Recovery of oculomotor nerve palsy after surgical and endovascular repair of unruptured internal carotid-posterior communicating artery aneurysms

OBJECTIVE

Unruptured posterior communicating artery (Pcom) aneurysms cause oculomotor nerve palsy (ONP). However, the time course of recovery after aneurysm repair remains unclear. We aimed to evaluate the ONP course after clipping and coiling for unruptured Pcom aneurysms.

METHODS

We retrospectively reviewed the medical records of 25 consecutive patients with ONP due to unruptured Pcom aneurysms, undergoing aneurysm repair at our institution during 2012-2022. We analyzed the clinical data, angiographic results, and surgical complications. The time to ONP recovery was evaluated using the Kaplan-Meier method.

RESULTS

This study included 14 patients undergoing surgical clipping and 11 undergoing endovascular coiling. The two groups exhibited no significant differences in complete or partial ONP percentage or in symptom presentation (ptosis, diplopia, ocular paralysis, pupillary light reflex disorder, or mydriasis). All patients achieved complete or partial recovery during the follow-up period. The median time to partial or complete improvement in ONP was significantly shorter for clipping compared to coiling (2 days vs. 33 days; p=0.009). Preoperative partial and complete ONP were stratified; clipping improved significantly earlier than coiling in the complete ONP group (p=0.010). In the early treatment group (based on the median duration of treatment), clipping resulted in earlier improvement than coiling (p=0.014). In the small aneurysm group (based on the median of the aneurysm maximum diameter), clipping resulted in earlier improvement than coiling (p=0.005).

CONCLUSION

In ONP caused by an unruptured Pcom aneurysm, clipping may provide faster recovery than coiling, particularly in cases of early onset, complete palsy, and small aneurysms.

Influence of Perioperative Three-Dimensional Computed Tomography (CT) Angiography and Surgical Clipping for Unruptured Cerebral Aneurysms on Renal Function in Patients with Chronic Kidney Disease

BACKROUND

Surgical clipping is a valuable treatment option for unruptured intracranial aneurysms in patients with chronic kidney disease (CKD). However, the comprehensive impact of clipping and perioperative three-dimensional computed tomography angiography (3D-CTA) on renal function remains unclear. This study aimed to evaluate the effects of perioperative 3D-CTA and surgical clipping on renal function in patients with CKD.

METHODS

We retrospectively analyzed 529 patients who underwent surgical clipping and perioperative 3D-CTA. An estimated glomerular filtration rate (eGFR) < 60 was defined as CKD. Patients were stratified according to their renal function (group 1: eGFR ≥60, group 2: 45 ≤ eGFR <60, group 3: 30 ≤ eGFR <45, group 4: eGFR <30 ml/min/1.73 m2), and eGFR was assessed preoperatively and 1 week and several months postoperatively.

RESULTS

Of the 529 patients, 442 did not have CKD and 87 had CKD. Hypertension, hyperlipidemia, and hyperuricemia were significantly more common in those with CKD. After the surgery and perioperative series of 3D-CTA, renal function deterioration was not observed in any group, whether in the acute or chronic postoperative period. Notably, eGFR significantly increased in groups 2 (66.7 ± 10.1, P < 0.01) and 3 (48.9 ± 9.2, P = 0.02) 1 week postoperatively, despite the CKD.

CONCLUSIONS

Surgical clipping of unruptured intracranial aneurysms and perioperative 3D-CTA with normal-dose contrast media did not impair renal function in patients with CKD. These results could be valuable in determining treatment strategies for those with CKD and intracranial aneurysms.

Clinical Outcomes in Elderly Patients with Chronic Subdural Hematoma: Validation of Irrigation Assignment Based on Hematoma Characteristics

The number of elderly patients with chronic subdural hematomas (CSDH) is increasing worldwide; however, there is limited data regarding the clinical outcomes in this population. Our therapeutic method using burr hole evacuation for CSDH is based on the hematoma characteristics, using simple drainage for single-layer lesions and drainage with irrigation for multiple-layer lesions. This study aimed to compare the postoperative outcomes of elderly and younger patients, identify the predictors of outcomes in elderly patients, and verify the validity of our therapeutic methods. In total, we included 214 patients who underwent burr hole evacuation between April 2018 and March 2022. Baseline characteristics, hematoma characteristics, recurrence, and clinical outcomes were compared between the elderly and younger patients. Overall, 96 elderly patients (44.9%) were included in the study, and more elderly patients underwent antithrombotic therapy than younger patients (33.3% vs. 19.5%, p = 0.027). Moreover, elderly patients had significantly fewer favorable outcomes than younger patients (70.8% vs. 91.5%; p < 0.001); however, this was not significant after adjusting for the baseline modified Rankin Scale (mRS). Similarly, elderly patients had higher recurrence rates than younger patients (10.4% vs. 2.5%; p = 0.021). However, the baseline mRS score was the only predictor of unfavorable outcomes. In conclusion, although the clinical outcomes of elderly patients were comparable to those of younger patients, the higher rate of preoperative antithrombotic therapy in elderly patients may result in a higher rate of recurrence requiring a long-term follow-up.

Cerebral Infarction Due to Post-traumatic Cerebral Vasospasm in a 12-Year-Old Female

Cerebral infarction due to post-traumatic cerebral vasospasm is rare. Although some modalities are recommended to detect post-traumatic cerebral vasospasm, its diagnosis remains controversial and challenging. Therefore, in this report, we will use a case report to highlight challenges and to delineate the characteristics of post-traumatic cerebral vasospasm in pediatric patients, including the diagnostic and treatment options. A 12-year-old female was admitted to our hospital following a motor vehicle collision. Her consciousness was severely impaired. Initial computed tomography (CT) revealed an acute subdural hematoma along the tentorium, and a focal subarachnoid hemorrhage was observed in the Sylvian fissure. The patient underwent the insertion of an intracranial pressure sensor and received therapy for increased intracranial pressure (ICP) control under sedation. On the second day, CT angiography (CTA) revealed no signs of arterial abnormality. A patient who is comatose or under sedation has masked neurological symptoms. Thus, new neurological events could only be detected via an intracranial pressure sensor. Her ICP increased on the seventh day, and a CT scan showed a new cerebral infarction in the right middle cerebral artery (MCA) region. We performed decompressive craniectomy to reduce ICP. Postoperative CTA confirmed severe vasospasm in the right MCA. The severe cerebral vasospasm induced the cerebral infarction. Our review suggests that physicians in trauma departments should frequently perform vascular evaluations by CTA, magnetic resonance angiography (MRA), transcranial Doppler ultrasound, or digital subtraction angiography (DSA), especially within two weeks from onset, to detect post-traumatic cerebral vasospasm.

Pharmacological Inhibition of Epidermal Growth Factor Receptor Prevents Intracranial Aneurysm Rupture by Reducing Endoplasmic Reticulum Stress

BACKGROUND

Multiple pathways and factors are involved in the rupture of intracranial aneurysms. The EGFR (epidermal growth factor receptor) has been shown to mediate inflammatory vascular diseases, including atherosclerosis and aortic aneurysm. However, the role of EGFR in mediating intracranial aneurysm rupture and its underlying mechanisms have yet to be determined. Emerging evidence indicates that endoplasmic reticulum (ER) stress might be the link between EGFR activation and the resultant inflammation. ER stress is strongly implicated in inflammation and apoptosis of vascular smooth muscle cells, both of which are key components of the pathophysiology of aneurysm rupture. Therefore, we hypothesized that EGFR activation promotes aneurysmal rupture by inducing ER stress.

METHODS

Using a preclinical mouse model of intracranial aneurysm, we examined the potential roles of EGFR and ER stress in developing aneurysmal rupture.

RESULTS

Pharmacological inhibition of EGFR markedly decreased the rupture rate of intracranial aneurysms without altering the formation rate. EGFR inhibition also significantly reduced the mRNA (messenger RNA) expression levels of ER-stress markers and inflammatory cytokines in cerebral arteries. Similarly, ER-stress inhibition also significantly decreased the rupture rate. In contrast, ER-stress induction nullified the protective effect of EGFR inhibition on aneurysm rupture.

CONCLUSIONS

Our data suggest that EGFR activation is an upstream event that contributes to aneurysm rupture via the induction of ER stress. Pharmacological inhibition of EGFR or downstream ER stress may be a promising therapeutic strategy for preventing aneurysm rupture and subarachnoid hemorrhage.

Efficacy, safety, and predictors for functional outcomes of mechanical thrombectomy in patients aged over 90 years with acute ischemic stroke and literature review

BACKGROUND

No evidence supports the efficacy and safety of mechanical thrombectomy (MT) in patients aged ≥ 90 years with acute ischemic stroke (AIS). This study clarifies the efficacy, safety, and predictors of MTs in patients aged ≥ 90 years by investigating our results and reviewing previous studies.

METHODS

We retrospectively investigated data from 80 consecutive patients who underwent MT at our hospital between 2018 and 2021. We analyzed outcomes using the modified Thrombolysis in the Cerebral Infarction (mTICI) scale and modified Rankin Scale (mRS). Functional outcomes were investigated at 90 days or discharge.

RESULTS

We obtained functional outcomes mRS ≤ 3 patients in 41.6%. The mortality rate was 16.6%. The rate of successful recanalization was 75%. Comparison mRS ≤ 3 and mRS ≥ 4 at 90 days or discharge showed statistical significance in the National Institute of Health Stroke Scale, the location of occluded vessels, and mTICI ≥ 2b at the first pass. Univariable logistic regression analysis indicated that the Alberta Stroke Program Early Computed Tomography Score was a predictor of mRS ≤ 3.

CONCLUSIONS

The efficacy is lower than that of patients aged < 90; however, MT is effective even in patients aged ≥ 90 years. The safety of MT in patients aged ≥ 90 years was similar to that in those aged < 90 years. Neuro-interventionalists should consider predictors and take the best strategies to achieve successful recanalization in patients aged ≥ 90 years with AIS.

Association between population changes and the number of endovascular thrombectomies

Background

Randomized controlled trials have demonstrated the efficacy of mechanical thrombectomy (MT) for acute ischemic stroke. However, few studies indicate an association between the number of mechanical thrombectomies and population changes. We aimed to clarify the association between population changes and the number of mechanical thrombectomies for proper allocation of limited medical resources.

Methods

We retrospectively analyzed data from 162 patients who underwent MT for large vessel occlusion at our hospitals and compared the number of mechanical thrombectomies per 100,000 person/year to population changes in five regions covered by our hospitals within 2015-2016 and 2017-2019. We performed a simple linear regression analysis to determine the association between population changes and the number of mechanical thrombectomies.

Results

Overall, the number of mechanical thrombectomies increased from 15.1 to 19. However, a significant decrease was noted in Toya Lake and Sobetsu/Toyoura. Furthermore, there was a significant negative linear correlation between the overall population reduction rate and the number of mechanical thrombectomies and a positive linear correlation between the increased proportion of the population aged >65 years and the number of mechanical thrombectomies.

Conclusion

The number of mechanical thrombectomies may decrease in areas where the overall population reduction rate exceeds 8% or the increased rate of the population aged >65 years is <4%. However, it is necessary to continue establishing a system for MT in areas that have yet to reach these levels.

Abstract TP204: Elimination Of Senescent Cells Prevents The Development Of Intracranial Aneurysm Rupture In Mice

Introduction: Aging is one of the risk factors for intracranial aneurysm rupture. Aging causes various changes in cellular homeostasis, including cellular senescence. Cellular senescence is defined as a state of irreversible cellular growth arrest. Senescence cells secrete pro-inflammatory senescence-associated secretory phenotypes (SASPs). SASPs affect surrounding cells and contribute to a vicious cycle of senescence and induce inflammation. Recent studies strongly suggest that inflammation promotes aneurysm rupture. Therefore, the accumulation of senescence cells may induce aneurysm rupture due to pro-inflammatory effects of SASPs. We hypothesized that the elimination of senescence cells reduces the aneurysm rupture. To test our hypothesis we used p16-3MR mice. P16-3MR mouse is a transgenic mouse model, in which senescence cells can be eliminated by treatment of ganciclovir (GCV). In previous reports, the elimination of senescence cells by GCV in p16-3MR mice improved senescence-related diseases. In this study, we tested whether the elimination of senescence cells by GCV in p16-3MR mice reduces the intracranial aneurysm rupture rate.

Methods: We induced intracranial aneurysms by combining systemic hypertension and a single injection of elastase into the cerebrospinal fluid in mice. We compared the vehicle to GCV group in p16-3MR aged male mice (10-15 months, vehicle vs GCV: 9 vs 6). We started GCV treatment the same day after aneurysm induction. Aneurysm rupture rate was used as the primary endpoint.

Results: There was no statistical difference in the formation rate of aneurysms between the vehicle and the GCV group. However, the aneurysmal rupture rate was significantly lower in the senescence cell-depleted mice (P < 0.05). Additionally, the symptom-free curve (Kaplan-Meier analysis curve) showed a significant reduction of aneurysm rupture in the GCV-treated group (P < 0.05).

Conclusions: The elimination of senescence cells reduced the aneurysm rupture rate in a mouse model of the aneurysm. Our results suggest that the accumulation of senescence cells induces aneurysm rupture. Therefore, the pharmacological prevention of the accumulation of senescence cells may be a new therapeutic target in aneurysm rupture.

Miliary Tuberculosis during R-MPV Therapy in an Elderly Patient with Primary Central Nerve System Lymphoma: A Case Report

Most elderly patients with tuberculosis (TB) have previously been infected with Mycobacterium tuberculosis, which remains dormant in the body for decades and may reactivate when their immunity declines due to underlying diseases. Elderly cancer patients are at a high risk for TB, and the treatment of TB reactivation in these patients is challenging. Among cancer patients, the incidence of TB reactivation is the highest in lymphoma patients. However, the impact of chemotherapy on TB reactivation in lymphoma patients is unknown. We report the case of an immunocompetent elderly patient with primary central nervous system lymphoma (PCNSL) having no prior history of TB, who developed miliary TB during multiagent chemotherapy consisting of rituximab, high-dose methotrexate, procarbazine, and vincristine (R-MPV therapy). Retrospectively, the chest computed tomography showed calcification of the pleura, suggesting that the patient had a latent tuberculosis infection (LTBI) and developed miliary TB from the reactivation of TB triggered by the R-MPV therapy. Our case emphasizes that when chemotherapy is administered to patients with PCNSL, interferon-gamma release assay (IGRA) should be performed if there are findings on chest examination suggestive of LTBI, such as pleural calcification, and if IGRA is positive, chemotherapy should be given concurrently with LTBI treatment.

Abstract TMP110: Impairment Of Efferocytosis Promotes The Rupture Of Intracranial Aneurysm

Background: Efferocytosis is an apoptotic cell clearing process that reduces the tissue-damaging effects of excessive apoptotic cells. Mer receptor tyrosine kinase (Mertk) is present on the surface of phagocyte cells, such as macrophages, and mediates efferocytosis of apoptotic cells. Cleavage of Mertk by metalloproteinases impairs efferocytosis. Several studies suggested that the severity of atherosclerosis, myocardial infarction, and aortic aneurysms were increased in Mertk KO mice due to the impairment of efferocytosis. Higher levels of apoptosis are found in ruptured aneurysms compared to in unruptured aneurysms, suggesting impaired efferocytosis in rupture-prone aneurysms. However, whether impaired efferocytosis plays a role in the pathophysiology of intracranial aneurysms is unclear. In this project, we investigated the effect of impaired efferocytosis in intracranial aneurysms.

Hypothesis: We hypothesize that impairment of efferocytosis promotes the rupture of intracranial aneurysms.

Methods: We induced intracranial aneurysms by combining systemic hypertension and a single injection of elastase into the cerebrospinal fluid in mice. Aneurysm rupture rate was used as the primary endpoint. We used Mertk knockout (KO) mice.

Results: There was no statistical difference in the formation rate of aneurysms between litter-mate control wild-type mice (WT) and Mertk KO mice. Interestingly, the aneurysmal rupture rate was significantly higher in Mertk KO mice (Mertk vs. WT: 94.7% vs. 61.5%, P < 0.05%).

Conclusions: Our experiment suggested that impairment of efferocytosis promotes aneurysm rupture. Inhibiting cleavage of Mertk may be a strategy for preventing the rupture of intracranial aneurysms.

Amyloid β aggregation induces human brain microvascular endothelial cell death with abnormal actin organization

Cerebral amyloid angiopathy (CAA) is a disease in which amyloid β (Aβ) is deposited on the walls of blood vessels in the brain, making those walls brittle and causing cerebral hemorrhage. However, the mechanism underlying its onset is not well understood. The aggregation and accumulation of Aβ cause the occlusion and fragility of blood vessels due to endothelial cell damage, breakdown of the blood-brain barrier, and replacement with elements constituting the blood vessel wall. In this study, we observed the effect of Aβ on human primary brain microvascular endothelial cells (hBMECs) in real-time using quantum dot nanoprobes to elucidate the mechanism of vascular weakening by Aβ. It was observed that Aβ began to aggregate around hBMECs after the start of incubation and that the cells were covered with aggregates. Aβ aggregates firmly anchored the cells on the plate surface, and eventually suppressed cell motility and caused cell death. Furthermore, Aβ aggregation induced the organization of abnormal actin, resulting in a significant increase in intracellular actin dots over 10 μm². These results suggest that the mechanism by which Aβ forms a fragile vessel wall is as follows: Aβ aggregation around vascular endothelial cells anchors them to the substrate, induces abnormal actin organization, and leads to cell death.

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Amyloid β (Aβ) aggregates anchor human endothelial cells to the substrate.

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Aβ induces abnormal actin organization in human endothelial cells.

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Aβ induces cell death of human endothelial cells.

Current treatment options and prognostic factors for ruptured distal anterior cerebral artery aneurysms

Background:

Distal anterior cerebral artery (ACA) aneurysms are rare, representing 1–9% of all intracranial aneurysms. The best treatment strategy for these aneurysms continues to be debated. We clarified the clinical features and treatment outcomes of patients with ruptured distal ACA aneurysms according to the treatment options at our institute.

Methods:

Thirty-seven consecutive patients (26 women; mean age, 65.2 years) with ruptured distal ACA aneurysms who underwent surgical clipping or coil embolization between 2012 and 2018 were included in the study. Clinical presentations, radiographic findings, and outcomes were retrospectively reviewed and compared between patients who underwent either surgical clipping or coil embolization. Risk factors associated with poor outcomes (modified Rankin Scale 4–6) were analyzed using multiple regression analysis.

Results:

Nineteen patients (51.4%) had World Federation Neurological Surgeons (WFNS) Grade IV-V, 18 (48.7%) had frontal lobe hematomas, and 13 (35.1%) had multiple aneurysms. Surgical clipping and endovascular coiling were performed in 28 (75.7%) and nine (24.3%) patients, respectively. Aneurysms located at the A4-5 portions were mainly treated by surgical clipping (P = 0.04). There were no significant between-group differences in procedure-related morbidity and mortality; however, the complete occlusion rate was higher in the surgical group (P < 0.01). Overall, a favorable neurological outcome at discharge (mRS 0–3) was obtained in 23 patients (62.5%). Multiple regression analysis revealed that WFNS Grade IV-V and frontal lobe hematomas were risk factors for poor outcomes (mRS 4–6).

Conclusion:

Acceptable outcomes were obtained in 62.5% of cases, and there were no significant between-group differences in treatment results between clipping and coiling. A poor WFNS grade and intracerebral hematomas were risk factors for a poor prognosis.

[Surgical Management of a Thromobotic Extracranial Carotid Artery Aneurysm:A Case Report]

Extracranial carotid artery aneurysms are relatively rare. We present a case involving a giant aneurysm arising from the extracranial carotid artery. The patient was a 79-year-old woman. She had a pulsating mass in the right side of her neck. However, she was neurologically intact. Contrast-enhanced CT scans of the neck showed an enhanced mass lesion with a thrombus in the right side of her neck. Angiography revealed a saccular aneurysm 3.4 cm in size near the bifurcation site of the right common carotid artery into the external carotid artery. She underwent an urgent resection of the aneurysm and a carotid artery reconstruction. Postoperatively, she recovered well and the total resection of the lesion was angiographically confirmed. Histopathological examination revealed that the wall of the aneurysm had undergone fibrosis and contained a few elastic fibers and microhemorrhages. The wall of the aneurysm was also infiltrated by inflammatory cells. The surgical strategy for and appropriate preoperative evaluation of this rare disease was discussed.

Disease-modifying effects of COX-2 selective inhibitors and non-selective NSAIDs in osteoarthritis: a systematic review

Osteoarthritis (OA) is a potentially disabling disease whose progression is dependent on several risk factors. OA management usually involves the use of non-steroidal anti-inflammatory drugs (NSAIDs) that are the primary pharmacological treatments of choice. However, NSAIDs have often been associated with unwanted side effects. Cyclooxygenase (COX)-2 specific inhibitors, such as celecoxib, have been successfully used as an alternative in the past for OA treatment and have demonstrated fewer side effects. While abundant data are available for the clinical efficacy of drugs used for OA treatment, little is known about the disease-modifying effects of these agents. A previous review published by Zweers et al. (2010) assessed the available literature between 1990 and 2010 on the disease-modifying effects of celecoxib. In the present review, we aimed to update the existing evidence and identify evolving concepts relating to the disease-modifying effects of not just celecoxib, but also other NSAIDs. We conducted a review of the literature published from 2010 to 2016 dealing with the effects, especially disease-modifying effects, of NSAIDs on cartilage, synovium, and bone in OA patients. Our results show that celecoxib was the most commonly used drug in papers that presented data on disease-modifying effects of NSAIDs. Further, these effects appeared to be mediated through the regulation of prostaglandins, cytokines, and direct changes to tissues. Additional studies should be carried out to assess the disease-modifying properties of NSAIDs in greater detail.

Hyperperfusion syndrome after aneurysm surgery: a case report

A 74-year-old woman exhibited sensory aphasia with abrupt blood pressure elevation 3 h after clipping of an unruptured large left middle cerebral artery aneurysm. Perfusion computed tomography and single-photon emission computed tomography demonstrated hyperperfusion in one of the distal parent artery areas. She gradually improved and was discharged without neurological deficits. Increased distal blood flow after occlusion of the large cerebral aneurysm and postischemic reperfusion after temporary occlusion of the parent artery during surgery presumably played an important role in the occurrence of this fairly rare condition associated with aneurysm surgery.

Lymph node metastases in hamster tongue cancer induced with 9,10-dimethyl-1,2-benzanthracene: association between histological findings and the incidence of neck metastases, and the clinical implications for patients with tongue cancer

An experimental study was carried out in hamster tongue cancer induced with 9,10-dimethyl-1,2-benzanthracene (DMBA) to examine the association between the histological features and the incidence of lymph node metastases. Squamous cell carcinoma was induced in 64 of 71 hamsters exposed to DMBA 3 times weekly for a period of 10-24 weeks, and lymph node metastases were found in 8 necks. Various histological variables in the primary lesion were examined, and the mode of invasion, degree of keratinization, and stage of invasion were found to be closely related to the development of neck metastases. We then did a prospective study in 37 human patients with T1-2 tongue cancer, which also showed a close association between the incidence of neck metastases and the histological variables of mode of invasion and degree of keratinization. These experimental and clinical studies suggest that the mode of invasion and degree of keratinization may be risk factors for neck metastases that are independent of T stage, and that the indications for elective neck dissection should be re-evaluated in that light.

DNA-dependent protein kinase inhibitor (OK-1035) suppresses p21 expression in HCT116 cells containing wild-type p53 induced by adriamycin

The tumor growth suppressor p21 has been shown to be induced by wild-type p53 (wt-p53) and to be a potent inhibitor of cyclin-dependent kinases and PCNA/DNA polymerase delta. Although wt-p53 is reported to be phosphorylated by several protein kinases, the function and significance of the phosphorylation of wt-p53 are not yet fully understood. Using OK-1035, a selective inhibitor of DNA-dependent protein kinase (DNA-PK), we demonstrated the importance of the phosphorylation of wt-p53 by DNA-PK in the DNA damage-mediated expression of the p21 gene. Treatment of HCT116, a human colon carcinoma cell line, with adriamycin induced the expression of wt-p53 and p21. By addition of OK-1035 to this culture, the induction of p21 protein was significantly decreased in a dose-dependent manner, whereas wt-p53 induction was not affected. Northern blot analysis revealed that suppression of p21 protein expression by OK-1035 resulted from reduction in the level of p21 mRNA. OK-1035 did not directly affect the binding ability of wt-p53 to its consensus DNA sequence. Our observations support the idea that wt-p53 induces the transcriptional activation of the p21 gene only after it is phosphorylated by DNA-PK.

OK-1035, a selective inhibitor of DNA-dependent protein kinase

Screening for inhibitors of DNA-dependent protein kinase (DNA-PK) revealed 3-cyano-5-(4-pyridyl)-6-hydrazonomethyl-2-pyridone, designated OK-1035, to be a potent and selective inhibitor. When a synthetic peptide was used as a substrate, OK-1035 caused 50% inhibition of DNA-PK activity at 8 microM, a concentration more than 50 times lower than those required against seven other protein kinases tested. OK-1035 inhibited the phosphorylation by DNA-PK of consensus peptide as well as that of recombinant human wild type-p53. Kinetic studies indicated that OK-1035 inhibited DNA-PK activity in an ATP-competitive manner.

The possible involvement of DNA-dependent protein kinase in the phosphorylation of P1 protein in cell-free DNA replication of Xenopus eggs

We prepared two types of antibodies: one directed against an oligopeptide corresponding to the C-terminal portion of P1 protein and the other against an oligopeptide corresponding to the C-terminal portion of the 80-kDa subunit of the Ku antigen (p80 Ku) essential for DNA-dependent protein kinase (DNA-PK) activity. Immunoprecipitation and immunoblot of sperm nuclei preincubated in Xenopus egg extracts by anti-P1 antibody showed that Xenopus P1 protein is a phosphoprotein with two phosphorylated forms: a hyperphosphorylated form extractable with Triton X-100 and a hypophosphorylated form resistant to Triton X-100. The immunodepletion of extracts with anti-p80 Ku IgG-bound beads caused the hyperphosphorylated form to disappear but hardly affected the hypophosphorylated form of P1 protein. DNA replication was stimulated by immunodepletion of the extract with anti-p80 Ku IgG-bound beads. These findings suggest that DNA-PK down-regulates DNA replication through inhibition of hyperphosphorylation of P1 protein during S phase in this cell-free system.

Lymph node metastasis in squamous cell carcinoma of the oral cavity: correlation between histologic features and the prevalence of metastasis

A retrospective study was made of the correlation between preoperative clinical or histologic findings and the prevalence of lymph node metastasis in 60 patients with squamous cell carcinoma of the oral cavity who had histologically confirmed neck metastasis. Of these 60 patients, 39 with clinically N+ necks underwent immediate therapeutic neck dissection, and 21 whose necks were initially N0 but progressed to N+ during observation underwent subsequent therapeutic neck dissection. The primary site, TNM staging, histologic grade of malignancy of biopsy specimen, and location and number of histologically positive lymph nodes were reviewed in each case. The results were as follows: (1) The prevalence of neck metastasis was not significantly correlated with primary site and T stage; however, there was an apparent correlation between histologic grade of malignancy and the prevalence of neck metastasis. Patients with grade I-II histologic malignancy showed limited metastases that involved lymph nodes in levels I-II. On the other hand, patients showing grade III-IV histologic malignancy often had metastases that extended beyond level III, regardless of T stage. These results suggest that histologic grade of malignancy, as well as clinical features, must be taken into consideration when deciding whether supraomohyoid neck dissection is indicated. (2) The group that underwent subsequent neck dissection exhibited less advanced neck metastasis and a better prognosis than the group which underwent immediate neck dissection. These findings show that if they are closely followed up, it is possible to delay neck dissection in N0 patients until a neck metastasis is detected.

Inhibition of proliferation of human immunodeficiency virus type 1 by novel heteropolyoxotungstates in vitro

Fifteen heteropolyoxotungstates were tested for their effects on the proliferation of human immunodeficiency virus type 1 (HIV-1) using an in vitro system consisting of MT-4 cells and HTLV-IIIb. Eight heteropolyoxotungstates (HPOTs) with the Keggin structure or dimerized deficient Keggin structure proved to be potent inhibitors of HIV-1. In contrast, seven non-Keggin HPOTs including HPA 23 did not have significant effects on HIV-1 proliferation at non-toxic doses. [PTi2W10O40]7- (PM-19) was the most potent inhibitor of HIV-1 among the 15 HPOTs tested. The inhibition of HIV-1 replication by PM-19 presumably results from impaired virus adsorption and/or penetration into target cells. Viral spread of HIV-1 and HIV-2 on cell-to-cell basis was also susceptible to PM-19. In combination, PM-19 and 3'-azido-3'-deoxythymidine were synergistic in inhibiting HIV-1 proliferation.

Inhibition of replication of human immunodeficiency virus by a heteropolyoxotungstate (PM-19)

A Keggin polyoxotungstate PM-19 K7[PTi2W10O40].6H2O was found to be a potent inhibitor of the replication of human immunodeficiency virus (HIV), which causes acquired immunodeficiency syndrome (AIDS), in OKT4+ cells. In contrast, the effect of HPA 23 (NH4)17Na[NaSb9W21O86], an inhibitor of reverse transcriptase of HIV, was not significant.

Biological properties of streptonigrin derivatives. III. In vitro and in vivo antiviral and antitumor activities

Antitumor antibiotic streptonigrin (STN-COOH) is a potent inhibitor of avian myeloblastosis virus (AMV) and human immunodeficiency virus reverse transcriptases. The carboxyl group at 2'-position of STN-COOH was modified to give esters, hydrazide, amides and amino acid derivatives for biological studies. Against AMV reverse transcriptase, the hydrazide, amides and amino acid derivatives showed inhibitory activity, which compared favorably to that of STN-COOH, with the ID50 values ranging 2-8 micrograms/ml. In contrast, the esters lacked this activity except for those having a dimethylamino group in the substituent. Splenomegaly caused by Friend leukemia virus infection was significantly inhibited by STN-COOH and STN-COO(CH2)3N(CH3)2, but not STN-CONH(CH2)3N(CH3)2. Doxorubicin-resistant murine lymphoblastoma L5178Y cells showed collateral sensitivity to both STN-COOH and STN-COO(CH2)3N(CH3)2 not only in vitro but also in vivo.

Effects of idebenone on memory impairment induced in ischemic and embolization models of cerebrovascular disturbance in rats

Two rat models of memory impairment in passive avoidance learning induced by cerebrovascular disturbance, were established to estimate the effects of a cerebral metabolic enhancer, idebenone. Transient and global cerebral ischemia in rats, produced by 4-vessel occlusion for 200 s immediately after the acquisition trial of passive avoidance learning, shortened the latencies in the retention test trial performed 24 h later. This retrograde amnesia was reversed significantly by idebenone administered orally or intraperitoneally at the doses of 10 and 30 mg/kg before the retention test trial. Idebenone at a dose of 10 mg/kg, given intraperitoneally before or immediately after the ischemia, also markedly inhibited the appearance of amnesia. In the second model, permanent and cerebral hemisphere embolization produced by injecting 2,000 microspheres into the internal carotid artery, significantly impaired passive avoidance learning performed 7 days later. The repeated administration of idebenone (30 mg/kg, i.p.). once a day after the embolization, significantly improved the impairment of passive avoidance learning in the embolized rats. Furthermore, physostigmine and arginine-vasopressin as reference compounds improved the impairment of passive avoidance learning in these models. These findings suggest that idebenone ameliorates memory impairment induced by cerebral vascular disturbance in rats.

Comparative studies of the inhibitory properties of antibiotics on human immunodeficiency virus and avian myeloblastosis virus reverse transcriptases and cellular DNA polymerases

The inhibition of human immunodeficiency virus (HIV) reverse transcriptase by certain antibiotics and related compounds was studied in comparison with that of avian myeloblastosis virus (AMV) reverse transcriptase and cellular DNA polymerases alpha and beta. In general, compounds that inhibited HIV reverse transcriptase also inhibited AMV reverse transcriptase. For example, 10 micrograms/ml of the isoquinoline quinones used in this study inhibited approximately 80% of the activity of reverse transcriptases of HIV and AMV, but did not inhibit the activity of DNA polymerases alpha and beta even at 50 micrograms/ml. AMV enzyme was more sensitive than HIV enzyme to colistin, enduracidins A and B, janiemycin, glysperin A, and thielavins A and B. The streptonigrin alkyl esters, however, inhibited HIV reverse transcriptase only. Sakyomicin A, luzopeptins, ellagic acid and suramine inhibited the activities of reverse transcriptases and cellular DNA polymerases.

Comparative study on biological activities of heterocyclic quinones and streptonigrin

Thirteen heterocyclic quinones (5 quinoline quinones, 7 isoquinoline quinones, 1 indole quinone) were tested for their effects on avian myeloblastosis virus reverse transcriptase, growth of murine lymphoblastoma L5178Y cells, respiration of rat liver mitochondria and oxidation of NADH by Clostridium kluyveri diaphorase in comparison with those of streptonigrin, in which the quinoline quinone moiety is considered to play a crucial role. Most of the quinoline quinones and isoquinoline quinones inhibited reverse transcriptase to the same extent as streptonigrin with the ID50 values ranging between 1 and 5 micrograms/ml, whereas the ID50 value of the indole quinone derivative, 4,7-dihydro-2,3-dimethylindole-4,7-dione, was 80 micrograms/ml. The cytotoxicities of the quinones were much lower than that of streptonigrin; the ID50 values of the quinones were higher than 0.15 micrograms/ml. In particular, the ID50 value of the ortho-quinoline quinone derivative, 8-methoxy-7-methyl-5,6-dihydroquinoline-5,6-dione, was as high as 16 micrograms/ml, while the 50% inhibition of cell growth was seen in the presence of 0.0025 micrograms/ml streptonigrin. The membrane transport of the quinones was evaluated by comparing the effects on oxygen consumption by mitochondria and oxidation of NADH by bacterial diaphorase, being proven not to be responsible for their lower cytotoxicities.

Role of the naphthoquinone moiety in the biological activities of sakyomicin A

The naphthoquinone moiety was proven to be essential to the biological activities of sakyomicin A using various naphthoquinone derivatives. Among the naphthoquinones tested, juglone (5-hydroxy-1,4-naphthoquinone) which resembles the partial structure of sakyomicin A was the most active in cytotoxicity against murine lymphosarcoma L5178Y cells, electron acceptor function in the oxidation of NADH by Clostridium kluyveri diaphorase or rat liver mitochondria and inhibition against avian myeloblastosis virus reverse transcriptase. The significantly lower cytotoxicity of sakyomicin A as compared with juglone was attributable to its poor membrane transport. The inhibition of reverse transcriptase activity may result from the interaction between a sulfhydryl group in the active center of the enzyme and quinone groups of the naphthoquinones and sakyomicin A.

Inhibition by sakyomicin A of avian myeloblastosis virus reverse transcriptase and proliferation of AIDS-associated virus (HTLV-III/LAV)

In the course of screening for inhibitors of reverse transcriptase, we have isolated an inhibitor from a strain of Nocardia and identified it as sakyomicin A. The antibiotic blocks avian myeloblastosis virus reverse transcriptase reaction: IC50 was ca. 30 micrograms/ml by the method employed. The drug affects proliferation of HTLV-III/LAV in HTLV-I-carrying MT-4 cells: ca. 60% inhibition was observed at an antibiotic concentration of 1.0 microgram/ml and ca. 20% inhibition at 0.1 microgram/ml, and there was no significant cytotoxicity.

[Pharmacological study of the temporary cerebral ischemic rats produced by bilateral vertebral and carotid artery occlusion. Effects of DN-1417]

We investigated the ameliorating effects of DN-1417 (a TRH analog) on the changes of behavior, EEG, neurochemical parameters and regional cerebral blood flow (rCBF) in rats with global cerebral ischemia. Global cerebral ischemia was produced by 10-min occlusion of both common carotid arteries 24 hr after the permanent electrocauterization of bilateral vertebral arteries. DN-1417 was administered intraperitoneally as soon as possible, following recirculation of carotid blood flow. DN-1417 shortened significantly the recovery times of righting reflex (RR) and spontaneous movement (SM) at 2.5 mg/kg and higher doses, and it recovered effectively the EEG activity at 10 mg/kg during recirculation after 10-min cerebral ischemia. In addition, DN-1417 (10 mg/kg) recovered the various changes such as decrease of 5-hydroxytryptamine (5-HT) levels, increase of cyclic AMP (cAMP) levels, inhibition of [3H]-choline uptake, depression of choline acetyltransferase (CAT) and acetylcholine esterase (AChE) activities, and shortened the durations of hyperperfusion and hypoperfusion of rCBF. As a result, it is identified that DN-1417 ameliorates the disturbance of consciousness supposedly caused by behavioral and EEG abnormalities during recirculation following the temporary cerebral ischemia, and the effect of DN-1417 seems to be mediated by normalizing of alterations in the brain monoaminergic and cholinergic systems, as well as rCBF, and the effectiveness for disturbance of consciousness in clinical situations would be expected.

[Regional cerebral blood flow in rats with cerebral ischemia produced by bilateral vertebral and carotid artery occlusion]

Regional cerebral blood flow (rCBF) was measured prior to, during and after global cerebral ischemia in rats. Global cerebral ischemia was produced by 10 or 30-min occlusion of both common carotid arteries which was done 24 hr after the permanent electrocauterization of bilateral vertebral arteries. The rCBF was measured using the radioactive microsphere technique. In rats subjected to 10-min cerebral ischemia, rCBF in 9 brain regions was reduced to 11.3-54.8% (mean: 26.9%) of that of the sham operated control. Ten min after recirculation, hyperperfusion was observed in the cerebral cortex, hippocampus and striatum, and a moderate recovery was detected in the n.accumb. + olfactory tub., thalamus and hypothalamus. However, rCBF in these 6 regions was again decreased 20-30 min later, and it recovered to levels more than 50% of the control 60 min after the ischemic event. In the other 3 regions (cerebellum, colliculus sup. + inf., pons + medulla), rCBF increased toward the control level gradually, and it completely recovered 60 min after recirculation. On the other hand, in rats subjected to 30-min cerebral ischemia, rCBF in 9 brain regions was reduced to 1.77-26.3% (mean: 9.6%) of that of the control. The post-ischemic hyperperfusion in the cerebral cortex and hippocampus and a moderate recovery of rCBF in the striatum and n.accumb. + olfactory tub. were observed 10 min after the cerebral ischemia. However, rCBF in these 4 regions remained under the control levels from 20 to 60 min after recirculation.(ABSTRACT TRUNCATED AT 250 WORDS)

[Neurochemical study of the temporary cerebral ischemic rats produced by bilateral vertebral and carotid artery occlusion]

The effects of global cerebral ischemia on neurochemical parameters in the brain were examined in rats. Global cerebral ischemia was produced by temporary occlusion of the bilateral common carotid arteries 24 hr after the permanent electrocauterization of the bilateral vertebral arteries. In 10-min cerebral ischemic rats, the brain levels of monoamine were unaltered. The brain levels of gamma-aminobutyric acid (GABA), which increased about 1.5-fold just before recirculation, almost recovered to the levels of the sham operated group (sham ope. levels) within 5 min after recirculation. The brain levels of cyclic AMP (cAMP), although they altered a little just before recirculation, increased about 6-fold 1 min after recirculation, and they recovered to the sham ope. levels 3-5 min later. In 30-min cerebral ischemic rats, the brain levels of monoamine decreased to about 40% of the sham ope. levels just before recirculation, and norepinephrine (NE) and 5-hydroxytryptamine (5-HT) levels did not recover within 30 min after recirculation in the telencephalon. The brain GABA levels which increased about 2-fold just before recirculation, recovered to the sham ope. levels in all brain regions by 30-min recirculation except for the levels in cerebral cortex and cerebellum. The brain cAMP levels which increased about 3.5-fold 10 min after recirculation, almost recovered 20 min later. However, the cAMP levels in the telencephalon decreased to levels lower than the sham ope. levels 30 min after recirculation. It is suggested that the changes of these neurochemical parameters in the telencephalon are related in part to the abnormalities of behavior and EEG activity which have been already reported.

[Physiological and biochemical study of temporary cerebral ischemic rats produced by bilateral vertebral and carotid artery occlusion]

We investigated the changes of behavioral, electrophysiological and biochemical parameters during and after global cerebral ischemia in rats. Global cerebral ischemia was produced by the temporary occlusion of both common carotid arteries 24 hr after the permanent electrocauterization of bilateral vertebral arteries. Just before recirculation following 10 or 30 min of cerebral ischemia, loss of righting reflex, flattenning of cortical EEG activity, and detrimental decrease of ATP content and marked increase of lactate content in the cerebrum were observed. The alterations of all parameters completely recovered within 60 min after recirculation in 10-min cerebral ischemic rats. However, the 30-min cerebral ischemic rats showed almost no recovery after recirculation, suggesting that some irreversible damages are produced in the cerebrum of the 30-min ischemic rat. On the other hand, it was found that the auditory brain stem evoked response (ABER) and ATP content in the pons plus medulla were only slightly affected by the ischemic procedure, which indicates that the ischemic damages do not ensue in the lower part of the brain stem.

Beneficial effect of idebenone (CV-2619) on cerebral ischemia-induced amnesia in rats

An experimental model of amnesia induced by cerebral ischemia after one-trial passive avoidance learning was established to test the effects of a novel compound, 6-(10-hydroxydecyl)-2,3-dimethoxy-5-methyl-1,4-benzoquinone (idebenone, CV-2619), and some commonly used drugs in rats. One day after the vertebral artery was electrocauterized bilaterally, the common carotid artery was transiently occluded bilaterally to produce cerebral ischemia. The amnesia was estimated by the response latency for a rat to step from a light safety compartment to a dark compartment in which a foot-shock was given. The results of the retention test given 24 hr after the ischemia indicated that amnesia was successfully produced when the 200-600 sec ischemia was provided within 20 min after the avoidance learning. The effects of drugs on the amnesia induced by a 200-sec ischemia immediately after the avoidance learning were as follows: CV-2619 (10, 30 mg/kg, i.p. or p.o.) given before the retention test significantly increased the response latency, indicating a reversal effect on the amnesia. Physostigmine (0.1, 0.2 mg/kg, i.p.) and arginine-vasopressin (10 micrograms/kg, s.c.) were also effective, and calcium hopantenate (500 mg/kg, p.o.) showed a slight reversal action. Furthermore, CV-2619 (10 mg/kg, i.p.), given before or after the ischemia, significantly inhibited the appearance of amnesia.(ABSTRACT TRUNCATED AT 250 WORDS)