Clinical outcomes of stereotactic biopsy on children with pontine diffuse midline glioma

INTRODUCTION

Diffuse midline glioma (DMG) of the pons occurs in pediatric patients and carries a dismal prognosis. Biopsy is not necessary for diagnosis but provides information, particularly H3K27M status, with prognostic implications. Additionally, biopsy information may open therapeutic options such as clinical trials that require mutation status. Therefore, we sought to assess the safety of surgical biopsy in DMG patients as well as its potential impact on clinical course.

METHODS

Retrospective analysis of patients who were radiographically and clinically diagnosed with pontine DMG in the last 5 years was performed. We assessed demographic, clinical, radiographic, surgical, and follow-up data.

RESULTS

25 patients were included; 18 (72%) underwent biopsy while 7 (28%) declined. 12 biopsies (67%) were performed with robotic arm and 5 (27%) with frameless stereotaxy. Three biopsied patients (17%) experienced new post-operative neurologic deficits (1 facial palsy, 1 VI nerve palsy and 1 ataxia) that all resolved at 2-week follow-up. All biopsies yielded diagnostic tissue. Fourteen patients (78%) had H3K27M mutation. Median OS for H3K27M patients was 10 months compared to 11 months in the wild-type patients (p = 0.30, log-rank test). Median OS for patients enrolled in clinical trials was 12 months compared to 8 months for non-trial patients (p = 0.076).

CONCLUSION

In our series, stereotactic pontine DMG biopsies did not carry any permanent deficit or complication and yielded diagnostic tissue in all patients. Similar post-operative course was observed in both robot-assisted and frameless stereotactic approaches. There was no significant difference in survival based on mutation status or clinical trial enrollment.

Seizure outcomes after resection of primary brain tumors in pediatric patients: a systematic review and meta-analysis

PURPOSE

Primary brain neoplasms are the most common solid tumors in pediatric patients and seizures are a common presenting symptom. Surgical intervention improves oncologic outcomes and seizure burden. A better understanding of factors that influence seizure outcomes in the surgical management of primary brain tumors of childhood can guide treatment approach thereby improving patient quality of life.

METHODS

We performed a systematic analysis using articles queried from PubMed, EMBASE, and Cochrane published from January 1990 to August 2022 to determine predictors of seizure outcomes in pediatric patients undergoing resection of primary brain tumors.

RESULTS

We identified 24 retrospective cohort studies, one prospective cohort study, and one mixed retrospective and prospective study for the systematic analysis. A total of 831 pediatric patients were available for analysis. 668 (80.4%) patients achieved seizure freedom after surgery. Complete tumor resection increased the likelihood of a seizure-free (Engel I) outcome compared to subtotal resection (OR 7.1, 95% CI 2.3-21.9). Rates of Engel I seizure outcomes did not significantly differ based on factors such as age at seizure onset, duration of epilepsy, gender, tumor laterality, or age at surgery, but trended towards significance for improved outcomes in temporal lobe tumors.

CONCLUSION

Primary brain tumors in the pediatric population are commonly associated with seizures. Resection of these lesions reduces seizure burden and is associated with high rates of seizure freedom. Complete resection, compared to subtotal resection, significantly increases the likelihood of seizure-free outcomes.

Integrated clinical genomic analysis reveals xenobiotic metabolic genes are downregulated in meningiomas of current smokers

INTRODUCTION

Meningiomas are the most common primary intracranial tumor. Recently, various genetic classification systems for meningioma have been described. We sought to identify clinical drivers of different molecular changes in meningioma. As such, clinical and genomic consequences of smoking in patients with meningiomas remain unexplored.

METHODS

88 tumor samples were analyzed in this study. Whole exome sequencing (WES) was used to assess somatic mutation burden. RNA sequencing data was used to identify differentially expressed genes (DEG) and genes sets (GSEA).

RESULTS

Fifty-seven patients had no history of smoking, twenty-two were past smokers, and nine were current smokers. The clinical data showed no major differences in natural history across smoking status. WES revealed absence of AKT1 mutation rate in current or past smokers compared to non-smokers (p = 0.046). Current smokers had increased mutation rate in NOTCH2 compared to past and never smokers (p < 0.05). Mutational signature from current and past smokers showed disrupted DNA mismatch repair (cosine-similarity = 0.759 and 0.783). DEG analysis revealed the xenobiotic metabolic genes UGT2A1 and UGT2A2 were both significantly downregulated in current smokers compared to past (Log2FC = - 3.97, padj = 0.0347 and Log2FC = - 4.18, padj = 0.0304) and never smokers (Log2FC = - 3.86, padj = 0.0235 and Log2FC = - 4.20, padj = 0.0149). GSEA analysis of current smokers showed downregulation of xenobiotic metabolism and enrichment for G2M checkpoint, E2F targets, and mitotic spindle compared to past and never smokers (FDR < 25% each).

CONCLUSION

In this study, we conducted a comparative analysis of meningioma patients based on their smoking history, examining both their clinical trajectories and molecular changes. Meningiomas from current smokers were more likely to harbor NOTCH2 mutations, and AKT1 mutations were absent in current or past smokers. Moreover, both current and past smokers exhibited a mutational signature associated with DNA mismatch repair. Meningiomas from current smokers demonstrate downregulation of xenobiotic metabolic enzymes UGT2A1 and UGT2A2, which are downregulated in other smoking related cancers. Furthermore, current smokers exhibited downregulation xenobiotic metabolic gene sets, as well as enrichment in gene sets related to mitotic spindle, E2F targets, and G2M checkpoint, which are hallmark pathways involved in cell division and DNA replication control. In aggregate, our results demonstrate novel alterations in meningioma molecular biology in response to systemic carcinogens.

Thoracolumbar Scoliosis in Pediatric Patients With Loeys-Dietz Syndrome: A Case Series

Background Loeys-Dietz syndrome (LDS) is a genetic connective tissue disorder that predominantly affects cardiovascular, skeletal, and craniofacial structures. Associated thoracolumbar scoliosis in LDS can be challenging to manage, though other etiologies of pediatric scoliosis have better-defined management guidelines. We examined our institutional experience regarding the treatment of pediatric patients with LDS and scoliosis. Methodology In this retrospective study, all patients seen at our pediatric tertiary care center from 2004 through 2018 with a diagnosis of LDS were reviewed, and those with radiographic diagnoses of scoliosis (full-length scoliosis X-rays) were included. Demographic, clinical, and radiographic parameters were collected, and management strategies were reported. Results A total of 39 LDS patients whose ages ranged between seven and 13 years were identified. A total of nine patients were radiographically diagnosed with scoliosis, but three patients were excluded due to incomplete medical records, leaving six patients. The median age at scoliosis diagnosis was 11.5 years, with a median follow-up of 51 months. Two patients were successfully managed with observation (average initial Cobb angle (CA): 14°, average final CA: 20.5°). Two were braced, one successfully (initial CA: 15°, final CA: 30°) and one with a progressive disease requiring surgery (initial CA: 40°, final CA: 58°). Of the two who were offered surgical correction, one underwent surgery with a durable correction of spinal deformity (CA: 33° to 19°). One patient underwent a recent correction of aortic root dilatation and was not a candidate for scoliosis surgery. Conclusions Principles of adolescent idiopathic scoliosis management such as bracing for CA of 20-50° and surgery for CA of >50° can be applied to LDS patients with good outcomes. This augments our understanding of the treatment algorithm for pediatric patients with LDS.

CXCR4 expression is associated with proneural-to-mesenchymal transition in glioblastoma

Glioblastoma (GBM) is the most common primary intracranial malignant tumor and consists of three molecular subtypes: proneural (PN), mesenchymal (MES) and classical (CL). Transition between PN to MES subtypes (PMT) is the glioma analog of the epithelial-mesenchymal transition (EMT) in carcinomas and is associated with resistance to therapy. CXCR4 signaling increases the expression of MES genes in glioma cell lines and promotes EMT in other cancers. RNA sequencing (RNAseq) data of PN GBMs in The Cancer Genome Atlas (TCGA) and secondary high-grade gliomas (HGGs) from an internal cohort were examined for correlation between CXCR4 expression and survival as well as expression of MES markers. Publicly available single-cell RNA sequencing (scRNAseq) data was analyzed for cell type specific CXCR4 expression. These results were validated in a genetic mouse model of PN GBM. Higher CXCR4 expression was associated with significantly reduced survival and increased expression of MES markers in TCGA and internal cohorts. CXCR4 was expressed in immune and tumor cells based on scRNAseq analysis. Higher CXCR4 expression within tumor cells on scRNAseq was associated with increased MES phenotype, suggesting a cell-autonomous effect. In a genetically engineered mouse model, tumors induced with CXCR4 exhibited a mesenchymal phenotype and shortened survival. These results suggest that CXCR4 signaling promotes PMT and shortens survival in GBM and highlights its inhibition as a potential therapeutic strategy.

Myeloid sarcoma of the skull base: A case report and systematic literature review

Background:

Myeloid sarcoma (MS), or chloroma, is a rare extramedullary malignant tumor that consists of undifferentiated granulocytic cells, and it is most commonly associated with acute myeloid leukemia (AML). Intracranial MS accounts for 0.4% of MS cases, and involvement of the skull base and visual dysfunction is rarely reported. However, the optimal treatment and response to treatment of skull base MS in the presence of visual symptoms is unknown.

Case Description:

A 30-year-old male with a history of AML presented with rapidly progressive vision loss and a sellar and parasellar mass with bilateral cavernous sinus and optic nerve encasement. The patient underwent endoscopic endonasal transsphenoidal biopsy revealing intracranial MS. He was treated postoperatively with high-dose intravenous and intrathecal cytarabine and had complete restoration of his vision by postoperative day 11. A systematic review of the literature identified six cases of skull base MS, five of whom presenting with visual symptoms. All patients underwent systemic chemotherapy with cytarabine and/or cyclophosphamide, with infrequent use of intrathecal chemotherapy or radiation. Those with reported visual outcomes were diagnosed 4 months or longer after symptom onset and demonstrated no visual improvement with treatment.

Conclusion:

Skull base MS is a rare disease entity with a high prevalence of visual dysfunction. Our patient’s complete disappearance of intracranial disease and resolution of visual symptoms with systemic and intrathecal chemotherapy highlight the importance of timely diagnosis and appropriate treatment without a need for direct surgical decompression.

PulseRider-assisted embolization of a distal anterior cerebral artery bifurcation aneurysm: illustrative case

BACKGROUND

PulseRider is an endovascular device that can be a useful adjunctive device for wide-necked bifurcation aneurysms. However, its use in distal vessels such as the anterior cerebral artery (ACA) has not been widely reported.

OBSERVATIONS

The authors reported the case of a 75-year-old woman who underwent coiling of a 6.9-mm distal ACA aneurysm with PulseRider assistance. Using a partially intraaneurysmal deployment technique, the wide-necked aneurysm was successfully embolized, resulting in Raymond-Roy class II occlusion without intra- or periprocedural complications.

LESSONS

This case illustrates a novel approach to treatment for wide-necked distal ACA aneurysms, which can be challenging to treat via traditional endovascular means. PulseRider can be safely used to treat distal ACA aneurysms with minimal residual aneurysm.

3D Modeling in Virtual Reality for Resection of a Pineal Region Falcotentorial Meningioma

We present a parietal interhemispheric approach to resect a pineal region falcotentorial meningioma. 3D modeling was utilized to visualize and plan the surgical approach in virtual reality. A 78-year-old woman was incidentally found to have a slow-growing falcotentorial meningioma. The tumor was first treated with stereotactic radiosurgery, but the patient had progressive confusion, memory issues, and bilateral temporal field cuts with interval expansion of the tumor and significantly increased peri-tumoral vasogenic edema on MRI. After recommending tumor resection, the patient consented to surgery and underwent resection via a posterior interhemispheric subsplenial approach. Using a 3D model in virtual reality, we discuss the advantages and disadvantages of various classical approaches to the pineal region for resection of this tumor.^1,2,3 Falcotentorial meningiomas often displace the deep veins inferiorly, making an interhemispheric approach more favorable.^4,5,6 Pre-operative visualization of critical deep venous structures with the 3D model was a valuable adjunct to MRI for achieving safe resection. We depict key steps of the surgical planning process using virtual reality and demonstrate how simulation can be used to evaluate risks and benefits of different surgical corridors. A small rim of residual tumor adherent to the deep cerebral veins was intentionally left behind in order to minimize risk of morbidity to the patient.⁷ At one month follow-up, the patient's cognition had returned to baseline and her vision had significantly improved. Ultimately, surgical planning using virtual reality promotes both neurosurgical education and patient safety through clear visualization and understanding of different surgical approaches.

Racial and Socioeconomic Disparities in Patients With Meningioma: A Retrospective Cohort Study

BACKGROUND

Meningiomas are the most common intracranial neoplasms. Although genomic analysis has helped elucidate differences in survival, there is evidence that racial disparities may influence outcomes. African Americans have a higher incidence of meningiomas and poorer survival outcomes. The etiology of these disparities remains unclear, but may include a combination of pathophysiology and other factors.

OBJECTIVE

To determine factors that contribute to different clinical outcomes in racial populations.

METHODS

We retrospectively reviewed 305 patients who underwent resection for meningiomas at a single tertiary care facility. We used descriptive statistics and univariate, multivariable, and Kaplan-Meier analyses to study clinical, radiographical, and histopathological differences.

RESULTS

Minority patients were more likely to present through the emergency department than an outpatient clinic (P < .0001). They were more likely to present with more advanced clinical symptoms with lower Karnofsky Performance scores, more frequently had peritumoral edema (P = .0031), and experienced longer postoperative stays in the hospital (P = .0053), and African-American patients had higher hospitalization costs (P = .046) and were more likely to be publicly insured. Extent of resection was an independent predictor of recurrence freedom (P = .039). Presentation in clinic setting trended toward an association with recurrence-free survival (P = .055). We observed no significant difference in gross total resection rates, postoperative recurrence, or recurrence-free survival.

CONCLUSION

Minority patients are more likely to present with severe symptoms, require longer perioperative hospitalization, and generate higher hospitalization costs. This may be due to socioeconomic factors that affect access to health care. Targeting barriers to access, especially to subspecialty care, may facilitate more appropriate and timely diagnosis, thereby improving patient care and outcomes.

Predictors of postoperative seizure outcome in supratentorial meningioma

OBJECTIVE

Meningiomas are the most common primary intracranial tumor. Seizures are common sequelae of meningioma development. Meningioma patients with seizures can be effectively treated with resection, with reports of seizure freedom of 60%-90%. Still, many patients manifest persistent epilepsy. Determining factors associated with worsened seizure outcomes remains critical in improving the quality of life for these patients. The authors sought to identify clinical, radiological, and histological factors associated with worse seizure outcomes in patients with supratentorial meningioma and preoperative seizures.

METHODS

The authors retrospectively reviewed the charts of 384 patients who underwent meningioma resection from 2008 to 2020. The charts of patients with a documented history of preoperative seizures were further reviewed for clinical, radiological, operative, perioperative, histological, and postoperative factors associated with seizures. Engel class at last follow-up was retrospectively assigned by the authors and further grouped into favorable (class I) and worse (class II-IV) outcomes. Factors were subsequently compared by group using comparative statistics. Univariable and multivariable regression models were utilized to identify independent predictors of worse seizure outcome.

RESULTS

Fifty-nine patients (15.4%) were found to have preoperative seizures, of whom 57 had sufficient postoperative data to determine Engel class outcome. Forty-two patients (74%) had Engel class I outcomes. The median follow-up was 17 months. Distinct margins on preoperative imaging (p = 0.012), Simpson grade I resection (p = 0.004), postresection ischemia (p = 0.019), WHO grade (p = 0.019), and recurrent disease (p = 0.015) were found to be the strongest predictors of Engel class outcome in univariable logistic regression. MIB-1 index (p = 0.001) and residual volume (p = 0.014) at last follow-up were found to be the strongest predictors of Engel class outcome in univariable generalized linear regression. Postresection ischemia (p = 0.012), WHO grade (p = 0.022), recurrent disease (p = 0.038), and MIB-1 index (p = 0.002) were found to be the strongest independent predictors of Engel class outcomes in multivariable analysis.

CONCLUSIONS

Postresection ischemia, higher WHO grade, elevated MIB-1 index, and disease recurrence independently predict postresection seizure persistence in patients with supratentorial meningioma. Further understanding of the etiology of these markers may aid in elucidation of this complex disease process and guide management to prevent worse outcomes.

Predictors of postoperative seizure outcome in supratentorial meningioma

OBJECTIVE

Meningiomas are the most common primary intracranial tumor. Seizures are common sequelae of meningioma development. Meningioma patients with seizures can be effectively treated with resection, with reports of seizure freedom of 60%-90%. Still, many patients manifest persistent epilepsy. Determining factors associated with worsened seizure outcomes remains critical in improving the quality of life for these patients. The authors sought to identify clinical, radiological, and histological factors associated with worse seizure outcomes in patients with supratentorial meningioma and preoperative seizures.

METHODS

The authors retrospectively reviewed the charts of 384 patients who underwent meningioma resection from 2008 to 2020. The charts of patients with a documented history of preoperative seizures were further reviewed for clinical, radiological, operative, perioperative, histological, and postoperative factors associated with seizures. Engel class at last follow-up was retrospectively assigned by the authors and further grouped into favorable (class I) and worse (class II-IV) outcomes. Factors were subsequently compared by group using comparative statistics. Univariable and multivariable regression models were utilized to identify independent predictors of worse seizure outcome.

RESULTS

Fifty-nine patients (15.4%) were found to have preoperative seizures, of whom 57 had sufficient postoperative data to determine Engel class outcome. Forty-two patients (74%) had Engel class I outcomes. The median follow-up was 17 months. Distinct margins on preoperative imaging (p = 0.012), Simpson grade I resection (p = 0.004), postresection ischemia (p = 0.019), WHO grade (p = 0.019), and recurrent disease (p = 0.015) were found to be the strongest predictors of Engel class outcome in univariable logistic regression. MIB-1 index (p = 0.001) and residual volume (p = 0.014) at last follow-up were found to be the strongest predictors of Engel class outcome in univariable generalized linear regression. Postresection ischemia (p = 0.012), WHO grade (p = 0.022), recurrent disease (p = 0.038), and MIB-1 index (p = 0.002) were found to be the strongest independent predictors of Engel class outcomes in multivariable analysis.

CONCLUSIONS

Postresection ischemia, higher WHO grade, elevated MIB-1 index, and disease recurrence independently predict postresection seizure persistence in patients with supratentorial meningioma. Further understanding of the etiology of these markers may aid in elucidation of this complex disease process and guide management to prevent worse outcomes.

Prolonged survival after laser interstitial thermal therapy in glioblastoma

Background:

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. Management includes surgical resection followed by chemoradiation, and prognosis remains poor. Surgical resection is not possible for some deep-seated or eloquent tumors. Laser interstitial thermal therapy (LITT) has emerged as a new, minimally invasive surgical option for deep-seated GBM.

Case Description:

We report a case of newly diagnosed thalamic GBM managed with LITT followed by radiation and chemotherapy.

Conclusion:

The patient remains well at 50-month post-LITT, indicating a potentially unique durability of LITT treatment in GBM.

Accuracy and Workflow Improvements for Responsive Neurostimulation Hippocampal Depth Electrode Placement Using Robotic Stereotaxy

Background: Robotic stereotaxy is increasingly common in epilepsy surgery for the implantation of stereo-electroencephalography (sEEG) electrodes for intracranial seizure monitoring. The use of robots is also gaining popularity for permanent stereotactic lead implantation applications such as in deep brain stimulation and responsive neurostimulation (RNS) procedures.

Objective: We describe the evolution of our robotic stereotactic implantation technique for placement of occipital-approach hippocampal RNS depth leads.

Methods: We performed a retrospective review of 10 consecutive patients who underwent robotic RNS hippocampal depth electrode implantation. Accuracy of depth lead implantation was measured by registering intraoperative post-implantation fluoroscopic CT images and post-operative CT scans with the stereotactic plan to measure implantation accuracy. Seizure data were also collected from the RNS devices and analyzed to obtain initial seizure control outcome estimates.

Results: Ten patients underwent occipital-approach hippocampal RNS depth electrode placement for medically refractory epilepsy. A total of 18 depth electrodes were included in the analysis. Six patients (10 electrodes) were implanted in the supine position, with mean target radial error of 1.9 ± 0.9 mm (mean ± SD). Four patients (8 electrodes) were implanted in the prone position, with mean radial error of 0.8 ± 0.3 mm. The radial error was significantly smaller when electrodes were implanted in the prone position compared to the supine position (p = 0.002). Early results (median follow-up time 7.4 months) demonstrate mean seizure frequency reduction of 26% (n = 8), with 37.5% achieving ≥50% reduction in seizure frequency as measured by RNS long episode counts.

Conclusion: Prone positioning for robotic implantation of occipital-approach hippocampal RNS depth electrodes led to lower radial target error compared to supine positioning. The robotic platform offers a number of workflow advantages over traditional frame-based approaches, including parallel rather than serial operation in a bilateral case, decreased concern regarding human error in setting frame coordinates, and surgeon comfort.

Identification of novel fusion transcripts in meningioma

INTRODUCTION

Meningiomas are the most common primary intracranial tumor. Recent next generation sequencing analyses have elaborated the molecular drivers of this disease. We aimed to identify and characterize novel fusion genes in meningiomas.

METHODS

We performed a secondary analysis of our RNA sequencing data of 145 primary meningioma from 140 patients to detect fusion genes. Semi-quantitative rt-PCR was performed to confirm transcription of the fusion genes in the original tumors. Whole exome sequencing was performed to identify copy number variations within each tumor sample. Comparative RNA seq analysis was performed to assess the clonality of the fusion constructs within the tumor.

RESULTS

We detected six fusion events (NOTCH3-SETBP1, NF2-SPATA13, SLC6A3-AGBL3, PHF19-FOXP2 in two patients, and ITPK1-FBP2) in five out of 145 tumor samples. All but one event (NF2-SPATA13) led to extremely short reading frames, making these events de facto null alleles. Three of the five patients had a history of childhood radiation. Four out of six fusion events were detected in expression type C tumors, which represent the most aggressive meningioma. We validated the presence of the RNA transcripts in the tumor tissue by semi-quantitative RT PCR. All but the two PHF19-FOXP2 fusions demonstrated high degrees of clonality.

CONCLUSIONS

Fusion genes occur infrequently in meningiomas and are more likely to be found in tumors with greater degree of genomic instability (expression type C) or in patients with history of cranial irradiation.

The Role of Merlin/NF2 Loss in Meningioma Biology

Mutations in the neurofibromin 2 (NF2) gene were among the first genetic alterations implicated in meningioma tumorigenesis, based on analysis of neurofibromatosis type 2 (NF2) patients who not only develop vestibular schwannomas but later have a high incidence of meningiomas. The NF2 gene product, merlin, is a tumor suppressor that is thought to link the actin cytoskeleton with plasma membrane proteins and mediate contact-dependent inhibition of proliferation. However, the early recognition of the crucial role of NF2 mutations in the pathogenesis of the majority of meningiomas has not yet translated into useful clinical insights, due to the complexity of merlin’s many interacting partners and signaling pathways. Next-generation sequencing studies and increasingly sophisticated NF2-deletion-based in vitro and in vivo models have helped elucidate the consequences of merlin loss in meningioma pathogenesis. In this review, we seek to summarize recent findings and provide future directions toward potential therapeutics for this tumor.

Endovascular "Boost": External Carotid Angioplasty to Augment Flow Before Superficial Temporal-Middle Cerebral Artery Bypass

BACKGROUND

Superficial temporal artery-middle cerebral artery (STA-MCA) bypass may be used to augment cerebral blood flow in patients with select cerebrovascular pathologies or after failed attempts at revascularization. In this article we describe the use of balloon angioplasty to boost the flow of the external carotid artery (ECA) including the STA to be later used as a donor artery for a STA-MCA bypass procedure.

CASE DESCRIPTION

A 67-year-old male with bilateral carotid artery stenosis presented 2 days after a right middle cerebral artery (MCA) stroke and was admitted for medical management. Over the next 4 days his examination worsened; magnetic resonance imaging and computed tomography perfusion confirmed a right MCA stroke with penumbra and angiography revealed complete occlusion of the right internal carotid artery within a prior carotid stent. There was also a right ECA stenosis at its origin, thus limiting options for traditional extracranial-intracranial bypass. Therefore the patient underwent balloon angioplasty of the right ECA by traversing the carotid stent followed by right STA-MCA bypass, resulting in increased flow, clinical stability, and improved cerebral perfusion.

CONCLUSIONS

This case highlights a unique strategy for the management of internal carotid artery occlusion in combination with an ipsilateral ECA stenosis. We also demonstrate the utility of endovascular adjuncts to open vascular surgery when complex patterns of stenosis or occlusion exist.

Inositol hexakisphosphate kinase-1 mediates assembly/disassembly of the CRL4-signalosome complex to regulate DNA repair and cell death

Inositol polyphosphates containing an energetic pyrophosphate bond are formed primarily by a family of three inositol hexakisphosphate (IP6) kinases (IP6K1-3). The Cullin-RING ubiquitin ligases (CRLs) regulate diverse biological processes through substrate ubiquitylation. CRL4, comprising the scaffold Cullin 4A/B, the E2-interacting Roc1/2, and the adaptor protein damage-specific DNA-binding protein 1, is activated by DNA damage. Basal CRL4 activity is inhibited by binding to the COP9 signalosome (CSN). UV radiation and other stressors dissociate the complex, leading to E3 ligase activation, but signaling events that trigger signalosome dissociation from CRL4 have been unclear. In the present study, we show that, under basal conditions, IP6K1 forms a ternary complex with CSN and CRL4 in which IP6K1 and CRL4 are inactive. UV dissociates IP6K1 to generate IP7, which then dissociates CSN-CRL4 to activate CRL4. Thus, IP6K1 is a novel CRL4 subunit that transduces UV signals to mediate disassembly of the CRL4-CSN complex, thereby regulating nucleotide excision repair and cell death.

Comparison of patients' assessment of urinary flow strength with uroflowmetry

OBJECTIVE

The objective of the study was to compare patients' self-assessment of urinary flow strength with uroflowmetry.

METHODS

The study was set in the routine uroflow clinic of the urology department. All patients had symptoms of bladder outlet obstruction. They answered 2 questions and a multiple-choice pictorial representation of flow trajectory. Patients were encouraged to provide 3 flows with at least one volume over 150 ml. The maximum flow rate Qmax was compared with the subjective evaluations.

RESULTS

Qmax was normally distributed. Answers to the questions did separate patients significantly (p < 0.001). However, overlap between groups was large; the group who answered that their flow was poor included many false positives. Pictorial assessment showed low correlation with Qmax, again with a high false-positive rate.

CONCLUSION

Patients' self-assessment of strength of stream is unreliable as a measure of Qmax and therefore of obstruction. Resection of prostate on history alone is not recommended.

Bladder transection revisited

OBJECTIVE

To ascertain the safety and effectiveness of bladder transection for the treatment of enuresis and urinary frequency.

PATIENTS AND METHODS

Twelve patients who had an open bladder transection performed at the Victoria Infirmary, Glasgow, were followed up for a mean of 37 months.

RESULTS

Of the 12 patients, three were 'cured', seven were better, two were no better and none were worse than before the operation. All six patients with preoperative enuresis were cured of this by the procedure.

CONCLUSIONS

Bladder transection remains a useful procedure in selected patients and avoids the problems associated with enterocystoplasty.

Amphotericin versus sodium stibogluconate in first-line treatment of Indian kala-azar

Patients do not always respond to treatment of visceral leishmaniasis with pentavalent antimony, and the drug has toxic effects. Amphotericin B might be useful as an alternative first-line treatment for the disease. We compared the efficacy of amphotericin and sodium stibogluconate in a prospective randomised trial in 80 uncomplicated and parasitologically confirmed cases of Indian kala-azar. None of the patients had received an antileishmanial agent before. Sodium stibogluconate was given at 20 mg/kg in two divided doses daily for 40 days, and amphotericin in fourteen doses of 0.5 mg/kg infused in 5% dextrose on alternate days. All 40 patients randomised to amphotericin were cured; of the 40 patients assigned to sodium stibogluconate, 28 (70%) showed initial cure and 25 (62.5%) showed definitive cure (p < 0.001). With amphotericin, there was quicker abatement of fever and more complete spleen regression with no serious adverse effects. Amphotericin is effective in the first-line treatment of Indian kala-azar and superior to antimony therapy.

Renal thoracic ectopia. A case report

We report a case that presented with an opacity on chest X-ray that was found to be an abnormal ectopic kidney. Renal ectopia is rare and usually does not require treatment.

Management of renal stab wounds by arteriographic embolisation

A 26 year old man was admitted with multiple stab wounds to his chest, abdomen and right loin. He was noted to have a large haemothorax, a tender abdomen and frank haematuria. At laparotomy, there was a small non expanding retroperitoneal haematoma that was not explored, and no visceral damage. Post operatively he continued to have haematuria. IVP and ultrasound showed perirenal haematoma and clot in the upper pole calyces but was otherwise normal. Renal arteriography demonstrated a pseudo-aneurysm in the right mid region, feeding an arteriovenous fistula (Figure 1). Selective renal artery embolisation with spring occlusion coils was performed which occluded the branch supplying the false aneurysm and fistula (Figure 2). He had no further haematuria. At six month follow up he remained well, normotensive and with no haematuria. Isotope renogram showed 30% loss of function at the upper pole.

Amphotericin versus pentamidine in antimony-unresponsive kala-azar

We compared the efficacy of amphotericin B and pentamidine isethionate in a prospective randomised trial in 120 uncomplicated and parasitologically confirmed cases of antimony-unresponsive kala-azar. Doses were twenty intramuscular injections of pentamidine 4 mg/kg on alternate days or fourteen definitive doses of amphotericin 0.5 mg/kg infused in 5% dextrose on alternate days. 48 (80%) patients given pentamidine showed initial cure and 46 (77%) showed definitive cure compared with 60 (100%) and 59 (98%) cases, respectively, on amphotericin (p < 0.001). Amphotericin also brought about quicker abatement of fever and more complete spleen regression.

Hypertension associated with increased renin concentrations in nephroblastoma

An infant with severe hypertension who had a nephroblastoma which was secreting active renin is described. Nephroblastoma must be included in the differential diagnosis of hypertension associated with increased renin concentrations, even in the absence of an abdominal mass.

Cisplatin therapy in recurrent childhood brain tumors

Twenty-two patients with brain tumors were initially treated with surgery, radiation therapy, and/or adjuvant chemotherapy. Histologic diagnosis included 11 gliomas, seven ependymomas, one dysgerminoma, one teratocarcinoma, one pinealoma, and one small cell tumor. At recurrence, documented on computerized tomographic scan, cisplatin (60 mg/m2/day iv X 2) was given every 3-4 weeks. Seventeen patients received two or more courses and were considered to be evaluable for response. Response parameters included change in the size of tumor on computerized tomographic scan and/or in clinical findings. Four patients had complete response, five had partial response, four had stable disease, and four had disease progression. Toxic effects were manageable. The number of patients with grade 3-4 toxic reactions, by category, were: thrombocytic, ten; leukocytic, four; renal, five; metabolic, four; gastrointestinal, none; and neurologic, seven. Two of the 14 patients tested had grade 3-4 ototoxicity. Acute fluid retention with decreased serum electrolytes and serious but reversible changes in the mental status, which were experienced in earlier patients, decreased in severity with increasing experience of the investigator. In summary, cisplatin appears to be active in a spectrum of brain tumors and should be studied further for therapeutic efficacy.

Emblica officinalis Gaertn and serum cholesterol level in experimental rabbits

Twelve albino rabbits of either sex weighing 1.0-1.25 kg were fed a standard laboratory diet of green grass and sattu (roasted Bengal gram). After a 2-week run-in period their serum cholesterol levels were estimated. All animals were now fed 0.5 g cholesterol and 1.0 g clarified butter daily and were not divided into 3 groups of 4 animals each. While all received the standard cholesterol-rich diet, Group A animals received no additional substances, animals in Group B were each fed 10 mg vitamin C daily, while those in Group C were each given 1.0 g fresh Amla (Emblica officinalis Gaertn). Mean serum cholesterol levels in all three groups rose to significantly higher levels by the end of the second week. There was a further rise by the end of the third and fourth weeks in Groups A and B. However, animals in Group C (i.e. those given Amla) showed significantly lower mean serum cholesterol levels at the end of the second week than their counterparts in Groups A and B. At the end of the third and fourth weeks the differences were even more pronounced.

Autoimmune disorders complicating adolescent Hodgkin's disease

Four adolescents with Hodgkin's disease also developed autoimmune diseases. There were two idiopathic thrombocytopenic purpura (ITP), one polymyositis, and one scleroderma. The first two patients developed ITP in the absence of a spleen, and with their Hodgkin's disease in remission. The first patient with Hodgkin's disease has been continuously free of cancer for over five years. The second patient was a 17-year-old male whoe Hodgkin's disease recurred, but whose disease was in remission at the time the ITP occurred. The polymyositis occurred in an 18-year-old youth when he was in his initial remission for his Hodgkin's disease, but his disease subsequently recurred two years later. This youth presented with Coombs positive autoimmune hemolytic anemia. The polymyositis did not respond to therapy, and he is left with severe muscle wasting and weakness; however, the polymyositis is now quiescent. The scleroderma occurred in an 18-year-old female who had been continuously free of Hodgkin's disease for eight years. The scleroderma did not respond to drug therapy and she now has moderate skin changes, but remains in continuous remission of her Hodgkin's disease. Although there are a few reports of Hodgkin's disease and concurrent autoimmune disorders, physicians dealing with cancer in adolescents should be aware of this association.

Effect of different host plants on growth and development of epilachna beetle

An experiment was conducted to study the effect of four different host plants viz., teasel gourd, bitter gourd, sponge gourd, and yard long bean on the growth and development of Epilachna dodecastigma Wied under laboratory condition. The number of eggs laid by female beetle was significantly highest feeding on teasel gourd leaves and lowest on yardlong bean leaves. Egg hatching was faster on yardlong bean and delayed on bitter gourd. The host plant, such as sponge gourd produced the large sized larvae, while large pupa and adult were developed by feeding teasel leaves. The smallest larvae, pupae, and adults were found on the consumption of yardlong bean leaves. Highest larval duration was found on sponge gourd followed by bitter gourd and yardlong bean. Both larval and adult food consumption was highest on teasel gourd and lowest on yardlong bean. Considering the biological characteristics and leaf consumption, the plant teasel gourd appeared to be the best host plant for E. dodecastigma. Key Words: Host plant, growth and development, Epilachna dodecastigma, leaf consumption. DOI: 10.3329/bjar.v34i3.3965 Bangladesh J. Agril. Res. 34(3) : 403-410, September 2009