Investigation of saccadic eye movement effects on the fluid dynamic in the anterior chamber

The aqueous humor (AH) flow in the anterior chamber (AC) due to saccadic movements is investigated in this research. The continuity, Navier-Stokes and energy equations in 3D and unsteady forms are solved numerically and the saccadic motion was modeled by the dynamic mesh technique. Firstly, the numerical model was validated for the saccadic movement of a spherical cavity with analytic solutions and experimental data where excellent agreement was observed. Then, two types of periodic and realistic saccadic motions of the AC are simulated, whereby the flow field is computed for various saccade amplitudes and the results are reported for different times. The results show that the acting shear stress on the corneal endothelial cells from AH due to saccadic movements is much higher than that due to normal AH flow by buoyancy induced due to temperature gradient. This shear stress is higher on the central region of the cornea. The results also depict that eye saccade imposes a 3D complicated flow field in the AC consist of various vortex structures. Finally, the enchantment of heat transfer in the AC by AH mixing as a result of saccadic motion is investigated.     

Effects of aspiration vacuum and needle diameter on cumulus oocyte complex morphology and developmental capacity of bovine oocytes

The effects of aspiration vacuum and needle diameter on the morphology of the cumulusoocyte-complex (COC) and developmental capacity of the oocyte after IVF was studied in 2 experiments using a disposable ovum pick-up needle guidance system whose construction permits its use in vitro. In Experiment 1, the relationship was determined between the aspiration vacuum, expressed in millimetre of mercury, and the actual amount of water aspirated by the system, expressed in millilitre per minute. In Experiment 2, five different levels of aspiration vacuum for 3 different needle diameters (18g, 19g and 21g) were tested in slaughterhouse ovaries. The cumulus-oocyte complexes (COCs) were divided into 3 categories: 1) oocytes with a compact cumulus, 2) oocytes with an expanded cumulus and 3) naked oocytes. The results show that a change of needle diameter can triple the amount of fluid actually aspirated. The highest oocyte recovery rates are obtained when using the thickest needle (18-g), regardless of the aspiration vacuum. On the average, for all needle types, more oocytes are recovered at the highest aspiration vacuum. For all needle diameters, the proportion of oocytes surrounded by a compact cumulus decreases progressively as the vacuum increases. Regardless of the vacuum applied, thinner needles result in a higher proportion of recovered COCs with a compact cumulus. At a high aspiration vacuum, naked oocytes become predominant regardless of the needle diameter. The prevalence of blastocysts, expressed in proportion to the recovered COCs, decreases as the aspiration vacuum increases, being especially noticeable between 70 and 130 mm Hg.     

Pure preovulatory follicular fluid promotes in vitro maturation of in vivo aspirated equine oocytes

In the mare, rates of fertilization and development are low in oocytes matured in vitro, and a closer imitation of in vivo conditions during oocyte maturation might be beneficial. The aims of the present study were, therefore, to investigate whether (1) equine oocytes can be matured in vitro in pure equine preovulatory follicular fluid, (2) priming of the follicular fluid donor with crude equine gonadotrophins (CEG) before aspiration of preovulatory follicular fluid promotes the in vitro maturation rate, (3) the in vitro maturation rate differs between oocytes aspirated during estrus and those aspirated again 8 days after the initial follicular aspiration, and (4) high follicular concentrations of meiosis activating sterols (MAS) are beneficial for in vitro maturation of equine oocytes. During estrus, 19 pony mares were treated with 25 mg CEG. After 24 h (Al) and again after 8 days (A2), all follicles >4mm were aspirated and incubated individually for 30 h in the following culture media: standard culture medium (SM), preovulatory follicular fluid collected before CEG containing low MAS concentrations (FF1), preovulatory follicular fluid collected before CEG containing high MAS concentrations (FF2) or preovulatory follicular fluid collected 35 h after administration of CEG containing low MAS concentrations (FF3). Cumulus expansion rate was significantly affected by culture medium. The overall nuclear maturation rate was significantly higher for oocytes collected at A1 (67%) than for oocytes collected at A2 (30%). For oocytes collected at A1, the maturation rates were 71% (FF1), 61% (FF2), 79% (FF3) and 56% (SM). An electrophoretic protein analysis of the culture media revealed the presence of a 200-kDa protein in FF3. The results demonstrate that (1) equine oocytes can be matured during culture in pure equine preovulatory follicular fluid, (2) preovulatory follicular fluid collected after gonadotrophin-priming seems superior in supporting in vitro maturation than standard culture medium, (3) oocytes aspirated 8 days after a previous aspiration are less competent for in vitro maturation than oocytes recovered during the initial aspiration, and (4) the regulation of meiotic resumption during in vitro culture of equine oocytes might be related to the presence of a 200-kDa protein.     

Determination of bovine fetal sex by PCR using fetal fluid aspirated by transvaginal ultrasound-guided amniocentesis

Fetal sex can be determined by the polymerase chain reaction (PCR) using cells from fetal fluid collected by transvaginal ultrasound-guided amniocentesis. A total of 35 aspirates from 30 cows, 15 Holsteins and 15 Japanese Blacks at 59 to 250 d of pregnancy were used. Five cows were aspirated twice at a 10-d interval. A 5.0 MHz convex array transducer connected to a scanner was inserted into the vagina under caudal epidural anesthesia. The transducer was equipped with a 65-cm long, 21-g needle within the probe carrier. A bovine male-specific primer and a bovine gender-neutral primer were used. Fetal fluid was obtained from all except 2 cows in early pregnancy. Five animals aborted within 1 wk following aspiration. A total of 33 samples, 29 of amniotic fluid and 4 of allantoic fluid, was subjected to PCR analysis. Fetal gender was verified in 31 33 samples (18 females and 13 males). Gender was also determined by gross examination of external genitalia of offspring after calving or abortion. Fetal gender was correctly identified by PCR analysis of aspirated fetal fluid in 16 16 females and in 13 15 males. Transvaginal ultrasound-guided amniocentesis followed by PCR analysis of aspirated cell DNA can be used accurately to determine fetal sex in cows at 70 to 100 d of gestation. The procedure requires considerable skill and is not without some risk to fetal viability.     

Ultrasound-guided follicle aspiration: the collection of bovine cumulus-oocyte complexes from ovaries of slaughtered or live cows

To increase the collection efficiency of bovine cumulus-oocyte-complexes (COCs) by transvaginal aspiration, the effects of aspiration pressure and needle diameter on bovine follicular oocyte collection were assessed. Oocytes were aspirated from ovaries of slaughtered cows using 2 different diameter needles (18- or 21-gauge) with 4 different aspiration pressures (40, 80, 120 or 160 mmHg) and of live cows using 18-gauge needles with 40 or 80 mmHg, or using 21-gauge needles with 80 or 120 mmHg. The recovered oocytes were divided into 4 categories according to the surrounding cumulus cells and quality of oocytes: 1) 4 or more layers, 2) between 1 and 3 layers, 3) completely or partially denuded and 4) all others, including expanded cumulus cells and degenerated oocytes. The highest oocyte recovery rates from Categories 1 and 2 were obtained using 18-gauge needles with 40 mmHg pressure and 21-gauge needles with 120 mmHg pressure, respectively, from the ovaries of slaughtered cows. When oocytes were collected from live cows, the highest recovery rates for Categories 1 and 2 were obtained using an 18-gauge needle and 40 mmHg pressure, and 21-gauge needle and 80 mmHg, respectively. In addition, the proportion of oocytes in each category were compared between ovaries from slaughtered and live cows. The proportion of Category 1 oocytes collected from live cows was lower than from slaughtered cows when 18-gauge needles at 80 mmHg (P<0.05). The results show that the combination of aspiration pressure and needle diameter is crucial for COC collection, and they suggest that optimal aspiration conditions for ovaries of slaughtered cows are not necessarily applicable to live cows.     

Experimental Study of Aqueous Humor Flow in a Transparent Anterior Segment Phantom by Using PIV Technique

Pupillary block is considered as an important cause of primary angle-closure glaucoma (PACG). In order to investigate the effect of pupillary block on the hydrodynamics of aqueous humor (AH) in anterior chamber (AC) and potential risks, a 3D printed eye model was developed to mimic the AH flow driven by fluid generation, the differential pressure between AC and posterior chambers (PC) and pupillary block. Particle image velocimetry technology was applied to visualize flow distribution. The results demonstrated obvious differences in AH flow with and without pupillary block. Under the normal condition (without pupillary block), the flow filed of AH was nearly symmetric in the AC. The highest flow velocity located at the central of AC when the differential pressure between AC and PC was under 5.83 Pa, while it appeared near the cornea and iris surface when the differential pressure was greater than 33.6 Pa. Once pupillary block occurred, two asymmetric vortices with different sizes were observed and the shear stress in the paracentral cornea and iris epithelium increased greatly. It can be concluded that the pupillary block and the elevated differential pressure between AC and PC could change the flow distribution and thus increase the risk of corneal endothelial cells detachment. This study could make a further understanding of the pathogenesis of PACG.     

Analysis of protein composition of rabbit aqueous humor following two different cataract surgery incision procedures using 2-DE and LC-MS/MS

Background  

The aqueous humor (AH), a liquid of the anterior and posterior chamber of the eye, comprises many proteins with various roles and important biological functions. Many of these proteins have not been identified yet and their functions in AH are still unknown. Recently, our laboratory published the protein database of AH obtained from healthy rabbits which expanded known protein identifications by 65%. Our present study extends our previous work and analyses AH following two types of cataract surgery incision procedures (clear corneal and limbal incisions) by using two dimensional gel electrophoresis (2-DE) and liquid chromatography tandem mass spectrometry (LC-MS/MS). Although both incision protocols are commonly used during cataract surgeries, the difference in protein composition and their release into AH following each surgery has never been systematically compared and remains unclear. The first step, which is the focus of this work, is to assess the scale of the protein change, at which time does maximum release occurs and when possible, to identify protein changes.     

Retroperitoneal lymphangiomyomatosis diagnosed by fine needle aspiration: a case report

BACKGROUND: Lymphangiomyomatosis is a rare condition affecting women of childbearing age. It is characterized by an abnormal proliferation of smooth muscle cells around lymphatics, giving rise to blockage of the large lymphatics, including the thoracic duct, and resulting in chylothorax and/or chyloascitis. The lung is the most common site of involvement. Retroperitoneum and lymph nodes can be also involved. CASE: A 40-year-old woman presented with lower urinary tract symptoms after a history of trauma and was found to have a retroperitoneal mass. Fine needle aspiration cytologic examination of the milky fluid aspirated from the mass revealed a few cohesive, 3-dimensional clusters of medium-sized cells with scanty cytoplasm, and ovoid and hyperchromatic nuclei. The background contained numerous mature lymphocytes. Laparoscopy revealed a multicystic mass filled with milky fluid. Histologic examination confirmed the cytologic diagnosis of lymphangiomyomatosis. CONCLUSION: Fine needle aspiration of lymphangiomyomatosis can be performed if cohesive clusters and a lymphoid background are present in chylous-type fluid and provided that adequate clinical information is available.     

Acinic Cell Tumour: A Metastasis In the Lung Diagnosed By Electron Microscopy of Aspirated Material

A case of acinic cell carcinoma, metastatic to lung is presented. Fine needle aspiration showed a low-grade adenocarcinoma. Electron microscopy of the aspirated material, however, allowed definite preoperative diagnosis of metastatic acinic cell carcinoma. The lesion was successfully resected and diagnosis confirmed on histology. Ten years previously an acinic cell carcinoma of similar histology had been excised from the left parotid region.     

Cytologic findings in aspirated hydatid fluid

A case of hydatid disease of the liver diagnosed by accidental needle aspiration of a cyst is reported. The patient presented with multiple symptoms, whose cause could not be readily determined. Since an amoebic abscess of the tender and enlarged liver was one possibility, that organ was aspirated with an 18-gauge needle, producing about 200 mL of slightly turbid fluid; the patient went into anaphylactic shock following the procedure, but was revived. Smears of the fluid showed brood capsules, free scolices and scattered hooklets pathognomonic of Echinococcus. The cytologic diagnosis of echinococcosis was confirmed by histopathologic examination of the surgically removed cysts.     

A model of retinal ischemia-reperfusion injury in rats by subconjunctival injection of endothelin-1

The retinal ischemia-reperfusion model is used in the study of transient ischemia-related diseases, such as central retinal artery occlusion, angle-closure glaucoma, and others. There are two methods for experimentally producing an ischemia-reperfusion model in the rat retina: (i) the intraocular pressure is greatly raised by increasing the height of the infusion bottle connected with the needle in the anterior chamber; or (ii) the blood vessel that accompanies the optic nerve in retina is ligated. However, each method has some drawbacks. For example, in the first method, the needle must be fixed in the anterior chamber for 1 hr, thus, the technique is not stable and mechanical damage to ocular structures sometimes occurs. In the second method, because of the unavoidable involvement of the optic nerve, damage to the nerve induces retinal changes unrelated to ischemia. In this study, we injected endothelin (ET)-1 under the conjunctiva of the eyeball (subconjunctival injection), and evaluated whether a retinal ischemia-reperfusion model could be generated by this method, simply and noninvasively. We injected 4 x 10(-5) M ET-1 solution into the right eye of the rat and injected a control vehicle (artificial tears) into the left eye. From 5-60 mins after the injection, 50 mg/ml fluorescein isothiocyanate (FITC)-dextran was injected to the left ventricle of heart. Then, the retina was removed and flat mounted. We compared the perfusion conditions of the FITC-dextran to each retina in the right and left eye. There was a complete perfusion of FITC-dextran in the retinal main artery, vein, and the capillary vessels in all of the control eyes. However, perfusion could not be completely observed in the ET-1 injected eye from 5-35 mins after injection; afterwards, the flow was returned. This method of subconjunctival injection of ET-1 is, thus, a feasible technical option for producing a retinal ischemia-reperfusion model in rat.     

Cotton block method: one-step method of cell block preparation after fine needle aspiration

OBJECTIVE: To describe the cotton block method, an easy, inexpensive, 1-step method of obtaining a cell block after fine needle aspiration biopsy. STUDY DESIGN: Before connection to a 10-mL syringe, the plastic hub of a 22-23-gauge needle is filled with the 3-4-mm, woolly tip of a cotton bud. Aspiration is performed as described elsewhere. After smear preparation, the material remaining in the needle and the material retained in the cotton wool mesh are immediately fixed by aspiration ofa fixative fluid (70% alcoholic formaldehyde-acetic acid). After fixation, the cotton tip is removed and routinely processed for paraffin embedding, and the sections are stained by routine methods used in cytopathology. RESULTS: The results demonstrate that the amount and quality of material obtained in the cotton wool tip is similar to that in the traditional cell block obtained from the pellet after centrifugation of aspirated fluid. CONCLUSION: The method is easy to perform and cost effective and is a rapid way to prepare cell blocks of high quality, allowing special staining techniques and improving cytohistologic correlation.     

Tumor marker measurements of cells in a fine needle used for aspiration cytology

OBJECTIVE: To investigate whether the needle washing could yield sufficient cells for tumor marker (TM) measurements as an ancillary technique to ensure the accuracy of fine needle aspiration cytology (FNAC) of tumors. STUDY DESIGN: After obtaining preliminary data that aspirated tumor cells within a 22-gauge needle could be collected by washing it with distilled water for TM measurements, we studied tumor cell numbers and TM values obtained by washing a 22-gauge needle directly after tumor aspiration and another needle after FNAC. RESULTS: Using 8 resected hepatobiliary and pancreatic carcinomas, the used needles yielded 16.8+/-10.5 x 10(4) cells per milliliter. Used needles from 6 adenocarcinomas expelled 479.2+/-406.5 ng/mL of carcinoembryonic antigen, and 6,561.3+/-5,713.1 ng/mL of CA 19-9, while the needles from 2 hepatomas showed normal values of those markers. CONCLUSION: A needle used for FNAC contains sufficient cells for TM measurements, which can be ancillary to the differential diagnosis.     

Immunocytochemical and ultrastructural findings in a case of rare carcinoma of the pancreas with predominance of malignant squamous cells in an intraoperative needle aspirate

The cytologic diagnosis by intraoperative needle aspiration of a rare carcinoma of the pancreas composed predominantly of malignant squamous cells is reported. Both poorly differentiated and keratinized well-differentiated squamous cells were seen in the aspirate. Tissue for histologic confirmation was not obtained because of the position of the mass. Confirmatory ultrastructural and immunoperoxidase studies were thus done on the aspirated material to confirm the diagnosis.     

Preparation and cytologic evaluation of intraocular fluids

The cytologic analysis of intraocular fluids obtained during vitreous surgery and anterior chamber aspiration can confirm the diagnosis of many intraocular conditions, including phacolytic glaucoma, fungal infection, proliferative diabetic retinopathy, intraocular neoplasm, ghost-cell glaucoma and certain inflammatory conditions. This paper describes our technique for processing intraocular fluids for cytologic examination and presents our findings in over 300 intraocular fluid specimens.     

Aspiration biopsy of pleomorphic lipoma of the breast. A case report

BACKGROUND: It is well known that subcutaneous lumps in the breast may create diagnostic confusion. We report, for the first time in the cytologic literature, the features of a pleomorphic lipoma in the breast. CASE: Pleomorphic lipoma of the breast was aspirated, showing typical floret cells and mononuclear, hyperchromatic cells with scalloped nuclei, masquerading as malignancy. CONCLUSION: Pleomorphic lipoma has rather typical cytologic features that may allow its recognition when they are present in the proper clinical setting. This report illustrates another diagnostic pitfall in fine needle aspiration biopsy of the breast.     

Experimental Glaucoma Induced by Ocular Injection of Magnetic Microspheres

Progress in understanding the pathophysiology, and providing novel treatments for glaucoma is dependent on good animal models of the disease. We present here a protocol for elevating intraocular pressure (IOP) in the rat, by injecting magnetic microspheres into the anterior chamber of the eye. The use of magnetic particles allows the user to manipulate the beads into the iridocorneal angle, thus providing a very effective blockade of fluid outflow from the trabecular meshwork. This leads to long-lasting IOP rises, and eventually neuronal death in the ganglion cell layer (GCL) as well as optic nerve pathology, as seen in patients with the disease. This method is simple to perform, as it does not require machinery, specialist surgical skills, or many hours of practice to perfect. Furthermore, the pressure elevations are very robust, and reinjection of the magnetic microspheres is not usually required unlike in some other models using plastic beads. Additionally, we believe this method is suitable for adaptation for the mouse eye.     

Intraoperative cytodiagnosis of metastatic brain tumors confused clinically with brain abscess. A report of three cases

BACKGROUND: Cystic lesions of the brain may have diverse etiologies, ranging from true cysts to malignant tumors with cystic degeneration. Preoperative determination of the exact nature of them as well as intraoperative diagnosis may be sometimes difficult or even impossible. Sensitivity and specificity of diagnosis will be improved by introducing new methods or combining traditional procedures. CASES: Three metastatic brain carcinomas with primary sites of breast, pancreas and prostate presented as cystic lesions and were confused clinically with abscess. Intraoperative frozen section was not revealing. Cytologic study of sediments of aspirated fluid uncovered malignant cells. CONCLUSION: When combined with frozen section, intraoperative cytologic studies in the form of crush preparation, fine needle aspiration or evaluation of aspirated fluid in cystic lesions (as in our cases) can improve diagnostic accuracy by detecting important diagnostic features that otherwise may be missed.     

Molluscum contagiosum. A case report with fine needle aspiration cytologic diagnosis and ultrastructural features

BACKGROUND: Cytomorphologic and ultrastructural features of molluscum contagiosum, a rare skin lesion of viral etiology, are presented. CASE: A 4-month-old female was referred for fine needle aspiration cytology of papules over the back and chest wall. A Giemsa-stained preparation of whitish material aspirated from the chest wall nodule showed numerous large, intracytoplasmic, basophilic bodies that pushed the host cell nucleus to the periphery, giving a signet-ring appearance to a few cells. A cytologic diagnosis of molluscum contagiosum was suggested. On electron microscopy numerous intracytoplasmic viral particles were demonstrated, thus confirming the cytologic diagnosis. CONCLUSION: In clinically unsuspected cases, the cytologic diagnosis of molluscum contagiosum can be suggested by demonstrating pathognomonic molluscum bodies in aspirated material.     

Fine Needle Aspiration For the Diagnosis and Management of Granulomatous Disease

Fine needle aspiration is a quick, minimally invasive and cost-effective technique for the diagnosis of granulomatous disease. Cytological diagnosis can often be specific, with the help of special stains and microbiological culture of aspirated material, particularly in the case of tuberculosis, the most common infective granulomatous disease in this country. At a fine needle aspiration clinic many cases of granulomatous disease, some from unusual sites, have been diagnosed and the use of more invasive investigations has been avoided. The problems involved in cytological diagnosis are discussed using seven cases as examples.