Differential distribution of stem cells in the auditory and vestibular organs of the inner ear

The adult mammalian cochlea lacks regenerative capacity, which is the main reason for the permanence of hearing loss. Vestibular organs, in contrast, replace a small number of lost hair cells. The reason for this difference is unknown. In this work we show isolation of sphere-forming stem cells from the early postnatal organ of Corti, vestibular sensory epithelia, the spiral ganglion, and the stria vascularis. Organ of Corti and vestibular sensory epithelial stem cells give rise to cells that express multiple hair cell markers and express functional ion channels reminiscent of nascent hair cells. Spiral ganglion stem cells display features of neural stem cells and can give rise to neurons and glial cell types. We found that the ability for sphere formation in the mouse cochlea decreases about 100-fold during the second and third postnatal weeks; this decrease is substantially faster than the reduction of stem cells in vestibular organs, which maintain their stem cell population also at older ages. Coincidentally, the relative expression of developmental and progenitor cell markers in the cochlea decreases during the first 3 postnatal weeks, which is in sharp contrast to the vestibular system, where expression of progenitor cell markers remains constant or even increases during this period. Our findings indicate that the lack of regenerative capacity in the adult mammalian cochlea is either a result of an early postnatal loss of stem cells or diminishment of stem cell features of maturing cochlear cells.

Automated end-to-side anastomosis to the middle cerebral artery: a feasibility study

The treatment of complex cerebrovascular or skull base pathological conditions necessitates a microsurgical blood flow preservation or augmentative revascularization procedure as either an adjunctive safety measure or a definitive treatment. The brain is susceptible to ischemia, and procedure-related risks can be minimized by the reduction of occlusion time or the use of a nonocclusive technique. The authors therefore analyzed the feasibility of an automatic device (C-Port xA, Cardica) designed for constructing an end-to-side anastomosis with or without flow interruption for a middle cerebral artery (MCA) bypass in a human cadaveric model and in an in vivo craniotomy simulation model.

[Thrombolysis of the middle cerebral artery]

Intravenous thrombolysis (IVT) is the evidence-based treatment of acute ischemic stroke in the first 3 h after symptom onset (IVT 3-4.5 h: off-label use with informed consent of the patient). However, intra-arterial thrombolysis (IAT) results in higher recanalization rates of the middle cerebral artery compared to IVT. Therefore it seems reasonable to apply IAT in addition or instead of IVT up to 6 h after symptom onset.

Automated, compliant, high-flow common carotid to middle cerebral artery bypass

The authors describe the use of the Cardica C-Port xA Distal Anastomosis System to perform an automated, high-flow extracranial-intracranial bypass. The C-Port system has been developed and tested in coronary artery bypass surgery for rapid distal coronary artery anastomoses. Air-powered, it performs an automated end-to-side anastomosis within seconds by nearly simultaneously making an arteriotomy and inserting 13 microclips into the graft and recipient vessel. Intracranial use of the device was first simulated in a cadaver prepared for microsurgical anatomical dissection. The authors used this system in a 43-year-old man who sustained a subarachnoid hemorrhage after being assaulted and was found to have a traumatic pseudoaneurysm of the proximal intracranial internal carotid artery. The aneurysm appeared to be enlarging on serial imaging studies and it was anticipated that a bypass would probably be needed to treat the lesion. An end-to-side bypass was performed with the C-Port system using a saphenous vein conduit extending from the common carotid artery to the middle cerebral artery. The bypass was demonstrated to be patent on intraoperative and postoperative arteriography. The patient had a temporary hyperperfusion syndrome and subsequently made a good neurological recovery. The C-Port system facilitates the performance of a high-flow extracranial-intracranial bypass with short periods of temporary arterial occlusion. Because of the size and configuration of the device, its use is not feasible in all anatomical situations that require a high-flow bypass; however it is a useful addition to the armamentarium of the neurovascular surgeon.

Ear acupuncture points in neonates

OBJECTIVE: The aim of this study was to determine the presence and absence of acupuncture ear points in healthy neonates. DESIGN: This was a prospective observational study performed at a university teaching hospital. Subjects: The subjects were healthy neonates. We compared male and female neonates, right and left lobe, term and preterm deliveries, and cesarean sections versus vaginal deliveries. Examinations took place on the fifth day after delivery and were performed by a neuronal pen (SVESA 1070, SVESA GmbH, Munich, Germany). An integrated optical signal detected the ear points that were assigned to the Chinese ear map. MAIN OUTCOME MEASURES: This study looked at the presence and absence of acupuncture ear points in neonates. RESULTS: There were 27 male neonates and 23 female neonates. In 66% of neonates, no points at all were found. We detected 0-4 points on the right lobe and 0-2 points on the left lobe. The psychovegetative rim was the most common point in 26% of all children. No psychic points were detected. No significant differences were found between right and left ear lobes, male and female neonates, or term and preterm deliveries with respect to numbers of points or access of points. Moreover, there were no differences among modes of delivery. CONCLUSIONS: Some ear points in healthy neonates are detectable and not dependent on side of the ear lobe. Females had significantly more acupuncture points. There was an extremely significant difference in the group with 2 active earpoints between cesarean and vaginally delivered neonates. The most important point was the psychovegetative rim and the absence of psychic points in favor of the organ points. Possibly, ear points in neonates could be used for diagnostic and therapeutic options in neonates in the future.

[Stem-cell-based approaches for treating inner ear diseases]

The capacity of stem cells to regenerate lost tissue cells has gained recognition among physicians. Despite the successful use of blood stem cells for treating blood cancers, other stem cell types have not yet been widely introduced into clinical practice. Therapy options involving stem cells for inner ear diseases consequently have not been implemented. Nonetheless, several reports have recently been published describing the generation of morphologically and immunologically distinctive inner ear cell types-such as hair cells, supporting cells, and spiral ganglion neurons-from stem cells. Although promising, all of these studies still lack functional results regarding hearing restoration or vestibular function.