A new medium composed of "cream of rice" infusion, oxgall, Tween 80, and agar is described for the sequential development of germ tubes and chlamydospores by Candida albicans. The procedure used (Dalmau's technique) is an improvement over the fluid substrate procedures previously advocated for germ tube formation. That the same preparation is then used for chlamydospore production is of practical importance for the clinical mycology laboratory.
Mycoses. 2008 May ;51 (3):205-8 18399901
Evaluation of Mueller-Hinton-agar as a simple medium for the germ tube production of Candida albicans and Candida dubliniensis.
Department of Medical Microbiology and Hospital Hygiene, University Hospital, Rostock, Germany. email@example.com
Candida albicans is the most frequently isolated yeast species from clinical specimens. A classical rapid presumptive differentiation from non-albicans species is based on its ability to produce germ tubes after incubation in human serum. The only non-albicans Candida species producing germ tubes is Candida dubliniensis. In this study, we evaluated Mueller-Hinton-agar (MH-agar) as a medium for germ tube formation of C. albicans and C. dubliniensis. A total of 859 yeast isolates from stool samples, including 632 strains of C. albicans, 10 C. dubliniensis and 217 other yeast strains from 20 different species, were grown on Sabouraud glucose (2%) agar at 37 degrees C for 24-72 h. Species were identified by standard methods. For the germ tube test (GTT), an inoculum from a single colony was streaked onto a MH-agar plate and covered by a sterile coverslip. After incubation at 37 degrees C for 2 h, the MH plates were examined using a light microscope at x200. The GTT was positive in 578 of 632 C. albicans strains (sensitivity 91.5%), in six of 10 C. dubliniensis strains (sensitivity 60.0%), and in none of the other yeast strains. MH-agar is a suitable medium for the GTT and the presumptive identification of C. albicans. It is safer to use than human serum and is widely available in microbiology laboratories.
Mutant alleles of the essential 14-3-3 gene in Candida albicans distinguish between growth and filamentation.
Louisiana State University School of Medicine, Department of Microbiology, Immunology, and Parasitology, Center of Excellence in Oral and Craniofacial Biology, 1100 Florida Ave, Box F8-130 New Orleans, LA 70119, USA.
The opportunistic fungal pathogen Candida albicans has the ability to exploit diverse host environments and can either reside commensally or cause disease. In order to adapt to its new environment it must respond to new physical conditions, nutrient sources, and the host immune response. This requires the co-regulation of multiple signalling networks. The 14-3-3 family of proteins is highly conserved in all eukaryotic species. These proteins regulate signalling pathways involved in cell survival, the cell cycle, and differentiation, and effect their functions via interactions with phosphorylated serines/threonines. In C. albicans there is only one 14-3-3 protein, Bmh1p, and it is required for vegetative growth and optimal filamentation. In order to dissect separate functions of Bmh1p in C. albicans, site-directed nucleotide substitutions were made in the C. albicans BMH1 gene based on studies in other species. Putative temperature-sensitive, ligand-binding and dimerization mutants were constructed. In addition two mutant strains identified through random mutagenesis were analysed. All five mutant strains demonstrated varying defects in growth and filamentation. This paper begins to segregate functions of Bmh1p that are required for optimal growth and the different filamentation pathways. These mutant strains will allow the identification of 14-3-3 target interactions and correlate the individual functions of Bmh1p to cellular processes involved in pathogenesis.
Using a slide culture technique, it was determined unequivocally that the chlamydospore of Candida albicans does germinate. The germination was by way of a multiple-budding process which was associated mostly with young spores following their transfer to a fresh environment. It is concluded the chlamydospore of C. albicans is a reproductive cell with a transient viability.
Descriptive and illustrative material in several recent diagnostic manuals for medical mycology are unclear with respect to proper designation of germ tubes formed by Candida albicans. Because of the increasing significance of this and other yeast species in human disease, mycologists should be aware that germ tubes, unlike buds or pseudohyphae, do not have constrictions at the point of origin. Light and scanning electron micrographs are presented to emphasize this diagnostic characteristic.
During the course of Candida albicans antigen production, a variant of this organism was encountered which did not produce hyphae at 37 degrees C. Presented here are some of the characteristics of this variant. It produces hyphae at 25 degrees C on cornmeal agar and synthetic medium plus N-acetylglucosamine and Tween 80. At 37 degrees C, it does not produce hyphae on these media, although C. albicans normally does produce hyphae under these circumstances. In liquid synthetic medium, this variant does not produce hyphae at 37 degrees C. The variant strain was analyzed for DNA, RNA, protein content, and particle size. After 50 to 70 h in balanced exponential-phase growth, particle size distribution was narrow, and there were no differences in the DNA, RNA, or protein content per particle in the two strains. When balanced exponential-phase cultures were brought into stationary phase, both strains contained the same amount of DNA per cell.
To find out whether smoking affects the prevalence and intraoral distribution of Candida albicans, swabs and saliva samples from 100 healthy persons, smokers and non-smokers were cultured for the presence of this fungus. The prevalence was the same (35%) in both smokers and non-smokers. Among carriers, the mean concentration of C. albicans colony-forming units in saliva of smokers was twice that of the non-smokers, and the isolation frequency of C. albicans at each of 5 mucosal sites was also higher in smokers than in non-smokers. However, a wide variation was found, and these differences were not significant at the 0.05 level. Men were carriers more often than women (p less than 0.025), and the mucosal site from which C. albicans was recovered most often was the posterior dorsum of the tongue. Although it has previously been claimed that cigarette smoking influences the carrier state of C. albicans, the present study suggests that the effect is only slight.
This review will survey environmental controls on the morphology of Candida albicans, describe the cellular and ultrastructural events associated with morphological transitions in this fungus, and attempt to relate biochemical phenomena that have been reported to be associated with dimorphic change to C. albicans cell biology. The synthesis of the cell wall of C. albicans and its control remain largely undiscovered, but it is clear that the cell wall is the principal component involved in shape determination. Possible models for C. albicans dimorphism will be critically reviewed.
Rhinosporidiosis is reviewed, and the first autochthonous case in Spain is presented (site: in the nasal cavity of a 19-year-old male from a rural background). Diagnosis was established morphologically after eliminating the possibilities of Cryptococcus neoformans, Coccidioides immitis, and Chrysosporium crescens. Clinico-pathological features are described. Preparations were stained with hematoxylin-eosin, PAS, and methenamine silver, and studied for fluorescence. Certain aspects of the epidemiology and diagnosis are commented upon.
Other papers by authors:
Department of Medicine, Division of Infectious Diseases, Medical University of South Carolina, Charleston, 29412, United States. firstname.lastname@example.org
INTRODUCTION Noninvasive methods are needed to detect distal sensory polyneuropathy in HIV-infected persons on antiretroviral therapy (ART). METHODS Quantitative sudomotor axon reflex test (QSART) and Utah Early Neuropathy Scale (UENS), small-fiber sensitive measures, were assessed in subjects with and without clinical neuropathy. Pain was assessed by visual analog scale (VAS). RESULTS Twenty-two subjects had symptoms and signs of neuropathy, 19 had neither, and all were receiving ART. Median sweat volume (μL) was lower at all testing sites in those with neuropathy compared to those without (p<0.01 for all). UENS and VAS (mm) were higher in neuropathy subjects (p<0.05 for each). Lower sweat volume at all sites correlated with higher pin UENS subscore, total UENS, and VAS (p<0.05 for all). In multivariable analyses adjusting for age, CD4(+) T cells, sex, and use of "d-drug" ART, QSART and UENS remained associated (p=0.003). CONCLUSION QSART and UENS have not been previously studied in this patient population and may identify small-fiber neuropathy in HIV-infected, ART-treated persons.
A G Smith, W Fan, L Regen, S Warnock, M Sprague, R Williams, B Nisperos, L P Zhao, M R Loken, J A Hansen, S Pereira
Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
Somatic mutations and genomic alterations are frequent events in the clonal evolution of hematologic malignancies. Recent studies have reported copy neutral loss of heterozygosity (LOH) for the mismatched human leukocyte antigen (HLA) haplotype in patients relapsed after haploidentical hematopoietic cell transplantation (HCT) for a hematologic malignancy. Herein, we report 15 cases of somatic mutations in the HLA genes of patients with a variety of hematologic diseases, including acute myelogenous leukemia, acute lymphocytic leukemia, chronic lymphocytic leukemia, chronic myeloid leukemia, myelodysplastic syndrome, and non-Hodgkin's lymphoma, encountered at our institute over the past decade. While two of the cases were identified in patient relapse specimens collected post-HCT, 13 cases were found in peripheral blood specimens submitted for HLA typing prior to transplantation. Ten patients exhibited acquired LOH for all or part of one HLA haplotype. Five other cases involved somatic mutations in the nucleotide sequences of common HLA-A or HLA-B alleles. Since they are not systematically evaluated prior to HCT, acquired mutations in HLA genes are likely under reported. Beyond the implications for accurate HLA typing and donor selection, alternations that result in the loss of HLA expression may allow escape from immune surveillance and adversely impact transplant outcome.
Eur J Cancer. 2012 Jan ;48 (2):263-9 22206862
Survival from childhood acute lymphoblastic leukaemia: the impact of social inequality in the United Kingdom.
Epidemiology & Genetics Unit, Department of Health Sciences, University of York, York YO10 5DD, United Kingdom. email@example.com
BACKGROUND Survival from childhood acute lymphoblastic leukaemia (ALL) has continued to improve in economically-developed regions of the world, but 20% of patients still die within 5-years of diagnosis. Treatment is prolonged and complex; and as survival rates plateau, factors relating to socio-economic status and/or treatment adherence are increasingly scrutinised as potentially important determinants of outcome. METHODS Predicated on the frame-work of the United Kingdom (UK) NHS, the relationship between socio-demographic factors and ALL survival is examined here using data from a large follow-up study conducted in the 1990s. One thousand five hundred and fifty nine children (0-14 years) diagnosed in England, Scotland &Wales during the era of the national UKALL XI randomized-controlled trial (RCT) were followed-up for an average of 15.9 years (20,826.3 person-years). Area-based deprivation scores and father's occupational social class at the time of the child's birth were used as markers of socio-economic status. Information on deaths was obtained from the NHS Information Centre for Health and Social Care. All children were included in the analyses, irrespective of RCT enrolment or participation in the founding epidemiological study (www.UKCCS.org).Survival effects were assessed using proportional hazards regressions models. RESULTS Survival varied with both area-based deprivation at diagnosis (hazard ratio (HR) 1.29; 95% confidence interval (CI) 1.05-1.57) and fathers occupational social class at birth (HR 1.12; 95% CI 0.97-1.29); the divergence beginning 6-9 months after diagnosis, and widening thereafter during home-administered therapy. The findings became more marked when analyses were restricted to those enrolled in UKALL XI (n = 1341). As expected, survival differences were also observed with sex, and age at diagnosis. CONCLUSION The existence of significant social disparities in ALL survival, which are not due to treatment accessibility, is of major clinical importance. Trends should be monitored and further research into potentially modifiable risk factors conducted.
Repetitive use of intra-arterial verapamil in the treatment of reversible cerebral vasoconstriction syndrome.
Kris F French, Robert E Hoesch, Juliann Allred, Michael Wilder, A G Smith, Kathleen B Digre, Donald V La Barge 3rd
Department of Neurology and Clinical Neurosciences, Clinical Neurosciences Center, University of Utah Hospitals and Clinics, 175 N Medical Drive East, Salt Lake City 84132, UT, USA. firstname.lastname@example.org
Reversible cerebral vasoconstriction syndrome (RCVS) typically presents with recurrent thunderclap headaches and neurological deficits that are usually self-limiting. The intra-arterial (IA) use of vasodilators for RCVS has been reported for severe cases. Patients with RCVS have the potential for serious and permanent neurological deficits. It is a rare disorder, with a recent surge in the number of reports, and probably continues to be under-diagnosed. We report two patients with RCVS with severe neurological sequelae, treated in a large tertiary hospital. Both patients received high-dose cortico steroids due to the possibility of angiitis of the central nervous system, but they deteriorated neurologically, which suggests that steroids may have a deleterious effect in RCVS. Treatment with IA verapamil resulted in reversal of vasoconstriction, but multiple treatments were necessary. Therefore, IA administration of verapamil is a possible treatment for severe RCVS, but there is only limited sustained improvement in vasodilation that may require repetitive treatments with a currently undetermined optimal treatment interval.
L Zilliox, A C Peltier, P A Wren, A Anderson, A G Smith, J R Singleton, E L Feldman, N B Alexander, J W Russell
Department of Neurology, University of Maryland and Maryland VA Healthcare System, Baltimore, MD, USA.
OBJECTIVE Autonomic symptoms may occur frequently in diabetic and other neuropathies. There is a need to develop a simple instrument to measure autonomic symptoms in subjects with neuropathy and to test the validity of the instrument. METHODS The Survey of Autonomic Symptoms (SAS) consists of 11 items in women and 12 in men. Each item is rated by an impact score ranging from 1 (least severe) to 5 (most severe). The SAS was tested in observational studies and compared to a previously validated autonomic scale, the Autonomic Symptom Profile (ASP), and to a series of autonomic tests. RESULTS The SAS was tested in 30 healthy controls and 62 subjects with neuropathy and impaired glucose tolerance or newly diagnosed diabetes. An increased SAS score was associated with the previously validated ASP (rank order correlation=0.68; p<0.0001) and with quantitative measures of autonomic function: a reduced quantitative sudomotor axon reflex test sweat volume (0.31; p<0.05) and an abnormal 30:15 ratio (0.53; p<0.01). The SAS shows a high sensitivity and specificity (area under the receiver operating characteristic curve 0.828) that compares favorably with the ASP. The SAS scale domains had a good internal consistency and reliability (Cronbach α=0.76). The SAS symptom score was increased in neuropathy (95% confidence interval [CI] 2.99-4.14) compared to control (95% CI 0.58-1.69; p<0.0001) subjects. CONCLUSIONS The SAS is a new, valid, easily administered instrument to measure autonomic symptoms in early diabetic neuropathy and would be of value in assessing neuropathic autonomic symptoms in clinical trials and epidemiologic studies.
European Federation of Neurological Societies/Peripheral Nerve Society Guideline on the use of skin biopsy in the diagnosis of small fiber neuropathy. Report of a joint task force of the European Fe-deration of Neurological Societies and the Peripheral Nerve Society.
G Lauria, S T Hsieh, O Johansson, W R Kennedy, J M Leger, S I Mellgren, M Nolano, I S J Merkies, M Polydefkis, A G Smith, C Sommer, J Valls-Solé
Neuromuscular Diseases Unit, IRCCS Foundation,'Carlo Besta' Neurological Institute, Milan, Italy.
Background: Revision of the guidelines on the use of skin biopsy in the diagnosis of peripheral neuropathy, published in 2005, has become appropriate owing to publication of more relevant articles. Most of the new studies focused on small fiber neuropathy (SFN), a subtype of neuropathy for which the diagnosis was first developed through skin biopsy examination. This revision focuses on the use of this technique to diagnose SFN. Methods: Task force members searched the Medline database from 2005, the year of the publication of the first EFNS guideline, to June 30th, 2009. All pertinent articles were rated according to the EFNS and PNS guidance. After a consensus meeting, the task force members created a manuscript that was subsequently revised by two experts (JML and JVS) in the field of peripheral neuropathy and clinical neurophysiology, who were not previously involved in the use of skin biopsy. Results and Conclusions: Distal leg skin biopsy with quantification of the linear density of intraepidermal nerve fibers (IENF), using generally agreed upon counting rules, is a reliable and efficient technique to assess the diagnosis of SFN (Recommendation Level A). Normative reference values are available for bright-field immunohistochemistry (Recommendation Level A) but not yet for confocal immunofluorescence or the blister technique. The morphometric analysis of IENF density, either performed with bright-field or immunofluorescence microscopy, should always refer to normative values matched for age (Recommendation Level A). Newly established laboratories should undergo adequate training in a well-established skin biopsy laboratory and provide their own stratified for age and gender normative values, intra- and interobserver reliability, and interlaboratory agreement. Quality control of the procedure at all levels is mandatory (Good Practice Point). Procedures to quantify subepidermal nerve fibers and autonomic innervated structures, including erector pili muscles, and skin vessels, are under development but need to be confirmed by further studies. Sweat gland innervation can be examined using an unbiased stereologic technique recently proposed (Recommendation Level B).A reduced IENF density is associated with the risk of developing neuropathic pain (Recommendation Level B), but it does not correlate with its intensity. Serial skin biopsies might be useful for detecting early changes of IENF density, which predict the progression of neuropathy, and to assess degeneration and regeneration of IENF (Recommendation Level C). However, further studies are warranted to confirm its potential usefulness as an outcome measure in clinical practice and research. Skin biopsy has not so far been useful for identifying the etiology of SFN. Finally, we emphasize that 3-mm skin biopsy at the ankle is a safe procedure based on the experience of 10 laboratories reporting absence of serious side effects in approximately 35 000 biopsies and a mere 0.19% incidence of non-serious side effects in about 15 years of practice (Good Practice Point).
Department of Dermatology, COPD, University Hospital of North Staffordshire, Hartshill Road, Stoke-on-Trent, England ST4 7PA, United Kingdom. James_Halpern@hotmail.com
Epithelioma cuniculatum (carcinoma cuniculatum) is a rare, low-grade verrucous carcinoma of the foot first described in 1954. We present a case report of a 55-year-old man with an enlarging lesion on the sole of his right foot. Despite initial benign pathology the lesion continued to grow, soften in consistency and develop a foul odour. Repeat biopsy showed a well-differentiated squamous cell carcinoma and below-the-knee amputation was required. Epithelioma cuniculatum presents as a slow growing mass on the plantar aspect of the foot. Diagnosis is often delayed and may require multiple biopsies. Lesions rarely metastasise but more commonly invade locally requiring wide surgical excision.
Commentary on:"Athletes foot: when all else fails" by William C.R. Agunwa [Foot Ankle Surg. 12 (2006) 209-210].
North Staffordshire Hospital, Stoke-on-Trent, United Kingdom. email@example.com
Leukaemia Research Fund Centre for Clinical Epidemiology, University of Leeds, Institute of Epidemiology, Margaret Smith Building, Leeds, UK.
PURPOSE To investigate the possible role of topical chloramphenicol in the development of adult acute leukaemia. METHODS The design of the study was a population-based age- and sex-matched case-control study, which collected cases of adult acute leukaemia between 1991 and 1996. Caucasian cases (807) and 1593 Caucasian controls were interviewed in person using a highly structured questionnaire. General practitioner medical records were abstracted for previous topical chloramphenicol use. RESULTS 797 cases and 1570 controls were included in the analysis. No association was observed for topical chloramphenicol use and acute leukaemia (adjusted odds ratio, 1-year lag period (OR) 0.91 95% confidence interval (CI) 0.70-1.17). Similar results were observed when the analysis was repeated by diagnostic subgroup and sex. For all the data, a small, non-significant increased risk was observed (OR=1.21, 95% CI 0.65-2.25) if chloramphenicol had been prescribed three, or more times, but there was no statistically significant dose-response relationship (chi(2)=1.40, two-sided p=0.24). CONCLUSIONS The results, based on a robust study design, show no evidence of an increased risk of developing adult acute leukaemia after topical chloramphenicol use. Copyright (c) 2000 John Wiley & Sons, Ltd.