Tear-film dynamics by combining double-pass images, pupil retro-illumination, and contrast sensitivity.

Tear-film dynamics were analyzed by a synchronizing recording of double-pass (DP) and pupil retro-illumination (RI) images with contrast sensitivity (CS) measurements. Simultaneous DP and RI images were acquired in three subjects wearing contact lenses while keeping the eye open. Changes in contrast sensitivity for an 18 c/deg green grating were also estimated. From the DP retinal images, the effect of the tear film is described through the objective scattering index (OSI). This presented a negative correlation with the increase in CS during tear-film deterioration (as observed by RI imaging). These results show a relationship between visual outcome degradation due to tear-film breakup and the increase in intraocular scattering. This work shows a combined methodology for the evaluation of tear-film dynamics.

Relationship between induced spherical aberration and depth of focus after hyperopic LASIK in presbyopic patients.

OBJECTIVE: To evaluate to what extent the modification of corneal asphericity to induce spherical aberration (SA) can improve the depth of focus and to determine whether preoperative adaptive optics assessment (Voptica SL) can predict an optimal SA value for each patient. DESIGN: Comparative, prospective clinical trial with paired eye control. PARTICIPANTS: Patients ≥45 years old who are hyperopic from +1.00 to +2.50 diopters (D), with eyes suitable for LASIK surgery. INTERVENTION: Bilateral hyperopic LASIK surgery using a 200-Hz Allegretto excimer laser. The dominant eye was operated using a conventional profile. The nondominant eye was programmed with an aspheric ablation profile and -0.75 D monovision. MAIN OUTCOME MEASURES: Primary outcome was the correlation between postoperative SA and depth of focus, defined as the pseudo-accommodation value (PAV = [1/reading distance {m}] - minimum addition [D]). Main secondary outcome was the comparison of depth of focus between patients with an induced SA close to the optimal one (group 1), patients with an induced SA far from the optimal one (group 2), and patients for whom SA induction did not increase the depth of focus (control group). RESULTS: We included 76 patients. Between preoperative and postoperative assessment, the mean increase of distance-corrected PAV for near vision was +0.25±0.64 D (P < 0.001) for dominant eyes and +0.63±0.55 D (P < 0.001) for nondominant eyes. As the level of negative or positive postoperative SA increased, PAV for intermediate and near vision increased. Among the 37 eyes that followed the preoperative adaptive optics assessment, the mean PAV increase at near was significantly higher (P < 0.05) in group 1 (0.93±0.50 D) than in group 2 (0.46±0.42 D) and than in the control group (0.35±0.32 D). The mean optimal SA value determined by the dynamic simulation procedure to optimize the depth of focus was -0.18±0.13 µm at 4.5 mm. CONCLUSIONS: Aspheric hyperopic LASIK can increase the depth of focus without impairing far vision, but this benefit would be maximal and reproducible if we could define and achieve an optimal SA value determined by preoperative assessment using an adaptive optics instrument.

Trichoderma and Mycosynthesis of Metal Nanoparticles: Role of Their Secondary Metabolites.

Nanocompounds are widely used in many fields such as environmental, medicine, or agriculture. Nowadays, these nanocompounds are mainly synthesized by chemical methods, causing environmental pollution and potential health problems. Thus, microorganisms have been investigated as potential nanoparticle green biosynthesizers. The main research is focused on the synthesis of nanoparticles (NPs) using algae, yeast, bacteria, and fungi. Among them, fungi have been the most used, due to their simple and effective mycosynthesis. Fungi as well as other organisms involved in green synthesis of NPs use their secondary metabolites (SMs) to mediate and catalyze the reactions to produce metal nanoparticles (MNPs) as well as being able to act as capping agents producing different physicochemical characteristics and biological activities in the MNPs. Among the various fungi used for mycosynthesis are Trichoderma species, which mediate the production of Ag, Cu, CuO, Zn, ZnO, and other MNPs. Here, we review the main SMs from Trichoderma that have been reported or suggested to contribute to synthesize or act as capping agents and their applications, as well as present the main challenges faced by this type of synthesis.

Colorectal serrated adenocarcinoma shows a different profile of oncogene mutations, MSI status and DNA repair protein expression compared to conventional and sporadic MSI-H carcinomas.

Molecular characterization has been extensively studied in serrated polyps but very little is known in serrated adenocarcinomas (SACs). We analyzed the incidence of KRAS, BRAF and PIK3CA mutations, microsatellite instability (MSI) status and loss of the DNA repair proteins MLH1, MSH2, MSH6 and MGMT in a series of 89 SAC, 81 matched conventional carcinomas (CC) and 13 sporadic colorectal cancer showing histological and molecular features of high-level MSI (sMSI-H). Our results demonstrate that KRAS are more prevalent than BRAF mutations in SAC (42.7% vs. 25.8%; p = 0.011) being the KRAS-mutated cases even more abundant in SAC displaying adjacent serrated adenomas (51%). G12D and E545K are the most common KRAS and PIK3CA mutations found in SAC, respectively. SAC show higher frequency of MGMT loss compared to CC (50.6% vs. 25.3%; p = 0.001) especially in distal colon/rectum (60.0% vs. 21.6%; p = 0.0009). SAC differ from sMSI-H in terms of KRAS and BRAF mutation prevalence, MSI status and MLH1 expression (p = 0.0003, p < 0.0001, p < 0.0001, p < 0.001, respectively). SACs are more often KRAS-mutated and microsatellite stable and display different molecular and immunohistochemical characteristics compared to CC and sMSI-H.

The wide-angle point spread function of the human eye reconstructed by a new optical method.

The point spread function (PSF) of the human eye spans over a wide angular distribution where the central part is associated mostly to optical aberrations while the peripheral zones are associated to light scattering. There is a plethora of optical methods for the direct and indirect measurements of the central part of the PSF as a result of monochromatic and polychromatic aberrations. The impact of the spatial characteristics of this central part of the PSF on the retinal image quality and visual function has been extensively analyzed and documented both by optical and psychophysical methods. However, the more peripheral areas of the PSF in the living human eye, ranging from about 1 to 10 degrees of eccentricity, have been investigated only psychophysically. We report here a new optical method for the accurate reconstruction of the wide-angle PSF in the living human eye up to 8 degrees. The methodology consists of projecting disks of uniform radiance on the retina, recording the images after reflection and double pass through the eye's optics and performing a proper analysis of the images. Examples of application of the technique in real eyes with different amount of scatter artificially induced are presented. This procedure allows the direct, accurate, and in vivo measurement of the effect of intraocular scattering and may be a step toward the comprehensive optical evaluation of the optics of the living human eye.

Cause of monocular diplopia diagnosed by combining double-pass retinal image assessment and Hartmann-Shack aberrometry.

PURPOSE: To report an advanced optical procedure developed for the diagnosis of a particular case of diplopia. METHODS: This approach combined the quantification of the level of intraocular scattering by using an Objective Scatter Index provided by a double-pass instrument (Optical Quality Analysis System) with the analysis of higher order aberrations using a Hartmann-Shack wavefront sensor. RESULTS: The value of the Objective Scatter Index revealed increased intraocular scattering; the Hartmann-Shack images showed the existence of an optically differentiated area at the upper region of both crystalline lenses. Simulation of retinal images computed from the wavefront maps confirmed that, under low luminance conditions, this inhomogeneous region of the lens was included in the pupil, generating a secondary image and therefore the diplopia. CONCLUSIONS: This report demonstrates the potential of combining two objective optical methods to show the presence of minor lens opacities that may severely degrade quality of vision.

Impact of scattering and spherical aberration in contrast sensitivity.

We investigated the impact in spatial visual performance of the combined presence of different amounts of spherical aberration and intraocular scattering in the eye. In a group of subjects, contrast sensitivity at 6 cycles per degree was measured when viewing through holographic diffusers to produce different levels of scattering and with their spherical aberration simultaneously controlled using an adaptive-optics visual simulator. For elevated levels of scattering, the addition of small amounts of spherical aberration either does not decrease, or even may slightly increase, contrast sensitivity under some conditions. This seems to be due to an optical effect also demonstrated in an artificial eye. Although the visual effect is quite small, this finding could suggest a balancing mechanism where larger spherical aberration could keep relatively stable the retinal image quality under the presence of elevated scattering. This is actually the situation in older eyes with both spherical aberration and intraocular scatter being higher than in young eyes.

Immunohistochemical detection of p53 protein could improve the management of some patients with Barrett esophagus and mild histologic alterations.

OBJECTIVE: To determine the usefulness of p53 immunostaining in identifying the subgroup of patients with Barrett esophagus who may be at increased risk of developing adenocarcinoma of the esophagus. MATERIALS AND METHODS: Tissue samples of 41 patients with Barrett esophagus and available sequential histologic data were processed for p53 immunostaining. Results from each patient were compared over time, and the results of a subset of patients were compared with each other. RESULTS: We observed a significant correlation between the percentage of samples with p53 expression and the severity of dysplasia. Moreover, in a subset of patients with mild dysplasia (cases classified as showing indefinite dysplasia), we observed a statistically significant difference in the percentage of p53-positive samples between the group that progressed to more severe dysplasia and the group that did not progress. CONCLUSION: Our results suggest that this procedure, which is technically simple, economical, and quick, could play a role in the evaluation and follow-up of patients with Barrett esophagus.

Aspiration cytology of palpable lesions of the scrotal content.

To date, we have studied 89 palpable lesions of the scrotum, testicle, and epididymis using fine-needle aspiration cytology (FNAC). Cystic lesions (48.3%) and inflammatory pathology (25.8%) were the most frequent findings. Tumors accounted for 11.2% of results, with a slight predominance of the malignant varieties. In this article, we describe the cytopathology of the main entities and discuss the principal problems of differential diagnosis, especially among inflammatory processes, seminomas, and embryonal carcinomas. The cytopathological pattern of the neoplasias is highly characteristic, and this permits their diagnosis with great precision. FNAC is essentially nontraumatic and easy to carry out, but it requires considerable practice in its execution and in the interpretation of the aspirates. We believe FNAC to be the technique of choice for the study of the pathology of the scrotal content, and we think that it should be employed on the patient's very first visit. The main advantage of FNAC is avoiding delays in diagnosis.

Malacoplakia and Rosai-Dorfman disease: two entities of histiocytic origin infrequently localized in the female breast--the cytologic aspect in aspirates obtained via fine-needle aspiration cytology.

We describe one case of Rosai-Dorfman disease (RDD) localized in the breast and one case of breast malacoplakia (MPK) both diagnosed by fine-needle aspiration cytology (FNAC). In RDD the cytologic features were lymphocytophagocytosis, large histiocytes with slight nuclear atypia, and lymphohistiocytic aggregates in a polymorphous background which included frequent plasma cells. In MPK the key diagnostic feature was the presence of Michaelis-Gutmann bodies (M-G bodies), in various stages of evolution, intermingled with vacuolized medium-sized histiocytes, other inflammatory cells, and debris. Pap staining is the technique of choice to show lymphocytophagocytosis and M-G bodies and there is no need to resort to special staining methods. RDD and MPK share a common cytologic background: the presence of numerous benign reactive histiocytes, either engulfing apparently intact lymphocytes, or phagocytizing M-G bodies. The cytologic findings seen in both cases suggest that the presence of histiocytes in a breast aspirate is far from being nonspecific and can represent an important lead to disparate diseases such as RDD and MPK.

Asteroid bodies and calcium oxalate crystals: two infrequent findings in fine-needle aspirates of parotid sarcoidosis.

We have studied 3 cases of sarcoidosis involving the parotid gland by means of fine-needle aspiration cytology (FNAC). The main findings were noncaseating granulomas, multinucleated giant cells (MGCs), and lymphocytes. In one case MGCs contained asteroid bodies and in another case we observed calcium oxalate crystals (COCs) over both stromal fragments and MGCs. Although nonpathognomonic for sarcoidosis, these 2 findings may help in the diagnosis of this condition. However, both are easily overlooked and must be borne in mind when viewing noncaseating granulomas. Sarcoid granulomas displaying COC must be differentiated from foreign-body granulomas. The aforementioned cytological findings must be assessed in conjunction with clinical findings. Nevertheless, in most cases the diagnosis of sarcoidosis is made by exclusion.

Basal-cell carcinoma: cytologic and immunocytochemical findings in fine-needle aspirates.

The smears of fine-needle aspirates corresponding to 137 histologically proven basal-cell carcinomas (BCCs) were reviewed. Satisfactory for evaluation were 127 smears; the remaining 10 were unsatisfactory. In 124 cases (97.6%), the cytologic diagnoses coincided with the histologic ones. The remaining 3 were false negatives, and the subsequent histologic correlation demonstrated superficial BCC missed by the needle. The cytologic criteria that permitted a diagnosis of BCC were: variable-sized and irregular-shaped cohesive epithelial clusters, round to oval monomorphic nuclei, bland chromatin pattern, and sparse cytoplasm. In 35 cases, a panel of antibodies was used in the smears and in the respective histologic sections. Epithelial clusters of BCC showed an intense and diffuse positivity for AE-3 and BerEP4, while UEAI and AE-1 were negative. Although HMB45 and S100-A tested negative in the epithelial clusters, a faint and sparse focal positivity for HMB45 and S-100A was seen in some clusters. This positivity is believed to correspond to just a few normal melanocytes and Langerhans cells trapped in the neoplastic epithelial clusters. In the histologic correlates, the same results were obtained, although HMB45 positivity was more conspicuous at the periphery of the neoplastic nests.

Malignant rhabdoid tumor of soft tissues: a cytopathological and immunohistochemical study.

We describe the cytopathological and immunohistochemical features of a primary malignant rhabdoid tumor (MRT) located in the left forehead region of an 8-mo-old female. The cardinal characteristics are hyaline cytoplasmic inclusions, rounded or bean-shaped nucleus, vesicular chromatin, central prominent nucleolus, and poorly defined cytoplasmic profile. Both the cytoplasm and the hyaline inclusion are vimentin and keratin positive, but negative with desmin, S-100 protein, neuron-specific enolase, (NSE) myoglobin, leukocyte common antigen (LCA), and alpha-1-antichymotrypsin. This immunohistochemical pattern, although not exclusive to MRT, is fairly typical of MRT, and when it is assessed in conjunction with cytopathological findings and clinical data permits a confident diagnosis of MRT. We emphasize the utility of immunohistochemical techniques in making the differential diagnosis of MRT against other childhood round-cell tumors.

Infantile cutaneous rhabdomyosarcoma (Li-Fraumeni syndrome): cytological presentation of fine-needle aspirate biopsy, report of a case.

We describe the cytopathological picture of a cutaneous rhabdomyosarcoma located in the left nasal furrow of a 4-mo-old girl, some of whose close relatives have died or suffered from different types of neoplasias (Li-Fraumeni syndrome). We believe that the cytological picture is highly characteristic and rules out other round cell tumours of childhood. We underline the usefulness of FNAC in dermatology and strongly advocate the introduction of this technique into the diagnostic armoury of every dermatologist.

Cytopathology of undifferentiated (embryonal) sarcoma of the liver.

We have studied one undifferentiated (embryonal) sarcoma of the liver (USL) by fine-needle aspiration cytology (FNAC) and have correlated the cytologic findings with those seen in the histologic sections. The main cytologic and immunocytochemical features were: cellular aspirates, mesenchymal clusters, disparity in individual cell size (small round cells, and multinucleated giant cells, sometimes bizarre), absence of biliary pigment, AFP-negative and vimentin-negative tumor cells, AFP-negative and PAS-positive hyaline globules, and apoptotic cells. Only immunostaining for alpha-1-antitrypsin, alpha-1-antichymotrypsin, and carcinoembryonic antigen were positive in tumor cells in histologic sections. The differential diagnosis should be carried out with rhabdomyosarcomas, hepatoblastomas, malignant fibrous histiocytomas, and poorly differentiated hepatocarcinomas. We think that the cytologic features observed in this case, evaluated both in the appropriate clinical context and in the light of the laboratory findings, may permit the correct diagnosis of this infrequent liver tumor. Nevertheless, more cases need to be studied to assess the reliability of our findings.

Follicular variant of papillary carcinoma of the thyroid: to what extent is fine-needle aspiration reliable?

We have reappraised the fine-needle aspirates (FNAs) of 5 cases of the follicular variant of papillary carcinoma of the thyroid (FVPCT). Three of these had been performed on cold thyroid nodules and had been diagnosed as follicular proliferations. The remaining 2 had been performed on cervical lymphadenopathies and had been diagnosed as metastatic papillary carcinoma, probably of thyroid origin. Careful reassessment of the slides did not allow any change of the original diagnoses. We found two constant cytologic features present in all cases studied: syncytial clusters without acinar formation, and monolayered sheets. Nonconstant findings included: follicular pattern, ropy colloid, multinucleated giant cells (MGCs), and nucleoli in FNAs performed on thyroid nodules, and papillae, pseudonuclear inclusions, nuclear grooves, MGCs, and nucleoli in FNAs performed on cervical lymphadenopathies. Our findings suggest that the cytologic diagnosis of FVPCT is very difficult if based solely on the cytologic features seen in FNAs, and that it is necessary to resort to the study of surgical specimens if a definitive diagnosis is to be achieved. We are also of the opinion that more weight should be given to the aforementioned nonconstant findings when faced by a thyroid aspirate with cell richness, syncytial clusters without acinar formation, and monolayered sheets.

Melanocytic schwannoma: the cytologic aspect in fine-needle aspiration cytology (FNAC): report of a case located in the spinal cord.

We describe a case of intramedullary melanocytic schwannoma (MS) studied by means of fine-needle aspiration cytology (FNAC). The main cytologic features were (1) large three-dimensional clusters overshadowed by heavy pigment deposits which tested positive for Fontana Masson (and bleached with potassium permanganate), HMB-45, Vimentin, and S-100 protein; (2) loose syncytial monolayered sheets with very little pigment deposit; and (3) isolated spindle cells with polarized nucleus and tapered, thin cytoplasmic ends. Both the cytologic features and the immunophenotypic profile were nonspecific and on their own were insufficient to allow the diagnosis of MS to be reached. Clinical data and the magnetic resonance image (MRI) in conjunction with the cytologic findings did suggest the diagnosis of intramedullary MS.

Diagnostic dilemmas in the interpretation of fine-needle aspirates of granulomatous prostatitis.

We have reassessed the fine-needle aspirates of ten cases previously diagnosed as granulomatous prostatitis (GP). Presence of unequivocal epithelioid granulomas (EG) or typical caseous necrosis was required for a smear to be diagnosed as nonspecific granulomatous prostatitis (NGP) or tuberculous prostatitis (TP), respectively. As a consequence only six cases met the criteria set up for the diagnosis of NGP and two for TP. The purpose of this revision was fourfold: to find out if there are other prostatic conditions which may be confused with GP cytologically, to investigate if there is a single cytologic finding that permits a confident diagnosis of GP, to find out if the etiology can be suggested on cytologic grounds alone, and, finally, to assess if carcinoma can be ruled out safely. We conclude the following: 1) There are various prostatic conditions which share some cytologic findings with GP; 2) the presence of distinct EG is the hallmark criterion of GP; 3) NGP and TP can be safely diagnosed cytologically but other forms of GP would require additional clinical data and ancillary techniques; and 4) carcinoma can be safely distinguished from GP cytologically. To succeed in this task the cytopathologist must diagnose carcinoma only if clear-cut carcinoma cells are present and must be aware of the reactive changes induced by the inflammatory infiltrate both in duct/acinar and metaplastic cells.

Merkel cell tumor of the eyelid and the cytologic aspect in fine-needle aspirates: report of a case.

We describe one case of Merkel cell tumor (MCT) of the eyelid diagnosed by fine-needle aspiration (FNA). The main cytologic features were: isolated cells, loose cohesive sheets, and rosette-like structures in a hematic background. The cells were round to ovoid and very uniform. Chromatin was finely granular and frequent mitotic figures were observed. Under close scrutiny small faintly stained juxtanuclear "caps" were seen. A strong dot-like positivity for CK22 and NFP was observed in the position corresponding to the "caps." NSE positivity was diffuse, although a weak dot-like positivity was seen in some cells. S-100 was negative. Both the cytologic features and the immunocytologic profile of Merkel cell tumor are very characteristic. FNA enables an early and confident diagnosis of this aggressive tumor and an early planning of surgery.