scholarly journals Comparison of direct microscopic methods using potassium hydroxide, periodic acid Schiff, and calcofluor white with culture in the diagnosis of onychomycosis

2013 ◽  
Vol 79 (2) ◽  
pp. 242 ◽  
Author(s):  
Sachin Yadav ◽  
AK Saxena ◽  
MaliniR Capoor ◽  
V Ramesh
Keyword(s):  
Potassium Hydroxide ◽  
Periodic Acid ◽  
Calcofluor White ◽  
Periodic Acid Schiff

Onychomycosis and Tinea Pedis in the Feet of Patients With Diabetes

2021 ◽  
pp. 153473462110094
Author(s):  
Javier Aragón-Sánchez ◽  
María E. López-Valverde ◽  
Gerardo Víquez-Molina ◽  
Ana Milagro-Beamonte ◽  
Luis Torres-Sopena
Keyword(s):  
Potassium Hydroxide ◽  
Tinea Pedis ◽  
Periodic Acid ◽  
Univariate Analysis ◽  
Significant Variable ◽  
Calcofluor White ◽  
Periodic Acid Schiff ◽  
Patients With Diabetes ◽  
History Of ◽  
Direct Fluorescence

This study aimed to determine the prevalence of onychomycosis and interdigital tinea pedis in a cohort of Spanish patients with diabetes in whom onychomycosis was clinically suspected (n = 101). Samples from a first toenail scraping and the fourth toe clefts were subjected to potassium hydroxide direct vision and incubated in Sabouraud and dermatophyte test medium. Fifty-eight samples were also analyzed by a pathologist using periodic acid-Schiff staining and Calcofluor white direct fluorescence microscopy. Onychomycosis was only confirmed in 41 patients (40.6%). The most frequent aetiological agent was Trichophyton rubrum, isolated in 10 patients (36%), followed by Candida parapsilosis in 7 patients (25%). Tests on the fourth toe cleft samples were only positive in 11 patients (10.9%), and in all cases, onychomycosis was also diagnosed. Neuroischemic foot was the only significant variable associated with onychomycosis in the univariate analysis ( P < .01). A positive result for mycosis in the fourth toe cleft was found in 11 cases (10.9%) and was associated with a history of myocardial infarction ( P< .01; odds ratio [OR]: 84.2, confidence interval [CI]: 6.8-1036.4) and neuroischemic foot ( P< .01; OR: 13.7, CI: 12.6-71.6) in the multivariate model. In conclusion, the prevalence of onychomycosis and tinea pedis in patients with diabetes in whom onychomycosis was clinically suspected was 40.6% and 10.9%, respectively. In addition, onychomycosis was not always associated with tinea pedis. These results show that clinical diagnosis has low accuracy in people with diabetes mellitus, and that diagnosis should not be based on clinical toenail characteristics alone.

Utility of Histopathologic Analysis in the Evaluation of Onychomycosis

2005 ◽  
Vol 95 (3) ◽  
pp. 258-263 ◽  
Author(s):  
Jeffrey M. Weinberg ◽  
Evelyn K. Koestenblatt ◽  
Maureen B. Jennings
Keyword(s):  
Potassium Hydroxide ◽  
Periodic Acid ◽  
False Negative ◽  
Nail Plate ◽  
Fungal Culture ◽  
Periodic Acid Schiff ◽  
Negative Results ◽  
False Negative Results ◽  
Histopathologic Analysis ◽  
Dermatophyte Infection

Onychomycosis is a common problem seen in clinical practice. Given the differential diagnosis of dystrophic nails, it is helpful to obtain a definitive diagnosis of dermatophyte infection before initiation of antifungal therapy. Potassium hydroxide preparation and fungal culture, which are typically used in the diagnosis of these infections, often yield false-negative results. Recent studies have suggested that nail plate biopsy with periodic acid–Schiff stain may be a very sensitive technique for the diagnosis of onychomycosis. In this article, we review the literature on the utility of histopathologic analysis in the evaluation of onychomycosis. Many of these studies indicate that biopsy with periodic acid–Schiff is the most sensitive method for diagnosing onychomycosis. We propose that histopathologic examination is indicated if the results of other methods are negative and clinical suspicion is high; therefore, it is a useful complementary technique in the diagnosis of onychomycosis. (J Am Podiatr Med Assoc 95(3): 258–263, 2005)

scholarly journals A histochemical method for the identification of 9-O-acyl sialic acid. An investigation of bovine submaxillary gland and intestinal mucins.

1978 ◽  
Vol 26 (3) ◽  
pp. 187-192 ◽  
Author(s):  
P E Reid ◽  
C F Culling ◽  
W L Dunn
Keyword(s):  
Sialic Acid ◽  
Potassium Hydroxide ◽  
Periodic Acid ◽  
Periodate Oxidation ◽  
Submaxillary Gland ◽  
Sialic Acids ◽  
Histochemical Method ◽  
Periodic Acid Schiff ◽  
Oxidation Step ◽  
Intestinal Mucins

Prolongation of the initial periodate oxidation step of the periodate-borohydride technique/potassium hydroxide/periodic acid-Schiff and periodic acid-Thionin Schiff/potassium hydroxide/periodic acid-Schiff sequences produced little or no change in the diagnostic staining for the potassium hydroxide/periodic acid-Schiff effect, exhibited by the colonic epithelial mucins of man and rat and the Brunner's gland mucin of rabbits. In contrast, there was a gradual, but clear decrease in the intensity of such staining of bovine submaxillary gland mucins. It was concluded that, in the intestinal mucins studied the potassium hydroxide/periodic acid-Schiff effect was due to sialic acids bearing O-acyl substitutents at positions C7 and/or C8 whereas in bovine submaxillary gland mucin the potassium hydroxide/periodic acid-Schiff effect is probably due, at least in part, to the presence of 9-O-acyl sialic acids. This investigation has led to the development of a technique which can be used to identify 9-O-acyl sialic acids.

A Retrospective Review of Diagnostic Testing for Onychomycosis of the Foot

2015 ◽  
Vol 105 (6) ◽  
pp. 503-508 ◽  
Author(s):  
Nell Blake ◽  
Junjia Zhu ◽  
Giselle Hernandez ◽  
Paul Joseph Juliano
Keyword(s):  
Periodic Acid ◽  
Diagnostic Testing ◽  
Insurance Companies ◽  
Fungal Culture ◽  
Test Results ◽  
Calcofluor White ◽  
Periodic Acid Schiff ◽  
Clinically Significant ◽  
Patient’S History ◽  
The Cost

Background Onychomycosis is a fungal infection of the nail that can be caused by dermatophytes, yeasts, or nondermatophyte molds. To diagnose onychomycosis, a clinician must use the patient's history, physical findings, and diagnostic testing, which can include calcofluor white/potassium hydroxide (KOH) mount, fungal culture (FC), and periodic acid–Schiff (PAS) stain. Some insurance companies require authorization for antifungal medication and request laboratory results to confirm infection. We sought to compare the reliability of KOH, PAS, and FC diagnostic results for confirmation of fungal disease, to determine the sensitivity and specificity of each test, and to investigate the cost of each test. In addition, we statistically observed the relationship between the test results and demographic variables. Methods Toenail clippings were obtained from 108 patients clinically diagnosed as having onychomycosis. Diagnostic tests were then performed on each sample; the results were obtained from medical records. Results For PAS, KOH, and FC, 60.2%, 43.5%, and 39.8% of results, respectively, were positive. Agreement for each pair of tests was slightly higher for FC and KOH. Sensitivities for KOH and PAS were 0.64 and 0.79, respectively. Specificity was 0.79 for KOH and 0.54 for PAS. Both PAS and KOH had a higher percentage of positive test results for men than for women. Conclusions Of the three tests evaluated, PAS gives the most consistent positive results and has the highest sensitivity. Therefore, PAS should be considered as the best test to verify clinically significant onychomycosis.

scholarly journals Bullous Tinea Pedis – Misdiagnosed for Long Time

2017 ◽  
Vol 6 (1) ◽  
pp. 28-30
Author(s):  
Md Mahabubur Rahaman ◽  
MA Wahab ◽  
Md Rezaul Kader ◽  
Md Rahmat Ullah Siddique ◽  
Saha Bijoy Kumar ◽  
...  
Keyword(s):  
Fungal Infection ◽  
Potassium Hydroxide ◽  
Tinea Pedis ◽  
Periodic Acid ◽  
Trichophyton Mentagrophytes ◽  
Laboratory Examination ◽  
Periodic Acid Schiff ◽  
Oral Steroids ◽  
Long Time ◽  
Oral Terbinafine

Fungal infection is very common in Dermatological practice in Bangladesh. Most of the cases can be diagnosed clinically and simple laboratory examination. But here we present a case of recurrent bullous tinea pedis that had been misdiagnosed for a long time and treated with oral steroids. Initially, direct microscopy of potassium hydroxide preparations was negative and culture did not reveal any fungal organism. In a biopsy taken simultaneously from the edge of a bulla and stained with periodic acid-Schiff, septate mycelia were clearly visible. Trichophyton mentagrophytes was later identified in repeated cultures. The patient was treated with oral Terbinafine 250 mg daily for 2 months cured completely. CBMJ 2017 January: Vol. 06 No. 01 P: 28-30

Seasonal changes in cambium activity from active to dormant stage affect the formation of secondary xylem in Pinus tabulaeformis Carr

2021 ◽  
Author(s):  
Yayu Guo ◽  
Huimin Xu ◽  
Hongyang Wu ◽  
Weiwei Shen ◽  
Jinxing Lin ◽  
...  
Keyword(s):  
Cell Walls ◽  
Secondary Xylem ◽  
Periodic Acid ◽  
Wood Formation ◽  
Vascular Cambium ◽  
Pinus Tabulaeformis ◽  
Calcofluor White ◽  
Periodic Acid Schiff ◽  
Dormant Stage ◽  
Cambium Activity

Abstract Understanding the changing patterns of vascular cambium during seasonal cycles is crucial to reveal the mechanisms that control cambium activity and wood formation, but this area has been underexplored, especially in conifers. Here, we quantified the changing cellular morphology patterns of cambial zones during the active, transition and dormant stages. With the help of toluidine blue and periodic acid Schiff staining to visualize cell walls and identify their constituents, we observed decreasing cambial cell layers, thickening of newly formed xylem cell walls and increased polysaccharide granules in phloem from June to the following March over the course of our collecting period. Pectin immunofluorescence showed that dormant stage cambium can produce highly abundant de-esterified homogalacturonan and (1–4)-β-D-galactan epitopes, while active cambium can strong accumulate high methylesterified homogalacturonan. Calcofluor white staining and confocal Raman spectroscopy analysis revealed regular changes in the chemical composition of cell walls, such as relative lower cellulose deposition in transition stage in vascular cambium, and higher lignin accumulation was found in dormant stage in secondary xylem. Moreover, RT-qPCR analysis suggested that various IAA (Aux/IAA protein), CesA, CslA and HDZ genes, as well as NAC, PME3 and PME4, may be involved in cambium activities and secondary xylem formation. Taken together, these findings provide new information about cambium activity and cell differentiation in the formation, structure, and chemistry in conifers during the active–dormant transition.

scholarly journals A new histochemical method for the identification and visualization of both side chain acylated and nonacylated sialic acids.

1976 ◽  
Vol 24 (12) ◽  
pp. 1225-1230 ◽  
Author(s):  
C F Culling ◽  
P E Reid ◽  
W L Dunn
Keyword(s):  
Potassium Hydroxide ◽  
Periodic Acid ◽  
Sialic Acids ◽  
Histochemical Method ◽  
Side Chain ◽  
Parotid Glands ◽  
Periodic Acid Schiff ◽  
Mucin Histochemistry ◽  
Single Section ◽  
General Field

A new histochemical method is described for the differentiation of mucins that utilizes two different Schiff reagents and allows single section identification of side chain O-acylated, and nonacylated, sialic acids in contrasting colors. In the event of mucins containing only one type of sialic acid, it may allow their specific identification (e.g., C7 or C8 side chain O-acylated). It has been shown to be useful in the identification of some metastases from adenocarcinomas of colon (where the primary is potassium hydroxide/periodic acid-Schiff positive) and should prove of great value in the investigation of diseases of the gastrointestinal tract and particularly those of the colon. It should also be valuable in the general field of epithelial mucin histochemistry, particularly for those mucins of the salivary and parotid glands, etc.

scholarly journals Histochemical study of Encephalitozoon cuniculi spores in the kidneys of naturally infected New Zealand rabbits

2017 ◽  
Vol 29 (3) ◽  
pp. 269-277 ◽  
Author(s):  
Luis E. Rodríguez-Tovar ◽  
Alejandra Villarreal-Marroquín ◽  
Alicia M. Nevárez-Garza ◽  
Uziel Castillo-Velázquez ◽  
Heidi G. Rodríguez-Ramírez ◽  
...  
Keyword(s):  
Light Microscopy ◽  
Background Noise ◽  
Histochemical Study ◽  
Periodic Acid ◽  
Encephalitozoon Cuniculi ◽  
Calcofluor White ◽  
Periodic Acid Schiff ◽  
Hematoxylin And Eosin ◽  
Schiff Reaction ◽  
Host Tissues

Encephalitozoon cuniculi is an important microsporidian pathogen that is considered an emergent, zoonotic, and opportunistic. It infects both domestic and laboratory rabbits, generating severe chronic interstitial and granulomatous nephritis with fibrosis and granulomatous encephalitis. Encephalitozoonosis is diagnosed in paraffin-embedded sections by examining the spores in the host tissues. The spores are difficult to observe when the samples are stained with hematoxylin and eosin (H&E), particularly when there is an inflammatory reaction and tissue damage. The spores are easily mistaken for other microorganisms, such as fungi (yeasts), protozoa, and bacteria. In our study, we used kidney samples from E. cuniculi–positive rabbits and employed 14 recommended histologic stains for detecting microsporidia spores: alcian blue, calcofluor white, Giemsa, Gram, Grocott, H&E, Luna, Luxol fast blue, Masson trichrome, modified trichrome stain (MTS), periodic acid–Schiff reaction (PAS), Van Gieson, Warthin–Starry (WS), and Ziehl–Neelsen (ZN).We concluded that MTS and Gram stain, detected by light microscopy, and calcofluor white stain, detected by ultraviolet light microscopy, are the best stains for detecting spores of E. cuniculi in paraffin-embedded tissues from infected rabbits. These stains were superior to WS, ZN, Giemsa, and PAS for identifying spores without background “noise” or monochromatic interference. Also, they allow individual spores to be discerned in paraffin-embedded tissues. MTS allows observation of the polar tube, polaroplast, and posterior vacuole, the most distinctive parts of the spore.

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