Multicentre retrospective analysis on pulmonary metastasectomy: an European perspective

OBJECTIVES

To assess the current practice of pulmonary metastasectomy at 15 European Centres. Short- and long-term outcomes were analysed.

METHODS

Retrospective analysis on patients ≥18 years who underwent curative-intent pulmonary metastasectomy (January 2010 to December 2018). Data were collected on a purpose-built database (REDCap). Exclusion criteria were: previous lung/extrapulmonary metastasectomy, pneumonectomy, non-curative intent and evidence of extrapulmonary recurrence at the time of lung surgery.

RESULTS

A total of 1647 patients [mean age 59.5 (standard deviation; SD = 13.1) years; 56.8% males] were included. The most common primary tumour was colorectal adenocarcinoma. The mean disease-free interval was 3.4 (SD = 3.9) years. Relevant comorbidities were observed in 53.8% patients, with a higher prevalence of metabolic disorders (32.3%). Video-assisted thoracic surgery was the chosen approach in 54.9% cases. Wedge resections were the most common operation (67.1%). Lymph node dissection was carried out in 41.4% cases. The median number of resected lesions was 1 (interquartile range 25-75% = 1-2), ranging from 1 to 57. The mean size of the metastases was 18.2 (SD = 14.1) mm, with a mean negative resection margin of 8.9 (SD = 9.4) mm. A R0 resection of all lung metastases was achieved in 95.7% cases. Thirty-day postoperative morbidity was 14.5%, with the most frequent complication being respiratory failure (5.6%). Thirty-day mortality was 0.4%. Five-year overall survival and recurrence-free survival were 62.0% and 29.6%, respectively.

CONCLUSIONS

Pulmonary metastasectomy is a low-risk procedure that provides satisfactory oncological outcomes and patient survival. Further research should aim at clarifying the many controversial aspects of its daily clinical practice.

Controlled donation after circulatory death lung transplantation: Results of the French protocol including in situ abdominal normothermic regional perfusion and ex vivo lung perfusion

BACKGROUND

The French national protocol for controlled donation after circulatory determination of death (cDCD) includes normothermic regional perfusion (NRP) in case of abdominal organ procurement and additional ex-vivo lung perfusion (EVLP) before considering lung transplantation (LT).

METHODS

We made a retrospective study of a prospective registry that included all donors considered for cDCD LT from the beginning of the program in May 2016 to November 2021.

RESULTS

One hundred grafts from 14 donor hospitals were accepted by 6 LT centers. The median duration of the agonal phase was 20 minutes [2-166]. The median duration from circulatory arrest to pulmonary flush was 62 minutes [20-90]. Ten lung grafts were not retrieved due to prolonged agonal phases (n = 3), failure of NRP insertion (n = 5), or poor in situ evaluation (n = 2). The remaining 90 lung grafts were all evaluated on EVLP, with a conversion rate of 84% and a cDCD transplantation rate of 76%. The median total preservation time was 707 minutes [543-1038]. Seventy-one bilateral LTs and 5 single LTs were performed for chronic obstructive pulmonary disease (n = 29), pulmonary fibrosis (n = 21), cystic fibrosis (n = 15), pulmonary hypertension (n = 8), graft-versus-host disease (n = 2), and adenosquamous carcinoma (n = 1). The rate of PGD3 was 9% (n = 5). The 1-year survival rate was 93.4%.

CONCLUSION

After initial acceptance, cDCD lung grafts led to LT in 76% of cases, with outcomes similar to those already reported in the literature. The relative impacts of NRP and EVLP on the outcome following cDCD LT should be assessed prospectively in the context of comparative studies.

Management of lung transplantation in the COVID-19 era-An international survey

It is unknown if solid organ transplant recipients are at higher risk for severe COVID-19. The management of a lung transplantation (LTx) program and the therapeutic strategies to adapt the immunosuppressive regimen and antiviral measures is a major issue in the COVID-19 era, but little is known about worldwide practice. We sent out to 180 LTx centers worldwide in June 2020 a survey with 63 questions, both regarding the management of a LTx program in the COVID-19 era and the therapeutic strategies to treat COVID-19 LTx recipients. We received a total of 78 responses from 15 countries. Among participants, 81% declared a reduction of the activity and 47% restricted LTx for urgent cases only. Sixteen centers observed deaths on waiting listed patients and eight centers performed LTx for COVID-19 disease. In 62% of the centers, COVID-19 was diagnosed in LTx recipients, most of them not severe cases. The most common immunosuppressive management included a decreased dose or pausing of the cell cycle inhibitors. Remdesivir, hydroxychloroquine, and azithromycin were the most proposed antiviral strategies. Most of the centers have been affected by the COVID-19 pandemic and proposed an active therapeutic strategy to treat LTx recipients with COVID-19.

RADIORYTHMIC: Phase III, Opened, Randomized Study of Postoperative Radiotherapy Versus Surveillance in Stage IIb/III of Masaoka Koga Thymoma after Complete Surgical Resection

INTRODUCTION

Thymomas are rare intrathoracic malignancies that may be aggressive and difficult to treat. Knowledge and level of evidence for treatment strategies are mainly based on retrospective studies or expert opinion. Currently there is no strong evidence that postoperative radiotherapy after complete resection of localized thymoma is associated with survival benefit in patients. RADIORYTHMIC is a phase III, randomized trial aiming at comparing postoperative radiotherapy versus surveillance after complete resection of Masaoka-Koga stage IIb/III thymoma. Systematic central pathologic review will be performed before patient enrollment as per the RYTHMIC network pathway.

PATIENTS AND METHODS

Three hundred fourteen patients will be included; randomization 1:1 will attribute either postoperative radiotherapy (50-54 Gy to the mediastinum using intensity-modulated radiation therapy or proton beam therapy) or surveillance. Stratification criteria include histologic grading (thymoma type A, AB, B1 vs B2, B3), stage, and delivery of preoperative chemotherapy. Patient recruitment will be mainly made through the French RYTHMIC network of 15 expert centers participating in a nationwide multidisciplinary tumor board. Follow-up will last 7 years. The primary endpoint is recurrence-free survival. Secondary objectives include overall survival, assessment of acute and late toxicities, and analysis of prognostic and predictive biomarkers.

RESULTS

The first patient will be enrolled in January 2021, with results expected in 2028.

Surgical management of esophageal sarcoma: a multicenter European experience

Esophageal sarcomas are rare and evidence in literature is scarce making their management difficult. The objective is to report surgical and oncological outcomes of esophageal sarcoma in a large multicenter European cohort. This is a retrospective multicenter study including all patients who underwent en-bloc esophagectomy for esophageal sarcoma in seven European tertiary referral centers between 1987 and 2016. The main outcomes and measures are pathological results, early and long-term outcomes. Among 10,936 esophageal resections for cancer, 21 (0.2%) patients with esophageal sarcoma were identified. The majority of tumors was located in the middle (n = 7) and distal (n = 9) third of the esophagus. Neoadjuvant chemoradiotherapy was performed in five patients. All the patients underwent en-bloc transthoracic esophagectomy (19 open, 2 minimally invasive). Postoperative mortality occurred in 1 patient (5%). One patient received adjuvant chemotherapy. Definitive pathological results were carcinosarcoma (n = 7), leiomyosarcoma (n = 5), and other types of sarcoma (n = 9). Microscopic R1 resection was present in one patient (5%) and seven patients (33%) had positive lymph nodes. Median follow-up was 16 (3-79) months in 20 of 21 patients (95%). One-, 3-, and 5-year overall survival rates were 74%, 43%, and 35%, respectively. One-, 3- and 5-years disease-free survival rates were 58%, 40%, and 33%, respectively. Median overall survival was 6 months in N+ patients vs. 37 months for N0 patients (p = 0.06). At the end of the follow-up period, nine patients had died from cancer recurrences (43%), three patients died from other reasons (14%), one patient was still alive with recurrence (5%) and the seven remaining patients were free of disease (33%). Recurrence was local (n = 3), metastatic (n = 3), or both (n = 4). In conclusion, carcinosarcoma and leiomyosarcoma were the most common esophageal sarcoma histological subtypes. Lymph node involvement was seen in one third of cases. A transthoracic en-bloc esophagectomy with radical lymphadenectomy should be the best surgical option to achieve complete resection. Long-term survival remained poor with a high local and distant recurrence rate.

Crystallographic and optical study of PbHfO3 crystals

The symmetry of the intermediate high-temperature phase of PbHfO₃ has been determined unambiguously to be orthorhombic using a combination of high-resolution X-ray diffraction and birefringence imaging microscopy measurements of crystal plates. While lattice parameter measurements as a function of temperature in the intermediate phase are consistent with either orthorhombic or tetragonal symmetry, domain orientations observed in birefringence imaging microscopy measurements utilizing the Metripol system are only consistent with orthorhombic symmetry with the unit cell in the rhombic orientation of the pseudocubic unit cell.

Nanomechanical electro-optical modulator based on atomic heterostructures

Two-dimensional atomic heterostructures combined with metallic nanostructures allow one to realize strong light–matter interactions. Metallic nanostructures possess plasmonic resonances that can be modulated by graphene gating. In particular, spectrally narrow plasmon resonances potentially allow for very high graphene-enabled modulation depth. However, the modulation depths achieved with this approach have so far been low and the modulation wavelength range limited. Here we demonstrate a device in which a graphene/hexagonal boron nitride heterostructure is suspended over a gold nanostripe array. A gate voltage across these devices alters the location of the two-dimensional crystals, creating strong optical modulation of its reflection spectra at multiple wavelengths: in ultraviolet Fabry–Perot resonances, in visible and near-infrared diffraction-coupled plasmonic resonances and in the mid-infrared range of hexagonal boron nitride's upper Reststrahlen band. Devices can be extremely subwavelength in thickness and exhibit compact and truly broadband modulation of optical signals using heterostructures of two-dimensional materials.

Van der Waals heterostructures can be combined with metallic nanostructures to enable enhanced light–matter interaction. Here, the authors fabricate a broadband mechanical electro-optical modulator using a graphene/hexagonal boron nitride vertical heterojunction, suspended over a gold nanostripe array.

Airway stenting in the management of iatrogenic tracheal injuries: 10-Year experience

BACKGROUND AND OBJECTIVE

Iatrogenic tracheal injury (ITI) is a rare yet severe complication of endotracheal tube (ETT) placement or tracheostomy. ITI is suspected in patients with clinical and/or radiographic signs or inefficient mechanical ventilation (MV) following these procedures. Bronchoscopy is used to establish a definitive diagnosis.

METHODS

We conducted a retrospective, single-centre chart review of 35 patients between 2004 and 2014. Depending on the nature and location of ITI and need for MV, patients were triaged to surgical repair, endoscopic management with airway stents or conservative treatment consisting of ETT or tracheotomy cannula (TC) placement distal to the wound and bronchoscopic surveillance.

RESULTS

Three of the four patients (11.43%) presenting with tracheoesophageal fistula (TEF) underwent surgery. Seven patients (20%) who did not require MV underwent endoscopic surveillance. Of the 24 ventilated patients (68.57%), 7 with ITI in the lower trachea were treated with silicone Y-stent (ETT or TC was placed inside the stent) and 17 patients with ITI in the upper trachea were managed by placing ETT or TC cuff distal to the injury. Overall management success, defined as complete healing of the ITI, was seen in 88.57% of patients. Four patients (11.43%) died of non-ITI-related comorbidities.

CONCLUSION

Conservative management should be considered in non-ventilated patients with ITI and when ITI is located in the upper trachea of ventilated patients where ETT or TC bypasses the injury. Airway stenting should be considered in ventilated patients with ITI located in the lower trachea. Surgery should be reserved for TEF and conservative and endoscopic management failure.

Pneumonectomy for lung cancer: contemporary national early morbidity and mortality outcomes

OBJECTIVE

The study objective was to determine contemporary early outcomes associated with pneumonectomy for lung cancer and to identify their predictors using a nationally representative general thoracic surgery database (EPITHOR).

METHODS

After discarding inconsistent files, a group of 4498 patients who underwent elective pneumonectomy for primary lung cancer between 2003 and 2013 was selected. Logistic regression analysis was performed on variables for mortality and major adverse events. Then, a propensity score analysis was adjusted for imbalances in baseline characteristics between patients with or without neoadjuvant treatment.

RESULTS

Operative mortality was 7.8%. Surgical, cardiovascular, pulmonary, and infectious complications rates were 14.9%, 14.1%, 11.5%, and 2.7%, respectively. None of these complications were predicted by the performance of a neoadjuvant therapy. Operative mortality analysis, adjusted for the propensity scores, identified age greater than 65 years (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.5-2.9; P < .001), underweight body mass index category (OR, 2.2; 95% CI, 1.2-4.0; P = .009), American Society of Anesthesiologists score of 3 or greater (OR, 2.310; 95% CI, 1.615-3.304; P < .001), right laterality of the procedure (OR, 1.8; 95% CI, 1.1-2.4; P = .011), performance of an extended pneumonectomy (OR, 1.5; 95% CI, 1.1-2.1; P = .018), and absence of systematic lymphadenectomy (OR, 2.9; 95% CI, 1.1-7.8; P = .027) as risk predictors. Induction therapy (OR, 0.63; 95% CI, 0.5-0.9; P = .005) and overweight body mass index category (OR, 0.60; 95% CI, 0.4-0.9; P = .033) were protective factors.

CONCLUSIONS

Several risk factors for major adverse early outcomes after pneumonectomy for cancer were identified. Overweight patients and those who received induction therapy had paradoxically lower adjusted risks of mortality.

Colon interposition for oesophageal replacement

The choice of the colon as an oesophageal substitute results primarily from the unavailability of the stomach. However, given its durability and function, colon interposition keeps elective indications in patients with benign or malignant oesophageal disease who are potential candidates for long survival. The choice of the colonic portion used for oesophageal reconstruction depends on the required length of the graft, and the encountered colonic vascular anatomy, the last being characterised by the near-invariability of the left colonic vessels, in contrast to the vascular pattern of the right side of the colon. Accordingly, the transverse colon with all or part of the ascending colon is the substitute of choice, positioned in the isoperistaltic direction, and supplied either from the left colic vessels for long grafts or middle colic vessels for shorter grafts. Technical key points are: full mobilisation of the entire colon, identification of the main colonic vessels and collaterals, and a prolonged clamping test to ensure the permeability of the chosen nourishing pedicle. Transposition through the posterior mediastinum in the oesophageal bed is the shortest one and thereby offers the best functional results. When the oesophageal bed is not available, the retrosternal route is the preferred alternative option. The food bolus travelling mainly by gravity makes straightness of the conduit of paramount importance. The proximal anastomosis is a single-layer hand-fashioned end-to-end anastomosis to prevent narrowing. When the stomach is available, the distal anastomosis is best performed at the posterior part of the antrum for the reasons of pedicle positioning and reflux prevention, and a gastric drainage procedure is added when the oesophagus and vagus nerves have been removed. In the other cases, a Roux-en-Y jejunal loop is preferable to prevent bile reflux into the colon. Additional procedures include re-establishment of the colonic continuity, a careful closure of the mesentery to avoid a further internal hernia, and routine appendectomy. When applying these technical aids, the chances of achieving a viable and well-functioning colon graft are excellent.

Ameliorative effect of naringenin on hyperglycemia-mediated inflammation in hepatic and pancreatic tissues of Wistar rats with streptozotocin- nicotinamide-induced experimental diabetes mellitus

In diabetes mellitus (DM), sustained hyperglycemia results in the generation of reactive oxygen species, ultimately leading to increased oxidative stress and inflammation in vital tissues. In the present study, possible ameliorative effects of naringenin on hyperglycemia-mediated inflammation in experimental streptozocin (STZ)-nicotinamide-induced DM were sought. DM was induced experimentally in overnight-fasted Wistar rats (150-180 g) by intra-peritoneal injection of STZ (50 mg/kg.b.w) and of nicotinamide (110 mg/kg.b.w); control rats (n = 6) received only vehicle (0.5 ml of 0.1 M of cold citrate buffer; pH 4.5). One group of diabetic rats (n = 6) was left untreated while another group of diabetic rats (n = 6) received naringenin (50 mg/kg b.w./day) orally for 21 days. At this time, hemotological indices (erythrocyte sedimentation rate [ESR], total white blood cell [WBC] count, differential WBC percentage, and platelet count) were measured. Significant alterations in expression of gene and protein biomarkers of inflammation in hepatic and pancreatic tissues were determined by measuring mRNA levels and the level of protein expressed, respectively, as was the total nitric oxide level in these tissues. Diabetic rats showed significantly higher mean ESR values, total WBC counts, differential WBC percentages, and platelet counts than those in control rats; similarly, mean mRNA levels of C-reactive protein, pro-inflammatory cytokine, nuclear factor-κB and inducible nitric oxide synthase genes and mean intensities of expression of the corresponding proteins in the hepatic and pancreatic tissue samples from diabetic rats significantly exceeded those in control rats. However, in diabetic rats treated with naringenin, the values of hematological, mRNA transcript and protein indices of inflammation were all lower than those in diabetic rats. These results suggest that naringenin possibly alleviates hyperglycemia-mediated inflammation in experimental STZ-nicotinamide-induced DM in Wistar rats.

Bronchogenic cyst: best time for surgery?

BACKGROUND

Bronchogenic cyst (BC) is a benign congenital mediastinal tumor whose natural course remains unclear. In adults, most BCs are removed by thoracotomy after complications. Currently, prenatal diagnosis is generally feasible and allows an early thoracoscopic intervention. The purpose of this retrospective study was to ascertain the best time for the operation.

METHODS

Reviewed were 36 patients (11 children, 25 adults) with a BC managed from 2000 to 2011. Clinical history, cyst size, duration of hospitalization, preoperative and postoperative complications, and detection of inflammatory elements were compared (Student t tests) between pediatric and adult patients.

RESULTS

In the pediatric group, diagnosis was made prenatally in 7 patients, during the neonatal period in 2, and later in 2. Nine were asymptomatic. In the adult group, 20 patients were treated for complications. Thoracotomy was performed in 2 children and thoracoscopy in 9 (no conversion). A thoracoscopic operation was performed in 9 adults (2 conversions), and 17 adults required additional procedures (4 pericardial and 9 lung resections, 3 bronchial, and 1 esophageal sutures). The average length of hospitalization was 4.45 days for children (3.33 days in the thoracoscopic subgroup) and 8 days for adults. Mean maximal cyst diameter was 2.2 cm in children and 6.5 cm in adults (p < 0.10). Pathologic study revealed inflammatory reaction in 2 children (18%) vs 21 adults (84%; p < 0.001).

CONCLUSIONS

Early surgical resection of BCs provides better conservation of pulmonary parenchyma, a lower incidence of inflammatory lesions, and a reduced rate of complications, and should be proposed after prenatal diagnosis, between the 6th and 12th month of life.

[Surgical results of type III and IV hiatal hernia with left thoracotomy]

OBJECTIVE

The goal of the study is to report the short- and long-term outcome of a left approach in the management of type III and IV hiatal hernia.

METHODS

We have retrospectively reviewed all the records of patients treated for type III and IV hiatal hernia with a left transthoracic approach. All the patients were evaluated before and after the surgery on clinical presentation, symptoms and functional assessment. We have specifically focused the evaluation on surgical results, mortality, morbidity and long term functional assessment.

RESULTS

Sixty-five patients were included in this study. Type III hiatal hernia (86%) were majority compared to type IV(14%). Surgical techniques included Nissen fundoplication (37%), Collis Nissen elongation gastroplasty (20%) and Belsey-Mark IV (15%). Morbidity was low and there was no hospital mortality. Mean follow-up was 42 months. Long-term reassessment demonstrated a significant improvement of symptoms. Erosive esophagitis persisted in one patient (P < 0.001). Pressure at the level of lower esophageal sphincter was normal in all patients. 24-hours pH-metry was normal in 92% of patients. Anti-acid medication was reduced significantly (P < 0.001).

CONCLUSION

Obesity, short esophagus, massive hiatal hernia, associated oesophageal diseases or previous failed surgery constituted the indications of choice for transthoracic approach. This procedure gives satisfactory functional and anatomical long term results with healing of mucosal damage.

Prosthetic reconstruction of the chest wall

Chest wall reconstructions can be complex and challenging procedures, especially when huge thoracic defects have been generated by radical excisions. Nonrigid reconstructions with meshes or patches have the goal of avoiding a lung hernia caused by the chest wall defect, or preventing the impaction of the scapula in case of posterior chest wall resections, especially when the resection is extended down to the 5th and 6th ribs. Large anterior and lateral resections result in thoracic instability and alteration of pulmonary physiology, and render intrathoracic structures vulnerable to external impact. They necessitate rigid reconstructions according to several techniques using alloplastic materials (eg, methyl methacrylate-based customized plates or neo-ribs, osteosynthesis systems, or dedicated prosthesis). Nowadays, the availability of these multiple, possibly combined, more adapted, and better tolerated materials have pushed past the limits of resection to those involving soft tissue coverage.

Single crystal study of competing rhombohedral and monoclinic order in lead zirconate titanate

Neutron diffraction data obtained on single crystals of PbZr(1-x)Ti(x)O3 with x=0.325 and x=0.460, which lie on the pseudorhombohedral side of the morphotropic phase boundary, suggest a coexistence of rhombohedral (R3m/R3c) and monoclinic (Cm) domains and that monoclinic order is enhanced by Ti substitution. A monoclinic phase with a doubled unit cell (Cc) is ruled out as the ground state.

Primary hyperparathyroidism: A report of two unusual cases

Primary hyperparathyroidism (PHPT) has a variable clinical expression. Majority of the patients are asymptomatic. Symptomatic PHPT with classical skeletal, renal, abdominal and neuro-psychiatric manifestations have become exceedingly rare. Asymptomatic maternal PHPT manifesting as neonatal hypocalcaemic convulsions is another rare entity. The commonest cause of PHPT are solitary parathyroid adenomas. These benign tumors are extremely small being difficult to identify even at surgical exploration. Very large tumors known as giant adenomas are uncommon. Double parathyroid adenomas account for only a small percentage of the lesions associated with PHPT. Considerable debate exists as to whether double adenomas are a distinct entity or represent early stages of four gland hyperplasia. We report two interesting cases of PHPT with classical features, that have become rare today such as nephrolithiasis, nephrocalcinosis, and X-ray findings of bone disease, caused by unusual pathological lesions like double and giant adenomas and discuss rare presentations like neonatal convulsions.

[Epithelial tumours of the thymus]

Epithelial tumours of the thymus include thymomas, thymic carcinomas and neuro-endocrine tumours. Rare, they nevertheless represent 20% of all mediastinal tumours and 50% of those located in the anterior mediastinum. Thymomas, in particular, can be associated to auto-immune disorders, among which predominates myasthenia gravis. Their clinical behaviour varies widely, from a relative indolence to the potential of lymph node and/or systematic metastases. However, even patients with an invasive disease may have a long clinical history, explaining that a 10-year or 20-year survival from diagnosis does not imply a definitive cure. In daily practice, both the clinical Masaoka's staging system and the WHO histological classification condition the treatment strategies and allow to anticipate the prognosis. The initial treatment, as well as that of the recurrence, is based mainly on a complete resection. Postoperative radiotherapy is systematically added to the treatment of invasive tumours and/or to those with an aggressive histological subtype. Inoperable or metastatic tumours require a cisplatine and anthracyclin-based chemotherapy, followed by radical surgery and/or radiotherapy.

Regulatory effect of acetyl-l-carnitine on expression of lenticular antioxidant and apoptotic genes in selenite-induced cataract

Differential expression of apoptotic genes has been demonstrated in selenite-induced cataract. Acetyl-l-carnitine (ALCAR) has been shown to prevent selenite cataractogenesis by maintaining lenticular antioxidant enzyme and redox system components at near normal levels and also by inhibiting lenticular calpain activity. The aim of the present experiment was to investigate the possibility that ALCAR also prevents selenite-induced cataractogenesis by regulating the expression of antioxidant (catalase) and apoptotic [caspase-3, early growth response protein-1 (EGR-1) and cytochrome c oxidase subunit I (COX-I)] genes. The experiment was conducted on 9-day-old Wistar rat pups, which were divided into normal, cataract-untreated and cataract-treated groups. Putative changes in gene expression in whole lenses removed from the rats were determined by measuring mRNA transcript levels of the four genes by RT-PCR analysis, using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as an internal control. The expression of lenticular caspase-3 and EGR-1 genes appeared to be upregulated, as inferred by detecting increased mRNA transcript levels, while that of COX-I and catalase genes appeared to be downregulated (lowered mRNA transcript levels) in the lenses of cataract-untreated rats. However, in rats treated with ALCAR, the lenticular mRNA transcript levels were maintained at near normal (control) levels. These results suggest that ALCAR may prevent selenite-induced cataractogenesis by preventing abnormal expression of lenticular genes governing apoptosis.

Anticataractogenic effect of an extract of the oyster mushroom, Pleurotus ostreatus, in an experimental animal model

PURPOSE

To evaluate the efficacy of Pleurotus ostreatus extract in preventing selenite-induced cataractogenesis.

METHODS

In vitro, enucleated rat lenses, divided into one control and three experimental groups (selenite only, simultaneous selenite and extract, initial extract and subsequent selenite), underwent morphological and biochemical evaluation. The anti-cataractogenic effect was also evaluated in vivo.

RESULTS

In vitro, simultaneous incubation of extract with selenite-challenged lenses caused a decrease in lens opacification by maintaining antioxidant components at near normal levels. In vivo, P.ostreatus (300 mg/kg body weight) prevented cataract in 75% of rats.

CONCLUSION

Extract of P. ostreatus prevents experimental selenite-induced cataractogenesis.

High-pressure effect on PbTiO3: an investigation by Raman and x-ray scattering up to 63 GPa

We report a room-temperature high-pressure x-ray and Raman scattering investigation of lead titanate (PbTiO3) up to 63 GPa. Three continuous phase transitions at 13, 20, and 45 GPa between tetragonal-like phases occur. As a result, no evidence is found for a pressure-induced morphotropic phase boundary. Our study provides experimental evidence that PbTiO3 presents a complex sequence of phases accommodating pressure through mechanisms involving oxygen octahedra tilting and reentrance of ferroelectricity.

Long-term results of redo gastro-esophageal reflux disease surgery

OBJECTIVE

To review the long-term results of redo gastro-esophageal reflux disease (GERD) surgery with special emphasis on residual acid-suppressing medications, pH monitoring results, and quality of life.

METHODS

Retrospective analysis of 52 patients (24 males) who underwent redo GERD surgery between 1986 and 2006 through a transthoracic (n=14), or a transabdominal (n=38) approach. Indications were recurrent GERD in 41 patients, and complication of the initial surgery in 11. Quality of life was evaluated by telephone enquiry using a validated French questionnaire (reflux quality score, RQS).

RESULTS

Postoperative complications occurred in 18 patients (35%), resulting in one death (2%). Reoperation was required in seven patients. At 1 year, 26 patients (51%) had 24h pH monitoring, among whom 2 (8%) were proved to have recurrence of GERD. RQS values were calculated in 38 patients with a mean follow-up of 113 months. Fifty percent of this subgroup had a RQS value beyond 26/32, indicating an excellent quality of life. Among these 38 patients, 20 (53%) had acid-suppressing medications whatever their RQS values. Patients who underwent transthoracic GERD surgery had the highest RQS values (p=0.02), a lower rate of complications (p=0.06) and a lower rate of reoperation (p=0.04).

CONCLUSION

Our experience confirms that selection of candidates for redo GERD surgery is a challenging issue. A transthoracic approach seems to produce better results and lower rates of complications.

Acetyl-L-carnitine prevents selenite-induced cataractogenesis in an experimental animal model

PURPOSE

To investigate whether acetyl-L-carnitine (ALCAR) retards selenite-induced cataractogenesis in vivo.

METHODS

On postpartum day 10, group I pups received intraperitoneal saline and group II and group III pups received subcutaneous sodium selenite; Group III pups also received intraperitoneal ALCAR once daily on postpartum days 9-14. Both eyes of each pup were examined up to postpartum day 30. After sacrifice, extricated pup lenses were analyzed for antioxidant and redox system components.

RESULTS

There was dense lenticular opacification in all group II pups, minimal opacification in 33% of group III pups, and no opacification in 67% of group III and in all group I pups. Group II lenses exhibited significantly lower values of antioxidant and redox system components and higher malondialdehyde concentrations than group I or group III lenses.

CONCLUSION

ALCAR prevents selenite-induced cataractogenesis in Wistar rat pups, possibly by inhibiting depletion of antioxidant enzyme and redox system components and inhibiting lipid peroxidation.

Prevention of selenite-induced cataractogenesis by acetyl-l-carnitine: An experimental study

Several studies have suggested that antioxidants retard the process of cataractogenesis by scavenging free oxygen radicals. The present study sought to assess the efficacy of the antioxidant acetyl-L-carnitine (ALCAR) in preventing selenite-induced cataractogenesis in an experimental setting. The first, in vitro phase of the study was performed on lenses from Wistar rats incubated for 24 h at 37 degrees C in Dulbecco's Modified Eagle Medium (DMEM) alone (control, Group I), or in DMEM containing 100 microM of selenite (Group II) or in DMEM containing 100 microM of selenite and 200 microM/ml ALCAR added at the same time as selenite (Group IIIa) or 30 min, 1 h or 2 h later (Groups IIIb, IIIc and IIId, respectively). Gross morphological examination of these lenses revealed dense opacification (cataract formation) in Group II, minimal opacification in some Group IIIa lenses and no opacification in Group I. The mean activities of the antioxidant enzymes catalase and glutathione peroxidase were significantly lower in Group II than in Group I or Group IIIa lenses, while malondialdehyde concentration (an indicator of lipid peroxidation) was significantly higher in Group II lenses than that in Group I or Group IIIa lenses. The second, in vivo phase of the study revealed dense opacification (cataract formation) in 100% of Wistar rat pups receiving subcutaneous sodium selenite alone (19 microM/kg body weight) but in only 37.5% of those receiving subcutaneous selenite and intraperitoneal ALCAR. These data suggest that ALCAR is able to significantly retard experimental selenite-induced cataractogenesis.

Long-term observation and functional state of the esophagus after primary repair of spontaneous esophageal rupture

BACKGROUND

Long-term outcome of patients treated for a spontaneous esophageal rupture (Boerhaave's syndrome) is seldom reported.

METHODS

From 1989 to 2004, 62 esophageal perforations were treated in a single institution. Eighteen patients presented with a spontaneous esophageal rupture. Among them, 15 could be treated with a transthoracic primary repair and constituted the material of the present study. A chart review was performed with special attention to survival, residual symptoms, and anatomic and motility disorders.

RESULTS

Three patients died postoperatively (20%). At last follow-up, 10 patients were alive and 2 had died from unrelated causes. At a median delay of 13 months (3 to 74), 7 patients accepted to undergo complementary investigations. None of them had any anatomic abnormality as checked by barium swallow. Six patients complained of mild symptoms from gastroesophageal reflux. Six patients (85%) presented with esophageal motility disorders on manometry and 4 (54%) had nocturne chronic reflux disease on pH monitoring. Two patients underwent endoscopic ultrasonography, of which one presented with a focal absence of one layer of the esophageal wall within the area of the suture. With time, no patient experienced recurrence, but one developed a cancer in the cervical esophagus.

CONCLUSIONS

These results suggest that esophageal functional disorders are the rule after primary repair of a Boerhaave's syndrome. Whether or not these findings are causal, coincidental, or related to the surgical treatment remains unclear. However, performance of routine postoperative explorations is strongly encouraged for a better understanding of this challenging condition.

Late pulmonary artery stump thrombosis with post embolic pulmonary hypertension after pneumonectomy

Ten years after right pneumonectomy for primary lung cancer, a 51 year old man developed a pulmonary artery stump thrombosis which produced microemboli in the remaining lung and, in turn, led to chronic pulmonary hypertension. This case strongly suggests that prolonged postoperative thromboembolic prophylaxis should be considered in patients undergoing right pneumonectomy.

Characteristic clinical features as an aid to the diagnosis of suppurative keratitis caused by filamentous fungi

AIM

To assess whether the presence of characteristic clinical features can be used as a diagnostic aid for suppurative keratitis caused by filamentous fungi.

METHODS

Patients presenting with suppurative keratitis in India underwent detailed clinical examination followed by microbiological investigation of corneal scrapes. A partial diagnostic score based upon the strength of the association, as estimated by the odds ratio, between reported clinical features and laboratory confirmed diagnoses was devised and subsequently tested using a case series from Ghana.

RESULTS

Serrated margins, raised slough, dry texture, satellite lesions and coloration other than yellow occurred more frequently in cases of filamentous fungal keratitis than bacterial keratitis (p<0.05). Hypopyon and fibrinous exudate were observed more frequently in bacterial keratitis (p<0.05). When incorporated into a backwards stepwise logisitic regression model only serrated margins, raised slough, and colour were independently associated with fungal keratitis; these features were used in the scoring system. The probability of fungal infection if one clinical feature was present was 63%, increasing to 83% if all three features were present.

CONCLUSIONS

Microbiological investigations should be performed whenever possible; however, where facilities are not available, a rapid presumptive diagnosis of suppurative keratitis may be possible by scoring clinical features.

Is ultrasonography essential before surgery in eyes with advanced cataracts?

BACKGROUND

Ultrasonography is an important tool for evaluating the posterior segment in eyes with opaque media.

AIM

To study the incidence of posterior segment pathology in eyes with advanced cataract and to see whether certain features could be used as predictors for an abnormal posterior segment on ultrasound.

SETTING

Tertiary care hospital in South India.

METHODS AND MATERIALS

In this prospective study conducted over a 6-month period, all eyes with dense cataracts precluding visualization of fundus underwent assessment with ultrasound. Presence of certain patient and ocular "risk" factors believed to be associated with a higher incidence of abnormal posterior segment on ultrasound were looked for and the odds ratio (OR) for posterior segment pathology in these eyes was calculated.

RESULTS

Of the 418 eyes assessed, 36 eyes (8.6%) had evidence of posterior segment pathology on ultrasound. Retinal detachment (17 eyes; 4.1%) was the most frequent abnormality detected. Among patient features, diabetes mellitus (OR= 4.9, P= 0.003) and age below 50 years (OR= 15.4, P= 0.001) were associated with a high incidence of abnormal ultrasound scans. In ocular features, posterior synechiae (OR= 20.2, P= 0.000), iris coloboma (OR= 34.6, P= 0.000), inaccurate projection of rays (OR= 15.1, P= 0.002), elevated intraocular pressure (OR= 15.1, P= 0.004) and keratic precipitates (OR= 22.4, P= 0.004) were associated with high incidence of posterior segment pathology. Only four eyes (1.5%) without these features had abnormal posterior segment on ultrasonography.

CONCLUSIONS

Certain patient and ocular features are indicative of a high risk for posterior segment pathology and such patients should be evaluated by ultrasonography prior to cataract surgery. In the absence of these risk factors, the likelihood of detecting abnormalities on preoperative ultrasonography in eyes with advanced cataracts is miniscule.

Comparison of in vitro Susceptibilities of Ocular Bacterial Isolates to Gatifloxacin and Other Topical Antibiotics

PURPOSE

To compare the in vitro activity of gatifloxacin with that of other topical antibiotics against fresh bacterial isolates from various types of human ocular infections.

METHODS

A total of 498 strains of ocular bacterial isolates were tested for their susceptibility to gatifloxacin, ofloxacin, ciprofloxacin, norfloxacin, gentamicin, tobramycin, neomycin, chloramphenicol, erythromycin, tetracycline and amikacin.

RESULTS

Ninety-nine percent of gram-positive and 92% of gram-negative bacterial strains were found to be susceptible in vitro to gatifloxacin, whereas lower percentages of gram-positive and gram-negative bacteria were found to be susceptible to other antibiotics.

CONCLUSIONS

In vitro, gatifloxacin exhibits good activity against various bacterial species isolated from different ocular sites. This requires corroboration in the clinical setting.

Creep and relaxation dynamics of domain walls in periodically poled KTiOPO4

Creep and relaxation of domain walls under ac electric fields are observed in an ideal model system, periodically poled KTiOPO4, to occur in different regimes, which are separated by dynamic phase transitions at frequencies f(m)(T)=f(m0)exp((-DeltaE/k(B)T), with f(m0)=3 x 10(9) Hz and DeltaE=0.6 eV. Power law dispersion of the creep susceptibility, chi proportional to 1+(iomegatau)(-beta), with beta approximately equal to 0.4, and large nonlinearity encountered at f < f(m), is contrasted with Cole-Cole-type relaxational dispersion, chi proportional to (1+[iomegatau](1-alpha))(-1), with alpha approximately 0.3, at f > f(m).