Decaffeinated green and black tea polyphenols decrease weight gain and alter microbiome populations and function in diet-induced obese mice.

PURPOSE: Decaffeinated green tea (GT) and black tea (BT) polyphenols inhibit weight gain in mice fed an obesogenic diet. Since the intestinal microflora is an important contributor to obesity, it was the objective of this study to determine whether the intestinal microflora plays a role in the anti-obesogenic effect of GT and BT. METHODS: C57BL/6J mice were fed a high-fat/high-sucrose diet (HF/HS, 32% energy from fat; 25% energy from sucrose) or the same diet supplemented with 0.25% GTP or BTP or a low-fat/high-sucrose (LF/HS, 10.6% energy from fat, 25% energy from sucrose) diet for 4 weeks. Bacterial composition was assessed by MiSeq sequencing of the 16S rRNA gene. RESULTS: GTP and BTP diets resulted in a decrease of cecum Firmicutes and increase in Bacteroidetes. The relative proportions of Blautia, Bryantella, Collinsella, Lactobacillus, Marvinbryantia, Turicibacter, Barnesiella, and Parabacteroides were significantly correlated with weight loss induced by tea extracts. BTP increased the relative proportion of Pseudobutyrivibrio and intestinal formation of short-chain fatty acids (SCFA) analyzed by gas chromatography. Cecum propionic acid content was significantly correlated with the relative proportion of Pseudobutyrivibrio. GTP and BTP induced a significant increase in hepatic 5'adenosylmonophosphate-activated protein kinase (AMPK) phosphorylation by 70 and 289%, respectively (P < 0.05) determined by Western blot. CONCLUSION: In summary, both BTP and GTP induced weight loss in association with alteration of the microbiota and increased hepatic AMPK phosphorylation. We hypothesize that BTP increased pAMPK through increased intestinal SCFA production, while GTPs increased hepatic AMPK through GTP present in the liver.

Dietary pomegranate extract and inulin affect gut microbiome differentially in mice fed an obesogenic diet.

Growing evidence suggests that dysbiosis of gut microbiota is associated with pathogenesis of a variety of human diseases. Using dietary intervention to shape the composition and metabolism of the gut microbiota is increasingly recognized. In the present study, we investigated the effects of polysaccharide inulin and polyphenol-rich pomegranate extract (PomX) alone or in combination on the cecal microbiota composition and function in a diet induced obesity mouse model. Male C57BL/6 mice were randomly divided into four experimental groups and consumed either high-fat/high-sucrose [HF/HS (32% energy from fat, 25% energy from sucrose, 17% energy from protein)] diet, HF/HS diet supplemented with PomX (0.25%), or inulin (9%) or PomX and inulin in combination for 4 weeks. In mice fed the PomX-diet the proportion of Turicibacteraceae and Ruminococcaceae was significantly increased compared to the control HF/HS diet. Supplementation with inulin alone and inulin + PomX combination significantly increased the proportion of Verrucomicrobiaceae (A. muciniphila) and decreased Clostridiaceae. Only mice fed the inulin diet experienced an increase in serum lipopolysaccharide (LPS) and monocyte chemoattractant protein 1 (MCP-1), which was reversed when feeding the inulin + PomX diet. Feeding the inulin + PomX diet was associated with a significant increase in Bifidobacteriaceae and Rikenellaceae, which may have contributed to the reduction of endotoxemia markers. Inulin supplementation showed lower species richness of gut microbiota compared to mice fed with HF/HS or HF/HS/PomX, and the reduction was reversed by the addition of PomX. Inulin alone and in combination with PomX had distinct microbial clusters determined by both weighted and unweighted UniFrac Beta-Diversity principle coordinate analysis. A total of 19 KEGG biological pathways were significantly regulated in the gut microbiota with PomX and inulin alone or combined treatment. Inulin significantly enhanced KEGG infectious disease-related pathway associated with increase of serum LPS and MCP-1. No changes in gene expression of ileal proinflammatory cytokine and tight junction genes were observed in mice treated with PomX and inulin. Our results demonstrated that the gut microbiota and their biological pathways were differentially effected by dietary PomX and inulin fed combined or alone. It is therefore very important to consider the interaction among bioactive components of food when evaluating potential prebiotic effects.

Optical detection of harmonic oscillations in fluorescent dye-loaded microbubbles ensonified by ultrasound.

A new optical contrast agent has been developed by exposing dye-loaded microbubbles to a rapidly-cooled thermal treatment to homogenize the dye distribution across the surface. Ultrasound causes these microbubbles to oscillate in size which changes the self-quenching efficiency of the dye molecules creating a "blinking" signal. We demonstrate for the first time that these microbubbles can reproducibly generate second, third, and even fourth harmonic fluorescence intensity modulations, in addition to the fundamental frequency of the driving ultrasound. Detecting these harmonic signals could produce a higher signal-to-noise ratio for fluorescence imaging in medical applications by allowing fundamental frequency interference and artifacts to be filtered out.

Manipulating nanoscale features on the surface of dye-loaded microbubbles to increase their ultrasound-modulated fluorescence output.

The nanoscale surface features of lipid-coated microbubbles can dramatically affect how the lipids interact with one another as the microbubble diameter expands and contracts under the influence of ultrasound. During microbubble manufacturing, the different lipid shell species naturally partition forming concentrated lipid islands. In this study the dynamics of how these nanoscale islands accommodate the expansion of the microbubbles are monitored by measuring the fluorescence intensity changes that occur as self-quenching lipophilic dye molecules embedded in the lipid layer change their distance from one another. It was found that when the dye molecules were concentrated in islands, less than 5% of the microbubbles displayed measurable fluorescence intensity modulation indicating the islands were not able to expand sufficiently for the dye molecules to separate from one another. When the microbubbles were heated and cooled rapidly through the lipid transition temperature the islands were melted creating an even distribution of dye about the surface. This resulted in over 50% of the microbubbles displaying the fluorescence-modulated signal indicating that the dye molecules could now separate sufficiently to change their self-quenching efficiency. The separation of the surface lipids in these different formations has significant implications for microbubble development as ultrasound and optical contrast agents.

Intraoperative optical imaging and tissue interrogation during urologic surgery.

PURPOSE OF REVIEW: To review optical imaging technologies in urologic surgery aimed to facilitate intraoperative imaging and tissue interrogation. RECENT FINDINGS: Emerging new optical imaging technologies can be integrated in the operating room environment during minimally invasive and open surgery. These technologies include macroscopic fluorescence imaging that provides contrast enhancement between normal and diseased tissue and microscopic imaging that provides tissue characterization. SUMMARY: Optical imaging technologies that have reached the clinical arena in urologic surgery were reviewed, including photodynamic diagnosis, near infrared fluorescence imaging, optical coherence tomography, and confocal laser endomicroscopy.

Rapid detection of dermatophytes and Candida albicans in onychomycosis specimens by an oligonucleotide array.

BACKGROUND: Onychomycosis is a fungal infection of nails, leading to the gradual destruction of the nail plate. Treatment of onychomycosis may need long-time oral antifungal therapy that can have potential side effects, thus accurate diagnosis of the disease before treatment is important. Culture for diagnosis of onychomycosis is time-consuming and has high false-negative rates. To expedite the diagnosis, an oligonucleotide array, based on hybridization between immobilized oligonucleotide probes and PCR products, for direct detection of dermatophytes and Candida albicans in clinical specimens was evaluated. METHODS: Species-specific oligonucleotide probes designed from the internal transcribed spacer (ITS) regions of the rRNA gene were immobilized on a nylon membrane. The assay procedures consisted of PCR amplification of the ITS using universal primers, followed by hybridization of the digoxigenin-labeled amplicons to probes on the array. Thirty two nail samples (29 patients) were analyzed by the array, and the results were compared with those obtained by culture. Array-positive but culture-negative samples were confirmed by cloning and re-sequencing of the amplified ITS and by reviewing patient's clinical data. The total recovery of culture and confirmed array-positive but culture-negative results was considered 100% and was used for performance evaluation of both methods. RESULTS: Concordant results were obtained in 21 samples (10 positives and 11 negatives) by both methods. Eleven samples were array-positive but culture-negative; among them, 9 samples were considered true positives after discrepant analysis. Comparing with culture, the array had significantly higher sensitivity [100% (95% CI 82.2% -100%) vs 52.6% (28.9% -75.5%), p <0.001] and negative predictive value [100% (71.3% -100%) vs 59.1% (36.4% -79.3%), p <0.05), while no significant differences were observed in specificity (84.6% vs 100%, p =0.48) and positive predictive value (90.5% vs 100%, p =1.0). The whole procedures of the array were about 24 h, whilst results from culture take 1 to 3 weeks. CONCLUSIONS: The array offers an accurate and rapid alternative to culture. Rapid diagnosis can expedite appropriate antifungal treatment of onychomycosis. However, the single site nature of this study conducted at a referral hospital invites caution.

Hiatal hernia mimicking ST elevation myocardial infarction.

A 72-year-old man with a history of hypertension, hiatal hernia, prostate cancer and lung cancer was admitted with complaints of abdominal pain, sweating and rigors. An electrocardiogram showed ST elevation in multiple leads. Noninvasive and invasive cardiovascular work-up was performed that was negative for occlusive coronary artery disease. Further studies demonstrated a large hiatal hernia; this was found to be the culprit causing his symptoms. Hiatal hernia is a very rare cause of ST segment elevation and should be considered in the differential diagnosis of disorders that can cause ST elevation.

Phospholipid/Carbocyanine Dye-Shelled Microbubbles as Ultrasound-Modulated Fluorescent Contrast Agents.

Fluorescent microbubbles have been fabricated with the capacity to have their emission modulated by ultrasound. These contrast agent particles could potentially be used in the future to extract fluorescence modulation from a strong light background to increase imaging depth and resolution in scattering media. Fluorescence intensity modulation was demonstrated at the ultrasound driving frequency.

The evolution of clinicopathologic features in eruptive lichen planus: a case report and review of literature.

"Eruptive" or "exanthematous" lichen planus (LP) is a rare variant of lichen planus. Here we report a middle-aged woman with a 6-month history of episodic eruptive LP presenting as generalized, erythematous, flat-topped, round, polygonal, or umbilicated papules and hyperpigmented macules. The disease was under good control with continuous low-dose prednisolone over one year. We had the opportunity to correlate the clinical and pathologic findings based on histopathologic examination of three separate skin lesions that appeared to represent different stages of evolution. Recognition of these 3 chronological manifestations (polygonal papule in active inflammation, centrally umbilicated papule in involution, and hyperpigmented macule in resolution) can aid the diagnosis.

Acute Late-Onset Cirrhosis in Zellweger Spectrum Disorder.

Zellweger spectrum disorders (ZSDs) are known to present with variable hepatic manifestations ranging from benign hepatosplenomegaly and elevated liver enzymes to advanced liver cirrhosis with hepatocellular carcinoma. However, the progression of liver disease in ZSD patients over time is poorly characterized due to scarcity of the disease. Herein, we report a case of newly diagnosed liver cirrhosis in a ZSD patient with rapid progression and fatal outcome to demonstrate key clinical learning points.

Safety and Efficacy of Fecal Microbiota Transplantation in Treatment of Inflammatory Bowel Disease in the Pediatric Population: A Systematic Review and Meta-Analysis.

Background and Aims: Fecal microbiota transplantation (FMT) has been increasingly studied in the inflammatory bowel disease (IBD) population. However, most studies have focused on the adult population, and the safety and efficacy of FMT in a pediatric population is less well understood. This systematic review and meta-analysis investigates the safety and efficacy of FMT in a pediatric IBD population. Methods: A comprehensive literature search of publications published prior to 30 June 2022 was undertaken. Safety data, IBD-related outcomes, and microbiome analysis were obtained from these studies when accessible. Individual estimates of each study were pooled, and sensitivity analysis was conducted. Results: Eleven studies satisfied our eligibility criteria. The calculated pooled rate of adverse events was 29% (95% confidence interval [CI]: 15.0%, 44.0%; p < 0.001; I2 = 89.0%, Q = 94.53), and the calculated pooled rate of serious adverse events was 10% (95% confidence interval [CI]: 6.0%, 14.0%; p = 0.28; I2 = 18.0%, Q = 9.79). One month after FMT, clinical response was achieved in 20/34 (58.8%) pediatric IBD patients, clinical remission was achieved in 22/34 (64.7%), and both clinical response and remission were achieved in 15/34 (44.1%) pediatric IBD patients. Conclusions: FMT can be a safe and effective treatment in the pediatric IBD population and may demonstrate improved safety and efficacy in the pediatric population compared to the adult population. However, our results are limited by a lack of established protocol as well as long-term follow-up for FMT in a pediatric IBD population.

Efficacy of Fecal Microbiota Transplant on Behavioral and Gastrointestinal Symptoms in Pediatric Autism: A Systematic Review.

Background and Aims: There is a high prevalence of gastrointestinal-related (GI) symptoms among children with autism spectrum disorder (ASD), which is associated with the severity of behavioral symptoms. Fecal microbiota transplantation (FMT) is a proposed therapeutic strategy that aims to address the dysregulation of the gut microbiome among children with ASD. Our study performed the first systematic review aimed to evaluate the benefits of FMT on the behavioral and gastrointestinal symptoms of pediatric patients with autism. Methods: A literature search was performed using variations of the keywords "pediatrics" and "fecal microbiota transplantation" in PubMed, EMBASE, CINAHL, Cochrane, and Web of Science from inception to 30 June 2022. Four studies that met the eligibility criteria were included in the systematic review. The efficacy of FMT on behavioral symptoms was measured by the difference in Aberrant Behavior Checklist (ABC) and Child Autism Rating Scale (CARS) scores before and after FMT. Results: We found a statistically significant improvement (p < 0.05) in ABC and CARS scores following FMT, with a statistically significant decrease in scores observed across all studies. In addition, substantial improvements in gastrointestinal symptoms were observed across all studies. Conclusion: Our findings suggest that FMT may offer a promising intervention for treating both behavioral and gastrointestinal symptoms in pediatric patients with autism.

Efficacy and Safety of Fecal Microbiota Transplantation in Treatment of Clostridioides difficile Infection among Pediatric Patients: A Systematic Review and Meta-Analysis.

Background and Aims: Cases of Clostridioides difficile infection have been rising among the pediatric and adolescent population. Fecal microbiota transplantation (FMT) has emerged as an alternative therapy for recurrent C. difficile infection. We aim to perform the first systematic review and meta-analysis investigating the safety and efficacy of fecal microbiota transplantation for C. difficile infection in children and adolescents. Methods: A literature search was performed using variations of the keywords "pediatrics", "C. difficile infection", and "fecal microbiota transplantation" in PubMed, EMBASE, CINAHL, Cochrane, and Google Scholar from inception to 30 June 2022. The resulting 575 articles were independently screened by three authors. Fourteen studies that satisfied the eligibility criteria were included in the meta-analysis. Results: The pooled success rate of FMT in the overall cohort was 86% (95% confidence interval: 77−95%; p < 0.001; I2 = 70%). There were 38 serious adverse events in 36 patients with a pooled rate of 2.0% (95% confidence interval: 0.0−3.0%; p = 0.1; I2 = 0.0%) and 47 adverse events in 45 patients with a pooled rate of 15% (95% confidence interval: 5.0−25.0%; p = 0.02; I2 = 54.0%). There was no death associated with FMT. Conclusions: FMT was concluded to be an effective and safe therapy in pediatric and adolescent patients with C. difficile infection. Underlying comorbidities may impede the efficacy. A rigorous screening process of the donors is recommended prior to embarking on FMT. There is no universal and cost-effective way to monitor the long-term outcomes of FMT. While promising, metagenomic sequencing may not be available in settings with limited resources. Robust data from randomized clinical trials is warranted.

Transcriptional profiling and network analysis of the murine angiotensin II-induced abdominal aortic aneurysm.

We sought to characterize temporal gene expression changes in the murine angiotensin II (ANG II)-ApoE-/- model of abdominal aortic aneurysm (AAA). Aortic ultrasound measurements were obtained over the 28-day time-course. Harvested suprarenal aortic segments were evaluated with whole genome expression profiling at 7, 14, and 28 days using the Agilent Whole Mouse Genome microarray platform and Statistical Analysis of Microarrays at a false discovery rate of <1%. A group of angiotensin-treated mice experienced contained rupture (CR) within 7 days and were analyzed separately. Progressive aortic dilatation occurred throughout the treatment period. However, the numerous early expression differences between ANG II-treated and control were not sustained over time. Ontologic analysis revealed widespread upregulation of inflammatory, immune, and matrix remodeling genes with ANG II treatment, among other pathways such as apoptosis, cell cycling, angiogenesis, and p53 signaling. CR aneurysms displayed significant decreases in TGF-ß/BMP-pathway signaling, MAPK signaling, and ErbB signaling genes vs. non-CR/ANG II-treated samples. We also performed literature-based network analysis, extracting numerous highly interconnected genes associated with aneurysm development such as Spp1, Myd88, Adam17 and Lox. 1) ANG II treatment induces extensive early differential expression changes involving abundant signaling pathways in the suprarenal abdominal aorta, particularly wide-ranging increases in inflammatory genes with aneurysm development. 2) These gene expression changes appear to dissipate with time despite continued growth, suggesting that early changes in gene expression influence disease progression in this AAA model, and that the aortic tissue adapts to prolonged ANG II infusion. 3) Network analysis identified nexus genes that may constitute aneurysm biomarkers or therapeutic targets.

Facile One-Pot Synthesis of Polymer-Phospholipid Composite Microbubbles with Enhanced Drug Loading Capacity for Ultrasound-Triggered Therapy.

This paper reports the one-pot synthesis of perfluorocarbon microbubbles with crosslinked shells of poly(acrylic acid) and phospholipid that boast excellent ultrasound contrast enhancement, enhanced loading capacity, and the ability to retain or release their contents through variation in the level of ultrasound exposure.

Length of site-specific positive surgical margins as a risk factor for biochemical recurrence following radical prostatectomy.

OBJECTIVES: Positive surgical margins (PSM) have been associated with biochemical recurrence (BCR) after radical prostatectomy, but the significance of PSM length and location are debated. We assessed the impact of PSM lengths at specific locations for BCR in an open radical prostatectomy series. METHODS: Detailed clinical and pathological data were collected from 117 post-prostatectomy patients with PSM from 1984 to 2004 at our institution. PSM locations were classified as apex, mid-gland, base, bladder neck, and anterior fibromuscular region with lengths measured at each site. Aggregate PSM length was obtained by summing lengths of all PSM areas in contact with the inked surface. BCR was defined as serum prostate specific antigen level 0.2 ng/mL or greater. Cox proportional hazards regression analyses of PSM lengths were conducted either as a continuous or categorical variable relative to location as a predictor of BCR. RESULTS: Multivariate analyses demonstrated that as a continuous variable, PSM length at the anterior fibromuscular region (Hazard ratio [HR] = 1.17; P = 0.027) and bladder neck (HR = 1.29; P = 0.046) were significant predictors for BCR. As a categorical variable, PSM length ≥ 2 mm at the anterior fibromuscular area was significant for BCR (HR = 3.02; P = 0.036). Increasing Gleason grade and positive lymph node status were also found to be significant independent predictors for BCR. CONCLUSION: PSM length at the anterior fibromuscular region (continuous and categorical) and the bladder neck (continuous) was significantly associated with BCR. Site-specific PSM length, along with Gleason grade and lymph node status, can be predictive of BCR and assist in risk stratification of patients with PSM following radical prostatectomy.

Pomegranate Metabolites Impact Tryptophan Metabolism in Humans and Mice.

BACKGROUND: We showed that pomegranate juice (PomJ) can help to maintain memory in adults aged >50 y. The mechanism for this effect is unknown, but might involve Trp and its metabolites, which are important in brain function. OBJECTIVES: We aimed to test the hypothesis that PomJ and its metabolites ellagic acid (EA) and urolithin A (UA) affect Trp metabolism. METHODS: Stool and plasma from a cohort [11 PomJ, 9 placebo drink (PL)] of subjects enrolled in our double-blind, placebo-controlled trial (NCT02093130) were collected at baseline and after 1 y of PomJ or PL consumption. In a mouse study, cecum and serum were collected from DBA/2J mice receiving 8 wk of dietary 0.1% EA or UA supplementation. Trp metabolites and intestinal microbiota were analyzed by LC-MS and 16S rRNA gene sequencing, respectively. RESULTS: In the human study, the change in the plasma Trp metabolite indole propionate (IPA) over 1 y was significantly different between PomJ and PL groups (P = 0.03). In serum of experimental mice, we observed a 230% increase of IPA by EA but not UA, a 54% increase of indole sulfate by UA but not EA, and 43% and 34% decreases of kynurenine (KYN) by EA and UA, respectively. In cecum, there was a 32% decrease of Trp by UA but not EA, and an 86% decrease of KYN by EA but not UA (P < 0.05). The abundance of 2 genera, Shigella and Catenibacterium, was reduced by PomJ in humans as well as by UA in mice, and their abundance was negatively associated with blood IPA in humans and mice (P < 0.05). CONCLUSIONS: These results suggest a novel mechanism involving the regulation of host and microbial Trp metabolism that might contribute to the health benefits of ellagitannins and EA-enriched food, such as PomJ.

Prospective randomized trial evaluating blood and prostate tissue concentrations of green tea polyphenols and quercetin in men with prostate cancer.

We evaluated if chronic consumption of quercetin (Q) with green tea extract (GTE) enhances the bioavailability of GT polyphenols (GTPs) and reduces methylation activity as previously observed in mouse xenograft tumors. In this prospective, randomized, parallel design, placebo controlled study, thirty-one men with prostate cancer consumed daily 1 gram of GTE (830 mg of GTP) with 800 mg of Q (GT + Q) or placebo (GT + PL) for four weeks before prostatectomy. First morning voided urine was collected at baseline, 3 weeks and the day of surgery, and prostate tissue on the day of surgery. In week 3, plasma concentration of GTPs and Q was measured in blood collected before and 2 hours after the morning dose. Prostate tissue epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) were detected in 67 and 93% of participants in the GT + Q group and 75 and 94% of participants in the GT + PL group. Q was increased 14-fold, 12-fold and 4.5-fold in plasma, urine, and prostate tissue, respectively, in the GT + Q compared to the GT + PL-group. There was a trend for decreased EGC levels in urine collected prior to prostatectomy in the GT + Q compared to GT + PL-group (p = 0.053). Plasma epigallocatechin (EGC) showed a trend to increase (p = 0.066) two hours after capsule intake in the GT + Q vs. the GT + PL-group. There was no significant difference between the groups in GTP content or methylation activity in prostate tissue or RBCs. No liver toxicity was observed. Although our findings are suggestive, further studies are warranted evaluating if Q alters GTP metabolism.

Demodicosis: a clinicopathological study.

BACKGROUND: Demodex mites are common commensal organisms of the pilosebaceous unit in human beings and have been implicated in pityriasis folliculorum, rosacea-like demodicosis, and demodicosis gravis. OBJECTIVE: We sought to describe the spectrum of clinicopathological findings and therapeutic responses of demodicosis in Taiwanese patients. METHODS: We conducted a retrospective study to review clinicopathologic findings and therapeutic responses of 34 cases of diagnosed demodicosis. RESULTS: Fifteen cases with positive results of potassium hydroxide examination, standardized skin surface biopsy specimen, and/or skin biopsy specimen, and resolution of skin lesions after anti-Demodex treatment were included for final analysis. Nineteen cases were excluded because of insufficient positive data to make a definite diagnosis. There were 4 male and 11 female patients (age 1-64 years, mean age 38.7 years). The disease was recurrent or chronic with a duration ranging from 2 months to 5 years (mean 15.7 months). The skin lesions were acne rosacea-like (n = 8), perioral dermatitis-like (n = 5), granulomatous rosacea-like (n = 1), and pityriasis folliculorum (n = 1). Skin biopsy was performed in 7 patients. Overall, the histopathology was characterized by: (1) dense perivascular and perifollicular lymphohistiocytic infiltrates, often with abundant neutrophils and occasionally with multinucleated histiocytes; (2) excessive Demodex mites in follicular infundibula; and (3) infundibular pustules containing mites or mites in perifollicular inflammatory infiltrate. The skin lesions resolved after treatment including systemic metronidazole, topical metronidazole, crotamiton, or gamma benzene hexachloride. LIMITATIONS: Small sample size and a fraction of patients without long-term follow-up are limitations. CONCLUSION: Demodicosis should be considered in the differential diagnosis of recurrent or recalcitrant rosacea-like, granulomatous rosacea-like, and perioral dermatitis-like eruptions of the face. Potassium hydroxide examination, standardized skin surface biopsy, skin biopsy, or a combination of these are essential to establish the diagnosis.

High-frequency intragenomic heterogeneity of the ribosomal DNA intergenic spacer region in Trichophyton violaceum.

The intergenic spacer (IGS) of the rRNA genes was analyzed from the dermatophyte Trichophyton violaceum isolated from cases of tinea capitis in Taiwan and Iran. T. violaceum strains were cultured from different colonies, from single conidial colonies derived by dilution plating, and from micromanipulation of single conidia from clinical samples. A ribosomal DNA probe hybridizing to multiple EcoRI fragments was used to compare restriction fragment length polymorphisms in different T. violaceum isolates. The arthroconidia of T. violaceum that form in vivo during infection were shown to contain a single nucleus by 4',6'-diamidino-2-phenylindole staining. IGS regions from an isolate cultured from a single conidium were amplified, cloned, and sequenced. The results identified that heterogeneity exists between IGS regions within a single T. violaceum genome due to different copy numbers of a 171-bp tandem repeat. This suggests that the IGS of T. violaceum is partially excluded from the concerted evolution of the rRNA gene locus. The heterogeneous character of the IGS regions in T. violaceum contrasts with the closely related dermatophyte Trichophyton rubrum, posing further questions on the phylogeny and the evolution of dermatophyte fungi.