away from 7-hydroxylation is the cause of the toxicity. Hence, poor CYP2A6 metabolizers are more likely to metabolize coumarin via the cytotoxic pathway. Identifying these patients, and not treating them with coumarin, may reduce the incidence of toxicity associated with this drug. The technology to do so exists, but more information is required regarding the mechanism of coumarin toxicity.     

Utility of immunohistochemistry for alpha-methylacyl-CoA racemase in distinguishing atrophic prostate cancer from benign atrophy

Small atrophic prostate cancers on needle biopsy are rare and difficult to distinguish from benign atrophy on needle biopsy. We report on a study of 23 needle biopsy specimens with small foci of atrophic prostate cancer from the consult service of one of the authors. In 19 cancer cases the atrophic component was pure; in 4 cases it was dominant with a minor (<5%) nonatrophic cancer component. These atrophic cancers and 16 cases of florid benign atrophy on needle biopsy were examined by immunohistochemistry for alpha-methylacyl-CoA-racemase (AMACR). All cases of cancer and atrophy were verified immunohistochemically with antibodies to basal cells (34betaE12 and p63). AMACR staining were scored as 1+ (5% to 25% of glands expressing AMACR), 2+ (26% to 50% of glands expressing AMACR), or 3+ (>50% of glands expressing AMACR). Positive staining was defined as staining above that of surrounding benign glands. AMACR was expressed in 69.6% of atrophic prostate cancers (3+, 11 cases; 2+, 3 cases; 1+, 2 cases); 30.4% (7 cases) of atrophic prostate cancer exhibited no AMACR expression. In the 4 cases with a few glands of ordinary (nonatrophic) prostate cancer, the nonatrophic cancer demonstrated more intense and a greater extent of AMACR staining. Fourteen cases (87.5%) of benign atrophy showed no AMACR expression. In 2 cases (12.5%) of benign atrophy, background immunostaining made it difficult to assess AMACR expression. We conclude that AMACR immunostaining alone is not sufficiently discriminatory in the differential diagnosis of atrophic prostate cancer versus benign atrophy. Atrophic prostate cancers are not as frequently or as strongly positive as ordinary prostate cancer. Using a panel of immunostains including AMACR, 34betaE12 and p63 (positive AMACR immunostaining along with negative basal cell markers) is recommended in the differentiation of atrophic prostate cancer and benign atrophy.     

Peripherical thioester functionalization induces J-aggregation in bithiophene-DPP films and nanoparticles

In this work we demonstrated that the peripherical thioacetylation of a bithiophene–DPP molecule can greatly influence the solid-state properties triggering the formation of NIR emitting J-aggregates in both bithiophene–DPP films and nanoparticles. The morphology and the kinetic and thermal stability of the organic nanoparticles were also investigated.

The peripherical thioacetylation of a bithiophene-DPP molecule can greatly influence the supramolecular aggregation triggering the formation of NIR emitting J-aggregates both in films and nanoparticles with high colloidal stability.

The control of supramolecular aggregation of organic semiconductors is a critical and fundamental achievement since aggregation strongly affects the solid-state optic, electronic and optoelectronic properties of conjugated systems. Although processing conditions play a key role in the solid-state arrangement of organic semiconductors in thin film,¹ chemists are attracted by the possibility to control the organization of conjugated molecules by the structural design.^2–5 In this context, it is particularly interesting the case of diketopyrrolo[3,4.c]pyrrole (DPP) derivatives. DPPs are gaining a prominent position among organic dyes for optics and electronics thanks to their simple synthesis, intense color, high photostability, and good charge transport properties.^6,7 Several studies have been reported on the control of the DPP aggregation varying the conjugation of the core or the N-substitution,^8–11 while less explored is the impact on the DPP self-assembly given by the presence of terminal non-conjugated flexible chains.^12,13 In our previous works we observed that varying the length of terminal aliphatic side chains (C₈vs. C₁₆) in a donor–acceptor–donor (DAD) triazole–thiophene–DDP derivative, it was possible to induce the formation of H- or J-aggregates in thin films and organic nanoparticles (ONPs).^14,15 Especially, we found that, for both the C₈ and C₁₆ substituted molecules, H-aggregates were preferentially formed during the self-assembly, but in the case of C₈ substituted species, the resulting ONPs were characterized by low colloidal stability with a remarkable tendency to form micrometric rod-like particles. This morphological evolution of ONPs was associated to an enhancement of the J-aggregate absorption, demonstrating the importance of terminal aliphatic chains in the supramolecular organization of the dye. The possibility to control the formation of H- or J-aggregates is a crucial aspect for the solid-state applications of DDPs. For instance, it has been reported that the increase in the DPP π–π stacking, with the consequent H-aggregation, improves carrier mobility in organic field-effect transistors¹⁶ while, in bulk heterojunction solar cells, DPPs that generate H-aggregates display distinctly lower performances than those forming J-aggregates.¹⁷ Furthermore, J-aggregates show NIR photoluminescence and they can be used as efficient solid state NIR emitters.^18–20 In this work we report the effect of introduction of thioacetyl groups at the end of long alkyl chains on the self-assembly behavior of a bithiophene–DPP derivative (DPP4T). The two compared molecules share the same conjugated core, N-substitution (2-ethylhexyl) and terminal aliphatic moieties (hexyl chains), which are unsubstituted for DPP4T-CH₃, or functionalized with terminal thioacetyl groups for DPP4T-CH₂SAc (Fig. 1). DPP4T-CH₃ represents the reference system for this study since it leads to the formation of both H- and J-aggregates once in the solid state.^13,21,22 Hence, even small variations in the ratio between the two supramolecular species induced by the introduction of different substituents, can be easily detected and quantified. The interest about the correlations between the thioester functionalization and the supramolecular assembly was driven by recent findings on the organization of photoactive ternary blends in the presence of -SAc functionalized oligo(arylenethiophene)s.²³ In fact, we showed that thioester polarizable group can modify the interactions with the solvent used for the processing, also impacting on the solid-state organization.Open in a separate windowFig. 1Molecular structure of DPP4T-CH₃ and of the thioacetate species DPP4T-CH₂SAc.In the present study, in order to distinguish the two effects, DPP4T-CH₃ and DPP4T-CH₂SAc were processed with different techniques and in different conditions: as thin films by spin-coating from a chloroform solution, or as ONPs obtained via re-precipitation method from a tetrahydrofuran (THF) solution in water. The two DPP derivatives were synthesized through a palladium-catalysed Suzuki–Miyaura coupling, a straightforward metal-catalyzed cross-coupling reaction.^24,25 Synthetic details are provided in the ESI.^† First, we performed the electrochemical and the optical characterization of the two dyes in solution. From the comparison between the cyclic voltammograms of the two species (Fig. S1^†) it is clear that the peripherical thioacylation has negligible effects on the electrochemical bandgap (E_g) of the conjugated molecules. Both the oligomers show HOMO and LUMO energies of −5.4 and −3.5 eV respectively, with a resulting bandgap of 1.9 eV (Table S1^†). Results are in perfect agreement with the literature data available for DPP4T-CH₃^21,22,26 and with the UV-VIS characterization in different solvents (CHCl₃, THF, toluene). In fact, from the comparison between the normalized UV-vis spectra of the two dyes in THF (black dotted line in Fig. 2a and b), only minor differences in the relative intensities between the vibronic peaks at 620 and 580 nm can be detected. This difference in the relative intensity between the two absorption maxima can be observed also in other solvents (Fig. S2a and b^†), suggesting a different solvation behaviour for two molecules due to the presence of the -SAc groups. The fluorescence is peaked in the red region at around 650 nm (Fig. S2c and d^†), with a Stoke''s shift of ≈30 nm. The main optical properties in solution are listed in Table S2.^† The solid-state aggregation properties were investigated on thin films of both species on quartz glasses (details in ESI^†). As already reported by Pron and co-workers, DPP4T-CH₃ exhibits poor filming properties,²² and even testing different solvents it was not possible to obtain uniform depositions. Contrarily, DPP4T-CH₂SAc can be deposited as thin film independently on the solvent used, indicating an easy processability of thioester-functionalized organic semiconductors.²³ The high uniformity of DPP4T-CH₂SAc film was confirmed by the AFM analysis (Fig. 3a), that revealed a film thickness of ≈137 nm and a surface roughness (R_g) of 2.42 ± 0.1 nm. The absorption behaviour of the two molecules as thin film completely differs as can be seen from Fig. 2. DPP4T-CH₃ film presents an absorption maximum blue-shifted with respect to the maximum in solution and attributed to the formation of H-aggregates, and a further, red-shifted relative maximum, associated to the J-species. The blue-shifted absorption peak is at 600 nm with a H-shift of 540 cm⁻¹ and a shoulder at 566 nm, while the peak of J-aggregates is red-shifted of 1020 cm⁻¹ at 663 nm. For the DPP4T-CH₂SAc oligomer instead, we record a remarkable trend in the formation of J-aggregates, with a bathochromic shift of the absorption maximum of 1660 cm⁻¹. The spectrum presents a main peak at 691 nm, and two vibronic peaks at 623 and 570 nm (ΔE ≈ 1550 cm⁻¹) with no clear evidence of H-species. The lower tendency to form stacked aggregates of acetylated derivative is supported also from the DSC analysis reported in Fig. 3b. No liquid crystal phase transition was apparently observed for any of the molecules. The melting (T_m) and crystallization (T_c) temperatures measured for the two dyes are lower with respect to those shown by other DPP compounds with unbranched chain substitution on the lactam nitrogen. This has been attributed by other authors to the increase of intermolecular distance in aggregates produced by the 2-ethylhexyl substitution.²⁷ The DPP4TS-CH₂SAc thermogram displays sharp and narrow melting and crystallization transitions, centred at 120 and 60 °C respectively. The presence of a single and sharp peak is consistent with the formation of a single aggregate species, likely J-like as already observed in the absorption spectra. Conversely, phase transitions for DPP4T-CH₃ look more complex, with a broad endothermic phase transition appearing as a bi-modal peak at 133 and 151 °C, and the exothermic phase transition centred at 98 °C. The broad and higher transition temperatures are consistent with the hypothesis of the oligomer DPP4T-CH₃ forming different aggregates with the highest melting energy required. The capability of the SAc-functionalization to trigger the formation of DPP4TJ-aggregates independently on the processing technique was also tested on suspensions of organic nanoparticles (ONPs) in water. The normalized absorption spectra of the DPP4T-CH₃ and DPP4T-CH₂SAc ONPs are reported in Fig. 2. For both molecules, the ONP absorption spectra resemble those of the films. Actually, the major differences can be seen at higher frequency due to the scattering of particles. DPP4T-CH₃ ONPs spectrum is characterized by peaks related to H- and J-aggregates at 598 and 663 nm respectively, as in the case of film. The peak at 663 nm results less intense in ONPs, suggesting a lower tendency to form J-like species in these conditions. Even the spectrum of DPP4T-CH₂SAc retraces the film spectrum, with the maximum of absorption at 682 nm (691 nm for the film), and the same vibronic distribution. Contrarily to non-emissive DPP4T-CH₃ ONPs, DPP4T-CH₂SAc ONPs gives photoluminescence in the NIR. As can be seen from Fig. 4a, the maximum of emission shifts from 650 to 711 nm (ΔE ≈ 1300 cm⁻¹) moving from the THF solution to the ONPs suspension, with a shoulder at 768 nm (ΔE ≈ 1050 cm⁻¹). The coexistence of different kinds of aggregates in DPP4T-CH₃ ONPs is confirmed from the analysis of the excitation spectra in Fig. 4b. In fact, the excitation spectra acquired close to the two maxima of emission (720 and 760 nm) have a different band-shape and they both differ from the absorption spectrum.⁹ In particular, the maximum of the excitation spectrum coincides with the maximum of absorption associated to the J-species at 663 nm. Instead, the excitation spectra measured at different wavelengths of DPP4T-CH₂SAc ONPs are quite similar, indicating that the luminescence at the two maxima is originated by the same species. Moreover, the excitation band-shape perfectly resembles the absorption spectrum, with a maximum at 683 nm and the same vibronic distribution. Combining the information derived from DSC and the excitation data it is clear that the peripherical SAc-groups inhibit the H-organization and strongly promote the formation of J-aggregates, which exhibit a dipole allowed transition in the NIR.¹³ This aspect, together with the low absorbance of biological tissues in this region, makes this system extremely interesting for the development of fluorescent biomarkers for in vitro and in vivo experiments. Finally, we studied the colloidal stability of the two ONP suspensions. In Fig. 5 are reported the absorption spectra on DPP4T-CH₃ and DPP4T-CH₂SAc ONPs acquired during four weeks. Both systems are characterized by a remarkable stability. All the spectra maintain unaltered the band-shape without showing any increasement of the scattering, that implies that no further agglomeration or precipitation occurred during this lapse of time. Results were confirmed by the dynamic light scattering (DLS) analysis (Fig. 5c). The DPP4T-CH₃ ONPs show a monomodal distribution (Fig. S3^†) with an average diameter of 150 nm and a width of about 70 nm (corresponding to a polydispersity index PDI = 0.22). The introduction of the thioacetyl group generates smaller nanoparticles. In fact, for the DPP4T-CH₂SAc ONPs, the average size is 110 nm with a width of 70 nm (PDI = 0.40). The intensity distribution in this case exhibits a bi-modal distribution with two peaks at 15 and 110 mm (Fig. S4^†). TEM images of samples, one day after their preparation, highlight the presence of nearly spherical objects in both DPP4T-CH₃ and DPP4T-CH₂SAc samples (Fig. 6). The statistical analysis of the nanoparticle size is in good agreement with DLS data. Indeed, the average diameter of sample DPP4T-CH₃ is 114 nm (σ = 19%), while the mean diameter of sample DPP4T-CH₂SAc is 106 nm (σ = 46%). During 20 days, storing the samples at 4 °C, no variations in the size distribution of the two species occurred. In order to better characterize the two systems, we studied the effects of the temperature and ionic strength on their colloidal stability. DPP4T-CH₃ e DPP4T-CH₂SAc ONP suspensions in water were heated in the temperature range 20–80 °C and the Z-average diameter was measured with a step of 5 °C. Finally, suspensions were cooled to room temperature and their size was measured again. As can be seen in Fig. 7, after this temperature scan, no variations in the average size of DPP4T-CH₂SAc ONPs was observed, while the unsubstituted system exhibited a size reduction of 17%.Open in a separate windowFig. 2Normalized absorption spectra for DPP4T-CH₃ (a) and DPP4T-CH₂SAc (b) in THF solution, as neat film and as ONP suspension in water. On the right are reported the picture of ONP suspensions of both species.Open in a separate windowFig. 3(a) AFM 10 × 10 μm² topography of DPP4TS-CH₂SAc thin-film processed from a chloroform solution; (b) DSC thermograms of DPP4T-CH₃ (blue line) and DPP4T-CH₂SAc (pink line) recorded between 30 and 300 °C at a scan rate of 10 °C min⁻¹. Scale bar 2 mW.Open in a separate windowFig. 4(a) Emission spectra of DPP4T-CH₃ ONPs (excited at 600 nm, absorbance = 0.295), DPP4T-CH₂SAc (excited at 620 nm, absorbance = 0.536), and the normalized emission spectrum of DPP4T-CH₂SAc in THF (dashed black line); (b) normalized excitation spectra of DPP4T-CH₃ and DPP4T-CH₂SAc ONPs recorded at different emission wavelength.Open in a separate windowFig. 5(a) Absorption spectra of a DPP4T-CH₃ ONP suspension acquired during 28 days; (b) absorption spectra of a DPP4T-CH₂SAc ONP suspension acquired during 28 days; (c) evolution of the average size distribution of DPP4T-CH₃ and DPP4T-CH₂SAc ONPs during 20 days. The error bar represents the polydispersity index expressed in nm.Open in a separate windowFig. 6(A) Representative TEM images of samples DPP4T-CH₃ and, (B) DPP4T-CH₂SAc 1 day after the preparation.Open in a separate windowFig. 7Temperature dependence of the Z-average diameter of DPP4T-CH₃ and DPP4T-CH₂SAc ONP suspensions in water, varying the temperature in the range 20–80 °C. After the heating, suspensions were cooled at room temperature and the Z-average was measured again.Interestingly, these temperature changes did not affect the supramolecular aggregation of the two oligomers in ONPs, since negligible variations in their absorption spectra were detected (Fig. S5^†). Indeed, in the case of DPP4T-CH₂SAc ONPs, varying the temperature from 25 to 65 °C, just an increment of about 7% was observe for the absorption peak at 660 nm (Fig. S5^†).Regarding the impact of ionic strength, in both cases, the addition of 1 ml of phosphate buffered saline to 1 ml of ONP suspension (final salt concentration: phosphate buffer 0.01 M, KCl 0.0027 M, NaCl 0.137 M) did not induce any precipitation at least for one week. Contrarily with what we observed in our previous studies on triazole–thiophene–DPP ONPs,^14,15 where the J-aggregation was associated with a poor colloidal stability and with a remarkable tendency to aggregation, DPP4T-CH₂SAc ONPs possess a high colloidal stability (observed also for the other derivative). Moreover, the presence of -SAc terminal group induces the formation of NIR emitting J-aggregates, opening the way to a promising system for the in vitro and in vivo bioimaging. In conclusion we demonstrated that the simple introduction of a bulky and polarizable terminal thioacetyl group on alkyl chains attached to a thiophene–DPP core, is able to improve the processability of the molecule and to strongly condition the supramolecular aggregation with the formation of stable NIR emitting J-aggregates, independently on the processing technique and conditions.     

Clinical utility of atypical glandular cells (AGC) classification: cytohistologic comparison and relationship to HPV results

OBJECTIVES: To determine the utility of the category of atypical glandular cells (AGC) in the management of patients with putative cervical neoplasia and to correlate HPV-DNA test results when available. METHODS: The Johns Hopkins Hospital cytopathology records of 50,668 women patients were searched for all liquid-based gynecologic cytology (LBP) results of Atypical Glandular cells of Undetermined Significance (AGUS) and AGC from January 1, 2001 through December 31, 2003, yielding 98 patients (0.19%). Oncogenic HPV-DNA tests were performed on the residual fluids of 43 of these patients, 37 of whom had follow-up biopsy. During the period of January 1, 2000 and December 31, 2002, we identified 237 patients (0.58%) with conventional Pap smears in the AGUS or AGC category, among 41,024 conventional smears collected contemporaneously. To avoid confusion in this paper, AGC will be used to replace those results that originally were AGUS. RESULTS: Following the 98 LBP AGC interpretations, 24 lesions (33.8%) were discovered out of 71 biopsies. HPV-DNA tests were performed on the residual of 43 LBPs, 18 (41.9%) were positive for oncogenic HPV. Only 37 patients had follow-up biopsy and 15 (40.5%) were positive for oncogenic HPV, of which 40% (6/15) had a significant lesion. Of the 237 conventional AGC Paps, 18 lesions (15.3%) were discovered out of 118 biopsies. CONCLUSIONS: Comparison of liquid-based and conventional Pap tests revealed a significant difference (33.8% vs. 15.3% respectively) (OR: 2.84, 95% CI: 1.4-5.73, p=0.004) in the detection of glandular and squamous lesions. HPV testing may prove beneficial to triage AGC patients with negative colposcopic findings and positive HPV results.     

Synthesis and Optical Properties of a Copolymer of Tetrafluoro‐ and Dialkoxy‐Substituted Poly(p‐phenylenevinylene) with a High Percentage of Fluorinated Units

A copolymer of 2,3,5,6‐tetrafluoro‐1,4‐phenylenevinylene and 2,5‐dioctyloxy‐1,4‐phenylenevinylene [co(TFPV‐DOPV)], containing more than 60% of tetrafluorophenylenevinylene monomeric units, was synthesized by the Stille cross‐coupling reaction. Its linear and nonlinear optical properties were investigated. Linear absorption and photoluminescence measurements performed on thin films and solution indicate interchain migration upon excitation. The Z‐scan technique was used to evaluate the third‐order nonlinear susceptibility at λ = 1064 nm. A very high refractive nonlinearity (n₂ = (?10 ± 2) × 10^?12 cm² · W^?1) was measured with a value one order of magnitude larger than that of the corresponding dialkoxy‐substituted homopolymer.

     

Adjuvant role of p53 immunostaining in detecting BK viral infection in renal allograft biopsies

BK virus infection is a significant threat to renal transplant outcome. Detecting viral infection in renal transplant biopsies using SV40 staining is less than ideal. SV40 antibody reacts with the large T-antigen of BK virus only at the early phases of infection and can miss cells in later stages of infection. As p53 is upregulated during both early and late phases of infection, this study set out to determine whether p53 staining could improve detection of BK virus infection in renal transplant patients. The control group consisted of 16 renal allograft biopsies without histologic evidence of BK virus infection, while the BK group consisted of 15 renal allograft biopsies with histologic evidence of BK virus infection. The biopsies from both groups were immunohistochemically stained with both SV40 and p53 antibodies. Dual staining with both markers was also performed to identify their nuclear co-localization. In the BK group, the percent of p53 staining (16.6 ± 4.8 %) was significantly higher than the percent of SV40 staining (5.4 ± 2.7%). BK virus infected cells revealed a unique p53 immunostaining pattern (strong nuclear staining with a central halo). Co-localization of SV40 and p53 was identified in cells that had characteristic nuclear features of BK virus infection by histology. The sensitivity and specificity for using p53 staining to identify BK infected cells was 92% and 86 %, respectively. In conclusion, p53 staining detects a higher percentage of BK virus infected cells than SV40 staining alone. Thus, for diagnosis of BK virus infection in renal allograft biopsies, p53 staining is a sensitive and specific method when used along with SV40 staining.