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At least 649 records · Page 36Linked to original sources
PubMed2006

Confocal microscopy for Nocardia keratitis.

PURPOSE: To assess the role of confocal microscopy for in vivo detection of Nocardia in patients with microbial keratitis. DESIGN: Retrospective interventional case series. PARTICIPANTS: Three patients with microbiologically proven Nocardia keratitis. INTERVENTION: Confocal microscopy. METHODS: We performed confocal microscopy in microbiologically proven cases of Nocardia asteroides keratitis. A masked observer examined the images. For better understanding of the images, we also performed confocal microscopy on a blood agar culture plate with Nocardia growth. RESULTS: Confocal microscopy of infiltrated cornea revealed highly reflective, short, thin branching filaments with bright inflammatory cells in the background. The filaments were seen clearly at the edge of the infiltrate. In scans with faint images, these filaments became more visible on inversion of bright and dark components. Confocal microscopy of cultured organisms also revealed filamentous beaded structures with a morphology identical to that of those seen in vivo. CONCLUSION: Nocardia, a filamentous bacterium, produces a distinct image on confocal microscopy. This in vivo examination technique may be useful in cases of deep-seated infiltrates where routine microbiology workup does not yield positive results.

Adult↗
PubMed1998

Confocal microscopy of cystic disorders of the corneal epithelium.

OBJECTIVE: This study aimed to describe the morphology of cystic disorders of the corneal epithelium by confocal microscopy. DESIGN: The study design was a prospective evaluation of confocal microscopic images of patients with cystic corneal disorders. PARTICIPANTS: Thirteen patients (19 eyes) were included. The corneal disorders included four patients with corneal decompensation (Fuchs' dystrophy), five patients with epithelial basement membrane dystrophy (e.g., Cogan's microcystic and map-dot dystrophies), one patient with Meesmann's dystrophy, and three patients with recurrent erosion syndrome of unknown etiology. Confocal images of diseased corneas were compared with those of ten normal control eyes (ten subjects). INTERVENTION: All patients were examined by slit-lamp biomicroscopic analysis and confocal microscopic analysis (Tomey, Erlangen-Temmenlohe, Germany). Image analysis was used to identify the corneal epithelial structures correlated with the corresponding pathology. MAIN OUTCOMES MEASURES: Confocal microscopy was used to assess the size, shape, light scatter, and reflection of the cysts. RESULTS: Slit-lamp examination results showed corneal epithelial cystic lesions in all cases. Confocal microscopy was able to identify cystic lesions in 9 (69.2%) of 13 patients. Of the four patients in whom lesions could not be found by confocal microscopy, three had recurrent erosion syndrome and the other one had epithelial basement membrane dystrophy. The confocal images were compatible with the clinical and histologic pictures of the disease. Normal control eyes did not show any epithelial lesion, either by biomicroscopy or confocal microscopy. CONCLUSIONS: Confocal microscopy provides an in vivo evaluation of cystic epithelial corneal lesions. This study shows that confocal microscopy is suitable for examining cystic lesions of the corneal epithelium. Nevertheless, it is not as sensitive as biomicroscopy in detecting cystic lesions in certain corneal conditions.

Corneal Diseases↗
PubMed2003

Corneal thickness measurements: scanning-slit corneal topography and noncontact specular microscopy versus ultrasonic pachymetry.

PURPOSE: To compare central corneal thickness measurements taken with 3 pachymetry systems: Orbscan scanning-slit corneal topography/pachymetry, Topcon SP2000P noncontact specular microscopy, and Tomey ultrasonic pachymetry. SETTING: Multicenter study, Tokyo, Japan. METHODS: In 216 healthy eyes of 114 subjects, scanning-slit topography, noncontact specular microscopy, and ultrasonic pachymetry were used in that sequence to record central corneal thickness. In another 20 healthy eyes of 13 subjects, 2 sets of measurements were repeated for each pachymetry to assess repeatability. RESULTS: The mean central corneal thickness was compatible between scanning-slit topography (546.9 micrometers +/- 35.4 [SD] ) and ultrasonic pachymetry (548.1 +/- 33.0 micrometers); however, noncontact specular microscopy gave a significantly smaller mean (525.3 +/- 31.4 micrometers) than the other 2 tests (P<.001, Tukey multiple comparison). There were significant linear correlations between scanning-slit topography and noncontact specular microscopy (r = 0.846, P<.001), noncontact specular microscopy and ultrasonic pachymetry (r = 0.897, P<.001), and ultrasonic pachymetry and scanning-slit topography (r = 0.852, P<.001). Noncontact specular microscopy tended to show the best repeatability; however, the difference was not statistically significant (P =.663, repeated-measure analysis of variance). CONCLUSIONS: Corneal thickness readings were comparable between scanning-slit topography and pachymetry; noncontact specular microscopy gave significantly smaller values. The measurements of the 3 methods showed significant linear correlations with one another. All methods provided acceptable repeatability of measurements.

Adult↗
PubMed1999

Ultrastructural characterization of isolated rat Kupffer cells by transmission X-ray microscopy.

The ultrastructure of primary cultured rat Kupffer cells was studied using transmission X-ray microscopy as well as transmission electron microscopy. X-ray microscopical images of intact, hydrated Kupffer cells demonstrated structures such as cell nucleus separated by a nuclear membrane and filaments concentrated in the perinuclear area. Within the cytoplasm, a number of vacuoles were visible; some of these were crescent-shaped vacuoles that were half X-ray lucent, half X-ray dense; others were uniformly dense. The number of crescent-shaped vacuoles was predominant. After phagocytosis of haematite particles, enlarged vacuoles containing the ingested material were visible within the cytoplasm of Kupffer cells while crescent-shaped vacuoles were no longer detectable. Densitometric analysis of the two types of vacuole revealed that the X-ray absorption of the uniform vacuole was approximately half that of the dense part of the crescent-shaped vacuoles. This observation led to speculation on the existence of only one type of vacuole in the cytoplasm of Kupffer cells. The different morphological aspects--crescent-shaped versus uniform vacuoles--might be due to different three-dimensional orientation with respect to the image plane. Using transmission electron microscopy, the morphology of vacuoles differed more widely in diameter, density and shape. Two main types of vacuole were identified: electron-lucent and electron-dense. Based on the observation of only one type of vacuole by transmission X-ray microscopy, the different morphological aspects of vacuoles obtained by transmission electron microscopy could be explained by imaging several different sections of a crescent-shaped vacuole. From the present data it can be concluded that transmission X-ray microscopy is a versatile technique that reveals the ultrastructure of intact, unsectioned biological specimens in their aqueous environment, thereby allowing a more comprehensive interpretation of data obtained by transmission electron microscopy.

Animals↗
PubMed2002

Comparison of stereoscopy, light microscopy and ultrastructural methods for evaluation of bovine embryos.

The most important point in embryo transfer success is the evaluation of the stage of development and quality of embryos. Therefore, the purpose of this study was to compare the morphological evaluation of embryos using stereoscopy, light microscopy and electron microscopy in order to establish the accuracy of former method compared with more invasive and accurate procedures. For this purpose, 23 Brahman x Swiss cows were used and synchronized with Norgestomet 6 mg plus, 5 mg Estradiol valerate (Syncromate B(R), Rhone Merieux, Mexico, Mexico City) and superovulated with Folltropin-V 240 mg (Vetrepharm, Mexico, Mexico City). Non-surgical embryo collection was performed 7.5 days after insemination. Descriptive statistics analysis was used to assess the data. Seventy-eight embryos were collected and classified by stereoscopic microscopy, finding 51.2% (40) of good quality, 25.6% (20) fair and 24.3% (19) poor. Later, under light microscopy observation, evaluation of the same embryos resulted in 25.6% (20) good, 32.0% (25) fair and 42.3% poor quality. Finally, in the evaluation of embryos under electron microscopy 24.3% (19) were found to be of good quality, 29.3% (23) fair and 46.1% (36) poor. Evaluation of embryos with stereoscopic microscopy was found to be very subjective, as nearly 50% of embryos classified by this method as good quality, showed features of degenerative stages under light and electron microscopy. Embryos with these features are generally frozen and transferred, which could be one of the reasons for having low fertility rate in embryo transfer programmes.

Animals↗
PubMed2005

Quantitative unspun-urine microscopy as a quick, reliable examination for bacteriuria.

The diagnosis and treatment of urinary infection are often delayed, causing renal damage, largely because of the unavailability of quick, accurate, diagnostic examinations. Three hundred and twenty-five urine samples from 130 patients were examined for significant bacteriuria using the standard culture method. The urine samples were also examined using the Gram-stain method and quantitative unspun-urine microscopy. When particles could not be distinguished definitely as bacilli by quantitative microscopy, the unspun urine was examined on a slide glass using oil-immersion microscopy at x 1000 magnification. Significant bacteriuria in 37 urine samples was detected by bacterial culture. Using quantitative microscopy, rods were found in 30, cocci in a chain in 3, and indefinite particles in 44 samples. In the 44 indefinite samples, oil-immersion microscopy was able to distinguish rods in one, cocci in a chain in one, cocci in a cluster in two, and negative in 40, which were confirmed by culture as rods, streptococci, staphylococci, and negative, respectively. The quantitative microscopy method was similarly reliable (94.6% sensitivity, 99.3% specificity) for diagnosis of significant bacteriuria when compared with the Gram-stain method (89.2% sensitivity, 98.6% specificity). Quantitative unspun-urine microscopy, confirmed by oil-immersion, is a quick, reliable method for diagnosis of significant bacteriuria, and is considered to be useful for early diagnosis of urinary infection.

Adolescent↗
PubMedDate not supplied

Digital microscopy imaging and new approaches in toxicologic pathology.

Digital microscopy, a comprehensive integration of digital imaging and light microscopy, can assist the pathologist to observe, acquire, record, share, analyze, and manage pathology image data. To lead the activity for establishing new generation digital microscopy capacity, novel concepts and strategies of digital pathology information flow and digital pathology platform were designed to integrate personal digital pathology microscopy workstations and other pathology imaging modalities with centralized data storage/management. In addition, a strategy for Web-enabled interactive telepathology that would permit global capacity was designed. A novel concept of high content pathology was also created to develop an automated tissue microscopy imaging and screening approach. These new concepts, strategies, and approaches guided the development and implementation of a digital pathology platform, a telepathology platform, and automated tissue slide imaging capacity. Digital microscopy photography is now able to replace photographic film in toxicologic pathology. Digital pathology and telepathology platforms can provide a networked environment for multisite, global team participation. Our practice also ascertained the central value of digital microscopy which can provide innovative quantitative pathology information and data mining capability with various imaging biomarkers via advanced digital image processing and pathology informatics; these are now the focus of ongoing development.

Image Enhancement↗
PubMed2002

Impact of microscopy error on estimates of protective efficacy in malaria-prevention trials.

Microscopy is an imperfect reference standard used for malaria diagnosis in clinical trials. The purpose of this study was to provide an assessment of the accuracy of basic microscopy, to compare polymerase chain reaction (PCR)-based diagnosis with microscopy results, and to assess the effect of microscopy error on apparent protective efficacy. The sensitivity and specificity of basic, compared with expert, microscopy was determined to be 91% and 71%, respectively. In a clinical trial, agreement between PCR and microscopy results improved with expert confirmation of initial results. In a simulated 12-week trial with weekly routine malaria smears, a very high specificity (>99%) for each malaria smear was found to be necessary for an estimate of protective efficacy to be within 10%-25% of the true value, but sensitivity had little effect on this estimate. Microscopy error occurs and can affect clinical trial results.

Animals↗
PubMed2004

Detection of Cryptosporidium parvum oocysts in experimentally contaminated lettuce using filtration, immunomagnetic separation, light microscopy, and PCR.

Recovery of Cryptosporidium parvum oocysts in a fecal suspension that experimentally contaminated onto lettuce leaves was investigated. Material recovered from the lettuce samples by washing in detergent solutions were concentrated by filtration using the Envirochek Sampling Capsule. Oocysts were concentrated by immunomagnetic separation (IMS) and detected by microscopy following modified Ziehl-Neelsen (MZN) staining. Cryptosporidal DNA was detected using a nested-PCR assay for amplification of a fragment of the Cryptosporidium oocyst wall protein (COWP) gene, which was applied to DNA extracted from both filtrates, and material recovered from MZN stained smears on glass slides after microscopy. No Cryptosporidium were detected by microscopy or by PCR of un-inoculated lettuce leaves. After IMS, means of 0-6.5% of the total numbers of oocysts inoculated were recovered and detected by microscopy. Detection by PCR was less sensitive than microscopy. There was a strong association between successful PCR amplification, the numbers of oocysts detected by microscopy and the numbers of oocysts in the inoculum. This study confirms that C. parvum oocysts can be recovered from contaminated lettuce using filtration and IMS, and detected by microscopy and PCR. However, further developments are required to improve recovery of this parasite.

Animals↗
PubMed2005

Endoscopic confocal microscopy.

PURPOSE OF REVIEW: Endoscopic confocal microscopy is a new endoscopic imaging technology that produces high-magnification cross-sectional images of the gastrointestinal epithelium during endoscopy. These high-magnification images might allow the endoscopist to make a tissue diagnosis during endoscopy without biopsy and histopathology. The purpose of this article is to review the salient features of endoscopic confocal microscopy, describe current clinical research areas using the technology, and depict its potential role in the management of gastrointestinal diseases. This review includes an overview of the technology, a review of recent publications describing its function, and a discussion of potential applications. RECENT FINDINGS: Endoscopic confocal microscopy has been technologically feasible only for a short time; therefore, the published experience is limited. Studies describing the use of endoscopic confocal microscopy for the detection of dysplastic tissue have been limited to a single paper in which endoscopic confocal microscopy was reported to be highly sensitive and specific for the detection of colonic dysplasia in a general screening population. Active areas of investigation include detecting dysplasia in ulcerative colitis and Barrett's esophagus. A recent case report detailed the ability of endoscopic confocal microscopy to detect gastric Helicobacter pylori in vivo. SUMMARY: Endoscopic confocal microscopy is a new imaging technology that produces high-magnification cross-sectional images of the gastrointestinal tract. Its role in detecting and managing diseases of the gastrointestinal tract has been studied in colon cancer screening and is currently being evaluated in a variety of premalignant conditions.

Endoscopes, Gastrointestinal↗
PubMed1994

Detection of Charcot-Leyden crystals by fluorescence microscopy of Papanicolaou-stained smears of sputum, bronchoalveolar lavage fluid, and bronchial secretions.

Fluorescence microscopy was used to examine Papanicolaou-stained smears of sputum and other secretions from the respiratory tract. Under these conditions Charcot-Leyden crystals (CLC) appear as bright yellow-green fluorescing needles. The study was performed to determine the value of this approach for the diagnosis of allergic lung diseases. The time taken to detect the crystals was recorded and the sensitivity of fluorescence microscopy for the detection of CLC was compared with light microscopy of the same samples. The data show that fluorescence microscopy is superior to light microscopy for the detection of CLC. The characteristic needle-shaped crystal can be recognized easily and fragments of crystals could be easily identified. In doubtful cases of allergic lung diseases, fluorescence microscopy may be used to supplement light microscopy for the detection of Charcot-Leyden crystals.

Adult↗
PubMed2006

Microscopy and outpatient malaria case management among older children and adults in Kenya.

OBJECTIVE: To evaluate the accuracy of routine malaria microscopy, and appropriate use and interpretation of malaria slides under operational conditions in Kenya. METHODS: Cross-sectional survey, using a range of quality of care assessment tools, at government facilities with malaria microscopy in two Kenyan districts of different intensity of malaria transmission. All patients older than 5 years presenting to outpatient departments were enrolled. Two expert microscopists assessed the accuracy of the routine malaria slide results. RESULTS: We analysed 359 consultations performed by 31 clinicians at 17 facilities. Clinical assessment was suboptimal. Blood slide microscopy was performed for 72.7% of patients, who represented 78.5% of febrile patients and 51.3% of afebrile patients. About 95.5% of patients with a positive malaria microscopy result and 79.3% of patients with a negative result received antimalarial treatment. Sulphadoxine-pyremethamine monotherapy was more commonly prescribed for patients with a negative test result (60.7%) than for patients with a positive result (32.4%). Conversely, amodiaquine or quinine were prescribed for only 14.7% of patients with a negative malaria microscopy result compared to 57.7% of patients with a positive result. The prevalence of confirmed malaria was low in both high (10.0%) and low-(16.3%) transmission settings. Combining data from both settings, the sensitivity of routine microscopy was 68.6%; its specificity, 61.5%; its positive predictive value, 21.6% and its negative predictive value, 92.7%. CONCLUSIONS: The potential benefits of microscopy are currently not realised because of the poor quality of routine testing and irrational clinical practices. Ambiguous clinical guidelines permitting treatment of older children and adults with a negative blood slide also undermine rational use of antimalarial drugs.

Adolescent↗
PubMed1992

Relative usefulness of electron microscopy and immunocytochemistry in tumour diagnosis: 10 years of retrospective analysis.

AIMS: To determine retrospectively the relative usefulness of electron microscopy and immunocytochemistry for tumour diagnosis; to monitor the influence of new antibodies and antisera on the use of these techniques in one laboratory. METHODS: During 1980 to 1989 inclusive, 726 tumours were examined by electron microscopy, 862 by immunocytochemistry, and 286 by both techniques. The choice of techniques and, for immunocytochemistry, the range of antibodies used were compared between each category of final diagnosis. RESULTS: During the study period there was a sharp fall in the use of electron microscopy and a corresponding rise in immunocytochemistry. These trends applied to all categories of final tumour diagnosis, but the use of electron microscopy was sustained longer for lesions suspected or eventually confirmed to be melanomas or amine precursor uptake decarboxylation cell carcinoma (APUDomas)--for example, carcinoid tumours. The immunocytochemistry:electron microscopy use ratios ranged from 2.07:1 to 0.44:1 for the categories in which lymphoma and APUDoma, respectively, were the final diagnoses. The abandonment of electron microscopy for suspected or confirmed lymphomas and carcinomas corresponded to the increasing availability of relevant antisera and antibodies. CONCLUSIONS: The wider application of immunocytochemistry for tumour diagnosis is endorsed, but electron microscopy should be retained for selected cases in which the results of immunocytochemistry might be predictably ambiguous or otherwise unhelpful.

Apudoma↗
PubMedDate not supplied

Magnetic resonance microscopy--a new tool for the toxicologic pathologist.

Parallel to its many applications in medical imaging, magnetic resonance (MR) microscopy is a potentially powerful tool in toxicologic pathology. Because of the intrinsic qualities of MR microscopy (noninvasiveness, 3-dimensionality, and slicing in any chosen plane), the scientist has a new means by which to investigate different types of lesions based on differential contrast. By choosing appropriate proton stains to probe the state of the water in tissues, organ structure and vasculature can be seen and progressive lesion development can be followed in a given animal. This paper discusses toxicologic pathology applications for MR microscopy and compares MR microscopy with conventional histopathology using a time-course study of bromobenzene-induced hepatotoxicity in rats. Hematoxylin and eosin (H&E)-stained histological sections are compared with MR microscopy images from fixed tissue blocks to demonstrate one of the applications of MR microscopy to toxicologic pathology. The results indicate that MR microscopy is as sensitive as conventional H&E staining in detecting bromobenzene-induced hepatic lesions.

Animals↗
PubMed1983

Value of electron microscopy in cytologic diagnosis of fine-needle biopsy.

Fine-needle biopsy in 14 consecutive patients with suspected malignancies were evaluated by routine cytology and electron microscopy. A protocol is described in which material from fine-needle biopsy can be held in glutaraldehyde and later processed for electron microscopy if necessary. Adequate tissue for electron microscopy was obtained in 12 of 14 cases. Specific classification of the tumor cells in these cases was achieved through electron microscopy. In six cases electron microscopy provided a more certain diagnosis than cytology alone. In two cases electron microscopy had significant impact on diagnosis and clinical management. The opportunity to examine tissues with electron microscopy increased the utility and specificity of the fine-needle technique without adding to patient discomfort or the cost of a second procedure.

Abdominal Neoplasms↗
PubMed2002

Comparison of field and expert laboratory microscopy for active surveillance for asymptomatic Plasmodium falciparum and Plasmodium vivax in western Thailand.

Microscopy of Giemsa-stained thick and thin films by a skilled microscopist has remained the standard laboratory method for the diagnosis of malaria. However, diagnosis of malaria with this method is problematic since interpretation of results requires considerable expertise, particularly at low parasite levels. We compared the efficacy of "field" and "expert laboratory" microscopy for active surveillance of Plasmodium falciparum and P. vivax in western Thailand. Field microscopy consisted of an approximately five-minute read (50-100 fields) of a thick film at x700 using a natural light source, whereas expert laboratory microscopy consisted of a 20-minute read (number of parasites per 500 leukocytes) at x1,000 using a high-quality, well-maintained microscope with an artificial light source. All discordant and 20% of concordant results were cross-checked blindly. A total of 3,004 blood films collected between May and November 2000 were included in the study, of which 156 (5.2%) were positive for P. falciparum, 177 (5.9%) for P. vivax, and 4 (0.1%) for both P. falciparum and P. vivax by expert microscopy. A total of 84.4% (135 of 160) of the P. falciparum-positive slides and 93.9% of the P. vivax-positive slides had a parasitemia of less than 500/microL. Field microscopy was specific (99.3%) but not sensitive (10.0%) for the diagnosis of P. falciparum malaria, with a positive predictive value (PPV) of 43.2% and a negative predictive value (NPV) of 95.1%. The corresponding specificity and sensitivity for the diagnosis of P. vivax malaria were 99.2% and 7.1%, respectively, with a PPV of 38.7% and an NPV of 93.9%. Field microscopy, as defined in this study, is not an effective method for active malaria surveillance in western Thailand, where prevalence and parasitemia rates are low.

Adolescent↗
PubMed1991

Detection of contact dermatitis in rat skin by intravital microscopy.

The sensitivity of fluorescence intravital microscopy for the detection of immunologically elicited inflammatory reactions in the skin was compared to assessment by tissue swelling measurement. Rats were immunized to the contact-sensitizing agent toluene diisocyanate (TDI) by its application to the skin and challenged by the same procedure at a different site one week thereafter. At 2, 6, or 12 hrs after challenge individual rats received a bolus of fluorescently labeled albumin intravenously. Vascular integrity was determined by estimating the surface of areas with increased vascular permeability as observed by fluorescence intravital microscopy; contact dermatitis (CD) was assessed just prior to infusion of labeled albumin determination of tissue swelling by a semi-automatic micrometer. At 12 hrs after challenge, CD was detectable by tissue swelling. Intravital fluorescence microscopy revealed massive extravasation of the fluorescent dye at the site of challenge. At 6 hrs after challenge, CD was not yet discernible by toe thickness measurements. However, by fluorescence intravital microscopy significant leakage of labeled albumin was observed. Thus, at 6 hrs after challenge fluorescence intravital microscopy was more sensitive than determination of tissue thickness increment for detection of a contact hypersensitivity reaction. At 2 hrs after challenge, CD was neither demonstrable by tissue swelling measurements, nor by fluorescence intravital microscopy. Therefore, an early component of a delayed-type hypersensitivity (DTH) reaction to a contact allergen as shown to occur in mice, remains to be demonstrated in the rat. On the other hand, fluorescence intravital microscopy revealed non-immunological skin irritation by a 5% TDI solution within 2 hrs after its application to the skin of non-immunized rats.

Animals↗
PubMed1988

[Electron microscopy of 300 tumors in the nervous system].

The results of 300 nervous system tumors observed by electron microscopy are reported. Of them, 12% depended on electron microscopy for diagnosis; 14% was further classified and typed by electron microscopy; 59% could be diagnosed by either electron or light microscopy but the former played an important role in confirming the diagnosis by light microscopy; 10% still could not be diagnosed even by electron microscopy; 5% failed in diagnosis due to faulty technique. The results indicate that the electron microscope is a useful tool in diagnosis of the nervous system tumor, particularly, in those whose diagnosis is difficult by light microscopy and in classification and typing of the tumor. In this paper, the pathognomonic ultrastructural features are described.

Diagnosis, Differential↗