Key differences between olfactory ensheathing cells and Schwann cells regarding phagocytosis of necrotic cells: implications for transplantation therapies.

Transplantation of peripheral nervous system glia is being explored for treating neural injuries, in particular central nervous system injuries. These glia, olfactory ensheathing cells (OECs) and Schwann cells (SCs), are thought to aid regeneration by clearing necrotic cells, (necrotic bodies, NBs), as well as myelin debris. The mechanism by which the glia phagocytose and traffic NBs are not understood. Here, we show that OECs and SCs recognize phosphatidylserine on NBs, followed by engulfment and trafficking to endosomes and lysosomes. We also showed that both glia can phagocytose and process myelin debris. We compared the time-course of glial phagocytosis (of both NBs and myelin) to that of macrophages. Internalization and trafficking were considerably slower in glia than in macrophages, and OECs were more efficient phagocytes than SCs. The two glial types also differed regarding their cytokine responses after NB challenge. SCs produced low amounts of the pro-inflammatory cytokine TNF-α while OECs did not produce detectable TNF-α. Thus, OECs have a higher capacity than SCs for phagocytosis and trafficking, whilst producing lower amounts of pro-inflammatory cytokines. These findings suggest that OEC transplantation into the injured nervous system may lead to better outcomes than SC transplantation.

Granzyme B PET Imaging of Immune Checkpoint Inhibitor Combinations in Colon Cancer Phenotypes.

PURPOSE: Immune checkpoint inhibitor (ICI) monotherapy and combination regimens are being actively pursued as strategies to improve durable response rates in cancer patients. However, the biology surrounding combination therapies is not well understood and may increase the likelihood of immune-mediated adverse events. Accurate stratification of ICI response by non-invasive PET imaging may help ensure safe therapy management across a wide number of cancer phenotypes. PROCEDURES: We have assessed the ability of a fluorine-labelled peptide, [18F]AlF-mNOTA-GZP, targeting granzyme B, to stratify ICI response in two syngeneic models of colon cancer, CT26 and MC38. In vivo tumour uptake of [18F]AlF-mNOTA-GZP following ICI monotherapy, or in combination with PD-1 was characterised and correlated with changes in tumour-associated immune cell populations. RESULTS: [18F]AlF-mNOTA-GZP showed good predictive ability and correlated well with changes in tumour-associated T cells, especially CD8+ T cells; however, overall uptake and response to monotherapy or combination therapies was very different in the CT26 and MC38 tumours, likely due to the immunostimulatory environment imbued by the MSI-high phenotype in MC38 tumours. CONCLUSIONS: [18F]AlF-mNOTA-GZP uptake correlates well with changes in CD8+ T cell populations and is able to stratify tumour response to a range of ICIs administered as monotherapies or in combination. However, tracer uptake can be significantly affected by preexisting phenotypic abnormalities potentially confusing data interpretation.

Clinical profile and outcome of chronic pancreatitis in children.

OBJECTIVE: To evaluate the etiology, presentation, complications and management of chronic pancreatitis in children. DESIGN: Retrospective chart review. SETTING: Gastroenterology department at Christian Medical College and Hospital, Vellore, India between January 2005 and December 2010. PARTICIPANTS: 99 Children (>18 yrs) diagnosed with chronic pancreatitis based on clinical and imaging features. MAIN OUTCOME MEASURES: Etiology, clinical presentation, complications and management of chronic pancreatitis in children. RESULTS: Of 3887 children who attended the Gastroenterology department, 99(2.5%) had chronic pancreatitis, of which 60 (60.6%) were males. In 95(95.9%) patients no definite cause was detected and they were labeled as Idiopathic chronic pancreatitis. All patients had abdominal pain, while 9(9.1%) had diabetes mellitus. Of the 22 children tested for stool fat, 10(45.5%) had steatorrhea. Pancreatic calcification was seen in 69 (69.7%). 68 (71.6%) patients with idiopathic chronic pancreatitis had calcification. Calcific idiopathic chronic pancreatitis was more frequent in males (67.6% vs. 48.1%, P=0.07), and was more commonly associated with diabetes mellitus (13.2% vs. none, P=0.047) and steatorrhea (61.5% vs. 16.7%, P=0.069). Pseudocyst (17.1%) and ascites (9.1%) were the most common complications. All children were treated with pancreatic enzyme supplements for pain relief. 57 patients were followed up. With enzyme supplementation, pain relief was present in 32 (56.1%) patients. Of those who did not improve, 10 underwent endotherapy and 15 underwent surgery. Follow up of 8 patients who underwent endotherapy, showed that 5 (62.5%) had relief. Follow up of 11 patients who underwent surgery showed that only 3 (27%) had pain relief. There was no death. CONCLUSIONS: Idiopathic chronic pancreatitis is the predominant form of chronic pancreatitis in children and adolescents. It can present with or without calcification. The calcific variety is an aggressive disease characterized by early morphological and functional damage to the pancreas.

Acquired differential regulation of caspase-8 in cisplatin-resistant non-small-cell lung cancer.

Failure to efficiently induce apoptosis contributes to cisplatin resistance in non-small-cell lung cancer (NSCLC). Although BCL-2-associated X protein (BAX) and BCL-2 antagonist killer (BAK) are critical regulators of the mitochondrial apoptosis pathway, their requirement has not been robustly established in relation to cisplatin. Here, we show that cisplatin can efficiently bypass mitochondrial apoptosis block caused by loss of BAX and BAK, via activation of the extrinsic death receptor pathway in some model cell lines. Apoptosis resistance following cisplatin can only be observed when both extrinsic and intrinsic pathways are blocked, consistent with redundancy between mitochondrial and death receptor pathways in cisplatin-induced apoptosis. In H460 NSCLC cells, caspase-8 cleavage was shown to be induced by cisplatin and is dependent on death receptor 4, death receptor 5, Fas-associated protein with death domain, acid sphingomyelinase and ceramide synthesis. In contrast, cisplatin-resistant cells fail to activate caspase-8 via this pathway despite conserving sensitivity to death ligand-driven activation. Accordingly, caspase-8 activation block acquired during cisplatin resistance, can be bypassed by death receptor agonism.

The Bcl-2 repertoire of mesothelioma spheroids underlies acquired apoptotic multicellular resistance.

Three-dimensional (3D) cultures are a valuable platform to study acquired multicellular apoptotic resistance of cancer. We used spheroids of cell lines and actual tumor to study resistance to the proteasome inhibitor bortezomib in mesothelioma, a highly chemoresistant tumor. Spheroids from mesothelioma cell lines acquired resistance to bortezomib by failing to upregulate Noxa, a pro-apoptotic sensitizer BH3-only protein that acts by displacing Bim, a pro-apoptotic Bax/Bak-activator protein. Surprisingly, despite their resistance, spheroids also upregulated Bim and thereby acquired sensitivity to ABT-737, an inhibitor of anti-apoptotic Bcl-2 molecules. Analysis using BH3 profiling confirmed that spheroids acquired a dependence on anti-apoptotic Bcl-2 proteins and were 'primed for death'. We then studied spheroids grown from actual mesothelioma. ABT-737 was active in spheroids grown from those tumors (5/7, ∼70%) with elevated levels of Bim. Using immunocytochemistry of tissue microarrays of 48 mesotheliomas, we found that most (33, 69%) expressed elevated Bim. In conclusion, mesothelioma cells in 3D alter the expression of Bcl-2 molecules, thereby acquiring both apoptotic resistance and sensitivity to Bcl-2 blockade. Mesothelioma tumors ex vivo also show sensitivity to Bcl-2 blockade that may depend on Bim, which is frequently elevated in mesothelioma. Therefore, mesothelioma, a highly resistant tumor, may have an intrinsic sensitivity to Bcl-2 blockade that can be exploited therapeutically.

Lopinavir loaded solid lipid nanoparticles (SLN) for intestinal lymphatic targeting.

The poor orally available lopinavir was successfully encapsulated in glyceryl behenate based solid lipid nanoparticles (Lo-SLN) for its ultimate use to target intestinal lymphatic vessels in combined chemotherapy-the so-called Highly Active Anti-Retroviral Therapy (HAART). SLN with mean particle size of 230 nm (polydispersity index, PDI<0.27) and surface electrical charge of approx. -27mV, were produced by hot homogenization process followed by ultrasonication. Particles were characterized using differential scanning calorimetry (DSC), wide angle X-ray scattering (WAXS) and atomic force microscopy (AFM) to confirm their solid character and the homogeneous distribution of drug within the lipid matrix. In vitro release studies at pH 6.8 phosphate buffer (PBS) and at pH 1.2 HCl 0.1N showed a slow release in both media. From the intestinal lymphatic transport study it became evident that SLN increased the cumulative percentage dose of lopinavir secreted into the lymph, which was 4.91-fold higher when compared with a conventional drug solution in methyl cellulose 0.5% (w/v) as suspending agent (Lo-MC). The percentage bioavailability was significantly enhanced. The AUC for the Lo-SLN was 2.13-fold higher than that obtained for the Lo-MC of similar concentration. The accelerated stability studies showed that there was no significant change in the mean particle size and PDI after storage at 25±2°C/60±5% RH. The shelf life of optimized formulation was assessed based on the remained drug content in the stabilized formulation and was shown to be 21.46 months.

Spectrum of malabsorption in India--tropical sprue is still the leader.

INTRODUCTION: Two decades ago tropical sprue, Immunoproliferative Small Intestinal Disease (IPSID) and infections were common causes of malabsorption in India. It is possible that implementation of preventive health measures and improved sanitation may have changed the spectrum of disorders causing malabsorption. The aim of this study therefore was to assess the spectrum of malabsorption seen at our center during the past nine years. METHODOLOGY: Patients seen at our center with malabsorption from January 2000 to December 2008 were included in this study. The etiological, clinical and investigation details were recorded on uniform structured data forms. The data obtained was retrospectively analyzed. RESULTS: Malabsorption was detected in 124 patients during the study period. The mean age of patients was 31.9+16 years and 60.5% were males. Tropical sprue was the commonest etiology (29%) followed by celiac and Crohn's disease (15.3% each). Other important etiologies included parasitic infestations (9.7%) and immune deficiency disorders (5.6%). Intestinal tuberculosis was seen in only 2.4% patients. CONCLUSIONS: We are witnessing a change in etiological spectrum of malabsorption . Celiac disease and inflammatory bowel disorders are emerging as important causes and ImmunoProliferative Small Intestinal Disease (IPSID) and intestinal tuberculosis are on the decline. Tropical Sprue however continues to be the commonest cause as in the past.

Pediatric inflammatory bowel disease in South India.

Among 34 children diagnosed to have inflammatory bowel disease (IBD) over past 8 years, 23 had Crohns disease and 11 had ulcerative colitis. Pediatric patients accounted for 7% of new cases of IBD seen annually. Median delay in diagnosis was 15 months. Nutritional impairment was significantly more common in Crohns disease.

BCL-2 family regulation by the 20S proteasome inhibitor bortezomib.

Bortezomib (Velcade, PS341) was licensed in 2003 as a first-in-class 20S proteasome inhibitor indicated for treatment of multiple myeloma, and is currently being evaluated clinically in a range of solid tumours. The mechanisms underlying its cancer cell toxicity are complex. A growing body of evidence suggests proteasome inhibition-dependent regulation of the BCL-2 family is a critical requirement. In particular, the stabilization of BH3-only proteins BIK, NOXA and BIM, appear to be essential for effecting BAX- and BAK-dependent cell death. These mechanisms are reviewed and the implications for favourable novel drug interactions are highlighted.

Oral triiodothyronine in the perioperative management of central hypothyroidism.

Oral triiodothyronine (T3) has never been described in literature as a major form of perioperative therapy. This series highlights the role of oral triiodothyronine in the perioperative management of patients with overt hypothyroidism for semi-urgent surgeries. We describe 12 patients with central hypothyroidism occurring secondary to pituitary tumours manifesting with severe neurological symptoms that required early surgical intervention. These patients were managed without any significant complications by administering perioperative oral triiodothyronine.

Solitary fibrous tumor of the lateral ventricle: CT appearances and pathologic correlation with follow-up.

Intracranial solitary fibrous tumors are rare, and intraventricular fibrous tumors are even more unusual. We report a case of solitary fibrous tumor in the region of trigone and body of the left lateral ventricle and discuss the clinical presentation, CT characteristics, and histopathologic features with 1-year follow-up. We speculate that the tumor arose from the perivascular connective tissue of the choroid plexus.

To assess the ability of MRI to predict consistency of pituitary macroadenomas.

We prospectively studied the ability of magnetic resonance imaging (MRI) to predict the consistency of pituitary adenomas. The hypothesis was that firm, fibrous tumours would appear homogeneously hypointense on T2-weighted images. Eighty patients who underwent surgery for pituitary macroadenomas were studied. MR images were evaluated preoperatively by the radiologist. The tumour consistency was reported by the surgeon as soft or firm. There were 68 soft tumours and 12 firm tumours. Of the firm tumours, four (33%) were homogeneously isointense, one (8%) homogeneously hyperintense and seven (59%) were heterogeneous in appearance in T2-weighted images. We conclude that the consistency of pituitary macroadenomas cannot be accurately predicted based on MRI signal intensities.

Suprabrow minicraniotomy for suprasellar tumours.

We present our experience with suprabow minicraniotomy in the excision of 18 suprasellar tumours between May 2001 and September 2003. There were 14 females and four males with ages ranging from 7 to 59 years. The tumours included one epidermoid cyst, 10 meningiomas, five craniopharyngiomas and two optico-chiasmatico-hypothalamic (OCHG) gliomas. The size of the one-piece craniotomy was about 2.5 cm. Both OCHGs were biopsied; one craniopharyngioma was totally excised, the remaining craniopharyngiomas and epidermoid cyst were subtotally excised. Four meningiomas were radically excised and six were subtotally removed. The patient with a craniopharyngioma that had a radical excision died of hypothalamic dysfunction. One patient developed a postoperative meningitis and subsequent hydrocephalus requiring a shunt. The other patients did well and the cosmetic result was excellent in all cases. This basal approach through a small craniotomy provided good surgical access to suprasellar tumours with minimal brain retraction.

Crohn's disease in rheumatology clinic--an Indian experience.

BACKGROUND: Prevalence of Crohn's disease (CD) among patients with rheumatic illnesses in India is grossly under estimated, especially when it has overtaken that of Ulcerative Colitis in the West. AIM: To study the frequency of histologically unequivocal CD amongst clinically suspected patients with enteropathic arthropathy and to ascertain if the arthritics with CD have any independent clinical predictor. SETTINGS AND DESIGNS: Retrospective datasheet analysis from a Rheumatology clinic of a large tertiary care centre. MATERIALS AND METHODS: Patients of suspected enteropathic arthropathy were studied by ileocolonoscopy and segmental colonic biopsy for histological evidence of Crohn's disease and followed up. STATISTICAL ANALYSIS: Logistic regression analysis was done to find out any clinical predictor of histologically proven CD. RESULTS: Fourteen of the twenty-nine patients studied had histologically confirmed CD. Those with CD were younger than those without (34.7 yr vs 41.6 yrs, p=0.057). The CD group also had significantly higher number of people with loss of weight (12 vs 1), fever (11 vs 0), perianal fistula (4 vs 0), abdominal pain (8 vs 2), history of dysentery (4 vs 0) and uveitis (6 vs 1) (p=0.00002, 0.00001, 0.026, 0.013, 0.026 & 0.01 respectively). However logistic regression analysis of the most relevant ones among these, namely, loss of weight, fever, and perianal fistula showed loss of weight as only independent predictor of CD in this subset of patients (p=0.03 with odds ratio of 28). CONCLUSION: Presence of significant loss of weight in an Indian patient with clinically suspected enteropathic arthropathy is an independent predictor of CD.

Extensive vertebral haemangioma with cord compression in two patients: review of the literature.

Two cases of extensive vertebral haemangioma with progressive neurological deficits are described. Successful treatment was accomplished with palliative surgical decompression after preoperative embolization in one case and with postoperative radiotherapy in the other. Preoperative embolization, palliative surgical decompression and postoperative radiotherapy appear to provide satisfactory outcome in patients with extensive haemangiomas.

Intratumoral abscess: an unusual complication of ventriculoperitoneal shunt infection.

INTRODUCTION: Ventriculoperitoneal shunts were routinely used in the past in children with posterior fossa tumors and hydrocephalus. They can, however, cause a multitude of problems. CASE REPORT: This report highlights a previously unencountered phenomenon of a pyogenic abscess forming within a posterior fossa ependymoma as a result of shunt infection. The shunt was exteriorized and the child treated with antibiotics before surgery was done. Only a partial excision of the tumor was possible, as the inflammatory response caused by the abscess had obliterated tissue planes.

The 'capsule' of pituitary macroadenomas represents normal pituitary gland: a histopathological study.

The goal of trans-sphenoidal pituitary adenoma surgery is radical excision of the tumour with preservation of endocrine function. Our hypothesis was that, even in macroadenomas extending into the suprasellar cistern, the 'capsule' of the tumour is the compressed normal pituitary gland. The biopsy material from 126 patients with pituitary macroadenomas were retrospectively reviewed to look for the presence of normal adenohypophysis. Fourteen patients with macroadenomas operated trans-sphenoidally were studied prospectively, sampling tissue from the periphery of the tumour for histopathology. From the retrospective data, we found that normal adenohypophysis was more often found at histopathology in the extracapsular excisions, rather than in the intracapsular excisions. In the 14 patients studied prospectively, normal adenohypophysial tissue was found histologically at all sites sampled except in areas where the tumour was invasive. In conclusion, while an extracapsular excision would offer the best chance for a surgical cure, preserving parts of the capsule may preserve normal and possibly functioning gland.

Intraoperative ultrasound in determining the extent of resection of parenchymal brain tumours--a comparative study with computed tomography and histopathology.

BACKGROUND: Radical excision of parenchymal brain tumours is generally associated with a better long-term outcome; however, it is difficult to ascertain the extent of resection at surgery. We used intra-operative ultrasound [IOUS] to help detect residual tumour and define the tumour-brain interface. METHODS: Thirty-five patients with parenchymal brain lesions including 11 low-grade and 22 high-grade tumours and 2 inflammatory granulomata were included in the study. The IOUS was used to localize tumours not seen on the surface, define their margins and assess the extent of resection at the end of surgery. Multiple samples from the tumour-brain interface which were reported as tumour or normal tissue on IOUS were submitted to histopathology. The IOUS findings were compared with a postoperative contrast enhanced computed tomogram [CT] and with histopathology. RESULTS: All tumours irrespective of histology were hyperechoic on IOUS. IOUS was useful in localizing those tumours not seen on the surface of the brain. In 71.4% of cases IOUS was useful in defining their margins, however in the remaining cases the margins were ill-defined. The tumour margins were ill-defined in those treated previously by radiation. With regard to the extent of excision, after excluding the cases who were irradiated, it was found that in the 28 patients who had parenchymal neoplasms, there was concordance between the ultrasound findings and the postoperative CT scan in 23 cases. Of the 79 samples taken from the tumor-brain interface which were reported as tumour on ultrasound, 66 had histopathological evidence of tumour while 13 samples were negative for tumour. On the other hand, in the tissue sent from 17 sites where the IOUS showed no residual tumour, 2 were positive for tumour on histopathology while 15 were negative. INTERPRETATION: In conclusion, IOUS is a cheap and useful real-time tool for localizing tumours not seen on the brain surface, for defining their margins and for determining the extent of resection.

A minimally invasive approach to deep-seated brain lesions using balloon dilatation and ultrasound guidance.

Conventional dissection techniques require the excision of a channel from the cortex through the white matter with suction and bipolar cautery for the excision of deep-seated brain lesions. An alternative approach, using a previously described technique, in four cases is illustrated in this article. After craniotomy and dural opening, the index finger portion of a surgical glove was removed, tied over a brain cannula and gently passed towards the lesion under ultrasound guidance. Once the needle-tip was sonologically confirmed to be on the lesion, the balloon was inflated with about 3 to 5 ml of saline. This created a track through which the lesion could be excised under the microscope. The lesions were satisfactorily excised through the track created without removal of brain tissue. The accuracy of this minimally invasive technique can be enhanced when used in conjunction with intraoperative ultrasound guidance.