Colorectal follicular lymphoma: A case report.

RATIONALE: Considering the low incidence of colorectal follicular lymphoma (FL) and its clinical features in endoscopic views, only a few studies have described the pathological diagnosis and treatment of this disease. This study aimed to reveal the overall process of clinical diagnosis and treatment of colorectal FL by conducting a case review. PATIENT CONCERNS: A 27-year-old female presented to our department because of "severe bloody stool" lasting for more than 1 month. Her primary symptom was melena. Colonoscopy revealed widespread flat polyps with various immunophenotypes (CD10+, BCL2+, BCL6+, cyclin D1-, CD5-) in the colorectal area. DIAGNOSIS: In accordance with manifestations on positron emission tomography-computed tomography (PET/CT), the patient was diagnosed with stage IV colorectal FL. INTERVENTIONS: PET/CT reexamination after 2 courses of rituximab, cyclophosphamide, liposomal doxorubicin, vincristine sulfate, and hydroprednisone (R-CHOP) regimen and 3 courses of R-CHOP plus etoposide regimen for chemotherapy indicated a significant reduction in tumor burden. Subsequently, rituximab was administered alone in 2 treatment courses. OUTCOMES: Lesions on PET/CT disappeared after reexamination. No recurrence was observed within the 12-month follow-up period. LESSONS: Colorectal FL is a rare disease with an inert clinical course and is common in the ileocecal area. Endoscopic views show multiple polyps. Interventional treatment is usually provided after observation of clinical symptoms or during disease progression. The disease has a relatively good prognosis.

Right atrial pressure alterations during echocardiography-guided-catheterization predict tricuspid valvular impairment: a novel method for the creation of a rabbit model of Staphylococcus aureus endocarditis.

BACKGROUND: We previously reported the use of a catheter system to damage the tricuspid valve and create infectious endocarditis (IE) in an animal model. The current study aims to create a faint IE model suitable for antibiotic prophylaxis using a low bacterial inoculum. We also aim to explore a way to quantitatively assess valvular impairment and to predict the success of the IE models during catheterization. METHODS: Ninety rabbits were assigned to two groups according to the density of bacteria inoculated (1 × 10(5) CFU for Group A and 1 × 10(4) CFU for Group B). A catheter system consisting of a polyethylene catheter and a guide wire were used to damage the valve. The catheter system was passed through the rabbits' tricuspid valves under echocardiographic guidance. A pressure transducer was used to assess right atrial pressure (P(RA)) before and just after valvular damage to calculate the pressure alterations (ΔP(RA)). The animals in group A and B were divided into 3 subgroups according to the ΔP(RA) (0-5 mmHg for Groups A1 and B1; 5-10 mmHg for Groups A2 and B2; 10-15 mmHg for Groups A3 and B3). Staphylococcus aureus (ATCC 29213) inoculation was performed 24 hr after cardiac catheterization. RESULTS: Faint IE was confirmed in 20%, 93.3%, 26.7%, 6.7%, 20%, and 33.3% of the rabbits in Groups A1, A2, A3, B1, B2, and B3, respectively. There was no difference in the LV/RV ratio and VTR of the No-IE, faint-IE, and severe IE animals. Faint IE rabbits had a larger ΔPRA than No-IE rabbits (7.81 ± 1.21 vs. 2.48 ± 1.0, P < 0.01, for Group A; 7.60 ± 1.32 vs. 2.98 ± 1.08, P < 0.01, for Group B). The ΔPRA of severe IE and faint IE rabbits was significantly different (13.11 ± 1.31 vs. 7.81 ± 1.21, P < 0.01, for Group A; 12.73 ± 1.44 vs.7.60 ± 1.32, P < 0.01, for Group B). CONCLUSION: ΔP(RA) could be used to assess valvular impairment. Controlling the value of ΔP(RA) during catheterization and inoculating of an appropriate dose of bacteria was associated with a successful IE model.

Parasite densities modulate susceptibility of mice to cerebral malaria during co-infection with Schistosoma japonicum and Plasmodium berghei.

BACKGROUND: Malaria and schistosomiasis are endemic and co-exist in the same geographic areas, even co-infecting the same host. Previous studies have reported that concomitant infection with Schistosoma japonicum could offer protection against experimental cerebral malaria (ECM) in mice. This study was performed to evaluate whether alterations in parasite density could alter this protective effect. METHODS: Mice were inoculated with 100 or 200 S. japonicum cercariae followed by infection with high or low density of Plasmodium berghei ANKA strain eight weeks after the first infection. Then, parasitaemia, survival rate and blood-brain-barrier (BBB) damage were assessed. Interferon-gamma (IFN-γ), interleukin (IL)-4, IL-5, IL-13, IL-10, and TGF-ß levels were determined in splenocyte supernatants using enzyme-linked immunosorbent assay (ELISA). Cell surface/intracellular staining and flow cytometry were used to analyse the level of CD4(+)/CD8(+) T cells, CD4(+)CD25(+)Foxp3(+) Tregs, IL-10-secreting Tregs, and IL-10(+)Foxp3-CD4(+) T cells in the spleen, and CD4(+)/CD8(+) T cells infiltrating the brain. RESULTS: Co-infection with low density P. berghei and increased S. japonicum cercariae significantly increased the levels of IL-4, IL-5, IL-13, TGF-ß and Tregs, but significantly decreased the levels of IFN-γ and the percentage of CD4(+) T cells and CD8(+) T cells in the spleen and CD8(+) T cell infiltration in the brain. Increased worm loads also significantly decreased mortality and BBB impairment during ECM. When challenged with higher numbers of P. berghei and increased cercariae, the observed cytokine changes were not statistically significant. The corresponding ECM mortality and BBB impairment also remained unchanged. CONCLUSIONS: This study demonstrates that protection for ECM depends on the numbers of the parasites, S. japonicum and P. berghei, during co-infection. Alterations in the regulatory response appear to play a key role in this adaptation.

Pre-existing Schistosoma japonicum infection alters the immune response to Plasmodium berghei infection in C57BL/6 mice.

BACKGROUND: Since helminths and malaria parasites are often co-endemic, it is important to clarify the immunoregulatory mechanism that occurs during the process of co-infection. A previous study confirmed that dendritic cells (DCs) are involved in the establishment and regulation of the T-cell-mediated immune response to malaria infection. In the current study, distinct response profiles for splenic DCs and regulatory T cell (Treg) responses were assessed to evaluate the effects of a pre-existing Schistosoma japonicum infection on malaria infection. METHODS: Malaria parasitaemia, survival rate, brain histopathology and clinical experimental cerebral malaria (ECM) were assessed in both Plasmodium berghei ANKA-mono-infected and S. japonicum-P. berghei ANKA-co-infected mice. Cell surface/intracellular staining and flow cytometry were used to analyse the level of splenic DC subpopulations, toll-like receptors (TLRs), DC surface molecules, Tregs (CD4⁺CD25⁺Foxp3⁺), IFN-γ/IL-10-secreting Tregs, and IFN-γ⁺/IL-10⁺-Foxp3⁻CD4⁺ T cells. IFN-γ, IL-4, IL-5, IL-10 and IL-13 levels were determined in splenocyte supernatants using enzyme-linked immunosorbent assay (ELISA). RESULTS: The co-infected mice had significantly higher malaria parasitaemia, compared with the mono-infected mice, on days 2, 3, 7 and 8 after P. berghei ANKA infection. Mono-infected mice had a slightly lower survival rate, while clinical ECM symptoms, and brain pathology, were significantly more severe during the period of susceptibility to ECM. On days 5 and 8 post P. berghei ANKA infection, co-infected mice had significantly lower levels of CD11c⁺CD11b⁺, CD11c⁺CD45R/B220⁺, CD11c⁺TLR4⁺, CD11c⁺TLR9⁺, CD11c⁺MHCII⁺, CD11c⁺CD86⁺, IFN-γ-secreting Tregs, and IFN-γ⁺Foxp3⁻CD4⁺ T cells in single-cell suspensions of splenocytes when compared with P. berghei ANKA-mono-infected mice. Co-infected mice also had significantly lower levels of IFN-γ and higher levels of IL-4, IL-5, and IL-13 in splenocyte supernatants compared to mono-infected mice. There were no differences in the levels of IL-10-secreting Tregs or IL-10⁺Foxp3⁻CD4⁺ T cells between co-infected and mono-infected mice. CONCLUSIONS: A Tregs-associated Th2 response plays an important role in protecting against ECM pathology. Pre-existing S. japonicum infection suppressed TLR ligand-induced DC maturation and had an anti-inflammatory effect during malaria infection not only by virtue of its ability to induce Th2 responses, but also by directly suppressing the ability of DC to produce pro-inflammatory mediators.

A rabbit model of right-sided Staphylococcus aureus endocarditis created with echocardiographic guidance.

BACKGROUND: The most widely used experimental models of infective endocarditis (IE) are the rabbit and rat models, in which cardiac valve lesions are induced by a polyethylene catheter introduced into the left ventricle through the aortic valve. Our study was designed to create a rabbit model of IE right-sided with echocardiographic guidance. METHODS: Thirty rabbits underwent both catheterization and inoculation (group A). These were divided into three subgroups of ten based on the time of catheter removal (immediately, after 24 h, and after death or moribundity for groups, A(1), A(2), and A(3), respectively). Ten inoculated-only and ten catheterized-only rabbits served as controls. A catheter system consisted of a polyethylene catheter and a guide wire inside it. This system was passed through the rabbits' tricuspid valves under echocardiographic guidance to damage them. The ratio of left ventricle to right ventricle (LV/RV) was measured in a four-chamber view before catheterization and at the time of death or moribundity. The peak velocity of tricuspid regurgitation (V(TR)) was measured in a four-chamber view at the time of catheterization and at the time of death or moribundity. Staphylococcus aureus (ATCC 29213) inoculation was performed 24 h after right heart catheterization to produce IE. RESULTS: IE was confirmed in 28 of 30 rabbits by macroscopic and histologic examination of tricuspid valves, blood cultures, and bacterial count in cardiac vegetations. Cardiac vegetations were confirmed in 25 of 28 IE rabbits by echocardiography. Enlargement of right ventricle dimension with a significantly decreased LV/RV ratio was confirmed in all IE rabbits at the time of death or moribundity than at the initial state (1.11 ± 0.35 vs. 1.95 ± 0.39, P < 0.01; 1.21 ± 0.34 vs. 1.98 ± 0.35, P < 0.01; 1.04 ± 0.31 vs. 2.00 ± 0.41, P < 0.01 for groups A(1), A(2), and A(3), respectively). V(TR) was significantly higher in all the IE rabbits at the time of death or moribundity than at the time of catheterization (1.89 ± 0.46 vs 0.76 ± 0.45, P < 0.01; 2.04 ± 0.73 vs 0.68 ± 0.66, P < 0.01; 2.24 ± 0.51 vs 0.87 ± 0.55, P < 0.01 for group A(1), A(2), and A(3), respectively). CONCLUSION: The models described herein closely reproduced the pathogenesis and pathophysiology of right heart catheter-induced endocarditis in humans. Echocardiographic guidance is helpful in the process of right heart catheterization. Some echocardiographic parameters, such as V(TR) and the LV/RV ratio could be used to assess the success or failure of the IE models.

Nasal carriage of methicillin-resistant Staphylococcus aureus among preclinical medical students: epidemiologic and molecular characteristics of methicillin-resistant S. aureus clones.

Between May 2008 and October 2009, a total of 2103 interns were randomly tested for nasal colonization of S. aureus and methicillin-resistant Staphylococcus aureus (MRSA). The prevalence of S. aureus among staphylococci specimens was 23.1%, and among the total S. aureus the MRSA prevalence was 9.4%. MRSA isolates were further subtyped using genetic element staphylococcal cassette chromosome mec (SCCmec) typing, pulsed-field gel electrophoresis (PFGE) band pattern, and multilocus sequence typing. SCCmec type IVa was the most prevalent strain, at 45.4 %. Eleven PFGE patterns were identified in MRSA strains, with 1 predominant (pulsotype A, 45.5%). Eight strains which belonged to clonal complex 78 carried type IVa SCCmec and produced type 3 coagulase. Panton-Valentine leukocidin (PVL) genes (lukS and F-PV) were identified in 10 (45.4%) MRSA strains; these predominately carried ϕSa2958type and ϕSa108PVL-like type PVL phages. After inducing prophages, 8 strains infected other S. aureus isolates and could generate novel PVL-positive strains of S. aureus. The present study demonstrates that interns can carry certain MRSA strains asymptomatically and contribute to the spread of MRSA between the community and hospital.

Short hairpin RNA-mediated inhibition of measles virus replication in vitro.

Rab9 has been identified as a key component for the replication of measles virus (MV). In this study, gene-specific shRNAs were developed to suppress the replication of MV in culture cells by silencing the expression of Rab9 GTPase gene. Rab9 GTPase gene-specific shRNAs were designed and cloned into the expression vector of pSUPER.neo+EGFP. Vero-E6 cells were transfected with the recombinant plasmid via liposome and then infected with MV. The expression of Rab9 GTPase mRNA and protein were assayed by RT-PCR and Western blotting, respectively. ShRNA-mediated inhibition of MV replication was further evaluated by detecting the titer of MV. The results showed that the expression of Rab9 GTPase was dramatically and stably downregulated by the generated shRNAs targeting Rab9 GTPase gene, which contribute to the inhibition of MV replication, indicating these shRNAs could be potentially developed into therapeutic agents for the treatment of MV infection in the future.

Effect of intermittent injection of recombinant human parathyroid hormone on bone histomorphometry of ovariectomized rats.

AIM: To observe the effect of intermittent parathyroid hormone (PTH) administration on bone histomorphology of relatively old ovariectomized rats. METHODS: The 6-month-old female SD rats were randomly divided into 5 groups: (1) sham-operated for baseline (ShamB, n=5), (2)ovariectomized for baseline (OVXB, n=6), (3) Sham-operated for end point (ShamE, n=6), (4) ovariectomized for end point (OVXE, n=6), (5) ovariectomized for PTH treatment (OVXEP, n=6). ShamB and OVXB rats were sacrificed 3 months after operation, ShamE, OVXE and OVXEP rats were sacrificed 4.5 months after operation. During 3-4.5 months after operation, OVXEP rats received daily subcutaneous injection of rhPTH1-84, while ShamE and OVXE received vehicle injection. The proximal tibiae of all rats were processed without decalcification for quantitative bone histomorphometry. RESULTS: The percent trabecular area (TbAr) of OVXEP was significantly greater than that of OVXE (P <0.05), and was similar to that of OVXB (P >0.05), but was smaller than that of ShamE (P <0.05); the trabecular thickness (TbTh) of OVXEP was thicker than any other group (all, P <0.05); the trabecular number (TbN) of OVXEP was only slightly higher than that of OVXE; the percent labeled perimeter (LPm), mineral apposition rate (MAR) and bone formation rate with bone area as referent (BFR/BV) of OVXEP were all higher than those of ShamE and OVXE respectively (P <0.01), whereas the osteoclast number (N of Oc) of OVXEP was similar to those of ShamE and OVXE (P >0.05). CONCLUSION: Short-term intermittent injection of rhPTH1-84 can prevent further bone loss in 9-month-old rats 3 months after ovariectomy, the mechanisms of this therapy are that PTH could increase TbTh while not alter TbN, and promote bone-forming activity while not influence bone-resorptive activity.