PubMed Health⌕ Search

Biomedical subjects

E S Beneke

Publications and source records attributed to E S Beneke.

At least 19 recordsLinked to original sources

Dermatophytosis of the scalp: incidence, immune response, and epidemiology.

Tinea capitis remains a common infection among the pediatric population of North America. The 'gray patch' Microsporum audouinii infections of the 1950's have been supplanted by the 'black dot' ringworm of Trichophyton tonsurans. The clinical presentation of T. tonsurans infection is quite variable and may be related to specific host T-lymphocyte response. This dermatophytosis is most frequently incurred from contact with an infected child either directly or via a variety of fomites. Current studies indicate that an asymptomatic adult carrier state may also exist which could contribute to the morbidity of this mycosis.

Humans↗

Effect of attachment of anticandidal antibody to the surfaces of liposomes encapsulating amphotericin B in the treatment of murine candidiasis.

The effect produced by antibody specific to Candida albicans when attached to liposomes containing amphotericin B was studied in vivo. Liposomal amphotericin B bearing specific immunoglobulin (LAMB-Ab) was compared with the unencapsulated drug (fAMB) and other liposomal amphotericin B formulations in the short-term survival (21 days) of mice with disseminated candidiasis. Both the treatment and prophylaxis of the murine model of candidiasis were explored in these trials. LAMB-Ab increased survival rates in the model more than other liposomal preparations containing amphotericin B. Liposomal amphotericin B compounds as a group prolonged survival over fAMB. Liposomal preparations used for comparison included liposomes with attached nonspecific antibody (LAMB-Ab-), liposomes without antibody (LAMB), and liposomes with unattached specific antibody (LAMB+).

Amphotericin B↗

Influence of mucosal cell origin on the in vitro adherence of Candida albicans: are mucosal cells from different sources equivalent?

The influence of collecting mucosal cells from various anatomical sites, and varying the date of collection and cell donor on adhesion of Candida albicans to human epithelial cells was examined by using an in vitro adherence assay. Examination of buccal mucosal cells from twenty-four donors showed statistically significant differences in the number of attached yeasts between individuals. Sex did not exert a significant influence on adhesion. Examination of buccal mucosal cells from ten donors collected on five different dates revealed that yeast attachment to mucosal epithelial cells varied significantly within subjects across time. Epithelial cells from some donors manifested greater date-to-date variations in yeast adhesion than others. Adherence of Candida to mucosal cells from three anatomical sites (mouth, vagina and urinary tract) collected from ten different donors was also tested. Yeast adherence to buccal cells was highest, lowest using urinary tract cells, while vaginal epithelium was intermediate. Adherence to mucosal cells from three sites was significantly different both within and between individuals although some subjects manifested larger variations than others. These data suggest that the in vitro adherence of Candida albicans is influenced by mucosal cell donor, date of collection and body site of origin. Mucosal cells from different sources do not appear to be equivalent in receptiveness to C. albicans and this might explain some of the discrepancies observed when adhesion studies performed by different investigators are compared. The existing need for a more uniform methodology with which to pursue studies on fungal attachment to mucosal surfaces is emphasized.

Adhesiveness↗

Variations in affinity to Candida albicans in vitro among human buccal epithelial cells.

Using an in-vitro adherence assay it was observed that the number of Candida albicans cells that attached to individual buccal mucosal cells varied greatly. Three mucosal-cell characteristics--state of aggregation, size and viability--that might influence yeast adhesion in vitro were studied. The number of attached yeast cells per mucosal cell varied from 0 to 32. The majority of buccal cells (88%) had none or very few yeasts attached, whereas a minority of cells (12%) bound more than one half of all the attached yeasts. In donors whose buccal cells had large numbers of attached yeasts this percentage increased and the number of cells with no attached yeast cells fell. Cells of an intermediate size (36-70 micron) had a greater affinity for yeasts than did cells of other sizes. Buccal cell viability appeared not to be necessary for adhesion of yeasts. No significant differences were observed in the number of yeast cells attached to single buccal cells compared with attachment to buccal cells within sheets. It would appear, therefore, that there are distinct subpopulations of epithelial cells with high and low affinity for attachment by C. albicans in vitro. Mucosal cell size or viability might influence this affinity.

Candida albicans↗

The effects of soluble Saccharomyces cerevisiae mannan on the phagocytosis of Candida albicans by mouse peritoneal macrophages in vitro.

Saccharomyces cerevisiae mannan inhibited the phagocytic activity and phagocytic capacity of mouse peritoneal macrophages elicited by Concanavalin A (Con A) for Candida albicans yeast cells that were either unopsonized or opsonized with C3. The mannan had no effect on the phagocytosis of C. albicans opsonized with normal human serum or immunoglobulins. Phagolysosome fusion in macrophages was unimpaired by the presence of S. cerevisiae mannan, which supports previous observations that mannan does not interfere with neutrophil degranulation.

Animals↗

Autoradiographic method to screen for soil microorganisms which accumulate zinc.

An autoradiographic method was developed to screen for and isolate soil microorganisms which accumulate zinc (Zn). Diluted soil samples (Rubicon fine sand, Entic Haplorthods [pH 5.9]) were plated on soil extract-glucose agar containing radioactive 65Zn. After 7 days of incubation, individual colonies which accumulated sufficient 65Zn could be detected by autoradiography. These colonies were isolated and confirmed as Zn accumulators in pure culture by using the autoradiographic plate technique. Most Zn accumulators were filamentous fungi, identified as Penicillium janthinellum, Aspergillus fumigatus, and Paecilomyces sp. Isolates of Penicillium janthinellum were the most common Zn accumulators. The most abundant Zn-accumulating bacteria were Bacillus spp. The validity of the autoradiographic plate technique to differentiate soil microbes which accumulate Zn was examined independently by energy dispersive X-ray analysis in a scanning electron microscope. This method confirmed that fungal isolates which gave positive autoradiographic responses in the plate assay bioaccumulated more Zn in their biomass than fungal isolates from the same soil sample which gave negative autoradiographic responses. Thus, this technique can be applied to specifically screen for and isolate microbes from the environment which bioaccumulate Zn.

Aspergillus fumigatus↗

Subcutaneous alternariosis.

Alternaria species are common plant pathogens, but a rare cause of human infection. Previously reported cases of cutaneous alternariosis (Alternaria alternata) in both healthy and immunosuppressed hosts have been characterized by a chronic localized ulcerative eruption in exposed sites. Dermal granulomatous infiltration and variable epidermal changes, with hyphae in both the dermis and epidermis, are characteristic. We present a case with certain unique features. This is the first reported human infection with Alternaria dianthicola. In addition, our patient showed the unusual presentation of clinically noninflammatory subcutaneous nodules of the chest wall. The subcutaneous location of the granulomatous process may have been attributable to deep traumatic inoculation. The circumscribed nodular quality of the infection allowed a surgical therapeutic approach.

Alternaria↗

Candida albicans resistance to 5-fluorocytosine: frequency of partially resistant strains among clinical isolates.

Resistance to 5-fluorocytosine was studied in 137 independent Candida albicans clinical isolates. Seventy-eight isolates (57%) were susceptible; 51 isolates (37%) were partially resistant; 8 isolates (6%) were highly resistant. All partially resistant isolates gave rise to variants which were highly resistant. Some susceptible isolates gave rise to variants which were highly resistant; two such isolates were shown to be heterozygous for resistance, and these isolates define a new type of heterozygote. A partially resistant isolate gave rise to resistant variants which were auxotrophic for lysine; this result was interpreted as preliminary evidence that the allele which determined resistance was linked to an allele which determined auxotrophy for lysine. It is suggested that heterozygotes constitute a source of preexisting mutant alleles which determine resistance, and that 5-fluorocytosine treatment of infections due to heterozygotes may result in significant selection for resistant variants. A simple screening procedure is described by which partially resistant strains may be recognized.

Candida albicans↗

Evidence for mannose-mediated adherence of Candida albicans to human buccal cells in vitro.

Various lectins and sugars were used to study the possible role of saccharide-containing moieties on the surface of Candida albicans and human buccal cells in the adherence of this yeast to mucosal surfaces. The lectins possessed affinities for several different sugar moieties and were used to pretreat C. albicans or buccal cells before mixing and incubating in the adherence assay. It was found that concanavalin A, a lectin that recognizes mannose and glucose, inhibited adherence of the pretreated yeasts to buccal cells and also inhibited adherence of pretreated buccal cells to nonpretreated yeast cells. Adherence was restored by preincubating the concanavalin A with a mannose derivative, but preincubation of concanavalin A with other sugars did not produce this effect. Lectins that do not recognize mannose had no effect on adherence. The presence of alpha-D-methyl mannopyranoside in the incubation medium during the assay inhibited adherence, whereas other sugars did not. Germinated yeasts adhered to buccal cells more effectively than nongerminated cells and were more susceptible to adherence inhibition by concanavalin A than were nongerminated yeasts. Thus, mannose-containing moieties on the surface of C. albicans and buccal cells could mediate the adherence of this yeast to human epithelium.

Adhesiveness↗

Hepatic clearance of Candida albicans in rats.

The initial clearance of Candida albicans from the blood stream of rats and from perfusion medium by perfused rat livers was characterized. Normal rats cleared over 90% of large doses of intravenously injected yeast cells in 5 min. All were recovered as viable cells among various reticulendothelial organs after 30 min. The perfused rat liver trapped an average of 85% of the yeast cells in a single pass. No significant killing occurred, even in the presence of 10% whole rat blood. Scanning electron microscopy of cryofractured livers revealed that the cells were trapped in liver sinusoids but outside phagocytic cells.

Animals↗