Pericytes promote abnormal tumor angiogenesis in a rat RG2 glioma model

In glioma angiogenesis, tumor vessels cause morphological and functional abnormalities associated with malignancy and tumor progression. We hypothesized that certain structural changes or scantiness of functional pericytes may be involved in the formation of dysfunctional blood vessels in gliomas. In this study, we performed morphological examinations to elucidate the possible involvement of pericytes in brain tumor vessel abnormalities using a rat RG2 glioma model. After implantation of RG2 glioma cells in the syngeneic rat brain, gliomas were formed as early as day 7. In immunohistochemical examinations, desmin-positive pericytes, characterized by morphological abnormalities, were abundantly found on leaky vessels, as assessed by extravasation of lectin and high-molecular-weight dextrans. Interestingly, desmin-positive pericytes seemed to be characteristic of gliomas in rats. These pericytes were also found to express heat-shock protein 47, which plays an important role in the formation of the basement membrane, suggesting that RG2 pericytes promoted angiogenesis by producing basement membrane as a scaffold for newly forming blood vessels and caused functional abnormalities. We concluded that RG2 pericytes may be responsible for abnormal tumor angiogenesis lacking the functional ability to maintain the blood-brain barrier.

Propentofylline administered by microdialysis attenuates ischemia-induced hippocampal damage but not excitatory amino acid release in gerbils

Systemic administration of propentofylline (PPF), an adenosine uptake inhibitor, has been demonstrated to protect CA1 pyramidal cells from death following transient cerebral ischemia in gerbils. In order to examine the direct effects of this inhibitor, we tested whether or not PPF administered into the hippocampus in situ through a microdialysis probe could attenuate ischemia-induced excitatory amino acid (EAA) release and prevent subsequent death of CA1 pyramidal cells in the gerbil. The EAA release and death of CA1 pyramidal cells observed in the hippocampus were compared with those in the contralateral hippocampus of the same animal into which vehicle alone was administered. The results indicated that pre- as well as post-treatments with PPF inhibited the death of CA1 pyramidal cells after 5-min ischemia in a dose-dependent manner, but did not significantly alter the EAA release during ischemia and reperfusion in the same animals. While the neuroprotective effect of PPF against ischemic damage has commonly been ascribed to attenuation of EAA release during ischemia, other actions of adenosine such as those influencing the synaptic responses, neuronal excitation, and local cerebral circulation, or as yet unidentified actions may be involved in the observed neuroprotective effects of PPF.

Analgesic effect of intrathecal desipramine on carrageenan-induced thermal hyperalgesia in the rat

We examined if intrathecal desipramine, a selective norepinephrine reuptake inhibitor, would modulate peripheral inflammation-induced hyperalgesia. Rats were chronically implanted with a lumbar intrathecal catheter and paw withdrawal latency (PWL) to noxious heat stimuli was assessed. Unilateral hindpaw inflammation was induced by intraplantar carrageenan injection. Carrageenan injection significantly (P < 0.05) reduced PWL of the injected paw (from mean 11.4 (SEM 0.6) s to 3.5 (0.2) s, 3 h after carrageenan), but not of the contralateral side (from 11.6 (0.2) s to 11.2 (0.5) s). Intrathecal desipramine 10, 30, 60 and 100 micrograms, which did not produce analgesic effects in untreated rats, dose-dependently reversed the shortened PWL on the ipsilateral side (3.3 (0.2), 5.3 (0.4), 6.2 (0.3) and 9.6 (0.2) s, respectively) without affecting the contralateral side. Pretreatment with intrathecal yohimbine 10 micrograms did not antagonize the anti-hyperalgesic effects of desipramine (from 9.6 (0.2) to 9.8 (0.3) s). Our results suggest that the mechanism underlying the analgesic effect of desipramine on inflammation-induced hyperalgesia is unlikely to be inhibition of norepinephrine reuptake within the spinal cord.

Case Report: Deep Cerebellar Stimulation for Tremor and Dystonia

Background: The cerebellum plays an important role in the pathogenesis and pathophysiology of movement disorders, including tremor and dystonia. To date, there have been few reports on deep cerebellar stimulation.

Case Report: The patient was a 35-year-old previously healthy man with no history of movement disorders. He developed a tremor and stiffness in his left hand at the age of 27 years, which was diagnosed as a dystonic tremor. We performed right thalamotomy, which resulted in a complete resolution of the tremor; however, the dystonia persisted. Subsequently, the patient developed left foot dystonia with inversion and a newly developed tremor in the right hand and foot. The patient underwent left ventralis intermedius (VIM) deep brain stimulation (VIM-DBS) and left pallidothalamic tract DBS (PTT-DBS). Left VIM-DBS completely resolved the right hand and foot tremor, and PTT-DBS significantly improved the left hand and foot dystonia. Three months postoperatively, the patient developed an infection and wound disruption at the surgical site. We performed palliative surgery for deep cerebellar stimulation via the posterior cranial region, which was not infected. The surgery was performed under general anesthesia with the patient lying in the prone position. Eight contact DBS electrodes were used. The placement of electrodes extended from the superior cerebellar peduncle to the dentate nucleus. Both the right hand and foot tremor improved with right cerebellar stimulation. Further, both the left hand and foot dystonia improved with left cerebellar stimulation. Right and left cerebellar stimulation led to no improvement in the left hand and foot dystonia and right hand and foot tremor, respectively. Stimulation-induced complications observed in the patient included dizziness, dysphagia, and dysarthria. After the surgery, the patient developed hypersalivation and hyperhidrosis in the left side of the body, both of which did not improve with adjustments of stimulation parameters. At the 6-month follow-up, the tremor and dystonia had almost completely resolved.

Conclusion: Deep cerebellar stimulation deserves consideration as a potential treatment for tremor and dystonia.

Rapamycin and FK506 induce long-term potentiation by pairing stimulation via an intracellular Ca(2+) signaling mechanism in rat hippocampal CA1 neurons

Immunophilin-CsA and -FK506 complexes bind to calcineurin (CaN) and inhibit its phosphatase activity leading to enhancement of neuronal activities. However, inhibition of CaN activity is not the mediator of modulatory activity for IP3 and ryanodine receptors and does not mediate the neurotrophic actions of FK506. FK506 binding protein (FKBP)-12 also binds rapamycin, another immunosuppressant which does not affect CaN activity. Using whole-cell patch clamp techniques, excitatory postsynaptic currents (EPSCs) were recorded and we analyzed the effect of immunosuppressants on the synaptic potentiation induced by pairing weak presynaptic stimulation with postsynaptic depolarization in CA1 neurons of rat hippocampal slices. We found that postsynaptic application of rapamycin or FK506, at low concentrations, but not cyclosporin A, in conjunction with weak pairing stimulation, induced NMDA-dependent long-term potentiation (LTP). The rapamycin-induced LTP was blocked by chelating intracellular Ca(2+) or by inhibiting the intracellular Ca(2+) release. Thus, Ca(2+) release from intracellular Ca(2+) stores is required for the induction of LTP by weak pairing stimulation in the presence of rapamycin or FK506 at postsynaptic sites. We propose that postsynaptic FKBP-12 regulates synaptic transmission by stabilizing the postsynaptic Ca(2+) signaling mechanism in rat hippocampal CA1 neurons.

Encoding of social exploration by neural ensembles in the insular cortex

The insular cortex (IC) participates in diverse complex brain functions, including social function, yet their cellular bases remain to be fully understood. Using microendoscopic calcium imaging of the agranular insular cortex (AI) in mice interacting with freely moving and restrained social targets, we identified 2 subsets of AI neurons—a larger fraction of “Social-ON” cells and a smaller fraction of “Social-OFF” cells—that change their activity in opposite directions during social exploration. Social-ON cells included those that represented social investigation independent of location and consisted of multiple subsets, each of which was preferentially active during exploration under a particular behavioral state or with a particular target of physical contact. These results uncover a previously unknown function of AI neurons that may act to monitor the ongoing status of social exploration while an animal interacts with unfamiliar conspecifics.

The insular cortex participates in diverse complex brain functions, including social function, but their cellular basis remains unclear. This study uses microendoscopic calcium imaging in mice interacting with conspecifics to identify “social cells” in the agranular insular cortex; multiple subsets of neurons encode distinct aspects of ongoing social behavior.

Impaired hippocampal plasticity in experimental chronic hydrocephalus

Schaffer collateral responses recorded from CA1 pyramidal cell layers in the hippocampus were analysed in kaolin-induced hydrocephalic rats. Other features of this rat model of chronic hydrocephalus were evaluated from measurements of the intracranial pressure, Na-fluorescein migration from the ventricle to the cerebral parenchyma, and behavioural changes. The results indicated that: (1) the conduction velocity of the Schaffer collaterals was unchanged; (2) the threshold to elicit population spikes was decreased; (3) the paired-pulse facilitation of EPSP tended to increase; (4) the paired-pulse inhibition of population spikes was unchanged; and (5) the long-term potentiation of population spikes was clearly attenuated in the hydrocephalic rats. The changes seen in the long-term potentiation were less pronounced in rats which underwent kaolin injection but did not develop hydrocephalus. The above findings suggest that disturbance in the postsynaptic integration processes, rather than axonal conduction or synaptic transmission, are more important for the production of the neurological deficits seen in chronic hydrocephalus. Electron microscopic observations supporting this inference are also briefly described.

Navigated transcranial magnetic stimulation for glioma removal: prognostic value in motor function recovery from postsurgical neurological deficits

OBJECTIVE The aim of the present study was to evaluate the usefulness of navigated transcranial magnetic stimulation (nTMS) as a prognostic predictor for upper-extremity motor functional recovery from postsurgical neurological deficits. METHODS Preoperative and postoperative nTMS studies were prospectively applied in 14 patients (mean age 39 ± 12 years) who had intraparenchymal brain neoplasms located within or adjacent to the motor eloquent area in the cerebral hemisphere. Mapping by nTMS was done 3 times, i.e., before surgery, and 1 week and 3 weeks after surgery. To assess the response induced by nTMS, motor evoked potential (nTMS-MEP) was recorded using a surface electromyography electrode attached to the abductor pollicis brevis (APB). The cortical locations that elicited the largest electromyography response by nTMS were defined as hotspots. Hotspots for APB were confirmed as positive responsive sites by direct electrical stimulation (DES) during awake craniotomy. The distances between hotspots and lesions (D_HS-L) were measured. Postoperative neurological deficits were assessed by manual muscle test and dynamometer. To validate the prognostic value of nTMS in recovery from upper-extremity paresis, the following were investigated: 1) the correlation between D_HS-L and the serial grip strength change, and 2) the correlation between positive nTMS-MEP at 1 week after surgery and the serial grip strength change. RESULTS From the presurgical nTMS study, MEPs from targeted muscles were identified in 13 cases from affected hemispheres. In one case, MEP was not evoked due to a huge tumor. Among 9 cases from which intraoperative DES mapping for hand motor area was available, hotspots for APB identified by nTMS were concordant with DES-positive sites. Compared with the adjacent group (D_HS-L < 10 mm, n = 6), the nonadjacent group (D_HS-L ≥ 10 mm, n = 7) showed significantly better recovery of grip strength at 3 months after surgery (p < 0.01). There were correlations between D_HS-L and recovery of grip strength at 1 week, 3 weeks, and 3 months after surgery (r = 0.74, 0.68, and 0.65, respectively). Postsurgical nTMS was accomplished in 13 patients. In 9 of 13 cases, nTMS-MEP from APB muscle was positive at 1 week after surgery. Excluding the case in which nTMS-MEP was negative from the presurgical nTMS study, recoveries in grip strength were compared between 2 groups, in which nTMS-MEP at 1 week after surgery was positive (n = 9) or negative (n = 3). Significant differences were observed between the 2 groups at 1 week, 3 weeks, and 3 months after surgery (p < 0.01). Positive nTMS-MEP at 1 week after surgery correlated well with the motor recovery at 1 week, 3 weeks, and 3 months after surgery (r = 0.87, 0.88, and 0.77, respectively). CONCLUSIONS Navigated TMS is a useful tool for identifying motor eloquent areas. The results of the present study have demonstrated the predictive value of nTMS in upper-extremity motor function recovery from postsurgical neurological deficits. The longer D_HS-L and positive nTMS-MEP at 1 week after surgery have prognostic values of better recovery from postsurgical neurological deficits.

The histochemical demonstration of monoamine oxidase-containing neurons in the human hypothalamus

Monoamine oxidase activity was revealed in a population of neurons, glial cells and some vessels in the post mortem human hypothalamus with monoamine oxidase histochemistry. The monoamine oxidase-containing neurons were observed in the caudal two-thirds of the basal hypothalamus, including the lateral hypothalamic area, tuberomammillary and posterior hypothalamic nucleus. The positive neurons were multipolar or fusiform in shape. The neuronal somata were medium to large in size, although the majority of the positive neurons were of a large type. The topographic localization of the monoamine oxidase-containing neurons in the human hypothalamus has been found to be more widespread than in the rat and cat hypothalamus, suggesting that the hypothalamic monoamine oxidase cell group is phylogenetically more highly organized in man compared with in the lower mammals.

New possibilities for stereotaxis. Information-guided stereotaxis

Information-guided stereotaxis, assisted by visualization of medical information, will become the next generation of neurosurgical systems. We performed 76 open MRI surgeries at Tokyo Women's Medical University between March 3, 2000 and April 12, 2001. Of them, comparisons of pre- and post-operative MR images for malignant gliomas in 21 cases revealed an average resection rate of 90.3% (the maximum 100%, the minimum 55%). In this article we describe real time updated navigation, augmented reality navigation, three-dimensional navigation, chemical navigation, information-guided navigation system (High definition visual Computer Aided Surgery System: HivisCAS), and open MRI-guided surgery that we are developing.

Immunohistochemical analysis of acid-sensing ion channel 2 expression in rat dorsal root ganglion and effects of axotomy

Several studies have suggested that acid-sensing ion channel 2 (ASIC2) plays a role in mechanoperception and acid sensing in the peripheral nervous system. We examined the expression and distribution of ASIC2 in the rat dorsal root ganglion, the co-localization of ASIC2 with tropomyosin-related kinase (trk) receptors, and the effects of axotomy on ASIC2 expression. ASIC2 immunoreactivity was observed in both neurons and satellite cells. ASIC2-positive neurons accounted for 16.5 +/- 2.4% of the total neurons in normal dorsal root ganglion. Most ASIC2-positive neurons were medium-to-large neurons and were labeled with neurofilament 200 kD (NF200). Within these neurons, ASIC2 was not evenly distributed throughout the cytoplasm, but rather was accumulated prominently in the cytoplasm adjacent to the axon hillock and axonal process. We next examined the co-localization of ASIC2 with trk receptors. trkA was expressed in few ASIC2-positive neurons, and trkB and trkC were observed in 85.2% and 53.4% of ASIC2-positive neurons, respectively, while only 6.9% of ASIC2-positive neurons were co-localized with trkC alone. Peripheral axotomy markedly reduced ASIC2 expression in the axotomized dorsal root ganglion neurons. On the other hand, intense ASIC2 staining was observed in satellite cells. These results show that ASIC2 is expressed in the distinct neurochemical population of sensory neurons as well as satellite cells, and that peripheral axotomy induced marked reductions in ASIC2 in neurons.

Excitatory amino acid antagonist administered via microdialysis attenuates lactate accumulation during cerebral ischemia and subsequent hippocampal damage

Our previous studies have shown that kynurenic acid (KYN), a broad-spectrum antagonist of excitatory amino acids (EAAs), administered in situ through a dialysis probe can delay the massive ionic fluxes in the rat hippocampus during cerebral ischemia. The present experiments demonstrated that the same procedure attenuates the increase in extracellular concentration of lactate ([lactate]e) during ischemia as measured by microdialysis. This finding suggests that the lactate accumulation is partially caused by a sudden increase in energy demand due to the rapid ionic fluxes through EAA-coupled ion channels. This inference is consistent with the hypothesis that the earlier ionic event during ischemia is a cause of energy depletion, rather than the result merely of energy failure. The present experiments also revealed that KYN administered by the same procedure attenuates death of hippocampal CA1 pyramidal cells after 5-min transient ischemia in gerbils. Since lactate accumulation is likely to be an important factor affecting cell viability, the protective effect of KYN may be attributable, in part, to inhibition of lactate accumulation.

Intrasellar remote metastasis from adenoid cystic carcinoma of parotid gland: case report

Adenoid cystic carcinoma is a tumor of exocrine glands originating primarily from the minor and major salivary glands, lacrimal gland, bronchus, breast, and intestinal and genital tracts. Intracranial remote metastasis from adenoid cystic carcinoma in salivary gland is quite rare. The authors encountered a case of intrasellar remote metastasis from an adenoid cystic carcinoma of parotid gland origin, presenting with hyponatremia secondary to the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). To our knowledge, this is the first reported case of metastasis from an adenoid cystic carcinoma to intrasellar area. A 78-year-old woman had an adenoid cystic carcinoma in the left parotid gland, which was resected surgically followed by local radiation therapy of 60 Gy. After 4 years, the patient presented with general malaise, followed by disturbed consciousness caused by hyponatremia. The clinical data showed severe hyponatremia induced by SIADH. An intrasellar heterogenous mass lesion compressing the optic chiasm was resected subtotally via an endonasal transsphenoidal approach. Histopathological examination of the tumor specimens revealed adenoid cystic carcinoma, which had identical histological findings as those of the painful superficial cervical lymph nodes resected in the same operation. Tumors such as the present case are easily confused with pituitary adenoma or craniopharyngioma. Although rare, metastasis from tumors including those of salivary gland origin should be considered in the differential diagnosis of unusual pituitary tumors.

The increase in local cerebral glucose utilization following fluid percussion brain injury is prevented with kynurenic acid and is associated with an increase in calcium

Immediately following a lateral fluid percussion brain injury, the cerebral cortex and hippocampus ipsilateral to the percussion show a marked accumulation of calcium and a pronounced increase in glucose metabolism. To determine if this increase in glucose metabolism was related to the indiscriminate release of the excitatory amino acid (EAA) glutamate, kynurenic acid (an EAA antagonist) was perfused into the cerebral cortex through a microdialysis probe for 30 min prior to injury. The results show that adding kynurenic acid to the extracellular space prior to trauma prevents the injury-induced increase in glucose utilization. These results indicate that calcium contributes to the ionic fluxes that are typically seen following brain injury and supports the concept of an increased energy demand upon cells to drive pumping mechanisms in order to restore membrane ionic balance.

Anterior interhemispheric approach for 100 tumors in and around the anterior third ventricle

OBJECTIVE

We report our experience with anterior interhemispheric approach for tumors in and around the anterior third ventricle, including surgical technique, instrumentation, pre- and postoperative hormonal disturbances, and resection rate.

METHODS

One hundred patients with 46 craniopharyngiomas, 12 hypothalamic gliomas, 12 meningiomas, 6 hypothalamic hamartomas, and 24 other lesions were operated on using an anterior interhemispheric approach with or without opening of the lamina terminalis. This surgical approach involves no frontal sinus opening; a narrow (approximately 15-20 mm in width) access between the bridging veins, which is sufficient to remove the tumor totally; and sparing of the anterior communicating artery. Specially designed long bipolar forceps and scissors are necessary for this approach, and concomitant use of angled instruments (endoscope, aspirator, and microforceps) is required frequently. The postsurgical follow-up period varied from 4 months to 18 years.

RESULTS

Total removal of the neoplasm was accomplished in 37 of 46 patients with craniopharyngiomas (80.4%), whereas subtotal resection was performed in hypothalamic gliomas. No significant differences in pre- and postoperative hormonal disturbances were observed in 37 craniopharyngiomas and 10 hypothalamic gliomas. There was no operative mortality. Visual acuity was preserved or improved in 68 of 75 patients assessed. The Karnofsky Performance Scale score did not deteriorate in 72 of 75 patients tested.

CONCLUSION

The minimally invasive anterior interhemispheric approach, with or without opening of the lamina terminalis, is useful for removal of tumors in and around the anterior third ventricle, such as craniopharyngiomas and hypothalamic gliomas.

Long-term outcomes following thrombectomy for acute ischemic stroke in patients with a left ventricular assist device: a case series and literature review

BACKGROUND

Left ventricular assist devices (LVADs) were developed for the treatment of patients with severe heart failure (HF) as a bridge to heart transplantation (HT). Although long-term LVAD support results in substantial improvements, their long-term use often leads to severe acute ischemic stroke (AIS). Serious neurological events make it difficult to continue LVAD support, and these patients are excluded as candidates for HT. AIS remains a challenging problem in patients receiving LVAD support. Recently, although thrombectomy has been established in selected patients who are independent, it has not been established in patients who are not completely independent, such as those with LVAD support.

METHODS

We describe four AIS patients with severe HF who were implanted with an LVAD as a bridge to HT. Five mechanical thrombectomies were performed for AIS associated with an LVAD in four patients. A literature review is presented and compared to the present results.

RESULTS

Good recanalization was achieved in all patients. In three cases, marked neurological improvement was observed, and modified Rankin Scale (mRS) scores were maintained without deterioration. The median total follow-up period was 592 days. In one patient, HT was successfully performed after thrombectomy. Currently, two of the patients without neurological deficits are awaiting HT.

CONCLUSIONS

Embolism is a major problem encountered by patients under LVAD support while waiting for an HT. Thrombectomy for AIS associated with LVAD support is a useful and safe treatment modality. It is possible to maintain a reasonable mRS score in patients who are not completely independent.

Pathogenesis of the mass effect of cerebral contusions: rapid increase in osmolality within the contusion necrosis

The non-hemorrhagic mass effect of cerebral contusions is commonly attributed to vasogenic edema and/or cytotoxic edema (cellular swelling). We propose that a marked increase in osmolality within the contusion necrosis proper, in which the cellular elements uniformly undergo shrinkage, disintegration and homogenation, represents an important and unique mechanism underlying the contusion edema. The present study demonstrates in a rat model of cerebral contusion, that 1) the osmolality of the contused brain tissue increases rapidly, 2) the increase in osmolality is not caused by changes in inorganic ion contents, suggesting a metabolic production of osmoles or release of idiogenic osmoles, and 3) the contused brain tissue strongly attracts water, provided that blood supply is maintained. We suggest that the primary driving force of water accumulation into contused brain tissue is the elevated colloid osmotic potential of contusion necrosis.

Application of indocyanine green fluorescence endoscopic system in transsphenoidal surgery for pituitary tumors

BACKGROUND

For the precise removal of pituitary tumors, preserving the surrounding normal structures, we need real-time intraoperative information on tumor location, margins, and surrounding structures. The aim of this study was to evaluate the benefits of a new intraoperative real-time imaging modality using indocyanine green (ICG) fluorescence through an endoscopic system during transsphenoidal surgery (TSS) for pituitary tumors.

METHODS

Between August 2013 and October 2014, 20 patients with pituitary and parasellar region tumors underwent TSS using the ICG fluorescence endoscopic system. We used a peripheral vein bolus dose of 6.25 mg/injection of ICG, started with a time counter, and examined how each tissue type increased and decreased in fluorescence through time.

RESULTS

A total of 33 investigations were performed for 20 patients: 9 had growth hormone secreting adenomas, 6 non-functioning pituitary adenomas, 3 Rathke's cleft cysts, 1 meningioma, and 1 pituicytoma. After the injection of ICG, the intensity of fluorescence of tumor and normal tissues under near-infrared light showed clear differences. We could differentiate tumor margins from adjacent normal tissues and define clearly the surrounding normal structures using the different fluorescent intensities time changes and tissue-specific fluorescence patterns.

CONCLUSIONS

The ICG endoscopic system is simple, user-friendly, quick, cost-effective, and reliable. The method offered real-time information during TSS to delimit pituitary and parasellar region tumor tissue from surrounding normal structures. This method can contribute to the improvement of total removal rates of tumors, reduction of complications after TSS, saving surgical time, and preserving endocrinological functions.

Hemodynamic depression and microthrombosis in the peripheral areas of cortical contusion in the rat: role of platelet activating factor

Cerebrovascular damages leading to subsequent reductions in regional cerebral blood flow (rCBF) may play an important role in secondary cell damages following traumatic brain injury (TBI). Recent studies have demonstrated that rCBF markedly decrease in experimental model of TBI (e.g. fluid percussion injury, acute subdural hematoma, contusion). However, precise mechanisms underlying post-traumatic CBF reduction remain unclear. In the present study, the rCBF changes and microthrombosis formation were investigated in a cortical contusional model in rats, and the effects of etizolam (platelet activating factor antagonist) on microthrombosis were tested. The rCBF in the peripheral areas increased transiently, and decreased to ischemic level 3 hours post- injury. The histological examinations revealed microthrombosis formation in the contused area, extending from the center to the peripheral areas within 6 hours post-injury. The rCBF decrease and the contusion necrosis volume were significantly attenuated by etizolam administration. These results indicate that platelet activating factor is involved in microthrombosis formation and hemodynamic depression, and resultant ischemic damages within areas surrounding the contusion.

Surgical management of early massive edema caused by cerebral contusion in head trauma patients

Early massive edema caused by severe cerebral contusion results in elevation of intracranial pressure (ICP) and clinical deterioration within 24-72 hours post-trauma. Previous studies indicate that cells in the central area of the contusion undergo shrinkage, disintegration, and homogenization, whereas cellular swelling is predominant in the peripheral area, suggesting that early massive edema is attributable to high osmolality within necrotic brain tissue and may generate an osmotic potential across central and peripheral areas. We analyzed the effects of surgical excision of necrotic brain tissue in 182 patients with cerebral contusion registered with Japan Neurotrauma Data Bank; 121 patients (66%; Group I) were treated conservatively, and 61 (34%; Group II) were treated surgically. Most Group II cases (90%) underwent complete excision of necrotic brain tissue and evacuation of clots. Group I demonstrated higher mortality at 6 months post-trauma compared to Group II (48%) vs. 23%; p = 0.0001; n = 182). Striking differences were observed in patients scoring 9 or more on Glasgow Coma Scale at admission (56% vs. 17%); p = 0.017; n = 45) and demonstrated "talk-and-deteriorate" (64% vs. 22%: p = 0.026; n = 29), supporting our hypothesis that early massive edema is caused by cerebral contusion accompanied by necrotic brain tissue, indicating that surgical excision of necrotic brain tissue provides satisfactory control of progressive elevation in ICP and clinical deterioration in many cases.

Monoamine oxidase-B-positive granular structures in the hippocampus of aged senescence-accelerated mouse (SAMP8)

We examined the histochemical localization of monoamine oxidase in the hippocampus of young and old senescence-accelerated mouse (SAM). We found a monoamine oxidase-B-positive granular structure (MGS) in the hippocampus of old SAMP8, an accelerated senescence-prone line of SAM. The MGS was a round-shaped granular structure of 0.5 to 5 microns diameter and usually formed a cluster, the largest diameter of which ranged from 50 to 150 microns. No MGS were found in the hippocampus of young SAMP8 or of young SAMR1, an accelerated senescence resistant line of SAM, and only few, if any, were seen in old SAMR1. A monoamine oxidase-positive astrocyte was usually observed in the central area of each cluster of MGS. Furthermore, the MGS was in close anatomical relationship with monoamine oxidase-positive astrocytic processes. The enzyme inhibition experiments showed that monoamine oxidase activities localized in the MGS and astrocytes were both predominantly of type B. These findings suggest MGS occurs at least partly in monoamine oxidase-B-positive astrocytes. Furthermore, the MGS was similar to a periodic acid-Schiff-positive granular structure, a polyglucosan body previously documented in the brains of old SAMP8 and some other aged mice strains including C57BL/6 and nude mice, in terms of their size, morphological appearances and topographical distribution in the hippocampus. Thus, the present results suggest that monoamine oxidase type B is a proteinaceous component of the periodic acid-Schiff-positive granular structure in aged mice brains, and might provide some clues for clarifying the mechanisms of age-related occurrence of periodic acid-Schiff-positive granular structures in mice brains.

The Japan Neurosurgical Database: Overview and Results of the First-year Survey

The Japan Neurosurgical Database (JND) is a prospective observational study registry established in 2017 by the Japan Neurosurgical Society (JNS) to visualize real-world clinical practice, promote science, and improve the quality of care and neurosurgery board certification in Japan. We summarize JND’s aims and methods, and describes the 2018 survey results. The JND registered in-hospital patients’ clinical data mainly from JNS training institutions in 2018. Caseload, patient demographics, and in-hospital outcomes of the overall cohort and a neurosurgical subgroup were examined according to major classifications of main diagnosis. Neurosurgical caseload per neurosurgeon in training in core hospitals in 2018 was calculated as an indicator of neurosurgical training. Of 523,283 cases (male 55.3%) registered from 1360 participating institutions, the neurosurgical subgroup comprised of 33.9%. Among the major classifications, cerebrovascular diseases comprised the largest proportion overall and in the neurosurgical subgroup (53.1%, 41.0%, respectively), followed by neurotrauma (19.1%, 25.5%), and brain tumor (10.4%, 12.8%). Functional neurosurgery (6.4%, 3.7%), spinal and peripheral nerve disorders (5.1%, 10.1%), hydrocephalus/developmental anomalies (2.9%, 5.3%), and encephalitis/infection/inflammatory and miscellaneous diseases (2.9%, 1.6%) comprised smaller proportions. Most patients were aged 70–79 years in the overall cohort and neurosurgical subgroup (27.8%, 29.4%). Neurotrauma and cerebrovascular diseases in the neurosurgical subgroup comprised a higher and lower proportion, respectively, than in the overall cohort in elderly patients (e.g. 80 years, 46.9% vs. 33.5%, 26.8% vs. 54.4%). The 2018 median neurosurgical caseload per neurosurgeon in training was 80.7 (25–75th percentile 51.5–117.5). These initial results from 2018 reveal unique aspects of neurosurgical practice in Japan.