Molecular differentiation of Culicoides biting midges (Diptera: Ceratopogonidae) from the subgenus Culicoides Latreille in Denmark

Identification of Culicoides biting midges to species has attracted attention due to the recent outbreak of bluetongue disease in Northern Europe. Identification of Culicoides to species level has been based on morphological characters and is difficult as several species belonging to species complexes are hard to distinguish. We evaluated the use of the mitochondrial DNA cytochrome oxidase I gene (COI) barcode region in the identification of species within the subgenus Culicoides. COI barcode sequence divergence within species was <1%, whereas it ranged from 12.5% to 19.8% between subgenus Culicoides species. The divergence of subgenus Culicoides species to C. nubeculosus from the subgenus Monoculicoides ranged from 24.4% to 26.1%. Specimens were differentiated into eight unique clusters, including the four common Palaearctic species Culicoides punctatus, Culicoides pulicaris, Culicoides impunctatus, and Culicoides grisescens. Additionally, this study confirms the existence of Culicoides halophilus as a valid taxon and presents the first Culicoides deltus barcode sequences. Three additional groups of specimens were identified: Culicoides dk1 with a COI barcode diverging by 14.3% to 17.2% from other subgenus Culicoides species and Culicoides Kalix and Culicoides dk3, which diverged by 5.9% from each other and showed 12.5% to 17.6% divergence in COI barcode to subgenus Culicoides specimens.     

Serological reagents for the immunohistochemical analysis of melanoma metastases in sentinel lymph nodes

For the immunohistochemical analysis of melanoma, various serological reagents are available. Melanocyte differentiation markers are reactive with cells and tumors of melanocytic lineage. HMB45 to gp100 has been the most commonly used melanocyte differentiation marker. Recently it was complemented by reagents such as antibodies to Melan-A/MART-1 and tyrosinase. Other reagents, whose reactivity is not strictly confined to melanocyte differentiation antigens, are also commonly used. Among them, the most prominent is S100. Other reagents are D5 to MITF or PNL-2. The properties of these reagents are presented, and their usefulness as markers in the setting of metastatic melanoma in sentinel lymph nodes is discussed.     

T cell surveillance of oncogene-induced prostate cancer is impeded by T cell-derived TGF-β1 cytokine

Tolerance induction in T?cells takes place in most tumors and is thought to account for tumor evasion from immune eradication. Production of the cytokine TGF-β is implicated in immunosuppression, but the?cellular mechanism by which TGF-β induces T?cell dysfunction remains unclear. With a transgenic model of prostate cancer, we showed that tumor development was not suppressed by the adaptive immune system, which was associated with heightened TGF-β signaling in T?cells from the tumor-draining lymph nodes. Blockade of TGF-β signaling in T?cells enhanced tumor antigen-specific T?cell responses and inhibited tumor development. Surprisingly, T?cell- but not Treg cell-specific ablation of TGF-β1 was sufficient to augment T?cell cytotoxic activity and blocked tumor growth and metastases. These findings reveal that T?cell production of TGF-β1 is an essential requirement for tumors to evade immunosurveillance independent of TGF-β produced by tumors.     

Extracapsular extension but not the tumour burden of lymph node metastases is an independent adverse risk factor in lymph node-positive bladder cancer

Seiler R, von Gunten M, Thalmann G N & Fleischmann A
(2011) Histopathology  58 , 571–578
Extracapsular extension but not the tumour burden of lymph node metastases is an independent adverse risk factor in lymph node‐positive bladder cancer Aims: To evaluate risk factors in lymph node‐positive bladder cancer. Methods and results: Lymph node‐positive bladder cancer patients (n = 162), preoperatively staged N0M0, underwent cystectomy and standardized extended lymphadenectomy. Five‐year overall survival of the cohort was 33%. In univariate analysis, tumour stage (P < 0.006), extracapsular extension of lymph node metastases (P < 0.001), total diameter of metastases (P < 0.04) and lymph node stage (P < 0.03) were significantly correlated with overall survival (OS), disease‐specific survival (DSS) and recurrence‐free survival (RFS). On multivariate analysis, only extracapsular extension (OS, P < 0.002; DSS, P < 0.02; RFS, P = 0.058) and primary tumour stage (OS, P = 0.058; DSS, P < 0.02; RFS, P < 0.02) added independent prognostic information. Extracapsular extension of lymph node metastases did not correlate with a specific recurrence pattern; patients with organ‐confined tumours (pT1/2) never had pelvic relapse. Conclusions: Extracapsular extension of lymph node metastases but not lymph node tumour burden adds independent prognostic information in lymph node‐positive bladder cancer. These biological differences in lymph node‐positive bladder cancer are not reflected in the sixth, and challenge future, TNM classification.     

IL-5 is essential for vaccine-induced protection and for resolution of primary infection in murine filariasis

The pathways conferring immunity to human filariases are not well known, in part because human-pathogenic filariae do not complete a full life cycle in laboratory mice. We have used the only fully permissive infection of mice with filariae, i.e., infection of BALB/c mice with the rodent filarial nematode Litomosoides sigmodontis. Our previous results showed that worm development is inversely correlated with Th2 cytokine production and eosinophilia. The scope of the present study was to directly elucidate the role of interleukin-5 (IL-5) and eosinophils in controlling the development of L. sigmodontis after vaccination and in primary infection. BALB/c mice immunized with irradiated third-stage larvae (L3) were confirmed to have elevated IL-5 levels as well as high subcutaneous eosinophilia and to attack and reduce incoming larvae within the first 2 days, resulting in 70% reduction of worm load. Treatment of vaccinated mice with anti-IL-5 antibody (TRFK-5) suppressed both blood and tissue eosinophilia and completely abolished protection. This demonstrates, for the first time in a fully permissive filarial infection, that IL-5 is essential for protection induced by irradiated L3 larvae. In contrast, in primary-infected mice, anti-IL-5 treatment did not modify filarial infection within the 1st month, most likely because during primary infection IL-5-dependent mechanisms such as subcutaneous eosinophilia are induced too late to disturb worm establishment. However, there is a role for IL-5 late in primary infection where neutrophil-dependent worm encapsulation is also under the control of IL-5. Received: 30 March 2000     

Antimycin A resistance in a mutant Leishmania tarentolae strain is correlated to a point mutation in the mitochondrial apocytochrome b gene

In this paper we report the first case of antimycin A resistance in a protozoan parasite that is attributable to a mutation in the mitochondrial apocytochrome b (CYb) gene. We selected for, and isolated, a mutant Leishmania tarentolae strain that is resistant to antimycin A. This resistance was evident at the levels of the in vitro growth and enzymatic activity of the cytochrome bc1 complex. Molecular characterisation of the mutant revealed a Ser35Ile mutation in the expected region of the CYb gene. In kinetoplastids, CYb and other structural genes of the mitochondrial genome are located on the maxicircle component of the mitochondrial DNA, which is present in 20–50 copies. Primer-extension analysis confirmed the presence of the mutation at the mRNA level. The phenotypic manifestation of the mutation implies that the CYb mRNA is edited and translated within the mitochondrion. Thus, this finding provides direct evidence that edited RNAs are translated in kinetoplastid mitochondria. Furthermore, a defined mutation conferring drug resistance to a mitochondrial gene product can be exploited for the development of mitochondrial transfection systems for trypanosomatids. Received: 6 October / Accepted: 17 December 1999     

Tyrosine kinase B protein expression is reduced in the cerebellum of patients with bipolar disorder

Background

The role of the cerebellum in coordinating mental activity is supported by its connections with cerebral regions involved in cognitive/affective functioning, with decreased activities on functional neuroimaging observed in the cerebellum of schizophrenia patients performing mental tasks. Brain-derived neurotrophic factor (BDNF)-induced activation of tyrosine kinase B (TrkB) is essential to synaptic plasticity. We hypothesized that alterations in BDNF and TrkB expression in the cerebellum were associated with schizophrenia and affective disorders.

Methods

We employed immunohistochemistry and immunoblotting to quantify protein expression of BDNF and TrkB in the cerebellum of patients with schizophrenia, bipolar disorder, and major depression compared to controls (n = 15 each).

Results

While TrkB immunoreactivity in each of the molecular and granule-cell layers was reduced in all 3 disease groups (12-34%) compared to the control (P = 0.018 and 0.038, respectively, ANOVA), only the reduction in bipolar disorder remained statistically significant upon Tukey-Kramer post hoc analyses (P = 0.019 and 0.021, respectively). Apparent decreases in BDNF immunoreactivity in all 3 disease groups (12-30%) compared to the control were not statistically significant. TrkB immunoreactivity was not significantly associated with any of the demographic, clinical, and postmortem variables. Immunoblotting displayed an 85-kDa TrkB-immunoreactive band, consistent with a truncated isoform, in all 60 cases.

Limitations

On immunoblotting, apparent decreases in 85-kDa-TrkB levels in all 3 disease groups compared to the control were not statistically significant.

Conclusions

Our finding of reduced TrkB expression in bipolar disorder suggests that dysregulation of TrkB-mediated neurotrophin signaling in the cerebellum may play a role in the pathophysiology of this disease.     

Protocadherin PCDH10, involved in tumor progression,is a frequent and early target of promoter hypermethylation in cervical cancer

Cervical cancer (CC) is the second most common cancer in women. Currently, no tractable molecular‐based therapeutic targets exist for patients with invasive CC and no predictive markers of risk assessment for progression of precancerous lesions are identified. New molecular insights into CC pathogenesis are urgently needed. Towards this goal, we first determined the copy number alterations of chromosome 4 and then examined the role of PCDH10 mapped to 4q28 as a candidate tumor suppressor gene. We identified monosomy 4 in 47% of 81 invasive CC studied by SNP array and found that 91% of 130 invasive CC harboring methylation in the promoter region of the PCDH10 gene. We then showed that aberrant promoter hypermethylation of PCDH10 is associated with downregulation of gene expression and cell lines exposed to demethylating agent resulted in profound reactivated gene expression. We also showed that the promoter methylation in the PCDH10 gene occurs at an earliest identifiable stage of low‐grade squamous intraepithelial lesion. Our studies demonstrate that inactivation of PCDH10 may be a critical event in CC progression and form a potentially useful therapeutic target for CC. © 2009 Wiley‐Liss, Inc.     

Auditory development in progressive motor neuronopathy mouse mutants

The present study was performed to elucidate the hearing development in the progressive motor neuronopathy (pmn) mouse mutant. This mouse has been used as a model for human motoneuron disease. A missense mutation in the tubulin-specific chaperon E (Tbce) gene on mouse chromosome 13 was localized as the underlying genetic defect. The protein encoded by the Tbce gene is essential for the formation of primary tubulin complexes. Studies on motoneurons show disorganization in microtubules and disturbed axonal transport, followed by retrograde degeneration of the motoneurons. A similar pathomechanism is also possible for hearing disorders where disrupted microtubules could cause functional deficits in spiral ganglion neurons or in cochlear hair cells. Click auditory brainstem response (ABR) audiometry in homozygous pmn mutants showed a normal onset of hearing, but an increasing hearing threshold from postnatal day 26 (P26) on to death, compared to heterozygous mutants and wild-type mice. Histological sections of the cochlea at different ages showed a regular morphology. Additionally, spiral ganglion explants from mutant and wild-type mice were cultured. The neurite length from pmn mutants was shorter than in wild-type mice, and the neurite number/explant was significantly decreased in pmn mutants. We show that the pmn mouse mutant is a model for a progressive rapid hearing loss from P26 on, after initially normal hearing development. Heterozygous mice are not affected by this defect. With the knowledge of the well-known pathomechanism of this defect in motoneurons, a dysfunction of cellular mechanisms regulating tubulin assembling suggests that tubulin assembling plays an essential role in hearing function and maintenance.     

Prevalence of lymph nodes in the parametrium of radical vaginal trachelectomy (RVT) specimen

Objective

In order to evaluate radicality in fertility preserving surgery in women with early invasive cervical cancer we analyzed the parametrium of specimens of patients treated by radical vaginal trachelectomy for the presence of lymph nodes. We tried to identify morphologic factors associated with the presence of parametrial lymph nodes.

Methods

We analyzed surgical specimens of 112 patients who underwent radical trachelectomy between June 2004 and April 2009 at the Department of Gynecologic Oncology at Charité Campus Benjamin Franklin and Campus Mitte. All parametrial tissue was step sectioned and a total of 1878H&;E stained histological sections were analyzed.

Results

In 8 patients (7.1%) a total of 13 lymph nodes were detected. Five lymph nodes in four patients had been primarily detected by routine histological examination. In one of these patients (0.9%) a 2 mm lymph node metastasis was found. Serial sectioning revealed additional seven lymph nodes in four patients. The thickness of parametrium correlated significantly with the presence of lymph nodes in the parametrium.

Conclusion

The presence of small lymph nodes in the parametrium of specimens of radical trachelectomy is low. In patients with early-stage cervical cancer, the incidence of metastasis is less than 1%. Preoperative assessment of the volume of the parametrium may indicate which patients need parametrial resection.