Multiple steps characterise ventricular layer attrition to form the ependymal cell lining of the adult mouse spinal cord central canal

The ventricular layer of the spinal cord is remodelled during embryonic development and ultimately forms the ependymal cell lining of the adult central canal, which retains neural stem cell potential. This anatomical transformation involves the process of dorsal collapse; however, accompanying changes in tissue organisation and cell behaviour as well as the precise origin of cells contributing to the central canal are not well understood. Here, we describe sequential localised cell rearrangements which accompany the gradual attrition of the spinal cord ventricular layer during development. This includes local breakdown of the pseudostratified organisation of the dorsal ventricular layer prefiguring dorsal collapse and evidence for a new phenomenon, ventral dissociation, during which the ventral‐most floor plate cells separate from a subset that are retained around the central canal. Using cell proliferation markers and cell‐cycle reporter mice, we further show that following dorsal collapse, ventricular layer attrition involves an overall reduction in cell proliferation, characterised by an intriguing increase in the percentage of cells in G1/S. In contrast, programmed cell death does not contribute to ventricular layer remodelling. By analysing transcript and protein expression patterns associated with key signalling pathways, we provide evidence for a gradual decline in ventral sonic hedgehog activity and an accompanying ventral expansion of initial dorsal bone morphogenetic protein signalling, which comes to dominate the forming the central canal lining. This study identifies multiple steps that may contribute to spinal cord ventricular layer attrition and adds to increasing evidence for the heterogeneous origin of the spinal cord ependymal cell population, which includes cells from the floor plate and the roof plate as well as ventral progenitor domains.

Surgical lung biopsy for diffuse lung disease. Our experience in the last 15 years

INTRODUCTION

Surgical lung biopsy is a technique that presents a morbi-mortality rate of considerable importance. We analyze our experience with surgical lung biopsies for the diagnosis of diffuse lung disease and the effect produced on the indications for surgical biopsy in these pathologies after the publication of the consensus of the ATS (American Thoracic Society) and ERS (European Respiratory Society) for Idiopathic Pulmonary Fibrosis (IPF).

PATIENTS AND METHODS

We performed a retrospective review of 171 patients operated between January 1997 and December 2011. We divided the series into 2 groups: group 1 (operated between 1997 and 2002) and group 2 (operated between 2003 and 2011). Suspected preoperative diagnosis, respiratory status, pathological postoperative diagnoses, percentage of thoracotomies, mean postoperative stay and perioperative morbidity and mortality were analyzed.

RESULTS

Group 1 consisted of 99 patients and group two 72. The most frequent postoperative diagnoses were: usual interstitial pneumonia and extrinsic allergic alveolitis. There were ten (5.84%) deaths. Death was caused by progressive respiratory failure that was related to interstitial lung disease in 7 (70%) of 10 cases, alveolar haemorrhage in 2 (20%) and heart failure in 1 (10%).

CONCLUSIONS

Since the publication of the ATS and ERS consensus on the IPF, we have observed a noticeable decrease in the number of indications for surgical lung biopsy. This technique, though simple, has a considerable morbidity and mortality.

Pulmonar collision tumor: metastatic adenoid cystic carcinoma and lung adenocarcinoma

We report an extraordinary case of collision tumor consisting of a lung adenocarcinoma and a metastatic adenoid cystic carcinoma in a 56 year-old man. He was diagnosed with a pulmonary nodule 11 years after treatment of an adenoid cystic carcinoma of the right maxillary sinus. A non-small cell carcinoma was observed when a transbronchial biopsy was performed. The other component of the nodule was only diagnosed with pathological examination of the resection specimen.

[Cytomegalovirus sensitivity to anti-retroviral agents in patients infected with the human immunodeficiency virus with chorioretinitis in Spain]

OBJECTIVES

To determine the prevalence of the in vitro resistance rate of cytomegalovirus (CMV) to gancyclovir (GCV) and foscarnet (FOS) among patients with AIDS and chorioretinitis. Furthermore, in vitro sensitivity results were compared with the clinical response to therapy.

PATIENTS AND METHODS

Thirty-six patients with the diagnosis of CMV retinitis and AIDS were included in the study. Antiviral sensitivity testing was performed to 51 clinical CMV strains from these patients. The in vitro sensitivity was compared with the clinical response to therapy. The resistance criteria were the inhibitory dose50 (ID50) GCV > 5 M and ID50 FOS > 400 M.

RESULTS

None of the CMV tested strains was resistant to GCV or FOS; however, six patients who had relapses of chorioretinitis while on maintenance therapy and isolation during the condition had mean ID50 of strains (n=8) of 1,95 M for GCV (standard deviation [SD] of 0.71) and 115.2 for FOS (SD, 34.7). These patients responded well when drugs were used at induction doses.

CONCLUSION

The in vitro sensitivity testing is not a good predictor of infection control when the drug is used at maintenance doses. This suggests that these strains should be classified in the intermediate resistant category.

[Hyoid fracture and traumatic subcutaneous cervical emphysema from an attempted hanging. Apropos a case]

We describe a patient with a history of psychiatric disorder who was brought to our hospital after attempted suicide by hanging. Severe subcutaneous facial, palpebral and cervical emphysema was present, with dysphonia, dysphagia and slight respiratory difficulty. Fiberoptic bronchoscopy revealed upper airway obstruction due to edema in an intact airway. Successive CAT scans gave evidence of hyoid fracture and laryngocele, in addition to the corresponding emphysema of the subcutaneous area and pneumomediastinum. Given the persistence of dysphagia, we ordered esophageal tests, which showed functional alteration of the upper esophageal sphincter. Suprasternal cervicotomy to drain the pneumomediastinum and laryngeal microsurgery to treat the laryngocele resolved the problem.

[Pneumothorax as the clinical presentation of bronchogenic carcinoma. A report of 3 cases]

The association of pneumothorax and lung cancer is rare and diagnosis is complex in such cases. Clinical suspicion of cancer must be based on radiological findings and the existence of risk factors. We discuss the mechanisms involved in the development of pneumothorax in patients with lung cancer, the clinical significance of the association, and the recommended diagnostic approach and therapeutic guidelines.

[Thymoma. A retrospective study]

We review cases of thymic cell tumor treated between January 1991 and March 1998. Nineteen of the 23 cases studied involved thymoma. Eight (42%) were asymptomatic, 4 (21%) were associated with myasthenia gravis and 7 (37%) were symptomatic. The most common symptom was non-specific chest pain, reported by 4 (47%) patients with symptoms. Classifying the cases of thymoma by Masaoka's system, we found that 12 were cases of thymoma in stage I (63.2%), 4 in stage II (21.1%) and 3 in stage III (15.8%). No stage IV patients were treated. Treatment consisted of full exeresis of the tumor in 17 (89.5%) cases, partial resection in one case (5.2%) and biopsy of the tumor in one non-resectable, case. Adjuvant radiotherapy was applied in seven cases. Chemotherapy was not prescribed. With follow-up ranging from 9 to 96 months, half the patients survived 21 months after surgery. Among the surviving patients, mortality was nil at the end of the study. The results of microscopic, cytologic and blood analyses were of scarce value in differentiating between benign and malignant tumors, even though p53 and bcl2 antigen positivity and clinical stage have been related to poor prognosis in recent years.