Evaluation of rhBMP‐2 and Natural Latex as Potential Osteogenic Proteins in Critical Size Defects by Histomorphometric Methods

This in vivo study evaluated the osteogenic potential of two proteins, recombinant human bone morphogenetic protein‐2 (rhBMP‐2) and a protein extracted from natural latex (Hevea brasiliensis, P‐1), and compared their effects on bone defects when combined with a carrier or a collagen gelatin. Eighty‐four (84) Wistar rats were divided into two groups, with and without the use of collagen gelatin, and each of these were divided into six treatment groups of seven animals each. The treatment groups were: (1) 5 μg of pure rhBMP‐2; (2) 5 μg of rhBMP‐2/monoolein gel; (3) pure monoolein gel; (4) 5 μg of pure P‐1; (5) 5 μg of P‐1/monoolein gel; (6) critical bone defect control. The animals were anesthetized and a 6 mm diameter critical bone defect was made in the left posterior region of the parietal bone. Animals were submitted to intracardiac perfusion after 4 weeks and the calvaria tissue was removed for histomorphometric analysis. In this experimental study, it was concluded that rhBMP‐2 allowed greater new bone formation than P‐1 protein and this process was more effective when the bone defect was covered with collagen gelatin (P < 0.05). Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.     

Diffusion tensor imaging of tract involvement in children with pontine tumors

BACKGROUND AND PURPOSE: Conventional MR imaging permits subcategorization of brain stem tumors by location and focality; however, assessment of white matter tract involvement by tumor is limited. Diffusion tensor imaging (DTI) is a promising method for visualizing white matter tract tumor involvement supratentorially. We investigated the ability of DTI to visualize and quantify white matter tract involvement in pontine tumors. METHODS AND MATERIALS: DTI data (echo-planar, 1.5T) were retrospectively analyzed in 7 patients with pontine tumors (6 diffuse, 1 focal), 4 patient controls, and 5 normal volunteers. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were calculated from the diffusion tensor in 6 regions of interest: bilateral corticospinal tracts, transverse pontine fibers, and medial lemnisci. Relationships between FA and ADC values and results of the neurologic examinations were evaluated. RESULTS: The corticospinal tracts and transverse pontine fibers were affected more often than the medial lemnisci. The DTI parameters (FA and ADC) were significantly altered in all tracts of patients with pontine tumors (P < .05), compared with those values in the control groups. A marginally significant (P = .057) association was seen between the severity of cranial nerve deficit and decreased FA. CONCLUSION: DTI provided superior visualization and quantification of tumor involvement in motor, sensory, and transverse pontine tracts, compared with information provided by conventional MR imaging. Thus, DTI may be a sensitive measure of tract invasion. Further prospective studies are warranted to assess the ability of DTI to delineate tumor focality and improve risk stratification in children with pontine tumors.     

Imaging features of medulloepithelioma: report of four cases and review of the literature

Background

Intraocular medulloepithelioma is a childhood tumor arising from the nonpigmented primitive ciliary neuroepithelium. Although rarer than retinoblastoma, it remains the second most common primary intraocular neoplasm in children. The rarity of intraocular medulloepithelioma creates the challenge in establishing a clinical diagnosis, and radiologically the tumor is often confused with other intraocular masses.

Objective

To describe the clinical, imaging and pathological features of intraocular medulloepithelioma with emphasis on the role of imaging to enable its differentiation from more common intraocular pathology.

Materials and methods

We retrospectively analyzed the clinical, histopathological and imaging data of four children with intraocular medulloepithelioma.

Results

All four children had medulloepithelioma arising from the ciliary body. The children were imaged with US (n?=?3), MRI (n?=?4), whole-body ^99mTc-MDP scintigraphy (n?=?2) and CT (n?=?1). All four children had enucleation of the involved eye. One tumor was a malignant teratoid variant, two tumors were malignant nonteratoid variants and one was a nonteratoid variant of uncertain malignant potential. None of the tumors had extraocular extension on histopathology or imaging. Two children had associated retinal detachment on US and MRI examinations. All tumors were iso/hyperintense to vitreous on T1-weighted and hypointense on T2-weighted MRI and showed marked contrast enhancement of the solid components. No calcifications were identified on US or CT examinations.

Conclusion

Our findings are consistent with previously reported cases of medulloepithelioma. This series emphasizes the roles of various imaging modalities, with pathological correlation, in differentiating the tumor from other ciliary body masses, in detecting tumor extension and in identifying associated ocular complications. In this series we also describe the results of postsurgical follow-up for tumor recurrence.     

Induction of immunogenicity by live attenuated Leishmania donovani centrin deleted parasites in dogs

Zoonotic visceral leishmaniasis, caused by the intracellular protozoan parasite Leishmania infantum, is a neglected tropical disease that is often fatal when untreated. Dogs are considered the main reservoir of L. infantum in zoonotic VL as the presence of infected dogs may increase the risk for human infection. Canine visceral leishmaniasis (CVL) is a major veterinary and public health problem in Southern Europe, Middle East and South America. Control of animal reservoirs relies on elimination of seropositive dogs in endemic areas. However, treatment of infected dogs is not considered a favorable approach as this can lead to emergence of drug resistance since the same drugs are used to treat human infections. Therefore, vaccination against CVL remains the best alternative in control of the animal reservoirs. In this study, we present data on the immunogenicity profile of a live attenuated parasite LdCen^−/− in a canine infection model and compared it to that of Leishmune^®, a commercially available recombinant vaccine. The immunogenicity of the LdCen^−/− parasites was evaluated by antibody secretion, production of intracytoplasmic and secreted cytokines, activation and proliferation of T cells. Vaccination with LdCen^−/− resulted in high immunogenicity as revealed by the higher IgGTotal, IgG1, and IgG2 production and higher lymphoproliferative response. Further, LdCen^−/− vaccinated dogs showed higher frequencies of activated CD4+ and CD8+ T cells, IFN-γ production by CD8+ T cells, increased secretion of TNF-α and IL-12/IL-23p40 and decreased secretion of IL-4. These results contribute to the understanding of immunogenicity elicited by live attenuated L. donovani parasites and, consequently, to the development of effective vaccines against visceral leishmaniasis.     

Pancreatic heterotopia and other uncommon causes of non-malignant biliary obstruction

The vast majority of patients developing obstructive jaundice will have an underlying malignancy. When the etiology of the obstruction cannot be defined prior to operative intervention, identification of a non-malignant process will occur only subsequent to a major operation. The clinical course of a patient with complete distal common bile duct obstruction as the result of pancreatic heterotopia is discussed. This uncommon diagnosis prompted a review of the literature on this subject enabling this detailed discussion inclusive of the embryology, prevalence and clinical presentations of this entity. Our review further identified a varied group of other non-malignant causes of biliary obstruction that may be mistakenly interpreted to represent biliary or pancreatic malignancy.     

Increase in dopaminergic, but not serotoninergic, receptors in T-cells as a marker for schizophrenia severity

Schizophrenia is characterized by a slow deteriorating mental illness. Although the pathophysiology mechanisms are not fully understood, different studies have suggested a role for the immune system in the pathogenesis of schizophrenia. To date, an altered expression or signaling of neurotransmitters receptors is observed in immune cells during psychiatric disorders. In the present study, we investigated the expression of different serotonin and dopamine receptors in T-cells of schizophrenic and control patients. We used flow cytometry to determine the pattern of expression of dopamine (D2 and D4) and serotonine receptors (SR1A, SR1C, SR2A, SR2B), as well as serotonin transporter (ST), in T-cell subsets (CD4 and CD8). Expression of serotonin receptors and ST in T-cells of schizophrenic patients were not different from controls. However, the percentages of CD4+D4+ and CD8+D4+ were increased in schizophrenic patients as compared to controls. In addition, increased percentages of CD8+D2+ cells were also observed in schizophrenic patients, albeit this population revealed lower CD4+D2+ cells in comparison to controls. Interestingly, a relationship between clinical symptoms and immunological parameters was also observed. We showed that the Brief Psychiatric Rating Scale (BPRS), the Positive and Negative Syndrome Scale (PANSS) and the Abnormal Involuntary Movement Scale (AIMS) were positively related to CD8+D2+ cells, though AIMS was inversely related to CD4+D4+ cells. In conclusion, the alteration in the pattern of cell population and molecules expressed by them might serve as a promising biomarker for diagnosis of schizophrenia.     

The active components of effective training in obstetric emergencies

Confidential enquiries into poor perinatal outcomes have identified deficiencies in team working as a common factor and have recommended team training in the management of obstetric emergencies. Isolated aviation-based team training programmes have not been associated with improved perinatal outcomes when applied to labour ward settings, whereas obstetric-specific training interventions with integrated teamwork have been associated with clinical improvements. This commentary reviews obstetric emergency training programmes from hospitals that have demonstrated improved outcomes to determine the active components of effective training. The common features identified were: institution-level incentives to train; multi-professional training of all staff in their units; teamwork training integrated with clinical teaching and use of high fidelity simulation models. Local training also appeared to facilitate self-directed infrastructural change.     

Enterolith Causing Afferent Loop Obstruction: A Case Report and Literature Review

Enterolith formation is a rare cause of afferent limb obstruction following Billroth II gastrectomy and Roux-en-Y hepaticojejunostomy surgery. A case of ascending cholangitis caused by an enterolith incarcerated in the afferent loop of a 15-year-old Roux-en-Y hepaticojejunostomy was emergently decompressed under direct ultrasound guidance prior to surgery. This is the thirteenth reported case of an enterolith causing afferent loop obstruction. A discussion of our management approach and a review of the relevant literature are presented.