Cases of Mixed Schwannoma-Meningioma With and Without Neurofibromatosis 2 with Emphasis on Tumorigenesis

Concurrent occurrence of schwannoma and meningiomas are rare, and are found especially in association with neurofibromatosis type 2 (NF2). Occurrence of mixed tumor without the aforementioned conditions is extremely rare. We present three cases of mixed tumor in different locations, including two with NF2 and one without NF2. We analyse the relationship of mixed tumor with NF2 and its clinical implications. Presence of mixed schwannoma-meningioma should prompt screening for NF2. Thus aids in early diagnosis of unsuspected NF2 cases. We observed that irrespective of different locations, cases with NF2 showed frequent recurrence of schwannoma as compared to case who did not fit in the existing clinical criteria for NF2. Collision tumor and thereby NF2 mutations indicates the prognosis and recurrence of the tumor, thereby guides in deciding the management.

Correlation between choroid plexus carcinoma and Li-Fraumeni syndrome: implications of TP53 mutations and management strategies-a case-based narrative review

BACKGROUND

Choroid plexus carcinomas (CPCs) are rare, aggressive grade 3 tumors of the central nervous system associated with Li-Fraumeni syndrome (LFS) in a notable percentage of cases due to TP53 germline mutations. Understanding the correlation between CPCs and LFS is crucial for tailored management strategies. However, distinguishing CPCs from benign choroid plexus papillomas (CPPs) remains challenging, relying largely on histologic features. This study aimed to explore the association between CPCs and LFS, emphasizing the impact of TP53 mutations on diagnosis, treatment, and clinical outcomes.

MATERIALS AND METHODS

Scientific databases such as PubMed, Scopus, and Web of Science were systematically searched up to January 2024 using keywords related to CPCs, LFS, TP53 mutation, and central nervous system tumors. Selection criteria included studies investigating the link between CPCs and LFS, their management approaches, and genetic implications of TP53 mutations. Ten relevant studies were selected for analysis after screening titles, abstracts, and full-text articles. Data extraction focused on clinical, genetic, and management factors related to CPCs associated with LFS.

RESULTS

The review highlighted the strong association (36%) between CPCs and LFS, primarily due to TP53 germline mutations. Studies emphasized the need for genetic testing in patients with CPCs, especially in pediatric cases, to identify LFS implications. Furthermore, the impact of TP53 mutations on treatment strategies was emphasized, recommending irradiation-sparing therapies due to inferior survival rates associated with radiotherapy in LFS patients with CPCs. Cases illustrated the challenges in diagnosing CPCs and the importance of immunohistochemistry and genetic testing for TP53 mutations.

CONCLUSION

CPCs pose challenges in diagnosis and management, particularly in distinguishing them from benign tumors. The association with LFS, often due to TP53 germline mutations, underscores the importance of genetic testing for early detection and tailored treatment strategies. Irradiation-sparing therapies are recommended for LFS-associated CPCs to mitigate the risk of secondary malignancies. Comprehensive profiling of CPC patients, especially in pediatric cases, is crucial for early detection and management of potential secondary cancers associated with LFS.

Author Response

How to cite this article: Vaithialingam B, Gopal S, Masapu D. Author Response. Indian J Crit Care Med 2024;28(1):87-88.

Spring-Assisted Cranial Expansion for Multisuture Craniosynostosis: First Case Report from the Indian Subcontinent

We present a first use case report from the Indian subcontinent of a 5-month-old child with multisuture craniosynostosis with raised intracranial pressure managed by spring-assisted cranial expansion followed by traditional fronto-orbital advancement and cranial vault remodeling. We emphasize the advantages of spring-assisted cranial expansion in extremely young infants with raised intracranial pressure over posterior vault distraction osteogenesis and open posterior vault remodeling.

"Locked-in State" Following Anterior Circulation Aneurysmal Subarachnoid Hemorrhage

How to cite this article: Vaithialingam B, Gopal S, Masapu D. "Locked-in State" Following Anterior Circulation Aneurysmal Subarachnoid Hemorrhage. Indian J Crit Care Med 2023;27(8):601-602.

Anesthetic management of super-selective intra-arterial Melphalan injection in an infant with retinoblastoma

Intra-arterial Melphalan injection is an emerging treatment for children with advanced retinoblastoma. The procedure, which is frequently performed under general endotracheal anesthesia, can be complicated by technical difficulty and cardiorespiratory instability, which the anesthesiologist should be aware of. We describe the anesthetic management and special concerns during super-selective intra-arterial Melphalan injection in an infant with advanced retinoblastoma.

Catheter Embolization of an Orbital Arteriovenous Fistula in a Patient With Wyburn-Mason Syndrome

A 24-year-old female presented to the emergency department with swelling of the forehead and oculus sinister. A soft, compressible glabellar swelling with proptosis of the oculus sinister was noted on clinical examination. Cerebral angiography revealed a left medial orbital wall arteriovenous fistula with feeders from the left internal maxillary artery, left superficial temporal artery, and left ophthalmic artery. During the cerebral angiography, a diffuse intracranial venous anomaly and left basal ganglia arteriovenous malformations were also noted. A diagnosis of Wyburn-Mason syndrome was made, and the patient underwent catheter embolization of the orbital arteriovenous fistula. After glue embolization of the left external carotid artery feeders, the patient experienced a 50% reduction in glabellar swelling in the immediate postoperative period. Glue embolization of the left ophthalmic artery feeder was planned after six months during the follow-up period.

Modern cemented Furlong hemiarthroplasty: Are dislocations rates better?

BACKGROUND

Dislocation following hip hemiarthroplasty is a major complication with increased mortality and morbidity. Data looking at dislocation following contemporary bipolar stems are lacking in literature.

METHODS

Retrospective review of our prospective national hip fracture database over a two-year period. Group 1 comprised of consecutive patients receiving bipolar Furlong prosthesis (N222) while Group 2 was made up of a historical cohort (uncemented; N254). Clinical and radiological records were reviewed to determine dislocation rates, causes and associative factors of dislocations. Data were analysed using SPSS.

RESULTS

Following 476 hemiarthroplasties performed during the study period, 12 (2.5%) dislocations were reported (eight in Group 1; four in Group 2). There was no significant difference in dislocation rates (3.6% vs 1.6%) between groups (p = 0.159). Subgroup analysis of Group 1 demonstrated a significant difference in dislocations with Furlong cemented (6%) as compared with Furlong uncemented (0%) hemiarthroplasties (p = 0.024). Following dislocation, death rates increased to 8.3% from 1.7% in both groups.

CONCLUSION

There is a statistically significant increase in dislocation rate following use of cemented Furlong prosthesis when compared to similar uncemented prosthesis at the same treatment period. However, when compared to traditional uncemented prosthesis, there is no difference in dislocation rates.

In hospital outcomes of orbital/rotational coronary atherectomy in diabetic vs non-diabetic population: insights from the nationwide inpatient sample

Background

Atherectomy (AT) using an orbital/rotational system is useful in altering calcified plaque thereby facilitating stent placement and optimal stent expansion. Patients with diabetes mellitus (DM) are known to have a higher rate of complications after percutaneous coronary intervention. We aimed to assess the incidence of major adverse cardiovascular events after atherectomy in the diabetic population using a nationwide inpatient sample (NIS).

Methods

NIS-HCUP database from 2015–2017 was used to identify patients who underwent atherectomy. A cohort of patients with and without diabetes was identified. Demographics, in-hospital outcomes, complications in both groups were compared. Statistical significance was assigned at p<0.05.

Results

Out of 6184 patients who underwent AT, 3134 (50.6%) patients had DM. Baseline characteristics have been outlined in the table below. Complications were comparable between the two groups except for higher incidence of post-procedure VTE in Diabetic patients. In-hospital mortality was lower among patients with DM (2.24% vs 3.29%, p-0.27), while the mean length of stay (5.92 vs 4.91 days, p-0.002) and the hospitalization charges ($165118.4 vs 151226, p-0.04) were higher, but this difference in length of stay and hospitalization charges were nullified on multivariate regression.

Conclusion

Our study suggests that an AT for severely calcified plaque in the coronary artery is a safe option in patients with DM with comparable in-hospital complications and outcomes to non-DM patients.

Funding Acknowledgement

Type of funding sources: None. Demographics and Outcomes of Atherectomy

Multidisciplinary Management of Primary Sacral Tumors: A Tertiary Care Center's Experience and Literature Review

Sacral tumors are rare and can be benign or malignant. Their management is multifactorial and is based on the pathology, extent, and local and distant spread. Managing sacral tumors is challenging due to their proximity to visceral and neural structures. Surgical wide excision has been the standard of care for aggressive benign and malignant tumors. Our purpose was to evaluate the outcomes of a multimodal approach to managing primary sacral tumors in Sakra World Hospital, a tertiary spine care center in Bengaluru, India and perform a literature review to determine a workflow pathway. Our study was a retrospective review of patient records and included 15 patients with primary sacral tumors. Eleven surgically treated patients were evaluated clinically and radiologically and underwent biopsy before surgical excision by an all-posterior approach. A multidisciplinary approach that included intraoperative neural monitoring, plastic reconstruction, adjuvant chemotherapy, and radiotherapy was implemented whenever necessary. Sacral root preservation was attempted whenever feasible. Functional outcomes (based on the Visual Analog Scale [VAS] and Biagini scoring system) were analyzed along with disease control, with a minimum of 2 years of follow-up. The mean follow-up was 29±9.8 months. The mean VAS score significantly improved from 7.8±2.6 to 3.7±3.8 (p=0.026). Bowel function showed statistically significant improvement, from a mean score of 0.81±0.47 to 0.63±0.52 (p=0.026) at 2 years of follow-up. The mean pretreatment motor and bladder function scores were 0.53±0.31 and 0.74±0.44, respectively, improving to 0.48±0.33 and 0.68±0.56 at follow-up but without statistical significance. There was no significant loss of function, which is expected in radical sacral resections. In conclusion, primary sacral tumors require a multidisciplinary approach and management for optimal outcomes. A stand-alone posterior approach can be employed to treat most sacral lesions. En-bloc wide resection is the optimal treatment for primary malignant and aggressive benign tumors. Preservation of at least one functional S2 nerve root is imperative to preserve bowel and bladder function.

Customized and Cost-Effective 3D Printed Mold for Cranioplasty: India's First Single Center Experience

Context

Autologous bone is the most commonly used flap in cranioplasty to repair the defect; however, synthetic materials are available. Poly methyl methacrylate (PMMA) is an effective polymer owing to its thermoplastic and radiolucent properties comparable to bone strength. Three-dimensional (3D) printing combined with computer-assisted design (CAD) is a simple, low-cost method to print molds that ensure surgical success.

Materials and Methods

A total of 114 patients underwent cranioplasty (July 2015-April 2018), and 25 of them using 3D printed template molds due to unavailability of autologous bone. The clinical features, patient demographics, and surgical parameters were analyzed. The visual analog score for cosmesis (VASC) and Odom's score was obtained pre and post-op.

Results

The mean age of the patients is 38.4 ± 14.6 years (Range, 9-66). The primary pathology for undergoing craniectomy is stroke (n = 13; 52%), traumatic brain injury (10; 40%) and tumor (2; 8%). The reason for nonavailability of flap was infection (n = 14;56%), flap resorption (4;16%), and trauma or tumor (7;28%). The mean time for manufacturing the 3D printed template is 13.2 ± 2.1 h. On follow-up, median Odom's score is excellent in 52% of cases, good in 40%, and fair in 8%. The mean VASC score on follow up is 8.2 ± 1.3. Three patients developed minor postoperative complications.

Conclusion

This is the first study from a single tertiary care center in India to systematically evaluate the outcomes in 3D cranioplasty using CAD and 3D printing technology. This method would be optimal especially in developing countries since PMMA is cost effective and also gives an ideal cosmetic effect.

Multimodal Intraoperative Neurophysiological Monitoring in Spine Surgeries: The Experience at a Spine Centre through Years

Study Design

Retrospective observational study.

Purpose

To share our experience of multimodal intraoperative neurophysiological monitoring (IONM) used in Sakra World Hospital, Bengaluru in various spine surgeries.

Overview of Literature

The development of new onset postoperative neurological deficits can be completely avoided. In order to avoid these, IONM has become a standard of care in recent times for early detection and manipulation of the surgical procedure to prevent postoperative neurological deficits.

Methods

This retrospective study was performed on 408 patients who had undergone spine surgeries with IONM during April 2014 to March 2020 at a single center. The operative report, anesthesia record, and IONM were reviewed. All the patients were reassessed for postoperative neurological deficits in the postoperative period and followed up based on the intraoperative findings and neurological deficits for 4 weeks. Signal changes in IONM were reviewed, and the obtained results were further categorized into true positive, true negative, false positive, or false negative. If changes were observed during the IONM, the patients were managed as per the algorithm.

Results

Of the 408 patients being monitored continuously during the intraoperative period, 38 showed changes in recordings, 28 developed postoperative neurological deficits, and one developed neurological deficit without any change in the IONM. Nine patients had transient neurological deficits, and the other 20 had permanent neurological deficits. Overall, the multimodal IONM used in our study had a sensitivity of 96.6%, specificity of 97.4%, a positive predictive value of 73.7%, and a negative predictive value of 99.7%.

Conclusions

Use of decision algorithm and multimodal neuromonitoring consisting of motor evoked potentials, somatosensory evoked potentials, and electromyography complement each other in the detection of neurological injury during the course the surgery, improve intraoperative care, and prevent further damage and morbidity in patients.

Idiopathic CD4+ T lymphocytopenia: A case report

Idiopathic CD4+ T lymphocytopenia (ICL) is a very rare immunodeficiency syndrome with an unexplained depletion of CD4+ T lymphocytes and no evidence of Human Immunodeficiency Virus (HIV) infection. Here we report a 29-year-old male patient who had severe ulcerative colitis with low level CD4+ count of 254 cells/mm³, and had no evidence of HIV or Human T cell Lymphotrophic virus type I or II infections. He had recurrent Candidiasis infection and his CD4 count was just 53 cells/mm³ after 3 months. The cause for the decline of CD4 T lymphocytes was unknown.

Is Transoral Surgery Still a Relevant Procedure in Atlantoaxial Instability?

BACKGROUND

The treatment of atlantoaxial instability (AAI) involves stable fixation and fusion with adequate decompression of spinal cord. After the advent of the Goel posterior joint manipulation technique, most of the once irreducible atlantoaxial dislocations (AAD) could be reduced and the need for transoral odontoidectomy became almost nil. Here we tried to iterate the indications of anterior transoral odontoid surgery for AAI in the current scenario.

METHODS

A retrospective study compiling the clinical, radiological, and surgical characteristics of 6 cases (5 scenarios). These patients underwent anterior transoral surgery alone or in combination with a posterior approach.

RESULTS

Two patients had a well-formed occipito-cervical fusion mass, with a displaced odontoid and unreduced C1-C2 joint causing cervical myelopathy. A middle-aged woman presented with unreduced AAD following failed C1-C2 joint distraction technique. A displaced dystopic os odontoideum ossicle was found in an adolescent boy, prohibiting the reduction of AAD. A young man had displacement of the fractured odontoid segment with intact transverse alar ligament and C1-C2 joint complex. One patient had a rare scenario of abnormal orientation of the C1-C2 joint. All 6 patients were successfully treated with adequate spinal cord decompression achieved by the anterior transoral route and stabilization by either the anterior approach itself or in combination with posterior surgery. All had significantly better postoperative outcomes except for 1 patient who expired due to poor respiratory reserve.

CONCLUSION

We tried to emphasize the indications for using transoral anterior odontoid surgery over the posterior approach in the management of AAI. This will prevent the surgical technique of anterior odontoidectomy from becoming an obsolete procedure in the current practice.

Unstable Hangman Fracture Complicated by Vertebral-Venous Fistula: Surgical Considerations and Review of Literature

BACKGROUND

Hangman fracture or traumatic spondylolisthesis of the axis associated with a traumatic vertebral venous fistula (VVF) is a rare entity and sparsely reported in literature. Standard recommendations for management of such rare and complex scenarios are not available and hence the strategy has to be individualized on a case-by-case basis.

METHODS

We report a 70-year-old man having an unstable hangman fracture with VVF. Both pathologies were simultaneously managed uniquely. The VVF was managed by endovascular occlusion. The fracture was managed by anterior fusion alone as posterior fusion was deemed riskier in the aftermath of a recently occluded VVF. The patient had good neck function and bony fusion at 1-year follow-up.

CONCLUSION

This case report emphasizes the need for timely recognition and management of a VVF, which can rarely coexist with hangman fracture, and discusses the interesting surgical paradigms in the management. We also present a review of literature.

Lumbar pseudomeningocele presenting as decerebrate rigidity-A rare case entity

INTRODUCTION

Spinal pseudomeningoceles are extradural collections of cerebrospinal fluid that result following a breach in the dural-arachnoid layer and is reported as one of the complications of lumbar disc surgery. Although they are often self subsiding and asymptomatic, they may occasionally cause low-back pain, headaches, and even nerve root entrapment. The purpose of this case report is to present an unreported presentation of pseudomeningocele PRESENTATION OF CASE: A 34 year obese male presented one month post lumbar discectomy with symptoms suggestive of raised intra cranial pressure presenting as repetitive decerebrate rigidity and altered sensorium lasting for few minutes when there is pressure on the pseudomeningocele sac and subsiding with change in position of the patient. He underwent surgical repair of the dural tear and was improved symptomatically with no recurrence of symptoms at five years follow up.

DISCUSSION

Radiological investigation helped in ruling out the other causes of decerebrate rigidity and the possible mechanism of development of such symptom in pseudomeningocele is discussed.

CONCLUSION

To the best of our knowledge, this is the first reported case of pseudomeningooele presenting as decerebrate rigidity. Spinal pseudomeningocele can present in varied ways and earliest detection is the key to avoid such complications.

International cancer seminars: a focus on esophageal squamous cell carcinoma

The International Agency for Research on Cancer (IARC) and the US National Cancer Institute (NCI) have initiated a series of cancer-focused seminars [Scelo G, Hofmann JN, Banks RE et al. International cancer seminars: a focus on kidney cancer. Ann Oncol 2016; 27(8): 1382-1385]. In this, the second seminar, IARC and NCI convened a workshop in order to examine the state of the current science on esophageal squamous cell carcinoma etiology, genetics, early detection, treatment, and palliation, was reviewed to identify the most critical open research questions. The results of these discussions were summarized by formulating a series of 'difficult questions', which should inform and prioritize future research efforts.

Effect of Two Long-acting Treatments, The Paliperidone Palmitate 1-month and 3-month Formulations on Caregiver Burden in European patients with Schizophrenia

Introduction

Schizophrenia puts a significant burden on caregivers.

Objectives

To explore the effects of two long-acting treatments (LAT), paliperidone palmitate 1-month and 3-month formulations on caregiver burden (CGB) in European patients with schizophrenia using the Involvement Evaluation Questionnaire (IEQ)

Aims

To conduct a subgroup analysis of two randomized, double-blind studies (NCT01515423 and NCT01529515).

Methods

Caregivers (≥ 1 h of contact/week with the patients) were offered to complete the IEQ (31 items, each scoring: 0–4; total score: sum of 27 items [0–108]).

Results

Among 756 European caregivers (53% parents, 18% spouse/partner or girl/boyfriend, 10% sister/brother), 60% reported a CGB of ≥ 32 hours/week at open-label baseline (BL-OL). CGB reduced significantly for patients with both BL-OL and at least one double-blind IEQ sum-score (n = 433): mean improvement [SD] (9.9 [12.66], P < 0.001) from BL-OL (mean [SD] 26.0 [13.30]) to study end (16.0 [10.47]); (reduction in burden associated with worrying [2.9 points] and urging [4.3 points]). CGB significantly improved in patients on prior oral antipsychotics post-switching to LAT with less leisure days impacted and less hours spent in caregiving (P < 0.001). There was significant relationship between improvements and relapse status, patient age (P < 0.001), age at diagnosis (P < 0.002), and number of prior psychiatric hospitalizations in the last 24 months (P < 0.05). Prior use of long-acting antipsychotics other than paliperidone palmitate 1-month or 3-month formulations at BL-OL and duration of prior psychiatric hospitalizations in the last 24 months did not show significant effect on improvements.

Conclusion

Switching from an oral antipsychotic to an LAT can provide a meaningful and significant improvement in caregiver burden.

Disclosure of interest

All authors are employees of Janssen Research & Development, LLC and hold stocks in the company.

Profile of pancreatic tumors at a tertiary care center

BACKGROUND

Pancreas, a relatively inaccessible organ, poses diagnostic difficulties with overlapping presentation among benign and malignant tumors. In the present study, pancreatic aspirates obtained by computed tomography (CT) guided procedures were used for cytodiagnosis. Our study aims at correlating clinical, cytological, biochemical, and histopathological results in obtaining a final diagnosis.

METHODOLOGY

A retrospective study of 2 years was done which included 32 cases of pancreatic tumors at a tertiary care center. Patient data were retrieved and analyzed.

RESULTS

Twenty-seven of the 32 (84.37%) cases were malignant tumors. Age distribution in malignant tumors was predominantly seen in the fourth to eighth decade, whereas in benign, it ranged in the second to third decade. Thirteen out of the 32 (40.62%) cases reported were females, with male:female ratio of 1.46:1. The most common presenting symptom was abdominal pain followed by jaundice and vomiting. Three of the 32 cases had visceral metastasis at the time of diagnosis. CT-guided aspirates in most cases yielded diagnostic material. Cytological and histopathological results concurred except for three cases. Cancer Antigen 19-9 was worked up for 14 of 27 malignant cases, 11 of which showed grossly elevated values (700-7000), and three cases showed mildly elevated values (100-300). Three of the four benign cases worked up for CA 19-9 showed normal values.

CONCLUSIONS

Among the mass forming lesions in pancreas, malignancy was more common compared to benign tumors. A multidisciplinary approach in the assessment and diagnosis of pancreatic tumors yields accurate results in spite of the limitations faced in obtaining adequate samples by needle aspirates.

Pathologically confirmed breast cancer in Malawi: a descriptive study: Clinical profile of breast cancer

BACKGROUND

Breast cancer is the most common female cancer in Africa, yet no published studies have investigated breast cancer in Malawi. Understanding the clinical profile of breast cancer is important to develop early diagnosis efforts.

AIM

To describe clinical and pathological characteristics of breast specimens from a pathology laboratory at a national teaching hospital.

METHODS

Secondary analysis of pathology reports from July 2011 to September 2013.

RESULTS

Among 85 breast cancer cases, 55% were < 50 years. Median tumor size was 4 cm and 49% were grade 3. Median symptom duration was eight months.

CONCLUSIONS

Malawian women with breast cancer commonly have long symptom durations prior to diagnosis, young age, and poorly differentiated tumors. Improved clinical and pathological characterization, including hormone receptor status, are urgently needed to better understand this disease in Malawi.

Review: Head and neck squamous cell carcinoma in sub-Saharan Africa

AIM

Review the literature from 1990 to 2013 to determine known anatomic sites, risk factors, treatments, and outcomes of head and neck squamous cell carcinoma (HNSCC) in sub-Saharan Africa.

METHODS

Using a systematic search strategy, literature pertaining to HNSCC in sub-Saharan Africa was reviewed and patient demographics, anatomic sites, histology, stage, treatment, and outcomes were abstracted. The contributions of human immunodeficiency virus (HIV), human papillomavirus (HPV) and behavioural risk factors to HNSCC in the region were assessed.

RESULTS

Of the 342 papers identified, 46 were utilized for review, including 8611 patients. In sub-Saharan Africa, the oropharyngeal/oral cavity was found to be the most common site, with 7750 cases (90% of all cases). Few papers distinguished oropharyngeal from oral cavity, making identification of possible HPV-associated oropharyngeal squamous cell carcinoma (SCC) difficult. SCC of the nasopharynx, nasal cavity, or paranasal sinuses was identified in 410 patients (4.8% of all cases). Laryngeal SCC was found in 385 patients (4.5% of all cases), and only 66 patients (0.8% of all cases) with hypopharyngeal SCC were identified. In 862 patients with data available, 43% used tobacco and 42% used alcohol, and reported use varied widely and was more common in laryngeal SCC than that of the oropharyngeal/oral cavity. Toombak and kola nut use was reported to be higher in patients with HNSCC. Several papers reported HIV-positive patients with HNSCC, but it was not possible to determine HNSCC prevalence in HIV-positive compared to negative patients. Reports of treatment and outcomes were rare.

CONCLUSIONS

The oropharyngeal/oral cavity was by far the most commonly reported site of HNSCC reported in sub-Saharan Africa. The roles of risk factors in HNSCC incidence in sub-Saharan Africa were difficult to delineate from the available studies, but a majority of patients did not use tobacco and alcohol.

Functional profiling in Streptococcus mutans: construction and examination of a genomic collection of gene deletion mutants

A collection of tagged deletion mutant strains was created in Streptococcus mutans UA159 to facilitate investigation of the aciduric capability of this oral pathogen. Gene-specific barcoded deletions were attempted in 1432 open reading frames (representing 73% of the genome), and resulted in the isolation of 1112 strains (56% coverage) carrying deletions in distinct non-essential genes. As S. mutans virulence is predicated upon the ability of the organism to survive an acidic pH environment, form biofilms on tooth surfaces, and out-compete other oral microflora, we assayed individual mutant strains for the relative fitness of the deletion strain, compared with the parent strain, under acidic and oxidative stress conditions, as well as for their ability to form biofilms in glucose- or sucrose-containing medium. Our studies revealed a total of 51 deletion strains with defects in both aciduricity and biofilm formation. We have also identified 49 strains whose gene deletion confers sensitivity to oxidative damage and deficiencies in biofilm formation. We demonstrate the ability to examine competitive fitness of mutant organisms using the barcode tags incorporated into each deletion strain to examine the representation of a particular strain in a population. Co-cultures of deletion strains were grown either in vitro in a chemostat to steady-state values of pH 7 and pH 5 or in vivo in an animal model for oral infection. Taken together, these data represent a mechanism for assessing the virulence capacity of this pathogenic microorganism and a resource for identifying future targets for drug intervention to promote healthy oral microflora.

Incidence of tardive dyskinesia: a comparison of long-acting injectable and oral paliperidone clinical trial databases

BACKGROUND

To assess the tardive dyskinesia (TD) rate in studies of once-monthly long-acting injectable (LAI) paliperidone palmitate (PP) and once-daily oral paliperidone extended release (Pali ER).

METHODS

Completed schizophrenia and bipolar studies for PP and Pali ER (≥ 6 month duration with retrievable patient-level data) were included in this post hoc analysis. Schooler-Kane research criteria were applied using Abnormal Involuntary Movement Scale (AIMS) scores to categorise probable (qualifying AIMS scores persisting for ≥ 3 months) and persistent TD (score persisting ≥ 6 months). Spontaneously reported TD adverse events (AEs) were also summarised. Impact of exposure duration on dyskinesia (defined as AIMS total score ≥ 3) was assessed by summarising the monthly dyskinesia rate.

RESULTS

In the schizophrenia studies, TD rates for PP (four studies, N = 1689) vs. Pali ER (five studies, N = 2054), were: spontaneously reported AE, 0.18% (PP) vs. 0.10% (Pali ER); probable TD, 0.12% (PP) vs. 0.19% (Pali ER) and persistent TD, 0.12% (PP) vs. 0.05% (Pali ER). In the only bipolar study identified [Pali ER (N = 614)], TD rate was zero (spontaneously reported AE reporting, probable and persistent TD assessments). Dyskinesia rate was higher within the first month of treatment with both PP (13.1%) and Pali ER (11.7%) and steadily decreased over time (months 6-7: PP: 5.4%; Pali ER: 6.4%). Mean exposure: PP, 279.6 days; Pali ER, 187.2 days.

CONCLUSIONS

Risk of TD with paliperidone was low (< 0.2%), regardless of the formulation (oral or LAI), in this clinical trial dataset. Longer cumulative exposure does not appear to increase the risk of dyskinesias.

Quantitative X-ray microradiography for high-throughput phenotyping of osteoarthritis in mice

OBJECTIVE

To investigate and validate digital X-ray microradiography as a novel, high-throughput and cost-effective screening approach to identify abnormal joint phenotypes in mice.

METHOD

Digital X-ray microradiography was used to quantify the subchondral bone mineral content (BMC) in the medial tibial plateau. Accuracy and reproducibility of the method were determined in 22 samples from C57BL/6(B6Brd;B6Dnk;B6N-Tyr(c-Brd)) wild-type mice. The method was then validated in wild-type mice that had undergone surgical destabilisation of medial meniscus (DMM) and in a genetically modified mouse strain with an established increase in trabecular bone mass.

RESULTS

The measurement of subchondral BMC by digital X-ray microradiography had a coefficient of variation of 3.6%. Digital X-ray microradiography was able to demonstrate significantly increased subchondral BMC in the medial tibial plateau of male mice 4 and 8 weeks after DMM surgery and in female mice 8 weeks after surgery. Furthermore, digital X-ray microradiography also detected the increase in subchondral BMC in a genetically modified mouse strain with high trabecular bone mass.

CONCLUSION

Quantitation of subchondral BMC by digital X-ray microradiography is a rapid, sensitive and cost-effective method to identify abnormal joint phenotypes in mice of both genders at several ages.