Computer-Based Diagnosis of Celiac Disease by Quantitative Processing of Duodenal Endoscopy Images

Celiac disease (CD) is a lifelong chronic autoimmune systemic disease that primarily affects the small bowel of genetically susceptible individuals. The diagnostics of adult CD currently rely on specific serology and the histological assessment of duodenal mucosa on samples taken by upper digestive endoscopy. Because of several pitfalls associated with duodenal biopsy sampling and histopathology, and considering the pediatric no-biopsy diagnostic criteria, a biopsy-avoiding strategy has been proposed for adult CD diagnosis also. Several endoscopic changes have been reported in the duodenum of CD patients, as markers of villous atrophy (VA), with good correlation with serology. In this setting, an opportunity lies in the automated detection of these endoscopic markers, during routine endoscopy examinations, as potential case-finding of unsuspected CD. We collected duodenal endoscopy images from 18 CD newly diagnosed CD patients and 16 non-CD controls and applied machine learning (ML) and deep learning (DL) algorithms on image patches for the detection of VA. Using histology as standard, high diagnostic accuracy was seen for all algorithms tested, with the layered convolutional neural network (CNN) having the best performance, with 99.67% sensitivity and 98.07% positive predictive value. In this pilot study, we provide an accurate algorithm for automated detection of mucosal changes associated with VA in CD patients, compared to normally appearing non-atrophic mucosa in non-CD controls, using histology as a reference.

Computer-Based Diagnosis of Celiac Disease by Quantitative Processing of Duodenal Endoscopy Images

Celiac disease (CD) is a lifelong chronic autoimmune systemic disease that primarily affects the small bowel of genetically susceptible individuals. The diagnostics of adult CD currently rely on specific serology and the histological assessment of duodenal mucosa on samples taken by upper digestive endoscopy. Because of several pitfalls associated with duodenal biopsy sampling and histopathology, and considering the pediatric no-biopsy diagnostic criteria, a biopsy-avoiding strategy has been proposed for adult CD diagnosis also. Several endoscopic changes have been reported in the duodenum of CD patients, as markers of villous atrophy (VA), with good correlation with serology. In this setting, an opportunity lies in the automated detection of these endoscopic markers, during routine endoscopy examinations, as potential case-finding of unsuspected CD. We collected duodenal endoscopy images from 18 CD newly diagnosed CD patients and 16 non-CD controls and applied machine learning (ML) and deep learning (DL) algorithms on image patches for the detection of VA. Using histology as standard, high diagnostic accuracy was seen for all algorithms tested, with the layered convolutional neural network (CNN) having the best performance, with 99.67% sensitivity and 98.07% positive predictive value. In this pilot study, we provide an accurate algorithm for automated detection of mucosal changes associated with VA in CD patients, compared to normally appearing non-atrophic mucosa in non-CD controls, using histology as a reference.

V-029 TOTALLY ENDOSCOPIC SUBLAY (TES) REPAIR FOR L2-L3 INCISIONAL HERNIA

Aim

Endoscopic lateral incisional hernia (IH) repair provides advantages in terms of low infection rates and hospital stay when compared with open repair.

Material and Methods

62 years old men with a history of HTA and an open radical right nephrectomy for a renal tumor, developed a symptomatic iliac IH. L2–3 W2 according to the European Hernia Society (EHS) classification was clinically diagnosed and confirmed with a CT scan.

Full endoscopic abdominal wall repair with defect closure was proposed.

3 trocars in right retrorectus space were placed. Once the lateral edge of the rectus sheath is reached, the posterior rectus sheath is incised, access to the preperitoneal lateral plane. During hernia sac dissection, an opening of the hernia sac occurs. The posterior layer is closed by a barbed suture, an accessory trocar placement was necessary for the closure. Subsequently, the internal oblique and transversus abdominis muscles that formed the defect were approximated with a barbed suture.

During dissection, a right inguinal hernia was identified and repaired.

A trimmed 20 x15 cm polipropilene mesh is placed in the preperitoneal space without fixation.

Results

The patient was discharged on the 3rd postoperative day without complications. Follow-up in the outpatient clinic at 6 months did not show any signs of recurrence.

Conclusion

Endoscopic abdominal wall reconstruction with posterior component separation is an alternative to the open procedure for lateral IH, providing a complete abdominal wall repair. The mesh is placed extraperitoneal with the advantages in terms of less adhesions and postoperative pain.

OC-074 BILAYERED RETICULAR AND LAMINAR POLYPROPYLENE MESH AS A USEFUL TEMPORARY ABDOMINAL CLOSURE FOR THE MANAGEMENT OF THE OPEN ABDOMEN

Aim

To demonstrate the utility of a bilayered reticular and laminar polypropylene (PLP) mesh as a temporary abdominal closure device for the management of the open abdomen.

Patients And Methods

Prospective multicentric study including consecutive patients with open abdomen of any etiology. A bilayerede PLP mesh is used as temporary abdominal closure. The mesh has a 30×40 cm laminar PLP intraperitoneal layer that is fully deployed covering the viscera, and a 30x 40 cm large pore PLP layer that is trimmed to the size of the defect and sutured to the border of the fascia. Depending on the evolution time and the clinical situation of the patient, successive plicatures of the reticular PLP are performed to reduce the fascial defect. At the end, the mesh is explanted, and a complete fascial closure is attempted.

Results

Eighteen patients were included. Etiologies of the open abdomen were vascular (22%), trauma (28%) and sepsis (50%). There were 72% female patients, mean age of 60 years (range 19–81). Four patients died in the first 72 hours due to complications of their pathology. The other 14 patients survived, with a mean time of open abdomen of 15 days (range 1–43). In all cases a total fascial closure was achieved, with absence of adhesions between the visceral and the parietal peritoneum. No complications related with the mesh took place during the follow up

Conclusion

Temporary abdominal closure with a bilayered reticular and laminar polypropylene mesh is efficient and safe, with a 100% rate of fascial closure

P-136 MANAGEMENT OF DIRTY ABDOMINAL WALL SITUATIONS WITH AN OVINE RUMEN BIOLOGIC MESH WITH POLYPROPYLENE REINFORCEMENT

Aim

To present our initial results of abdominal wall surgery in dirty situations with an ovine rumen (OR) biologic mesh reinforced with polypropylene.

Patients and Methods

Five patients with elective abdominal wall surgery in a dirty setting were included. Two cases were previous PTFE mesh infections after IPOM repairs, one case of enteroatmospheric fistula through a previous posterior component separation repair, one deep tissue infection after a MILOS retromuscular repair and one definitive closure after a 8 weeks open abdomen in a liver transplantation patient. In the five cases cultures showed polymicrobian infections. Both PTFE meshes were removed and substituted by the OR biologic mesh. In the enteroatmospheric fistula patient the exposed mesh was resected together with the fistula take down, and a re-Rives was performed. In the case of the MILOS deep tissue infection after two weeks with an open abdomen and a temporary abdominal closure the definitive closure was performed with the biologic mesh in the retromuscular space. In the definitive closure of the liver transplantation patient the mesh was placed intraperitoneally as prophylaxis.

Results

In four cases there weren´t any surgical sites ocurrences. In the case of the enteroatmospheric fistula the patient presented a partial fascial dehiscence with mesh exposure, managed with a VAC system. With less than a year follow up no hernia recurrence has taken place.

Conclusión

The use of an OR biologic mesh with polypropylene reinforcement seems to be safe in abdominal wall repair in dirty settings, with good results during early follow up.

V-049 E-TEP RIVES-STOPPA AND OPEN REVERSE TRANVERSUS ABDOMINIS RELEASE (TAR): A HYBRID APPROACH FOR LARGE LATERAL-INFERIOR INCISIONAL HERNIAS

Aim

To present hybrid approach with open/endoscopic extraperitoneal dissection for large lateral-inferior incisional hernias

Material and Methods

64 years-old man who underwent left laparoscopic nephrectomy (2019) due to hypernephroma with specimen extraction by a left oblique iliac incision. He presents L3–4 W3 incisional hernia (14×10 cm)

Technique description

Results

After 48 hours ICU admission patient was discharged to hospital ward. Drainages were removed at 2nd-4thpostoperative day and hospital stay was 5 days.

Conclusion

The hybrid approach to large lateral incisional hernias allowed us to use a large sublay mesh with an increased overlap beyond the hernia defect, trying to reduce hernia recurrence rate.

V-007 LESSONS LEARNED DURING THE ABDOMINAL WALL RECONSUTRCTION FOR A MULTIRECURRENT LUMBAR HERNIA AFTER BONE GRAFT HARVESTING

The best approach for lateral incisional hernia is not known. Among these difficult hernias, those arising from iliac crest harvesting can be particularly challenging. The objective of this video is to illustrate the surgical approach of a multirecurrent case with the need of adding a posterior component separation

A 70 years old woman with 2 previous attempts of repair was referred to our center. With the patient in a 45 degrees lateral decubitus, a posterior lumbar approach was initiated through the previous scar. The retromuscular preperitoneal plane was accessed with difficulty due to previous meshes in the subdiaphragmatic, iliac and posterior areas. A big tear on the medial peritoneum changed our plan to add a posterior component separation. As we did not want to enlarge the lumbar incision to denervate more the lateral abdominal wall, we decided to make an accessory midline incision. Probably, an ETEP approach could have been better even before making the posterior incision. Once the retromuscular plane was dissected, the hole in the peritoneum could be closed. The reconstructive phase consisted in making a taco configuration using the combination of a permanent and absorbable mesh.

We have learned from this case, that an eTEP dissection of the retromuscular plane could have helped to avoid the accessory midline incision. It is also important to consider the potential iatrogenic denervation we could add in case of enlargement of the incision.

P-127 E-TEP ASSISTED REVERSE-TAR FOR THE TREATMENT OF LARGE LUMBAR INCISIONAL HERNIAS ASSOCIATED TO MIDLINE DEFECTS

Aim

To describe a new hybrid surgical approach of large lumbar incisional hernias (IH) associated to synchronic midline defects.

Material and Methods

Prospective multicentric study including patients with large lumbar hernias (L4W3) associated to midline abdominal wall defects. Surgical intervention starts with a bilateral retrorectus dissection performed through a minimally invasive extraperitoneal endoscopic approach (eTEP). Once this space has been dissected, the lumbar IH is treated with an overextended centrifugal preperitoneal open approach through the previous lumbar incision. Afterwards the dissected spaces are communicated performing a reverse transversus abdominis release (TAR) from lateral to medial. A prosthetic preperitoneal repair is performed with an absorbable and permantent meshes that cover the space dissected.

Results

Five patients were included in the study. All patients had lumbar hernias L4W3 associated to primary or incisional midline hernias M1–5 W1–2. Eighty percent of the patients were women, with a mean age of 62 years. Mean BMI was 32 (range 30–34), with a 60% of diabetic patients, and 80% of recurrent lumbar hernias (between 1 and 3 previous repair attempts). Mean surgical time was 198 minutes (range 160–250). Mean hospital stay was 5 days (range 4–8 days). Two lumbar hematomas which didn't required any interventional procedure took place as the only surgical site occurrences, without any systemic complications. No recurrence has taken place after 5 months mean follow up (range 2–9 months)

Conclusion

Hybrid eTEP and open approach of large lumbar hernias associated with small midline defects seem to be an efficient and safe approach.

OS01.7.A Detection of methylation-based prognostic signatures in liquid biopsy specimens from patients with meningiomas

Background

Detection of distinct epigenetic biomarkers in circulating cell-free DNA (cfDNA) of liquid biopsy (LB) specimens (e.g. blood) fosters opportunity for prognostication of central nervous system (CNS) tumors and has not been thoroughly explored in patients with meningiomas.

Material and Methods

We profiled the cfDNA methylome (EPIC array) in serum specimens from patients with meningiomas (MNG; n= 63) and harnessed internal and external meningioma tissue methylome data with reported follow up (n=48). To predict recurrence risk (RR), we consolidated a tissue cohort with at least 5 years of follow up and divided them into confirmed recurrence (CR; either reported progressive disease in post-surgical imaging, or additional resections following initial surgery) and confirmed no-recurrence (CNR: no confirmed disease progression w/in at least 5-years of follow-up). Then through application of an iterative process consisting of multiple tissue- and serum-based supervised analyses, we identified risk-specific methylation markers with serum specific features which, when inputted into a random forest algorithm allowed for segregation of both tumor tissue and liquid biopsy specimens according to recurrence risk. We estimated immune cell composition using MethylCIBERSORT, where a reference methylome atlas of chosen immune cell types was utilized to deconvolute the MNG samples.

Results

The resulting recurrence risk classifier demonstrated an appreciable predictive power in classifying samples as high or low recurrence risk across the tumor tissue cohort (ACC: 87.5%, CUI+: 85.2%). When compared to another classifier, our model demonstrated statistically significant agreement across primary meningioma samples (κ=0.269, p=0.002), and more accurately predicted samples to recur across an expanded time window (time to recurrence >5yrs). Across resulting liquid biopsy classifications, recurrence risk subgroups were analogous with reported risk factors, including WHO grade, extent of resection, and tumor location. Recurrence risk subgroups (high and low) also demonstrated differential estimated immune cell contributions, with low-risk samples exhibiting a “hot” profile, or enrichment of B-Cells, CD56- and CD4 T-Cells, and natural killer cells. Notably, the estimated neutrophil to lymphocyte ratio, previously purported to be relevant to tumor prognosis, was appreciably higher for those meningioma samples with the highest recurrence risk.

Conclusion

DNA methylation markers identified in the serum are suitable for the development of machine learning-based models which present high predictive power to prognosticate patients with meningioma and estimate a differential immune profile across recurrence risk groups. After validation in an external cohort, this noninvasive approach may improve the presurgical therapeutic management of patients with meningiomas.

OS08.3.A Distinct systemic and tumor microenvironment immune landscapes discriminate across sellar tumor types and controls through a methylation-based deconvolution method

Background

Systemic (Sys) and tumor microenvironment (TME) immune milieus play a pivotal role in tumor development, outcome and immunotherapy response predictions across a variety of central nervous system tumors. Genome-wide methylation profiling can reliably discriminate and estimate immune cell proportions present in the blood and within the tumor and has not been reported across sellar tumor types (STT).

Material and Methods

We estimated cell composition in liquid biopsy (LB, serum/plasma) and tissue specimens from 42 STT collections (i.e., pituitary neuroendocrine tumors [PitNETs; n=37] and craniopharyngiomas [CP; n=5]), and 26 nontumor controls (LB: 11; Tissue: 15) using MethylCIBERSORT, a methylation-based deconvolution algorithm and established immune cell signatures as reference. LB methylation was profiled with EPIC array. Correlations between estimated cell proportions across sample sources were explored (Spearman). Immune cell proportion hierarchical k-means clustering was performed across tissue and LB specimens. Similarly, mean comparisons between and across sample types and subgroups of interest were performed [Non-parametric Kruskal-Wallis, Wilcoxon rank-sum tests; p<0.05].

Results

We identified three immune-clusters across tissue specimens which distinguished controls (k3-cluster) from sellar tumor specimens (k1- and k2- clusters), primarily attributable to differential B-cell and monocyte proportions. Interestingly, a subset of PitNET and CP, belonging to the k2-cluster, presented a distinct immune profile compared to their K1-sellar tumor counterparts. Analysis of plasma-derived immune clusters revealed that PitNETs were distributed across four distinct immune patterns and CP clustered together with controls and a PitNET subset. One of the PitNET clusters was enriched with patients that died during follow-up and presented an enrichment of CD4-(including the regulatory subtype), CD8 and CD56-T and depletion of natural killer cells. Differences across serum- and tissue-derived clusters were present but less prominent than their plasma counterparts. No correlation between immune cell proportions across other clinicopathological features within each tumor type (sex, age, histotypes, invasion etc) was observed.

Conclusion

Our results suggest that PitNETs are characterized by differential TME and systemic immune subtypes which also distinguish these tumors from CP and controls. Additionally, distinct systemic immune composition between tissue and LB sources, more readily observed in plasma, suggest that the systemic response to the presence of the tumor is distinct from the immune response noted in the TME. Tumor immune subtyping may allow the stratification of STT according to immunotherapy response vulnerabilities.

[Impact of a service protocol on the practice of vaginal delivery of breech presentations at term]

OBJECTIVES

The delivery of breech presentations remains controversial. Our study analysed the impact of a service protocol on the proportion of planned vaginal delivery and its success. Immediate neonatal morbidity and factors that may influence the success of vaginal delivery were studied.

METHODS

Retrospective study, between 2009 and 2020 at the CHRU of Limoges, type 3 maternity hospital, on patients with a breech foetus at term. The proportion of planned vaginal delivery and the rate of effective vaginal delivery were compared before/after 2015. Neonatal morbidity was compared for planned vaginal delivery and planned cesarean delivery groups.

RESULTS

We included 923 patients. The rate of planned vaginal delivery was significantly higher after 2015 from 5.2% to 19% (P<0.001), with a success rate increasing from 60% to 82.1% (P=0.06). The rate of vaginal breech deliveries significantly increased from 3.8% to 17% (P<0.001). We found significantly more newborns with moderate acidosis when a vaginal delivery was attempted (P<0.001). The success of vaginal delivery was correlated to the Magnin index (P=0.044), to gestational age (P=0.037), and to multiparity (OR 3.78 95% CI [1.42-10.03] P=0.006).

CONCLUSION

Our study demonstrates the benefits of setting up a service protocol for the practice of breech vaginal delivery.

Failure of talc seromadesis for the treatment of subcutaneous chronic seromas after incisional hernia surgery

BACKGROUND AND AIM

Talc poudrage has been used since many years for sclerosing chronic pleural effusion. Several reports have shown good results managing chronic seromas after breast, vascular, and incisional hernia surgeries. The purpose of this study is to determine the utility of talc seromadesis for the management of chronic seromas after incisional hernia surgery.

MATERIALS AND METHODS

Multicentric prospective observational study including patients diagnosed of chronic seromas after incisional hernia surgery. Under local anesthesia and ultrasonographic control, two percutaneous trocars were placed in the seroma, washing the seroma cavity with 0.9% saline solution and aspirating the remaining liquid. A sample of 4 g of talcum powder was introduced in the seroma cavity, and a 15-F drain was left in place. Patients were followed each week during at least 4 weeks after drainage removal.

RESULTS

Between January 2013 and December 2016, a total of six patients were enrolled in the study. Talc poudrage was performed without any complications. Drains were pulled out in a mean time of 3 (range: 2-4) weeks. One case of the chronic seromas was efficiently sclerosed with talc without recurrence in time. In three cases, the seroma recurred, and the final solution was surgical decortication of the seroma. In the other two cases, seroma also recurred and were managed with instillation of ethanol and iodine povidone.

CONCLUSION

In our experience, the management of chronic seromas after incisional hernia repair with talc seromadesis is ineffective and is associated with a high rate of seroma recurrence.

P01.02 Serum-derived DNA methylation markers distinguish functional and invasiveness subtypes in patients harboring pituitary tumors

BACKGROUND

Molecular profiling of circulating biomarkers released by tumors has a relevant clinical value in central nervous system (CNS) tumors, but its feasibility has not been investigated in pituitary tumors (PT) despite being the second common intraaxial tumors of the CNS (~15%). Although usually benign and slow-growing, they can be nonfunctioning and invade surrounding structures resulting in significant comorbidities. DNA methylation aberrations distinguish PT according to their functional status but their role in invasiveness is still unclear. Pre-surgical detection of clinically relevant molecular markers associated with tumor behavior can address current diagnostic and therapeutic challenges. We hypothesized that PT release cell-free DNA (cfDNA) into the bloodstream allowing for the profiling of epigenetic markers associated with relevant clinicopathological features.

MATERIAL AND METHODS

Genome-wide methylome profile of paired serum cfDNA (EPIC array) and tissue from 13 patients with pituitary macroadenomas (9 males; median age: 62; 9 NFPT, 6 invasive) and 3 controls serum (patients with epilepsy).

RESULTS

Unsupervised analysis of the serum methylome from patients harboring PT was distinct from controls and other diseases (hypopituitarism, glioma and colorectal cancer) and supervised analysis (Wilcoxon Rank-sum Test) identified significant differentially methylated probes (DMP) that segregated PT from control serum specimens. Nonfunctioning and invasive-specific DMPs identified in the serum also defined functional, and less prominently invasive status, in the tissue of an independent cohort of PT.

CONCLUSION

This is the first study to show the feasibility to profile the methylome in the serum of patients with PT using cfDNA. In addition, we identified unique methylation signatures that distinguished PT according to functional and invasiveness subtypes. These results underpin the potential role of methylation profile and liquid biopsy as a noninvasive approach to assess clinically relevant molecular features in the serum of patients harboring PT.

OS1.5 Detection of glioma and prognostic subtypes by non-invasive circulating cell-free DNA methylation markers

BACKGROUND: Genome-wide DNA methylation profiling has shown that epigenetic abnormalities are biologically important in glioma and can be used to classify these tumors into distinct prognostic groups. Thus far, DNA profiling has required surgically resected glioma tissue; however, gliomas release tumoral material into biofluids providing an opportunity for a minimally invasive testing. While prior studies have shown that molecular markers can be detected in liquid biopsy (LB), there has been low sensitivity for tumor-specific markers. We hypothesize that the low sensitivity is due to the targeted assay methods. METHODS: Genome-wide CpG methylation levels in DNA of tumor tissue and cell-free DNA serum of glioma patients. RESULTS: We defined glioma-specific and IDH-specific epigenetic LB (eLB) signatures (Glioma-eLB and IDH-eLB, respectively) from serum cell-free DNA from patients diagnosed with glioma (N=15 IDH mutant and N=7 IDH wildtype) and with epilepsy (N=3). The epigenetic profiles of the matched tissue demonstrate that these eLB signatures reflected the signature of the tumor. Through cross-validation we show that Glioma-eLB can accurately predict a patient’s glioma from those with other neoplasias (N=6 Colon; N=14 Pituitary; N=3 Breast; N=4 Lung), non-neoplastic immunological conditions (N=22 sepsis; N=9 pancreatic islet transplantation), and from healthy individuals (sensitivity: 98%; specificity: 99%). Finally, IDH-eLB includes promoter methylated markers associated with genes known to be involved in glioma tumorigenesis (PVT1 and CXCR6). CONCLUSIONS: The application of the non-invasive eLB signature discovered in this study has the potential to complement the standard of care for patients harboring glioma.

This project is supported by the Henry Ford Health System, Department of Neurosurgery and the Hermelin Brain Tumor Center Foundation (A30935), United States National Institutes of Health (R01CA222146), and United States Department of Defense (CA170278)

Negative prognostic value of high levels of intracellular poly(ADP-ribose) in non-small cell lung cancer

BACKGROUND

Cisplatin-resistant non-small cell lung cancer (NSCLC) cells are often characterized by alterations in vitamin B-related metabolic processes, including the overexpression and hyperactivation of poly(ADP-ribose) polymerase 1 (PARP1) and the downregulation of pyridoxal kinase (PDXK), correlating with elevated apoptosis resistance. Low PDXK expression is an established negative prognostic factor in NSCLC.

PATIENTS AND METHODS

We determined by immunohistochemistry the expression of PARP1 and the level of its product, poly(ADP-ribose) (PAR), in two independent cohorts of patients with resected NSCLC.

RESULTS

Intratumoral high levels (above median) of PAR (but not PARP1 protein levels) had a negative prognostic impact in both the training (92 stage I subjects) and validation (133 stage I and II subjects) cohorts, as determined by univariate and multivariate analyses. The simultaneous assessment of PAR and PDXK protein levels improved risk stratification.

CONCLUSION

NSCLC patients with high intratumoral PARP1 activity (i.e. elevated PAR levels above median) and low PDXK expression (below median) had a dismal prognosis, while patients with low PARP1 activity and high PDXK expression had a favorable outcome. Altogether, these results underscore the clinical potential and possible therapeutic relevance of these biomarkers.

Modification of a commercial DNA extraction kit for safe and rapid recovery of DNA and RNA simultaneously from soil, without the use of harmful solvents

An optimized method, based on the coupling of two commercial kits, is described for the extraction of soil nucleic acids, with simultaneous extraction and purification of DNA and RNA following a cascade scheme and avoiding the use of harmful solvents. The protocol canmonitor the variations in the recovery yield of DNA and RNA from soils of various types.The quantitative version of the protocol was obtained by testing the starting soil quantity, the grinding parameters and the final elution volumes, in order to avoid saturation of both kits.

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A first soil-crushing step in liquid nitrogen could be added for the assessment of fungal parameters.

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The protocol was efficienton different tropical soils, including Andosol, while their high contents of clays, including poorly crystalline clays, and Fe and Al oxides usually make the nucleic acid extraction more difficult.

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The RNA recovery yield from the previous tropical soils appeared to correlate better to soil respiration than DNA, which is positively influenced by soil clay content.

[Recurrent unilateral optic neuropathy associated with human immunodeficiency virus (HIV)]

HIV-related optic neuropathy is rare compared to optic neuropathies secondary to opportunistic infections in seropositive patients. We report the case of a 39-year-old HIV-positive woman referred for unilateral visual loss leading to the diagnosis of recurrent, unilateral, inflammatory optic neuropathy directly associated with HIV. Despite initial recovery after steroid treatment, she relapsed twice. Absence of any opportunist infections or toxic causes and presence of a very high viral load due to non-compliance with treatment led to the diagnosis of HIV-related optic neuropathy. Steroids and effective anti-retroviral treatment resulted in definitive and complete recovery. Inflammatory, degenerative and/or vascular mechanisms have been hypothesized to explain the occurrence of these rare HIV-related optic neuropathies. This diagnosis remains a diagnosis of exclusion to be considered in the work-up of seropositive patients with optic neuropathies.

["Teddy bear granuloma", a rare condition: a case report of a 3-year-old child]

Conjunctival synthetic fiber granulomas, or "Teddy bear granulomas", are rare granulomatous responses to synthetic fabric fibers. We report the case of a 3-year-old boy with no prior infectious or traumatic history, brought in by his parents for an incidentally discovered conjunctival growth in his right eye. Slit lamp examination revealed a 10-mm growth in the inferior fornix surrounding a small greyish foreign body. Surgical excision and histopathology revealed granulomatous inflammatory cell response with foreign body giant cells surrounding exogenous material. This foreign material was birefringent in polarized light, very suggestive of synthetic fabric fibers, which permitted the diagnosis of Teddy bear granuloma. Synthetic fiber granulomas present in children as unilateral, more or less inflammatory growths in the inferior conjunctival fornix. Surgical excision with histopathology makes the diagnosis and effects the cure.

Seasonal depth-related gradients in virioplankton: standing stock and relationships with microbial communities in Lake Pavin (France)

This study presents a depth-related survey of virioplankton abundance in Lake Pavin (Massif Central, France), in relation to the abundances of heterotrophic prokaryotes, picocyanobacteria (Pcy), autotrophic picoeukaryotes (Peu), and of autotrophic (ANF) and heterotrophic (HNF) nanoflagellates. The sampling strategy was designed to be representative of the physico-chemical gradients of the whole water column of the lake, and the seasonal variability as well. In mixolimnic surface waters, all communities were present and viral abundance peaked in summer and autumn. Viral abundance was significantly correlated (p < 0.001) with Pcy, Peu, and ANF, indicating that cyanophages and perhaps other phytoplankton viruses represent a significant pool of viral standing stocks in the mixolimnion of Lake Pavin. Microautotrophs were absent in the deep monimolimnic water masses, where viruses and heterotrophic prokaryotes exhibited highest seasonal abundances in summer and/or autumn and were significantly correlated (p < 0.001) to each other. This indicates that the anoxic monimolimnion of Lake Pavin is an exclusive habitat for viruses and heterotrophic prokaryotes. We conclude that in this habitat, host availability is prevalent over other factors (temperature, oxygen, nutrients, grazers) in favoring viral proliferation.

In vivo anti-malarial effect of the beta-amino alcohol 1t on Plasmodium berghei

Glycerol derivatives are a class of compounds, which are easy and inexpensive to produce with potent anti-malarial activities against blood stages of Plasmodium falciparum in vitro. In the present study, one of these compounds, termed 1t, which had the lowest IC(50) values, was assessed in a murine malarial model. Nuclear magnetic resonance imaging and Balb/c mice infected with Plasmodium berghei ANKA strain were treated in a 4-day suppressive test. Mice received a once-daily intraperitoneal administration of 50 mg/Kg of the drug for 4 days. Although no parasitaemia clearance was reached, a slower parasite proliferation and a slightly longer survival time compared with the placebo group were observed.

Virioplankton ‘pegylation’: Use of PEG (polyethylene glycol) to concentrate and purify viruses in pelagic ecosystems

We have described the use of Polyethylene glycol (PEG) for the precipitation of natural communities of aquatic viruses, and its comparison with the usual concentration method based on ultracentrifugation. Experimental samples were obtained from different freshwater ecosystems whose trophic status varied. Based on transmission electron microscope observations and counting of phage-shaped particles, our results showed that the greatest recovery efficiency for all ecosystems was obtained when we used the PEG protocol. On average, this protocol allowed the recovery of >2-fold more viruses, compared to ultracentrifugation. In addition, the diversity of virioplankton, based on genomic size profiling using pulsed field gel electrophoresis, was higher and better discriminated when we used the PEG method. We conclude that pegylation offers a valid, simple and cheaper alternative method to ultracentrifugation, for the concentration and the purification of pelagic viruses.

Local spin polarization at surfaces probed by hollow atoms

The relaxation of hollow atoms produced by slow multiply charged ions impinging on surfaces produces characteristic Auger electron spectra. These spectra, which serve as fingerprints of the interaction, can be used to probe local spin ordering at surfaces by relating changes in the intensities of different spin states to local spin polarization at the surface. The area from which the electrons are captured is of the order of a few Angstrom(2), only. The potential of the method is illustrated by He(2+) and N(6+) ions interacting with a ferromagnetic Ni(110) crystal. From the Auger spectra we determine a spin polarization of approximately 90% at room temperature.

Irinotecan combined with gemcitabine, 5-fluorouracil, leucovorin, and cisplatin (G-FLIP) is an effective and noncrossresistant treatment for chemotherapy refractory metastatic pancreatic cancer

BACKGROUND

Single agents have only modest activity as treatment for metastatic pancreatic cancer with response rates of less than 10% and median survivals of less than 6 months. Evaluations of single-agent gemcitabine and rubitecan as second-line treatment for relapsed pancreatic cancer have reported good patient tolerability and median survivals of 3.85 months and 4.7 months, respectively. Regimens incorporating two drugs have demonstrated encouraging activity and clinical impact compared with single-agent therapy. G-FLIP is a regimen designed to incorporate four active single agents into a tolerable and active combination. This analysis is a retrospective evaluation of the efficacy and safety of the G-FLIP regimen as second-line chemotherapy in a series of consecutively treated patients with metastatic pancreatic cancer.

METHODS

G-FLIP was administered over 48 hours and repeated every 2 weeks. Day 1 treatment consisted of sequentially administered gemcitabine 500 mg/m(2), irinotecan 80 mg/m(2), leucovorin 300 mg, 5-fluorouracil (5-FU) 400 mg/m(2) bolus followed by infusional 5-FU 600 mg/m(2) over 8 hours. Day 2 treatment consisted of leucovorin 300 mg and 5-FU 400 mg/m(2) bolus, followed by cisplatin 50 to 75 mg/m(2), and then infusional 5-FU 600 mg/m(2) over 8 hours.

RESULTS

Thirty-four patients with histologically confirmed metastatic pancreatic cancer were consecutively treated. The median patient age was 64.5 years (range 41-82 years) and all patients had objective disease progression on prior therapy: 32 patients had disease progression with gemcitabine and 31 had disease progression with a gemcitabine/5-fluorouracil/cisplatin combination. Grade 3-4 hematological toxicities included anemia (23%), thrombocytopenia (53%), and neutropenia (38%). There were no grade 3-4 neutropenic fevers, treatment-related mortalities, or withdrawals. Nonhematological grade 3-4 toxicities were rare: nausea/vomiting (3%), neurotoxicity (3%), nephrotoxicity (6%), and diarrhea (3%). Based on RECIST criteria a partial response (PR) was attained in eight patients (24%) and seven patients had stable disease (SD). Seven and six patients who attained a PR or SD, respectively, had disease progression with prior gemcitabine-based therapy. The median time to disease progression for all 34 patients was 3.9 months and 5.9 months for the eight patients who attained a PR. Median overall survival for all 34 patients was 10.3 months.

CONCLUSION

Adding a single new drug such as irinotecan to the same first-line chemotherapy combination upon disease progression may be an important alternative to switching to different drug classes for treatment of relapsed/resistant cancer. The promising clinical outcomes and moderate toxicity associated with G-FLIP in this heavily pretreated group warrant development of this novel regimen including tests as first-line therapy in patients with diseases likely to be responsive to the drugs contained in this combination.