Results of semimonthly 5-florouracil/leucovorin combined with paclitaxel and oxaliplatin in treatment of advanced gastric cancer (AGC)

15045

Background: At present there is still no standard chemotherapy regimen for AGC, the progress of AGC exhibits a pessimistic result with a median survival of less than 9 months. The purpose of this trial was designed to enhance the treatment efficacy for AGC by using semimonthly FU/LV combined with paclitaxel and oxaliplatin. Methods: Patients chosen with histologically proven diagnosis of adenocarcinoma of the stomach or gastroesophageal junction, locally advanced (i.e., unresectable) or metastatic and measurable disease. The chemotherapy regimen was comprised of a 3-hour infusion of 135 mg/m2 of paclitaxel followed by oxaliplatin 85 mg/m2 and LV 400 mg/m2, administered simultaneously as a 2-hour infusion, then continued a 46-hour infusion of FU 2.4 g/m2 using an ambulatory pump. Treatment was continued until disease progressed, unacceptable toxicity, or patient choice. The primary endpoint was response rate. Results: Twenty-seven patients were enrolled onto this study in our center between September 19, 2005 and December 25, 2006. The median patient age was 51 years (range, 28 to 66 years), 21 were males and 6 were females. All patients received the chemotherapy between at least two cycles and maximum eight cycles with a median of three. Four CRs of 27 enrolled patients, fifteen PRs and eight SDs were observed. Nineteen patients were chemonaive within enrolled patients: Four CRs, eleven PRs. At a median follow-up of 8.7 months, the median survival was 6.8 months. Frequent grade 3 to 4 toxicities were: neutropenia (37.0%), stomatitis (7.4%), nausea (7.4%), vomiting (7.4%), hepatic dysfunction (3.7%), paresthesia (18.5%). No treatment-related death occurred. Conclusion: Semimonthly FU/LV combined with paclitaxel and oxaliplatin appears to be of well efficacy and is well tolerated in patients with AGC. Currently, this regimen is being tested in the phase III trial involving patients with AGC on the basis of well result.

No significant financial relationships to disclose.

Expression of hepatoma-derived growth factor in early-stage cervical adenocarcinoma

16002

Background: Hepatoma-derived growth factor (HDGF) is a unique nuclear/growth factor and plays an important role in the progression of different types of cancer. The current study was designed to elucidate the role of HDGF expression during the development of. early-stage cervical adenocarcinoma. Methods: A total of 63 patients with early-stage cervical adenocarcinoma were enrolled in this retrospective study. The HDGF expression in cervical adenocarcinoma was determined by immunohistochemistry. The HDGF immunostaining in the nuclei and cytoplasm of clinical samples was scored and expressed as labeling index to correlate with the clinical parameters of patients with early-stage cervical adenocarcinoma using SPSS software. Results: HDGF immunostaining was detected in both cytoplasm and nucleus of cervical adenocarcinoma. Compared with adjacent non-tumor tissue samples, HDGF expression was significantly increased in either nuclear or cytoplasmic compartment in cervical adenocarcinoma samples (P < 0.001). Moreover, elevated nuclear HDGF levels were correlated with lymph-vascular space invasion (P < 0.05), lymph node metastasis (P < 0.001), recurrence (P < 0.001), advaced grade(P < 0.001). Conclusions: HDGF overexpression is involved in the carcinogenesis of cervical adenocarcinoma.

[Table: see text]

No significant financial relationships to disclose.

Assessing adherence to the American College of Chest Physicians’ (ACCP) recommendations for thromboprophylaxis in hospitalized cancer patients

9047

Background: This study evaluates whether clinicians are providing appropriate VTE prophylaxis to at-risk surgical and non- surgical cancer patients in accordance with ACCP guidelines. Methods: Premier's inpatient administrative data were used to assess VTE prophylaxis rates in fourteen cancer types. Patients age 40 or older, with a minimum length of stay of six days, and no contraindications for anti-coagulation were included in the study. Two rates were determined; the rate of discharges receiving any level of anticoagulation and the rate of patients receiving appropriate prophylaxis by comparing daily use of anti-coagulants and compression devices, dosage, and prophylaxis duration with ACCP recommendations. The 6th guidelines were used due to their release prior to the study period. Rates based on the 7th guidelines were calculated for the same patient cohort to assess how the revised guidelines affect our findings. Trends were assessed by comparing prophylaxis rates by quarter. Results: 72,391 discharges from 225 hospitals between January 2002 and September 2005 met the inclusion criteria. 29% of all at-risk cancer discharges received the recommended prophylaxis regimen. Rates varied by cancer type ranging from 18.7% in prostate to 36.3% in colorectal cancer discharges. 55% did not receive any anti-coagulation prophylaxis, 9.5% received insufficient dosage and 5.8% did not receive prophylaxis for the appropriate duration. The appropriate VTE prophylaxis rate is higher for surgical cancer than for non-surgical cancer discharges (32.3% vs. 27.7%). Trends suggest a slight increase in appropriate prophylaxis rates for all types of cancer discharges. Appropriate prophylaxis rates based on 7th guidelines are lower than rates based on the 6th guidelines due to the more specific recommendation in the 7th guidelines. Conclusions: Cancer patients are known to have significant risk for VTE, yet VTE prophylaxis for at-risk non-surgical cancer patients in hospitals is not optimal. Rates for surgical cancer patients were only slightly higher. Using the 7th recommendations results in lower prophylaxis rates. More effort is required to increase awareness of the ACCP recommendations for thromboprophylaxis in cancer patients.

No significant financial relationships to disclose.

Positioning and tracking of a linear motion stage with friction compensation by fuzzy logic approach

In this paper, the development of a fuzzy controller that compensates for nonlinear friction in a linear motion stage is presented. The experimental work and instrumentation set up is presented for this research. Based upon a nonlinear friction model, friction parameters were estimated from experimental results. Simulation and experimental validation on a ball-screw mechanism is presented, showing the effectiveness of the proposed controller. Furthermore, it is shown that the proposed fuzzy control scheme offers several implementation advantages such as smaller control effort, and reduced effect of measurement noise. Moreover, the fuzzy logic methodology displays superior performance when compared to a conventional PID controller. It also shows good and robust tracking with respect to system parameters variation.

Genetic and epigenetic alterations in the differential diagnosis of malignant melanoma and spitzoid lesion

BACKGROUND

The histopathological differentiation of malignant melanoma and Spitz naevus often presents diagnostic problems.

OBJECTIVES

We aimed to find out applicable diagnostic parameters other than routine pathology.

METHODS

The cases included conventional melanomas and Spitz naevi as well as atypical spitzoid lesions that had posed diagnostic difficulties. We examined hotspots of mutation in the BRAF, NRAS and HRAS genes by polymerase chain reaction-based direct sequencing. We also analysed DNA copy number aberrations and the methylation of CpG sequences in several cancer-related genes by utilizing a novel methylation-specific multiplex ligation-dependent probe amplification method.

RESULTS

Twenty three of 24 conventional melanomas showed at least one of the genetic and epigenetic alterations examined, although one acral melanoma did not show any alteration. By sharp contrast, 12 Spitz naevi with an unambiguous histopathology showed no or few chromosomal aberrations, no oncogene mutations and no methylation of CpG sequences. Of the 16 ambiguous spitzoid lesions, most of which were designated atypical Spitz tumour by one of the authors, all but one showed no mutations, no methylations and few copy number aberrations. However, three tumours showed copy number loss of the cyclin-dependent kinase inhibitor 2A gene (CDKN2A), an alteration observed frequently in melanomas but not found in conventional Spitz naevi. These results show that, although most atypical Spitz tumours do not differ from conventional Spitz naevi showing virtually no genetic and epigenetic aberrations, some cases may have chromosomal aberrations that include copy number loss of the CDKN2A gene.

CONCLUSIONS

Genetic and epigenetic analyses may be useful as an additional diagnostic tool to distinguish between melanoma and Spitz naevus, and may help to define subgroups in atypical Spitz tumours.

Oncogenic activation of c-Abl in non-small cell lung cancer cells lacking FUS1 expression: inhibition of c-Abl by the tumor suppressor gene product Fus1

In lung cancer, frequent loss of one allele of chromosome 3p is seen in both small cell lung cancer and non-small cell lung cancer (NSCLC), providing evidence of tumor suppressor genes (TSGs) in this chromosomal region. The mechanism of Fus1 tumor suppressor activity is unknown. We have found that a Fus1 peptide inhibits the Abl tyrosine kinase in vitro (IC(50) 35 microM). The inhibitory Fus1 sequence was derived from a region that was deleted in a mutant FUS1 gene (FUS1 (1-80)) detected in some lung cancer cell lines. Importantly, a stearic acid-modified form of this peptide was required for the inhibition, but stearic acid alone was not inhibitory. Two NSCLC cell lines, which lack expression of wild-type Fus1, contain activated c-Abl. Forced expression of an inducible FUS1 cDNA in H1299 NSCLC cells decreased levels of activated c-Abl and inhibited its tyrosine kinase activity. Similarly, treatment of c-Abl immune complexes with the inhibitory Fus1 peptide also reduced the level of c-Abl in these immune complexes. The size and number of colonies of the NSCLC cell line, H1,299, in soft agar was strongly inhibited by the Abl kinase inhibitor imatinib mesylate. Co-expression of FUS1 and c-ABL in COS1 cells blocked activation of c-Abl tyrosine kinase. In contrast, co-expression of mutant FUS1 (1-80) with c-ABL had little inhibitory activity against c-Abl. These findings provide strong evidence that c-Abl is a possible target in NSCLC patients that have reduced expression of Fus1 in their tumor cells.

A novel Bacillus thuringiensis strain LLB6, isolated from bryophytes, and its new cry2Ac-type gene

AIMS

To isolate and characterize the novel Bacillus thuringiensis strains from bryophytes collected from Wuyi Mountain, Fujian Province of China, and identify new B. thuringiensis strains and toxins active against mosquitoes.

METHODS AND RESULTS

Twelve novel B. thuringiensis strains were isolated from 76 bryophyte samples. According to the results of this preliminary screening, LLB6 was the most toxic to Aedes albopictus. Then phase-contrast as well as scanning electron microscopy, bioassays, cloning, sequencing and expression were performed to characterize the novel isolate LLB6 and its new gene cry2Ac5.

CONCLUSIONS

Bacillus thuringiensis occurred naturally on bryophytes. LLB6 isolated from Physcomitrium japonicum was toxic to A. albopictus. A new cry2Ac5 gene of LLB6 was detected, cloned and expressed successfully. Bioassays on A. albopictus showed that the expressed Cry2Ac5 was also toxic to the third instar larvae.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report of B. thuringiensis strains isolated from bryophytes. It represents a specific source of new B. thuringiensis strains and is of great importance for the knowledge of the ecology of B. thuringiensis. Novel LLB6 harboring the new gene cry2Ac5 and its expressed Cry2Ac5 protein revealed activity against A. albopictus and became a new member of B. thuringiensis toxins.

Biofunctionalization of CeF(3):Tb(3+) nanoparticles

CeF(3):Tb(3+) nanoparticles (short pillar-like morphology with an average length and width of 11 and 5 nm, respectively) were successfully prepared by a polyol process using diethyleneglycol (DEG) as solvent. After being functionalized with a SiO(2)-NH(2) layer, these CeF(3):Tb(3+) nanoparticles can be conjugated with biotin molecules (activated by thionyl chloride) and further with avidin. The as-formed CeF(3):Tb(3+) nanoparticles, CeF(3):Tb(3+) nanoparticles functionalized with amino groups, biotin conjugated amino-functionalized CeF(3):Tb(3+) nanoparticles and biotinylated CeF(3):Tb(3+) nanoparticles bonded with avidin were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), UV/vis absorption spectra and luminescence spectra, respectively. The biofunctionalization of the CeF(3):Tb(3+) nanoparticles has less effect on their luminescence properties, i.e. they still show strong green emission (from Tb(3+), with (5)D(4)-(7)F(5) at 543 nm as the most prominent group), indicative of the great potential for these CeF(3):Tb(3+) nanoparticles to be used as biological fluorescence probes.

Adaptive bolus-based set-point regulation of hyperglycemia in critical care

Critically ill patients are often hyperglycemic and extremely diverse in their dynamics. Consequently, fixed protocols and sliding scales can result in error and poor control. A two-compartment glucose-insulin system model that accounts for time-varying insulin sensitivity and endogenous glucose removal, along with two different saturation kinetics is developed and verified in proof-of-concept clinical trials for adaptive control of hyperglycemia. The adaptive control algorithm monitors the physiological status of a critically ill patient, allowing real-time tight glycemic regulation. The bolus-based insulin administration approach is shown to result in safe, targeted stepwise glycemic reduction for three critically ill patients.

Long term verification of glucose-insulin regulatory system model dynamics

Hyperglycaemia in critically ill patients increases the risk of further complications and mortality. A long-term verification of a model that captures the essential glucose- and insulin-kinetics is presented, using retrospective data gathered in an intensive care unit (ICU). The model uses only two patient specific parameters, for glucose clearance and insulin sensitivity. The optimization of these parameters is accomplished through a novel integration-based fitting approach, and a piecewise linearization of the parameters. This approach reduces the non-linear, non-convex optimization problem to a simple linear equation system. The method was tested on long-term blood glucose recordings from 17 ICU patients, resulting in an average error of 7%, which is in the range of the sensor error. One-hour predictions of blood glucose data proved acceptable with an error range between 711%. These results verify the model's ability to capture long-term observed glucose-insulin dynamics in hyperglycaemic ICU patients.

Vasopressin administration facilitates fluid removal during hemodialysis

Inadequate secretion of vasopressin during fluid removal by hemodialysis may contribute to the cardiovascular instability that complicates this therapy and administration of exogenous hormone, by supporting arterial pressure, may facilitate volume removal. To test this, we measured plasma vasopressin in patients with end-stage renal disease (ESRD) during hemodialysis and found that despite significant fluid removal, plasma vasopressin concentration did not increase. We further found that ESRD did not alter the endogenous removal rate of plasma vasopressin and that plasma hormone is not dialyzed. Finally, in a randomized, double-blinded, placebo-controlled trial in 22 hypertensive patients, we examined the effect of a constant infusion of a non-pressor dose of vasopressin on the arterial pressure response during a hemodialysis in which the target fluid loss was increased by 0.5 kg over the baseline prescription. We found that arterial pressure was more stable in the patients receiving vasopressin and that while only one patient (9%) in the vasopressin group had a symptomatic hypotensive episode, 64% of the patients receiving placebo had such an episode (P=0.024). Moreover, increased fluid removal was achieved only in the vasopressin group (520+/-90 ml vs 64+/-130 ml, P=0.01). Thus, administration of non-pressor doses of vasopressin to hypertensive subjects improves cardiovascular stability during hemodialysis and allows increased removal of excess extracellular fluid. Inadequate vasopressin secretion during hemodialysis-induced fluid removal is a likely contributor to the intradialytic hypotension that limits fluid removal.

Methylation patterns ofIGFBP7 in colon cancer cell lines are associated with levels of gene expression

Altered expression of insulin-like growth factor binding protein 7 (IGFBP7) has been found in colon cancer, but the exact regulatory mechanism has not been fully investigated. In order to elucidate the mechanisms underlying aberrant IGFBP7 expression in colon cancer, we used bisulphite sequencing PCR (BSP) to detect the detailed methylation profiles of the IGFBP7 5' CpG island. Exon 1 of the IGFBP7 gene was highly methylated in IGFBP7-negative cell lines but unmethylated in IGFBP7-positive lines. The methylation status of the promoter region and the intron 1 region was not so discriminating in IGFBP7-positive and -negative cell lines. Methylation-specific PCR (MSP) confirmed the hypermethylation of IGFBP7 exon 1 in IGFBP7-negative cell lines. Treatment with 5-aza-2'-deoxycytidine (5-aza-dC) induced demethylation of the CpG island in exon 1 of IGFBP7, as examined by both MSP and bisulphate genomic sequencing. Furthermore, the expression of IGFBP7 was restored, as detected by both RT-PCR and immunocytochemistry. Our study is the first to provide detailed methylation profiles of the IGFBP7 5' CpG island and shows that hypermethylation of the CpG island in exon 1 of IGFBP7 is closely related to the absence of its expression in colon cancer cells.

Subinsular vascular lesions: an analysis of 119 consecutive autopsied brains

The insula of Reil constitutes a functionally intriguing complex of the brain related to multifunctional activities. We examined the subinsular region in 119 consecutively autopsied patients, as T2 hyperintense lesions are frequently observed in magnetic resonance diagnosis of this region. The patients were admitted in neurology wards and were diagnosed as having cerebrovascular disease in 55 patients (46%), other neurological diseases in 57 patients (48%) and non-neurological diseases in seven patients (6%). Demyelination of the white matter was semi-quantified as a fiber density score (percent stained area/total area) with computer-assisted image analysis on Klüver-Barrera-stained sections. Astrogliosis was assessed by immunohistochemistry for glial fibrillary acidic protein. The lesion analysis showed a dilated perivascular space in 29 patients (24%), demyelination (fiber density score less than the mean - 1 SD) in 27 patients (23%), slit-shaped lesion in six patients (5%), lacunar infarction in one patient (1%) and cerebral hemorrhage in one patient (1%). A histologic-radiologic comparison in two patients with subcortical ischemic vascular dementia showed correspondence between subinsular hyperintensities, and demyelination, gliosis and a dilated perivascular space. These results indicate that subinsular lesions rarely signifies focal vascular lesions, and are consisted of demyelination, gliosis and a dilated perivascular space.

Anomalous intracranial venous drainage associated with basal ganglia calcification

We describe the neuroradiologic findings in a 7-year-old boy with anomalous intracranial venous drainage and cerebral calcification. CT scans demonstrated that his scalp mass was a plexus of scalp veins filled through the emissary foramen, and there were cerebral calcifications. Angiography revealed bilateral sigmoid sinus atresia with most of the intracranial venous drainage via the prominent mastoid emissary veins into dilated scalp vein. The possible relationship between cerebral calcification and anomalous intracranial venous drainage is discussed.

Interleukin-10 gene promoter polymorphisms and their protein production in peritoneal fluid in patients with endometriosis

Although associations of interleukin-10 (IL-10) gene promoter polymorphisms and their protein production with endometriosis risk have been reported, the correlations remain controversial. The objective of this study was to determine IL-10 gene promoter polymorphisms at -1082, -819 and -592 sites and their protein production in peritoneal fluid (PF) in patients with and without endometriosis. IL-10 gene promoter polymorphisms at -1082 site were detected by amplification refractory mutation system (ARMS)-PCR and that at -819 and -592 sites was genotyped by restriction fragment length polymorphism (RFLP)-PCR. Protein levels of IL-10 in PF were measured by enzyme-linked immunosorbent assay (ELISA). There were no significant differences in the genotype and allele frequencies of IL-10 gene promoter polymorphisms at position -1082 between the endometriosis and the control groups. However, the frequency of -819 or -592 C alleles was significantly increased in patients with endometriosis compared with controls. The protein levels of IL-10 in PF were statistically higher in the endometriosis group than in the control group. Moreover, the polymorphisms at -1082, -819 and -592 sites were associated with protein levels of IL-10 in PF in the endometriosis group while in the control group only the polymorphisms at position -1082 correlated with protein levels. Increased frequency of -819 or -592 C allele and increased protein production of IL-10 in PF in patients with endometriosis compared with controls and correlations of polymorphisms at -819 and -592 sites with protein levels of IL-10 in PF in patients with endometriosis may suggest that polymorphisms at -819 and -592 sites and their protein production are associated with endometriosis risk.

African Americans and participation in clinical trials: differences in beliefs and attitudes by gender

OBJECTIVES

To explore gender differences in perceptions of 1) barriers and motivators to participation in clinical trials and perceived need of clinical trials and 2) perceptions of risks and benefits of participation in clinical trials in African American men and women.

METHODS

Focus groups were conducted among African American participants by gender. A total of 67 African American participated in the focus groups. All focus groups were audio-taped and transcribed verbatim. Data analysis was performed by combining the key elements of grounded theory and content analysis with the assistance of the qualitative software ATLAS.ti 5.0.

RESULTS

Different themes emerged for men versus women. The business and economic of research were important to male participants. The researcher-participant relationship emerged as one of the strongest themes related to potential female participation in research.

DISCUSSION

Focus group results indicate that African American men and women present different preferences, beliefs and barriers to participation. Men expressed the desire to know information on funding issues, financial benefit and impact of the research. Women expressed the desire to be treated respectfully and as an individual as opposed to just a study subject. Integrating gender preferences into researcher-participant interactions, advertisement, informed consent delivery and advertisement of research studies may lead to increased participation rates. Discussing and presenting relevant information on clinical research funding mechanisms, and the business of clinical research with potential participants may be helpful in building trust with the researcher and the research team. Creating a process for information exchange and methods to minimize the power imbalance between the researcher and participant may also build trust and help participants feel more comfortable to participate in research.

E-cadherin promoter polymorphism (C-160A) and risk of recurrence in patients with superficial bladder cancer

Tumor recurrence is a hallmark of superficial bladder cancer. Currently, a molecular marker for bladder cancer recurrence is lacking. E-cadherin plays an important role in epithelial development and in the establishment and maintenance of cell-cell adhesion and tissue architecture. The purpose of this study is to investigate the association of an E-cadherin promoter polymorphism (CDH1c-160a) with the risk of bladder cancer recurrence. This study included 302 patients with superficial bladder cancer. Genomic DNA was extracted from peripheral blood lymphocytes and genotyping was performed using Taqman assay. Clinical data were collected by medical chart review. Cox proportional hazard model was used to estimate the hazard ratios (HRs) associated with genotypes while adjusting for age, gender, smoking status, tumor stage and grade where appropriate. During a median follow-up of 27.65 months, 151 patients experienced disease recurrence. Subsequent analyses were restricted to Caucasians only due to the small sample size of other ethnic groups (13 in recurrence group and 15 in non-recurrence group). Among the 274 Caucasian patients, 138 developed recurrence during the same length of follow-up time. In Caucasian patients, having at least one variant A allele conferred a 32% reduction in recurrence risk (adjusted HR: 0.68; 95% CI: 0.48-0.96). The median recurrence-free survival for patients carrying at least one variant A allele was significantly longer than that for patients with a homozygous CC genotype (40.4 vs 12.5 months, p=0.04). Our findings suggest that the E-cadherin promoter polymorphism may be a valuable molecular marker for bladder cancer recurrence.

Hip and non-spine fracture risk reductions differ among antiresorptive agents: Evidence from randomised controlled trials

A number of antiresorptive agents reduce the risk of vertebral fractures, but few have shown consistent effects on hip and other non-spine fractures. Meta-analysis provides a more precise estimate than individual trials when results are consistent across pooled trials. Earlier meta-analyses summarised the results for vertebral and non-spine fractures. New data have emerged for hormone therapy (HT), alendronate (ALN), risedronate (RIS) and ibandronate (IBN). We surveyed recent reports of randomised, placebo-controlled trials with non-spine and/or hip fracture data, and used meta-analysis where appropriate to test for heterogeneity and derive pooled estimates. The magnitude of effect on hip fracture appears to be similar to that for non-spine fracture for each drug, but differs among drugs. Based on the current data, ALN reduces the risk of hip and non-spine fracture by 49-55%, HT by 25-36% and RIS by 26-27%. There is insufficient and/or inconsistent evidence of an effect on these fractures for IBN, calcitonin and raloxifene.

Relationships among genotypes, virulence and clinical forms of Sporothrix schenckii infection

This study explored the relationships among genotypes, virulence and clinical forms of Sporothrix schenckii. Genomic DNA from isolates of S. schenckii, collected from different clinical forms of sporotrichosis, was amplified by randomly amplified polymorphic DNA (RAPD). Suspensions of different isolates of S. schenckii were inoculated into healthy BALB/c mice to compare their virulence, and the numbers and distribution of spores were determined by histological analysis. RAPD analysis indicated that the isolates from different clinical forms of sporotrichosis belonged to different genotypes. The mice inoculated with isolates from disseminated sporotrichosis showed an earlier onset of illness and more severe lesions than those inoculated with isolates from lymphocutaneous sporotrichosis, which, in turn, showed an earlier onset of illness and more severe lesions than those inoculated with isolates from fixed cutaneous sporotrichosis. Healthy BALB/c mice injected with isolates from disseminated sporotrichosis died within 10 days, whereas isolates from lymphocutaneous sporotrichosis and fixed cutaneous sporotrichosis failed to cause death. Histologically, mice inoculated with isolates from disseminated sporotrichosis had more spores than those inoculated with isolates from lymphocutaneous sporotrichosis and fixed cutaneous sporotrichosis. Thus, different genotypes may be associated closely with the virulence of different clinical forms of S. schenckii infection.