Advanced optoacoustic methods for multiscale imaging of in vivo dynamics.

Visualization of dynamic functional and molecular events in an unperturbed in vivo environment is essential for understanding the complex biology of living organisms and of disease state and progression. To this end, optoacoustic (photoacoustic) sensing and imaging have demonstrated the exclusive capacity to maintain excellent optical contrast and high resolution in deep-tissue observations, far beyond the penetration limits of modern microscopy. Yet, the time domain is paramount for the observation and study of complex biological interactions that may be invisible in single snapshots of living systems. This review focuses on the recent advances in optoacoustic imaging assisted by smart molecular labeling and dynamic contrast enhancement approaches that enable new types of multiscale dynamic observations not attainable with other bio-imaging modalities. A wealth of investigated new research topics and clinical applications is further discussed, including imaging of large-scale brain activity patterns, volumetric visualization of moving organs and contrast agent kinetics, molecular imaging using targeted and genetically expressed labels, as well as three-dimensional handheld diagnostics of human subjects.

Generating CTLs against the subdominant EBV LMP antigens by transient expression of an A20 inhibitor with EBV LMP proteins in human DCs.

Epstein-Barr virus (EBV) infection leads to Hodgkin's disease (HD) in some immunocompetent hosts. The malignant Reed-Sternberg cells of HD only express a limited array of subdominant EBV antigens to evade pre-existing immune responses to EBV. The EBV-encoded latent membrane proteins (LMP1 and LMP2), which are expressed by HD and various EBV-associated malignancies, have been proposed as a potential target for cytotoxic T lymphocyte (CTL)-based therapy. However, the precursor frequency for LMP-specific CTL is generally low in healthy EBV-infected hosts, and immunotherapy based on these antigens is often compromised by the poor immunogenicity and the oncogenic potential. In the present study, we report that transiently expressing an inhibitor of A20, a key negative regulator of inflammatory signaling pathways, together with the LMP antigens (truncated LMP1 and full-length LMP2) greatly enhances maturation and cytokine production of human (h) monocyte-derived dendritic cells (DCs). As a consequence, LMP1/2-expressed, A20-silenced hDCs have an enhanced potency to prime LMP-specific T-cell response. When the in vitro primed T cells are adoptively transferred into tumor-xenografted, severe-combined immunodeficient mice, some of the xenografted tumors approach complete regression. Thus, the study may provide an available resource of LMP-specific T cells for T-cell immunotherapy.

A phase II study evaluating the safety and efficacy of an adenovirus-ΔLMP1-LMP2 transduced dendritic cell vaccine in patients with advanced metastatic nasopharyngeal carcinoma.

BACKGROUND: Individuals with metastatic Epstein-Barr virus (EBV)-positive nasopharyngeal carcinoma (NPC) continue to have poor outcomes. To evaluate the ability of a dendritic cell (DC) vaccine to target subdominant EBV antigens LMP1 and LMP2 expressed by NPC cells, we vaccinated patients using autologous DCs transduced with an adenovirus encoding a truncated LMP1 (ΔLMP1) and full-length LMP2 (Ad-ΔLMP1-LMP2). MATERIALS AND METHODS: Sixteen subjects with metastatic NPC received Ad-ΔLMP1-LMP2 DC vaccines i.d. biweekly for up to five doses. Toxicity, immune responses and clinical responses were determined. RESULTS: Most patients had extensive disease, with a median of three visceral sites of involvement (range 1-7). No significant toxicity was observed. Ad-ΔLMP1-LMP2 DCs induced delayed type hypersensitivity responses in 9 out of 12 patients, but although these DCs activated LMP1/2-specific T cells in vitro, no such increase in the frequency of peripheral LMP1/2-specific T cells was detected. Three patients had clinical responses including one with partial response (for 7½ months) and two with stable disease (for 6½ and 7½ months). CONCLUSIONS: Ad-ΔLMP1-LMP2 transduced DCs can be successfully generated and safely administered to patients with advanced NPC. Since efficacy was limited, future studies should focus on DC vaccines with greater potency administered to subjects with less tumor burden.

Vergence deficits in patients with cerebellar lesions.

The cerebellum is part of the cortico-ponto-cerebellar circuit for conjugate eye movements. Recent animal data suggest an additional role of the cerebellum for the control of binocular alignment and disconjugate, i.e. vergence eye movements. The latter is separated into two different components: fast vergence (to step targets) and slow vergence (to ramp and sinusoidal targets). The aim of this study was to investigate whether circumscribed cerebellar lesions affect these dynamic vergence eye movements. Disconjugate fast and slow vergence, conjugate smooth pursuit and saccades were binocularly recorded by a scleral search coil system in 20 patients with acute cerebellar lesions (all ischemic strokes except for one) and 20 age-matched healthy controls. Patients showed impairment of slow vergence while fast vergence was unaffected. Slow vergence gain to sinusoidal targets was significantly reduced, both in convergence and divergence direction. Divergence but not convergence velocity to ramp targets was reduced. Conjugate smooth pursuit eye movements to sinusoidal and to step-ramp targets were impaired. Patients had saccadic hypometria. All defects were particularly expressed in patients with vermis lesions. In contrast to recent animal data fast vergence was not impaired in any of our patient subgroups. We conclude that (i) the human cerebellum, in particular the vermis, is involved in the processing of dynamic vergence eye movements and (ii) cerebellar lesions elicit dissociable effects on fast and slow vergence.

[Posttraumatic gusher phenomenon following fracture of the petrous bone]. / Posttraumatisches Gusher-Phänomen nach Felsenbeinquerfraktur.

The gusher phenomenon is a very rare complication that may occur during stapedectomy or cochleostomy. A sudden perilymphatic flow of cerebrospinal fluid can be seen following platinotomy. The cause is an abnormal connection between subarachnoid and perilymphatic spaces due to congenital malformation, leading to an abnormally wide cochlear aqueduct or due to an internal auditory canal fistula. We describe a case of posttraumatic gusher phenomenon after a fracture of the petrous bone.

Analysis of mouse brain using a clinical 1.5 T scanner and a standard small loop surface coil.

With increasing numbers of in vivo experiments in the field of neuroscience, the interest in methods for in vivo imaging of animal brains as small as those of mice has increased. Because highly specialized small bore scanners with high field strengths are not commonly available, clinical magnetic resonance imaging (cMRI) scanners have been used in the past to image rat and more recently also mouse brains in combination with specifically developed RF coils. These studies have demonstrated that imaging of small animal brains is feasible, and that tumor volumes measured by cMRI correlate well with histological tumor volume analysis. This protocol describes the cMRI settings at 1.5 T for imaging of mouse brain with resolutions up to 120 x 120 microm using an inexpensive, commercially available small loop surface coil. This allows easy establishment of a small animal MRI facility without the need for cost intensive dedicated small animal scanners or special custom made coils. In this study, we demonstrate high-resolution imaging of intracranial xenografts in a mouse glioma model and monitor the treatment effect of external field irradiation by cMRI.

Disseminated mycobacterium bovis infection in an immunocompetent host.

We report about a rare case of disseminated Mycobacterium bovis infection in a 61 year old female immunocompetent patient with involvement of the lung, the brain, the spleen and spine. The patient had intracerebral tuberculomas with paradoxical enlargement during the first weeks of therapy. We reviewed the data of our microbiological department and found five other patients with Mycobacterium bovis infection diagnosed between 1999 and 2004, which are 5.8 % of all diagnoses of tuberculosis during this period.

The Cape Triage Score: a new triage system South Africa. Proposal from the Cape Triage Group.

The Cape Triage Group (CTG) convened with the intention of producing a triage system for the Western Cape, and eventually South Africa. The group includes in-hospital and prehospital staff from varied backgrounds. The CTG triage protocol is termed the Cape Triage Score (CTG), and has been developed by a multi-disciplinary panel, through best available evidence and expert opinion. The CTS has been validated in several studies, and was launched across the Western Cape on 1 January 2006. The CTG would value feedback from readers of this journal, as part of the ongoing monitoring and evaluation process.

[Squamous cell carcinoma of the conjunctiva with orbital invasion: orbital exenteration or minimally invasive procedure?]. / Plattenepithelkarzinom der Bindehaut mit Orbitainvasion : Exenteratio orbitae oder minimal-invasives Vorgehen?

BACKGROUND: Here we present a case of a female patient with squamous cell carcinoma with orbital invasion who insisted on a globe-sparing excisional biopsy rather than a more invasive procedure. CASE: A 48-year-old patient presented with a conjunctival tumor at the medial canthus of the right eye. The visual acuity in this eye was 1.0. MRI showed a 25 mm x 12 mm tumor, with orbital invasion, no metastasis, but on CT scan damage of the lamina papyracea was suspected. Histology of a punch biopsy confirmed a moderately differentiated, squamous cell carcinoma. As requested by the patient, simple tumor excision with a 5-mm safety margin, reconstruction of the lower fornix with amniotic membrane, and adjuvant mitomycin C therapy were performed. Intraoperatively the medial orbital wall was found to be intact. No local or systemic recurrence has occurred 3.5 years postoperatively. The patient's VA is still 1.0; no visual field defects are detectable, and there are only minor upper lid levator restriction and diplopia in maximum upgaze. CONCLUSION: In view of this case the choice of surgical treatment for malignant tumors of the conjunctiva with orbital invasion - between exenteration or a minimally invasive procedure - should be carefully discussed with the patient. A follow-up of 5 years is strongly recommended.

CAD generated mold for preoperative implant fabrication in cranioplasty.

Intraoperative fabrication of acrylic cranial implants may be difficult and will increase operation time. In addition forming implants directly on the defect, intracranial tissues are exposed to heat of polymerization and residual monomer, that occurs, when autopolymerizing methyl methacrylate is used intraoperatively. Furthermore the cosmetical result may be unacceptable. Preoperatively formed acrylic implants may reduce these disadvantages compared to conventional techniques in cranioplasty. We will present methods for preoperative fabrication of cranial implants for a cadaver specimen. Implants were fabricated using a Rapid prototyping (RP) models of the skull built by Fused Deposition Modeling (FDM). In addition a mold of the defect was generated by CAD techniques, that can serve as a template for implant design.

Paraplegia due to peripheral venous air embolus in a neonate: a case report.

A term male infant with pneumonia was receiving fluid and antibiotics through an intravenous line in the scalp. Air was accidentally infused in this line. Subsequently, discoloration of the skin, a flaccid paraplegia, hematuria, and gastrointestinal bleeding occurred as the presumed effect of venous air entering the systemic arteries. The umbilical vessels were never catheterized. Absence of any apparent cerebral air embolism is interpreted as being due to the infant's position (head down) at the time of air infusion. The pathogenesis and prevention of this tragic complication are discussed.

SPECT resolution and uniformity improvements by noncircular orbit.

A noncircular orbit implemented by a combination of rotational and translational motions in single photon emission computed tomography improves significantly the image resolution and uniformity. The former is realized by closer access of the detector to the object at each projection angle, and the latter by suppression of ring artifacts through the shifts in the distance between the centers of detector and object. This has been demonstrated by comparing the SPECT images for an elliptical orbit of 40 cm X 30 cm with the equivalent circular orbit of 40 cm diameter, performed by SPECT system with a high resolution collimator. Resolution FWHM improvements were 1.5-2.5 mm. Lesion contrast improved by a factor of 2.8 for a nonradioactive rod of 6 mm diam. In phantom images, the elliptical orbit showed better definition of lesion shape, sharper edge response, and clearly increased detectability. Translational motion reduced ring artifacts, particularly near the image center.

Caffeine enhances the expression of the angiotensin II Type 2 receptor mRNA in BeWo cell culture and in the rat placenta.

Although chronic caffeine exposure during pregnancy has been shown to affect fetal growth, adverse effects of caffeine on embryogenesis are not only well understood, but also controversial. We have used gene chip technology in an attempt to identify to what extent, if any, caffeine could possibly alter gene expressions in the cytotrophoblast-like cell line BeWo. Few down-regulated genes were found; most of the genes were up-regulated, suggesting that chronic caffeine exposure during the gestational period could exert certain influences on embryogenesis. The highest up-regulated gene expression of BeWo cells by caffeine was angiotensin II type 2 (AT(2)) receptor gene. We focused the genes of the renin-angiotensin system (RAS), angiotensin II type 1 (AT(1)) and AT(2)receptors and angiotensin I converting enzyme, for study on caffeine's responsive gene expression in BeWo cells and in the placentae of pregnant rats that were fed a diet supplemented with caffeine (2 mg/100 g body weight) during gestation, and analysed the gene expressions using RT-PCR and LightCycler system. A significantly increased AT(2)receptor gene expression and a slight decreased AT(1)receptor gene expression demonstrated the caffeine's effect to the placental RAS.

Classification of nosocomial and community-acquired infections in the neonate.

The concept of nosocomial versus community-acquired infection is an important one in terms of hospital surveillance and infection control. Risk factors, time of onset, and type of organism are presented in tabular form to assist in classifying infection in the newborn.

Assessment of blood flow velocity and diameter of the middle cerebral artery during the acetazolamide provocation test by use of transcranial Doppler sonography and MR imaging.

BACKGROUND AND PURPOSE: Our purpose was to show changes in the diameter of the M1 segment of the middle cerebral artery (MCA) by using high-resolution MR imaging in patients with chronic internal carotid artery occlusion after IV administered acetazolamide challenge. Changes in blood flow velocity of the basal cerebral arteries are thought to correlate with changes of cerebral blood flow. Changes in the diameter of the basal cerebral arteries, however, might influence the validity of transcranial Doppler measurements. METHODS: Eight patients with internal carotid artery occlusion who were undergoing acetazolamide testing for assessment of cerebrovascular vasomotor reactivity were included in the study. Blood flow velocities of both MCAs were measured with transcranial Doppler sonography before and 25 minutes after the administration of acetazolamide. Before and 15 minutes after the administration of medication, MR imaging was performed contralateral to the occlusion side. A T2-weighted turbo-gradient spin-echo sequence was chosen to show a cross section of the M1 segment in high resolution (pixels, 0.27 x 0.29 mm). Based on interpolated data, the smallest and greatest MCA diameters were determined. RESULTS: We did not find changes in the diameter of the MCA after acetazolamide provocation testing with high-resolution MR imaging in patients with occlusive extracranial carotid artery disease. CONCLUSION: The results of our study support the hypothesis that changes in MCA flow velocity measured by transcranial Doppler sonography reflect relative changes in cerebral blood flow after acetazolamide provocation testing.

Lasting effects of early chronic caffeine feeding on rats' behavior and brain in later life.

Pregnant dams were fed a 20% protein diet with caffeine (2 mg/100 g b.wt.), starting on day 9 of gestation. At birth, each dam with 8 assigned pups was fed this diet until weaning, day 22. On day 22, female rats were caged and fed this diet until day 93. Starting on day 93, the caffeine-supplemented diet was replaced with a caffeine-free, 20% protein diet until day 388. Starting on day 31, each animal was placed in a photoactivity cage, and locomotive activity was measured until day 375. On day 388, the animals were killed, and their brains were removed and divided into 7 regions. The weight, DNA, protein and zinc contents, and alkaline phosphatase activity of each region were determined. Locomotive activity of the caffeine-fed group was higher than in the noncaffeine control group. Accumulative activity scores showed 3 subgroups (high, medium, and low) in both groups at day 93. The medium activity subgroup in the caffeine group was greater than the controls from day 72 to day 93. These differences reappeared 5 weeks after cessation of caffeine supplementation and continued until day 375. The differences in activity were minimum in the high and low subgroups. Chronic caffeine intake in early life permanently affected the medium activity subgroup. Furthermore, various regions of the brain were biochemically altered in spite of the feeding of a noncaffeine diet for almost 300 days after caffeine.

[Contrast-enhanced intracranial 3 D MR angiography (CE-MRA) in assessing arterial stenoses and aneurysms]. / Kontrastmittelgestützte 3D-MR-Angiographie (CE-MRA) bei intrakraniellen Stenosen und Aneurysmen.

PURPOSE: The aim of this study was to evaluate the diagnostic potential of CE-MR angiography in intracranial arterial stenoses and aneurysms. MATERIAL AND METHODS: Thirteen patients with intracranial arterial stenoses and ten patients with aneurysms, including 6 cases with GDC coil-occluded aneurysms, were examined by both 3 D TOF-MR angiography and CE-MR angiography. In cases of stenoocclusive diseases colour-coded duplex sonography and in cases of aneurysms arterial digital subtraction angiography served as reference method. RESULTS: Both TOF-MRA and CE-MRA could well depict filiform stenosis. In contrast to TOF-MRA, CE-MRA did not show any false positive stenosis or occlusion in regions of turbulent or slow blood flow. Stenoses of the medial cerebral artery could not be graded sufficiently by CE-MRA. In aneurysms the parent vessel was better shown by TOF-MRA. CE-MRA, however, more sensitively detected reperfusion in GDC coil-occluded aneurysms. CONCLUSION: Stenoses of small vessels were graded less exactly by CE-MRA than by TOF-MRA due to lower spatial resolution. CE-MRA, however, seems to be superior in regions of turbulent or slow blood flow. CE-MRA also offers advantages in follow-up examinations of coil-occluded aneurysms.

Infarction of the gallbladder--an unusual cause of acute abdomen in the neonate.

Infarction of the gallbladder, while rare, must now be included in the growing list of possible and proven complications of umbilical artery catheterization.

[Pneumatosis cystoides intestinalis of the splenic flexure].

We describe a case of pneumatosis cystoides intestinalis with unusual localization and radiologic features. Barium enema showed multiple, rounded, submucosal masses, which were polypoid and airless and were localized to a 20 cm segment of the splenic flexure. There was no extraluminal gas on X-ray. Puncture of these formations via colonoscopic biopsy did not result in deflation of air. Surgical resection was performed and the classical features of pneumatosis cystoides intestinalis were found. Isolated splenic flexure involvement in conjunction with atherosclerotic cardiovascular disease may suggest that pneumatosis cystoides intestinalis is a reparative process after ischemic injury.